Jackson Core Source Code

Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

Jackson Core Source Code files are provided in the source packge (jackson-core-2.12.4-sources.jar). You can download it at Jackson Maven Website.

You can also browse Jackson Core Source Code below:

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com/fasterxml/jackson/core/json/ReaderBasedJsonParser.java

package com.fasterxml.jackson.core.json;

import java.io.*;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.base.ParserBase;
import com.fasterxml.jackson.core.io.CharTypes;
import com.fasterxml.jackson.core.io.IOContext;
import com.fasterxml.jackson.core.sym.CharsToNameCanonicalizer;
import com.fasterxml.jackson.core.util.*;

import static com.fasterxml.jackson.core.JsonTokenId.*;

/**
 * This is a concrete implementation of {@link JsonParser}, which is
 * based on a {@link java.io.Reader} to handle low-level character
 * conversion tasks.
 */
public class ReaderBasedJsonParser
    extends ParserBase
{
    @SuppressWarnings("deprecation")
    private final static int FEAT_MASK_TRAILING_COMMA = Feature.ALLOW_TRAILING_COMMA.getMask();

    @SuppressWarnings("deprecation")
    private final static int FEAT_MASK_LEADING_ZEROS = Feature.ALLOW_NUMERIC_LEADING_ZEROS.getMask();

    @SuppressWarnings("deprecation")
    private final static int FEAT_MASK_NON_NUM_NUMBERS = Feature.ALLOW_NON_NUMERIC_NUMBERS.getMask();

    @SuppressWarnings("deprecation")
    private final static int FEAT_MASK_ALLOW_MISSING = Feature.ALLOW_MISSING_VALUES.getMask();
    private final static int FEAT_MASK_ALLOW_SINGLE_QUOTES = Feature.ALLOW_SINGLE_QUOTES.getMask();
    private final static int FEAT_MASK_ALLOW_UNQUOTED_NAMES = Feature.ALLOW_UNQUOTED_FIELD_NAMES.getMask();

    private final static int FEAT_MASK_ALLOW_JAVA_COMMENTS = Feature.ALLOW_COMMENTS.getMask();
    private final static int FEAT_MASK_ALLOW_YAML_COMMENTS = Feature.ALLOW_YAML_COMMENTS.getMask();

    // Latin1 encoding is not supported, but we do use 8-bit subset for
    // pre-processing task, to simplify first pass, keep it fast.
    protected final static int[] _icLatin1 = CharTypes.getInputCodeLatin1();

    /*
    /**********************************************************
    /* Input configuration
    /**********************************************************
     */

    /**
     * Reader that can be used for reading more content, if one
     * buffer from input source, but in some cases pre-loaded buffer
     * is handed to the parser.
     */
    protected Reader _reader;

    /**
     * Current buffer from which data is read; generally data is read into
     * buffer from input source.
     */
    protected char[] _inputBuffer;

    /**
     * Flag that indicates whether the input buffer is recycable (and
     * needs to be returned to recycler once we are done) or not.
     *<p>
     * If it is not, it also means that parser can NOT modify underlying
     * buffer.
     */
    protected boolean _bufferRecyclable;

    /*
    /**********************************************************
    /* Configuration
    /**********************************************************
     */

    protected ObjectCodec _objectCodec;

    final protected CharsToNameCanonicalizer _symbols;

    final protected int _hashSeed;

    /*
    /**********************************************************
    /* Parsing state
    /**********************************************************
     */

    /**
     * Flag that indicates that the current token has not yet
     * been fully processed, and needs to be finished for
     * some access (or skipped to obtain the next token)
     */
    protected boolean _tokenIncomplete;

    /**
     * Value of {@link #_inputPtr} at the time when the first character of
     * name token was read. Used for calculating token location when requested;
     * combined with {@link #_currInputProcessed}, may be updated appropriately
     * as needed.
     *
     * @since 2.7
     */
    protected long _nameStartOffset;

    /**
     * @since 2.7
     */
    protected int _nameStartRow;

    /**
     * @since 2.7
     */
    protected int _nameStartCol;

    /*
    /**********************************************************
    /* Life-cycle
    /**********************************************************
     */

    /**
     * Method called when caller wants to provide input buffer directly,
     * and it may or may not be recyclable use standard recycle context.
     *
     * @since 2.4
     */
    public ReaderBasedJsonParser(IOContext ctxt, int features, Reader r,
            ObjectCodec codec, CharsToNameCanonicalizer st,
            char[] inputBuffer, int start, int end,
            boolean bufferRecyclable)
    {
        super(ctxt, features);
        _reader = r;
        _inputBuffer = inputBuffer;
        _inputPtr = start;
        _inputEnd = end;
        _objectCodec = codec;
        _symbols = st;
        _hashSeed = st.hashSeed();
        _bufferRecyclable = bufferRecyclable;
    }

    /**
     * Method called when input comes as a {@link java.io.Reader}, and buffer allocation
     * can be done using default mechanism.
     */
    public ReaderBasedJsonParser(IOContext ctxt, int features, Reader r,
        ObjectCodec codec, CharsToNameCanonicalizer st)
    {
        super(ctxt, features);
        _reader = r;
        _inputBuffer = ctxt.allocTokenBuffer();
        _inputPtr = 0;
        _inputEnd = 0;
        _objectCodec = codec;
        _symbols = st;
        _hashSeed = st.hashSeed();
        _bufferRecyclable = true;
    }

    /*
    /**********************************************************
    /* Base method defs, overrides
    /**********************************************************
     */

    @Override public ObjectCodec getCodec() { return _objectCodec; }
    @Override public void setCodec(ObjectCodec c) { _objectCodec = c; }

    @Override // @since 2.12
    public JacksonFeatureSet<StreamReadCapability> getReadCapabilities() {
        return JSON_READ_CAPABILITIES;
    }

    @Override
    public int releaseBuffered(Writer w) throws IOException {
        int count = _inputEnd - _inputPtr;
        if (count < 1) { return 0; }
        // let's just advance ptr to end
        int origPtr = _inputPtr;
        _inputPtr += count;
        w.write(_inputBuffer, origPtr, count);
        return count;
    }

    @Override public Object getInputSource() { return _reader; }

    @Deprecated // since 2.8
    protected char getNextChar(String eofMsg) throws IOException {
        return getNextChar(eofMsg, null);
    }
    
    protected char getNextChar(String eofMsg, JsonToken forToken) throws IOException {
        if (_inputPtr >= _inputEnd) {
            if (!_loadMore()) {
                _reportInvalidEOF(eofMsg, forToken);
            }
        }
        return _inputBuffer[_inputPtr++];
    }

    @Override
    protected void _closeInput() throws IOException {
        /* 25-Nov-2008, tatus: As per [JACKSON-16] we are not to call close()
         *   on the underlying Reader, unless we "own" it, or auto-closing
         *   feature is enabled.
         *   One downside is that when using our optimized
         *   Reader (granted, we only do that for UTF-32...) this
         *   means that buffer recycling won't work correctly.
         */
        if (_reader != null) {
            if (_ioContext.isResourceManaged() || isEnabled(Feature.AUTO_CLOSE_SOURCE)) {
                _reader.close();
            }
            _reader = null;
        }
    }

    /**
     * Method called to release internal buffers owned by the base
     * reader. This may be called along with {@link #_closeInput} (for
     * example, when explicitly closing this reader instance), or
     * separately (if need be).
     */
    @Override
    protected void _releaseBuffers() throws IOException
    {
        super._releaseBuffers();
        // merge new symbols, if any
        _symbols.release();
        // and release buffers, if they are recyclable ones
        if (_bufferRecyclable) {
            char[] buf = _inputBuffer;
            if (buf != null) {
                _inputBuffer = null;
                _ioContext.releaseTokenBuffer(buf);
            }
        }
    }

    /*
    /**********************************************************
    /* Low-level access, supporting
    /**********************************************************
     */

    protected void _loadMoreGuaranteed() throws IOException {
        if (!_loadMore()) { _reportInvalidEOF(); }
    }
    
    protected boolean _loadMore() throws IOException
    {
        if (_reader != null) {
            int count = _reader.read(_inputBuffer, 0, _inputBuffer.length);
            if (count > 0) {
                final int bufSize = _inputEnd;
                _currInputProcessed += bufSize;
                _currInputRowStart -= bufSize;

                // 26-Nov-2015, tatu: Since name-offset requires it too, must offset
                //   this increase to avoid "moving" name-offset, resulting most likely
                //   in negative value, which is fine as combine value remains unchanged.
                _nameStartOffset -= bufSize;

                _inputPtr = 0;
                _inputEnd = count;

                return true;
            }
            // End of input
            _closeInput();
            // Should never return 0, so let's fail
            if (count == 0) {
                throw new IOException("Reader returned 0 characters when trying to read "+_inputEnd);
            }
        }
        return false;
    }

    /*
    /**********************************************************
    /* Public API, data access
    /**********************************************************
     */

    /**
     * Method for accessing textual representation of the current event;
     * if no current event (before first call to {@link #nextToken}, or
     * after encountering end-of-input), returns null.
     * Method can be called for any event.
     */
    @Override
    public final String getText() throws IOException
    {
        if (_currToken == JsonToken.VALUE_STRING) {
            if (_tokenIncomplete) {
                _tokenIncomplete = false;
                _finishString(); // only strings can be incomplete
            }
            return _textBuffer.contentsAsString();
        }
        return _getText2(_currToken);
    }

    @Override // since 2.8
    public int getText(Writer writer) throws IOException
    {
        JsonToken t = _currToken;
        if (t == JsonToken.VALUE_STRING) {
            if (_tokenIncomplete) {
                _tokenIncomplete = false;
                _finishString(); // only strings can be incomplete
            }
            return _textBuffer.contentsToWriter(writer);
        }
        if (t == JsonToken.FIELD_NAME) {
            String n = _parsingContext.getCurrentName();
            writer.write(n);
            return n.length();
        }
        if (t != null) {
            if (t.isNumeric()) {
                return _textBuffer.contentsToWriter(writer);
            }
            char[] ch = t.asCharArray();
            writer.write(ch);
            return ch.length;
        }
        return 0;
    }
    
    // // // Let's override default impls for improved performance

    // @since 2.1
    @Override
    public final String getValueAsString() throws IOException
    {
        if (_currToken == JsonToken.VALUE_STRING) {
            if (_tokenIncomplete) {
                _tokenIncomplete = false;
                _finishString(); // only strings can be incomplete
            }
            return _textBuffer.contentsAsString();
        }
        if (_currToken == JsonToken.FIELD_NAME) {
            return getCurrentName();
        }
        return super.getValueAsString(null);
    }

    // @since 2.1
    @Override
    public final String getValueAsString(String defValue) throws IOException {
        if (_currToken == JsonToken.VALUE_STRING) {
            if (_tokenIncomplete) {
                _tokenIncomplete = false;
                _finishString(); // only strings can be incomplete
            }
            return _textBuffer.contentsAsString();
        }
        if (_currToken == JsonToken.FIELD_NAME) {
            return getCurrentName();
        }
        return super.getValueAsString(defValue);
    }

    protected final String _getText2(JsonToken t) {
        if (t == null) {
            return null;
        }
        switch (t.id()) {
        case ID_FIELD_NAME:
            return _parsingContext.getCurrentName();

        case ID_STRING:
            // fall through
        case ID_NUMBER_INT:
        case ID_NUMBER_FLOAT:
            return _textBuffer.contentsAsString();
        default:
            return t.asString();
        }
    }

    @Override
    public final char[] getTextCharacters() throws IOException
    {
        if (_currToken != null) { // null only before/after document
            switch (_currToken.id()) {
            case ID_FIELD_NAME:
                if (!_nameCopied) {
                    String name = _parsingContext.getCurrentName();
                    int nameLen = name.length();
                    if (_nameCopyBuffer == null) {
                        _nameCopyBuffer = _ioContext.allocNameCopyBuffer(nameLen);
                    } else if (_nameCopyBuffer.length < nameLen) {
                        _nameCopyBuffer = new char[nameLen];
                    }
                    name.getChars(0, nameLen, _nameCopyBuffer, 0);
                    _nameCopied = true;
                }
                return _nameCopyBuffer;
            case ID_STRING:
                if (_tokenIncomplete) {
                    _tokenIncomplete = false;
                    _finishString(); // only strings can be incomplete
                }
                // fall through
            case ID_NUMBER_INT:
            case ID_NUMBER_FLOAT:
                return _textBuffer.getTextBuffer();
            default:
                return _currToken.asCharArray();
            }
        }
        return null;
    }

    @Override
    public final int getTextLength() throws IOException
    {
        if (_currToken != null) { // null only before/after document
            switch (_currToken.id()) {
            case ID_FIELD_NAME:
                return _parsingContext.getCurrentName().length();
            case ID_STRING:
                if (_tokenIncomplete) {
                    _tokenIncomplete = false;
                    _finishString(); // only strings can be incomplete
                }
                // fall through
            case ID_NUMBER_INT:
            case ID_NUMBER_FLOAT:
                return _textBuffer.size();
            default:
                return _currToken.asCharArray().length;
            }
        }
        return 0;
    }

    @Override
    public final int getTextOffset() throws IOException
    {
        // Most have offset of 0, only some may have other values:
        if (_currToken != null) {
            switch (_currToken.id()) {
            case ID_FIELD_NAME:
                return 0;
            case ID_STRING:
                if (_tokenIncomplete) {
                    _tokenIncomplete = false;
                    _finishString(); // only strings can be incomplete
                }
                // fall through
            case ID_NUMBER_INT:
            case ID_NUMBER_FLOAT:
                return _textBuffer.getTextOffset();
            default:
            }
        }
        return 0;
    }

    @Override
    public byte[] getBinaryValue(Base64Variant b64variant) throws IOException
    {
        if ((_currToken == JsonToken.VALUE_EMBEDDED_OBJECT) && (_binaryValue != null)) {
            return _binaryValue;
        }
        if (_currToken != JsonToken.VALUE_STRING) {
            _reportError("Current token ("+_currToken+") not VALUE_STRING or VALUE_EMBEDDED_OBJECT, can not access as binary");
        }
        // To ensure that we won't see inconsistent data, better clear up state
        if (_tokenIncomplete) {
            try {
                _binaryValue = _decodeBase64(b64variant);
            } catch (IllegalArgumentException iae) {
                throw _constructError("Failed to decode VALUE_STRING as base64 ("+b64variant+"): "+iae.getMessage());
            }
            /* let's clear incomplete only now; allows for accessing other
             * textual content in error cases
             */
            _tokenIncomplete = false;
        } else { // may actually require conversion...
            if (_binaryValue == null) {
                @SuppressWarnings("resource")
                ByteArrayBuilder builder = _getByteArrayBuilder();
                _decodeBase64(getText(), builder, b64variant);
                _binaryValue = builder.toByteArray();
            }
        }
        return _binaryValue;
    }

    @Override
    public int readBinaryValue(Base64Variant b64variant, OutputStream out) throws IOException
    {
        // if we have already read the token, just use whatever we may have
        if (!_tokenIncomplete || _currToken != JsonToken.VALUE_STRING) {
            byte[] b = getBinaryValue(b64variant);
            out.write(b);
            return b.length;
        }
        // otherwise do "real" incremental parsing...
        byte[] buf = _ioContext.allocBase64Buffer();
        try {
            return _readBinary(b64variant, out, buf);
        } finally {
            _ioContext.releaseBase64Buffer(buf);
        }
    }

    protected int _readBinary(Base64Variant b64variant, OutputStream out, byte[] buffer) throws IOException
    {
        int outputPtr = 0;
        final int outputEnd = buffer.length - 3;
        int outputCount = 0;

        while (true) {
            // first, we'll skip preceding white space, if any
            char ch;
            do {
                if (_inputPtr >= _inputEnd) {
                    _loadMoreGuaranteed();
                }
                ch = _inputBuffer[_inputPtr++];
            } while (ch <= INT_SPACE);
            int bits = b64variant.decodeBase64Char(ch);
            if (bits < 0) { // reached the end, fair and square?
                if (ch == '"') {
                    break;
                }
                bits = _decodeBase64Escape(b64variant, ch, 0);
                if (bits < 0) { // white space to skip
                    continue;
                }
            }

            // enough room? If not, flush
            if (outputPtr > outputEnd) {
                outputCount += outputPtr;
                out.write(buffer, 0, outputPtr);
                outputPtr = 0;
            }

            int decodedData = bits;

            // then second base64 char; can't get padding yet, nor ws

            if (_inputPtr >= _inputEnd) {
                _loadMoreGuaranteed();
            }
            ch = _inputBuffer[_inputPtr++];
            bits = b64variant.decodeBase64Char(ch);
            if (bits < 0) {
                bits = _decodeBase64Escape(b64variant, ch, 1);
            }
            decodedData = (decodedData << 6) | bits;

            // third base64 char; can be padding, but not ws
            if (_inputPtr >= _inputEnd) {
                _loadMoreGuaranteed();
            }
            ch = _inputBuffer[_inputPtr++];
            bits = b64variant.decodeBase64Char(ch);

            // First branch: can get padding (-> 1 byte)
            if (bits < 0) {
                if (bits != Base64Variant.BASE64_VALUE_PADDING) {
                    // as per [JACKSON-631], could also just be 'missing'  padding
                    if (ch == '"') {
                        decodedData >>= 4;
                        buffer[outputPtr++] = (byte) decodedData;
                        if (b64variant.usesPadding()) {
                            --_inputPtr; // to keep parser state bit more consistent
                            _handleBase64MissingPadding(b64variant);
                        }
                        break;
                    }
                    bits = _decodeBase64Escape(b64variant, ch, 2);
                }
                if (bits == Base64Variant.BASE64_VALUE_PADDING) {
                    // Ok, must get padding
                    if (_inputPtr >= _inputEnd) {
                        _loadMoreGuaranteed();
                    }
                    ch = _inputBuffer[_inputPtr++];
                    if (!b64variant.usesPaddingChar(ch)) {
                        if (_decodeBase64Escape(b64variant, ch, 3) != Base64Variant.BASE64_VALUE_PADDING) {
                            throw reportInvalidBase64Char(b64variant, ch, 3, "expected padding character '"+b64variant.getPaddingChar()+"'");
                        }
                    }
                    // Got 12 bits, only need 8, need to shift
                    decodedData >>= 4;
                    buffer[outputPtr++] = (byte) decodedData;
                    continue;
                }
            }
            // Nope, 2 or 3 bytes
            decodedData = (decodedData << 6) | bits;
            // fourth and last base64 char; can be padding, but not ws
            if (_inputPtr >= _inputEnd) {
                _loadMoreGuaranteed();
            }
            ch = _inputBuffer[_inputPtr++];
            bits = b64variant.decodeBase64Char(ch);
            if (bits < 0) {
                if (bits != Base64Variant.BASE64_VALUE_PADDING) {
                    // as per [JACKSON-631], could also just be 'missing'  padding
                    if (ch == '"') {
                        decodedData >>= 2;
                        buffer[outputPtr++] = (byte) (decodedData >> 8);
                        buffer[outputPtr++] = (byte) decodedData;
                        if (b64variant.usesPadding()) {
                            --_inputPtr; // to keep parser state bit more consistent
                            _handleBase64MissingPadding(b64variant);
                        }
                        break;
                    }
                    bits = _decodeBase64Escape(b64variant, ch, 3);
                }
                if (bits == Base64Variant.BASE64_VALUE_PADDING) {
                    /* With padding we only get 2 bytes; but we have
                     * to shift it a bit so it is identical to triplet
                     * case with partial output.
                     * 3 chars gives 3x6 == 18 bits, of which 2 are
                     * dummies, need to discard:
                     */
                    decodedData >>= 2;
                    buffer[outputPtr++] = (byte) (decodedData >> 8);
                    buffer[outputPtr++] = (byte) decodedData;
                    continue;
                }
            }
            // otherwise, our triplet is now complete
            decodedData = (decodedData << 6) | bits;
            buffer[outputPtr++] = (byte) (decodedData >> 16);
            buffer[outputPtr++] = (byte) (decodedData >> 8);
            buffer[outputPtr++] = (byte) decodedData;
        }
        _tokenIncomplete = false;
        if (outputPtr > 0) {
            outputCount += outputPtr;
            out.write(buffer, 0, outputPtr);
        }
        return outputCount;
    }

    /*
    /**********************************************************
    /* Public API, traversal
    /**********************************************************
     */

    /**
     * @return Next token from the stream, if any found, or null
     *   to indicate end-of-input
     */
    @Override
    public final JsonToken nextToken() throws IOException
    {
        /* First: field names are special -- we will always tokenize
         * (part of) value along with field name to simplify
         * state handling. If so, can and need to use secondary token:
         */
        if (_currToken == JsonToken.FIELD_NAME) {
            return _nextAfterName();
        }
        // But if we didn't already have a name, and (partially?) decode number,
        // need to ensure no numeric information is leaked
        _numTypesValid = NR_UNKNOWN;
        if (_tokenIncomplete) {
            _skipString(); // only strings can be partial
        }
        int i = _skipWSOrEnd();
        if (i < 0) { // end-of-input
            // Should actually close/release things
            // like input source, symbol table and recyclable buffers now.
            close();
            return (_currToken = null);
        }
        // clear any data retained so far
        _binaryValue = null;

        // Closing scope?
        if (i == INT_RBRACKET || i == INT_RCURLY) {
            _closeScope(i);
            return _currToken;
        }

        // Nope: do we then expect a comma?
        if (_parsingContext.expectComma()) {
            i = _skipComma(i);

            // Was that a trailing comma?
            if ((_features & FEAT_MASK_TRAILING_COMMA) != 0) {
                if ((i == INT_RBRACKET) || (i == INT_RCURLY)) {
                    _closeScope(i);
                    return _currToken;
                }
            }
        }

        /* And should we now have a name? Always true for Object contexts, since
         * the intermediate 'expect-value' state is never retained.
         */
        boolean inObject = _parsingContext.inObject();
        if (inObject) {
            // First, field name itself:
            _updateNameLocation();
            String name = (i == INT_QUOTE) ? _parseName() : _handleOddName(i);
            _parsingContext.setCurrentName(name);
            _currToken = JsonToken.FIELD_NAME;
            i = _skipColon();
        }
        _updateLocation();

        // Ok: we must have a value... what is it?

        JsonToken t;

        switch (i) {
        case '"':
            _tokenIncomplete = true;
            t = JsonToken.VALUE_STRING;
            break;
        case '[':
            if (!inObject) {
                _parsingContext = _parsingContext.createChildArrayContext(_tokenInputRow, _tokenInputCol);
            }
            t = JsonToken.START_ARRAY;
            break;
        case '{':
            if (!inObject) {
                _parsingContext = _parsingContext.createChildObjectContext(_tokenInputRow, _tokenInputCol);
            }
            t = JsonToken.START_OBJECT;
            break;
        case '}':
            // Error: } is not valid at this point; valid closers have
            // been handled earlier
            _reportUnexpectedChar(i, "expected a value");
        case 't':
            _matchTrue();
            t = JsonToken.VALUE_TRUE;
            break;
        case 'f':
            _matchFalse();
            t = JsonToken.VALUE_FALSE;
            break;
        case 'n':
            _matchNull();
            t = JsonToken.VALUE_NULL;
            break;

        case '-':
            /* Should we have separate handling for plus? Although
             * it is not allowed per se, it may be erroneously used,
             * and could be indicate by a more specific error message.
             */
            t = _parseNegNumber();
            break;
        case '.': // [core#61]]
            t = _parseFloatThatStartsWithPeriod();
            break;
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            t = _parsePosNumber(i);
            break;
        default:
            t = _handleOddValue(i);
            break;
        }

        if (inObject) {
            _nextToken = t;
            return _currToken;
        }
        _currToken = t;
        return t;
    }

    private final JsonToken _nextAfterName()
    {
        _nameCopied = false; // need to invalidate if it was copied
        JsonToken t = _nextToken;
        _nextToken = null;

// !!! 16-Nov-2015, tatu: TODO: fix [databind#37], copy next location to current here
        
        // Also: may need to start new context?
        if (t == JsonToken.START_ARRAY) {
            _parsingContext = _parsingContext.createChildArrayContext(_tokenInputRow, _tokenInputCol);
        } else if (t == JsonToken.START_OBJECT) {
            _parsingContext = _parsingContext.createChildObjectContext(_tokenInputRow, _tokenInputCol);
        }
        return (_currToken = t);
    }

    @Override
    public void finishToken() throws IOException {
        if (_tokenIncomplete) {
            _tokenIncomplete = false;
            _finishString(); // only strings can be incomplete
        }
    }

    /*
    /**********************************************************
    /* Public API, nextXxx() overrides
    /**********************************************************
     */

    // Implemented since 2.7
    @Override
    public boolean nextFieldName(SerializableString sstr) throws IOException
    {
        // // // Note: most of code below is copied from nextToken()

        _numTypesValid = NR_UNKNOWN;
        if (_currToken == JsonToken.FIELD_NAME) {
            _nextAfterName();
            return false;
        }
        if (_tokenIncomplete) {
            _skipString();
        }
        int i = _skipWSOrEnd();
        if (i < 0) {
            close();
            _currToken = null;
            return false;
        }
        _binaryValue = null;

        // Closing scope?
        if (i == INT_RBRACKET || i == INT_RCURLY) {
            _closeScope(i);
            return false;
        }

        if (_parsingContext.expectComma()) {
            i = _skipComma(i);

            // Was that a trailing comma?
            if ((_features & FEAT_MASK_TRAILING_COMMA) != 0) {
                if ((i == INT_RBRACKET) || (i == INT_RCURLY)) {
                    _closeScope(i);
                    return false;
                }
            }
        }

        if (!_parsingContext.inObject()) {
            _updateLocation();
            _nextTokenNotInObject(i);
            return false;
        }

        _updateNameLocation();
        if (i == INT_QUOTE) {
            // when doing literal match, must consider escaping:
            char[] nameChars = sstr.asQuotedChars();
            final int len = nameChars.length;

            // Require 4 more bytes for faster skipping of colon that follows name
            if ((_inputPtr + len + 4) < _inputEnd) { // maybe...
                // first check length match by
                final int end = _inputPtr+len;
                if (_inputBuffer[end] == '"') {
                    int offset = 0;
                    int ptr = _inputPtr;
                    while (true) {
                        if (ptr == end) { // yes, match!
                            _parsingContext.setCurrentName(sstr.getValue());
                            _isNextTokenNameYes(_skipColonFast(ptr+1));
                            return true;
                        }
                        if (nameChars[offset] != _inputBuffer[ptr]) {
                            break;
                        }
                        ++offset;
                        ++ptr;
                    }
                }
            }
        }
        return _isNextTokenNameMaybe(i, sstr.getValue());
    }

    @Override
    public String nextFieldName() throws IOException
    {
        // // // Note: this is almost a verbatim copy of nextToken() (minus comments)

        _numTypesValid = NR_UNKNOWN;
        if (_currToken == JsonToken.FIELD_NAME) {
            _nextAfterName();
            return null;
        }
        if (_tokenIncomplete) {
            _skipString();
        }
        int i = _skipWSOrEnd();
        if (i < 0) {
            close();
            _currToken = null;
            return null;
        }
        _binaryValue = null;
        if (i == INT_RBRACKET || i == INT_RCURLY) {
            _closeScope(i);
            return null;
        }
        if (_parsingContext.expectComma()) {
            i = _skipComma(i);
            if ((_features & FEAT_MASK_TRAILING_COMMA) != 0) {
                if ((i == INT_RBRACKET) || (i == INT_RCURLY)) {
                    _closeScope(i);
                    return null;
                }
            }
        }
        if (!_parsingContext.inObject()) {
            _updateLocation();
            _nextTokenNotInObject(i);
            return null;
        }

        _updateNameLocation();
        String name = (i == INT_QUOTE) ? _parseName() : _handleOddName(i);
        _parsingContext.setCurrentName(name);
        _currToken = JsonToken.FIELD_NAME;
        i = _skipColon();

        _updateLocation();
        if (i == INT_QUOTE) {
            _tokenIncomplete = true;
            _nextToken = JsonToken.VALUE_STRING;
            return name;
        }
        
        // Ok: we must have a value... what is it?

        JsonToken t;

        switch (i) {
        case '-':
            t = _parseNegNumber();
            break;
        case '.': // [core#61]]
            t = _parseFloatThatStartsWithPeriod();
            break;
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            t = _parsePosNumber(i);
            break;
        case 'f':
            _matchFalse();
            t = JsonToken.VALUE_FALSE;
            break;
        case 'n':
            _matchNull();
            t = JsonToken.VALUE_NULL;
            break;
        case 't':
            _matchTrue();
            t = JsonToken.VALUE_TRUE;
            break;
        case '[':
            t = JsonToken.START_ARRAY;
            break;
        case '{':
            t = JsonToken.START_OBJECT;
            break;
        default:
            t = _handleOddValue(i);
            break;
        }
        _nextToken = t;
        return name;
    }

    private final void _isNextTokenNameYes(int i) throws IOException
    {
        _currToken = JsonToken.FIELD_NAME;
        _updateLocation();

        switch (i) {
        case '"':
            _tokenIncomplete = true;
            _nextToken = JsonToken.VALUE_STRING;
            return;
        case '[':
            _nextToken = JsonToken.START_ARRAY;
            return;
        case '{':
            _nextToken = JsonToken.START_OBJECT;
            return;
        case 't':
            _matchToken("true", 1);
            _nextToken = JsonToken.VALUE_TRUE;
            return;
        case 'f':
            _matchToken("false", 1);
            _nextToken = JsonToken.VALUE_FALSE;
            return;
        case 'n':
            _matchToken("null", 1);
            _nextToken = JsonToken.VALUE_NULL;
            return;
        case '-':
            _nextToken = _parseNegNumber();
            return;
        case '.': // [core#61]]
            _nextToken = _parseFloatThatStartsWithPeriod();
            return;
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            _nextToken = _parsePosNumber(i);
            return;
        }
        _nextToken = _handleOddValue(i);
    }

    protected boolean _isNextTokenNameMaybe(int i, String nameToMatch) throws IOException
    {
        // // // and this is back to standard nextToken()
        String name = (i == INT_QUOTE) ? _parseName() : _handleOddName(i);
        _parsingContext.setCurrentName(name);
        _currToken = JsonToken.FIELD_NAME;
        i = _skipColon();
        _updateLocation();
        if (i == INT_QUOTE) {
            _tokenIncomplete = true;
            _nextToken = JsonToken.VALUE_STRING;
            return nameToMatch.equals(name);
        }
        // Ok: we must have a value... what is it?
        JsonToken t;
        switch (i) {
        case '-':
            t = _parseNegNumber();
            break;
        case '.': // [core#61]]
            t = _parseFloatThatStartsWithPeriod();
            break;
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            t = _parsePosNumber(i);
            break;
        case 'f':
            _matchFalse();
            t = JsonToken.VALUE_FALSE;
            break;
        case 'n':
            _matchNull();
            t = JsonToken.VALUE_NULL;
            break;
        case 't':
            _matchTrue();
            t = JsonToken.VALUE_TRUE;
            break;
        case '[':
            t = JsonToken.START_ARRAY;
            break;
        case '{':
            t = JsonToken.START_OBJECT;
            break;
        default:
            t = _handleOddValue(i);
            break;
        }
        _nextToken = t;
        return nameToMatch.equals(name);
    }

    private final JsonToken _nextTokenNotInObject(int i) throws IOException
    {
        if (i == INT_QUOTE) {
            _tokenIncomplete = true;
            return (_currToken = JsonToken.VALUE_STRING);
        }
        switch (i) {
        case '[':
            _parsingContext = _parsingContext.createChildArrayContext(_tokenInputRow, _tokenInputCol);
            return (_currToken = JsonToken.START_ARRAY);
        case '{':
            _parsingContext = _parsingContext.createChildObjectContext(_tokenInputRow, _tokenInputCol);
            return (_currToken = JsonToken.START_OBJECT);
        case 't':
            _matchToken("true", 1);
            return (_currToken = JsonToken.VALUE_TRUE);
        case 'f':
            _matchToken("false", 1);
            return (_currToken = JsonToken.VALUE_FALSE);
        case 'n':
            _matchToken("null", 1);
            return (_currToken = JsonToken.VALUE_NULL);
        case '-':
            return (_currToken = _parseNegNumber());
            /* Should we have separate handling for plus? Although
             * it is not allowed per se, it may be erroneously used,
             * and could be indicated by a more specific error message.
             */
        case '.': // [core#61]]
            return (_currToken = _parseFloatThatStartsWithPeriod());
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            return (_currToken = _parsePosNumber(i));
        /*
         * This check proceeds only if the Feature.ALLOW_MISSING_VALUES is enabled
         * The Check is for missing values. In case of missing values in an array, the next token will be either ',' or ']'.
         * This case, decrements the already incremented _inputPtr in the buffer in case of comma(,) 
         * so that the existing flow goes back to checking the next token which will be comma again and
         * it continues the parsing.
         * Also the case returns NULL as current token in case of ',' or ']'.    
         */
// case ']':  // 11-May-2020, tatu: related to [core#616], this should never be reached
        case ',':
            // 11-May-2020, tatu: [core#616] No commas in root level
            if (!_parsingContext.inRoot()) {
                if ((_features & FEAT_MASK_ALLOW_MISSING) != 0) {
                    --_inputPtr;
                    return (_currToken = JsonToken.VALUE_NULL);
                }
            }
        }
        return (_currToken = _handleOddValue(i));
    }
    // note: identical to one in UTF8StreamJsonParser
    @Override
    public final String nextTextValue() throws IOException
    {
        if (_currToken == JsonToken.FIELD_NAME) { // mostly copied from '_nextAfterName'
            _nameCopied = false;
            JsonToken t = _nextToken;
            _nextToken = null;
            _currToken = t;
            if (t == JsonToken.VALUE_STRING) {
                if (_tokenIncomplete) {
                    _tokenIncomplete = false;
                    _finishString();
                }
                return _textBuffer.contentsAsString();
            }
            if (t == JsonToken.START_ARRAY) {
                _parsingContext = _parsingContext.createChildArrayContext(_tokenInputRow, _tokenInputCol);
            } else if (t == JsonToken.START_OBJECT) {
                _parsingContext = _parsingContext.createChildObjectContext(_tokenInputRow, _tokenInputCol);
            }
            return null;
        }
        // !!! TODO: optimize this case as well
        return (nextToken() == JsonToken.VALUE_STRING) ? getText() : null;
    }

    // note: identical to one in Utf8StreamParser
    @Override
    public final int nextIntValue(int defaultValue) throws IOException
    {
        if (_currToken == JsonToken.FIELD_NAME) {
            _nameCopied = false;
            JsonToken t = _nextToken;
            _nextToken = null;
            _currToken = t;
            if (t == JsonToken.VALUE_NUMBER_INT) {
                return getIntValue();
            }
            if (t == JsonToken.START_ARRAY) {
                _parsingContext = _parsingContext.createChildArrayContext(_tokenInputRow, _tokenInputCol);
            } else if (t == JsonToken.START_OBJECT) {
                _parsingContext = _parsingContext.createChildObjectContext(_tokenInputRow, _tokenInputCol);
            }
            return defaultValue;
        }
        // !!! TODO: optimize this case as well
        return (nextToken() == JsonToken.VALUE_NUMBER_INT) ? getIntValue() : defaultValue;
    }

    // note: identical to one in Utf8StreamParser
    @Override
    public final long nextLongValue(long defaultValue) throws IOException
    {
        if (_currToken == JsonToken.FIELD_NAME) { // mostly copied from '_nextAfterName'
            _nameCopied = false;
            JsonToken t = _nextToken;
            _nextToken = null;
            _currToken = t;
            if (t == JsonToken.VALUE_NUMBER_INT) {
                return getLongValue();
            }
            if (t == JsonToken.START_ARRAY) {
                _parsingContext = _parsingContext.createChildArrayContext(_tokenInputRow, _tokenInputCol);
            } else if (t == JsonToken.START_OBJECT) {
                _parsingContext = _parsingContext.createChildObjectContext(_tokenInputRow, _tokenInputCol);
            }
            return defaultValue;
        }
        // !!! TODO: optimize this case as well
        return (nextToken() == JsonToken.VALUE_NUMBER_INT) ? getLongValue() : defaultValue;
    }

    // note: identical to one in UTF8StreamJsonParser
    @Override
    public final Boolean nextBooleanValue() throws IOException
    {
        if (_currToken == JsonToken.FIELD_NAME) { // mostly copied from '_nextAfterName'
            _nameCopied = false;
            JsonToken t = _nextToken;
            _nextToken = null;
            _currToken = t;
            if (t == JsonToken.VALUE_TRUE) {
                return Boolean.TRUE;
            }
            if (t == JsonToken.VALUE_FALSE) {
                return Boolean.FALSE;
            }
            if (t == JsonToken.START_ARRAY) {
                _parsingContext = _parsingContext.createChildArrayContext(_tokenInputRow, _tokenInputCol);
            } else if (t == JsonToken.START_OBJECT) {
                _parsingContext = _parsingContext.createChildObjectContext(_tokenInputRow, _tokenInputCol);
            }
            return null;
        }
        JsonToken t = nextToken();
        if (t != null) {
            int id = t.id();
            if (id == ID_TRUE) return Boolean.TRUE;
            if (id == ID_FALSE) return Boolean.FALSE;
        }
        return null;
    }

    /*
    /**********************************************************
    /* Internal methods, number parsing
    /**********************************************************
     */

    // @since 2.11, [core#611]
    protected final JsonToken _parseFloatThatStartsWithPeriod() throws IOException
    {
        // [core#611]: allow optionally leading decimal point
        if (!isEnabled(JsonReadFeature.ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS.mappedFeature())) {
            return _handleOddValue('.');
        }
        return _parseFloat(INT_PERIOD, _inputPtr-1, _inputPtr, false, 0);
    }

    /**
     * Initial parsing method for number values. It needs to be able
     * to parse enough input to be able to determine whether the
     * value is to be considered a simple integer value, or a more
     * generic decimal value: latter of which needs to be expressed
     * as a floating point number. The basic rule is that if the number
     * has no fractional or exponential part, it is an integer; otherwise
     * a floating point number.
     *<p>
     * Because much of input has to be processed in any case, no partial
     * parsing is done: all input text will be stored for further
     * processing. However, actual numeric value conversion will be
     * deferred, since it is usually the most complicated and costliest
     * part of processing.
     */
    protected final JsonToken _parsePosNumber(int ch) throws IOException
    {
        /* Although we will always be complete with respect to textual
         * representation (that is, all characters will be parsed),
         * actual conversion to a number is deferred. Thus, need to
         * note that no representations are valid yet
         */
        int ptr = _inputPtr;
        int startPtr = ptr-1; // to include digit already read
        final int inputLen = _inputEnd;

        // One special case, leading zero(es):
        if (ch == INT_0) {
            return _parseNumber2(false, startPtr);
        }

        /* First, let's see if the whole number is contained within
         * the input buffer unsplit. This should be the common case;
         * and to simplify processing, we will just reparse contents
         * in the alternative case (number split on buffer boundary)
         */

        int intLen = 1; // already got one

        // First let's get the obligatory integer part:
        int_loop:
        while (true) {
            if (ptr >= inputLen) {
                _inputPtr = startPtr;
                return _parseNumber2(false, startPtr);
            }
            ch = (int) _inputBuffer[ptr++];
            if (ch < INT_0 || ch > INT_9) {
                break int_loop;
            }
            ++intLen;
        }
        if (ch == INT_PERIOD || ch == INT_e || ch == INT_E) {
            _inputPtr = ptr;
            return _parseFloat(ch, startPtr, ptr, false, intLen);
        }
        // Got it all: let's add to text buffer for parsing, access
        --ptr; // need to push back following separator
        _inputPtr = ptr;
        // As per #105, need separating space between root values; check here
        if (_parsingContext.inRoot()) {
            _verifyRootSpace(ch);
        }
        int len = ptr-startPtr;
        _textBuffer.resetWithShared(_inputBuffer, startPtr, len);
        return resetInt(false, intLen);
    }

    private final JsonToken _parseFloat(int ch, int startPtr, int ptr, boolean neg, int intLen)
        throws IOException
    {
        final int inputLen = _inputEnd;
        int fractLen = 0;

        // And then see if we get other parts
        if (ch == '.') { // yes, fraction
            fract_loop:
            while (true) {
                if (ptr >= inputLen) {
                    return _parseNumber2(neg, startPtr);
                }
                ch = (int) _inputBuffer[ptr++];
                if (ch < INT_0 || ch > INT_9) {
                    break fract_loop;
                }
                ++fractLen;
            }
            // must be followed by sequence of ints, one minimum
            if (fractLen == 0) {
                reportUnexpectedNumberChar(ch, "Decimal point not followed by a digit");
            }
        }
        int expLen = 0;
        if (ch == 'e' || ch == 'E') { // and/or exponent
            if (ptr >= inputLen) {
                _inputPtr = startPtr;
                return _parseNumber2(neg, startPtr);
            }
            // Sign indicator?
            ch = (int) _inputBuffer[ptr++];
            if (ch == INT_MINUS || ch == INT_PLUS) { // yup, skip for now
                if (ptr >= inputLen) {
                    _inputPtr = startPtr;
                    return _parseNumber2(neg, startPtr);
                }
                ch = (int) _inputBuffer[ptr++];
            }
            while (ch <= INT_9 && ch >= INT_0) {
                ++expLen;
                if (ptr >= inputLen) {
                    _inputPtr = startPtr;
                    return _parseNumber2(neg, startPtr);
                }
                ch = (int) _inputBuffer[ptr++];
            }
            // must be followed by sequence of ints, one minimum
            if (expLen == 0) {
                reportUnexpectedNumberChar(ch, "Exponent indicator not followed by a digit");
            }
        }
        --ptr; // need to push back following separator
        _inputPtr = ptr;
        // As per #105, need separating space between root values; check here
        if (_parsingContext.inRoot()) {
            _verifyRootSpace(ch);
        }
        int len = ptr-startPtr;
        _textBuffer.resetWithShared(_inputBuffer, startPtr, len);
        // And there we have it!
        return resetFloat(neg, intLen, fractLen, expLen);
    }

    protected final JsonToken _parseNegNumber() throws IOException
    {
        int ptr = _inputPtr;
        int startPtr = ptr-1; // to include sign/digit already read
        final int inputLen = _inputEnd;

        if (ptr >= inputLen) {
            return _parseNumber2(true, startPtr);
        }
        int ch = _inputBuffer[ptr++];
        // First check: must have a digit to follow minus sign
        if (ch > INT_9 || ch < INT_0) {
            _inputPtr = ptr;
            return _handleInvalidNumberStart(ch, true);
        }
        // One special case, leading zero(es):
        if (ch == INT_0) {
            return _parseNumber2(true, startPtr);
        }
        int intLen = 1; // already got one

        // First let's get the obligatory integer part:
        int_loop:
        while (true) {
            if (ptr >= inputLen) {
                return _parseNumber2(true, startPtr);
            }
            ch = (int) _inputBuffer[ptr++];
            if (ch < INT_0 || ch > INT_9) {
                break int_loop;
            }
            ++intLen;
        }

        if (ch == INT_PERIOD || ch == INT_e || ch == INT_E) {
            _inputPtr = ptr;
            return _parseFloat(ch, startPtr, ptr, true, intLen);
        }
        --ptr;
        _inputPtr = ptr;
        if (_parsingContext.inRoot()) {
            _verifyRootSpace(ch);
        }
        int len = ptr-startPtr;
        _textBuffer.resetWithShared(_inputBuffer, startPtr, len);
        return resetInt(true, intLen);
    }

    /**
     * Method called to parse a number, when the primary parse
     * method has failed to parse it, due to it being split on
     * buffer boundary. As a result code is very similar, except
     * that it has to explicitly copy contents to the text buffer
     * instead of just sharing the main input buffer.
     */
    private final JsonToken _parseNumber2(boolean neg, int startPtr) throws IOException
    {
        _inputPtr = neg ? (startPtr+1) : startPtr;
        char[] outBuf = _textBuffer.emptyAndGetCurrentSegment();
        int outPtr = 0;

        // Need to prepend sign?
        if (neg) {
            outBuf[outPtr++] = '-';
        }

        // This is the place to do leading-zero check(s) too:
        int intLen = 0;
        char c = (_inputPtr < _inputEnd) ? _inputBuffer[_inputPtr++]
                : getNextChar("No digit following minus sign", JsonToken.VALUE_NUMBER_INT);
        if (c == '0') {
            c = _verifyNoLeadingZeroes();
        }
        boolean eof = false;

        // Ok, first the obligatory integer part:
        int_loop:
        while (c >= '0' && c <= '9') {
            ++intLen;
            if (outPtr >= outBuf.length) {
                outBuf = _textBuffer.finishCurrentSegment();
                outPtr = 0;
            }
            outBuf[outPtr++] = c;
            if (_inputPtr >= _inputEnd && !_loadMore()) {
                // EOF is legal for main level int values
                c = CHAR_NULL;
                eof = true;
                break int_loop;
            }
            c = _inputBuffer[_inputPtr++];
        }
        // Also, integer part is not optional
        if (intLen == 0) {
            return _handleInvalidNumberStart(c, neg);
        }

        int fractLen = 0;
        // And then see if we get other parts
        if (c == '.') { // yes, fraction
            if (outPtr >= outBuf.length) {
                outBuf = _textBuffer.finishCurrentSegment();
                outPtr = 0;
            }
            outBuf[outPtr++] = c;

            fract_loop:
            while (true) {
                if (_inputPtr >= _inputEnd && !_loadMore()) {
                    eof = true;
                    break fract_loop;
                }
                c = _inputBuffer[_inputPtr++];
                if (c < INT_0 || c > INT_9) {
                    break fract_loop;
                }
                ++fractLen;
                if (outPtr >= outBuf.length) {
                    outBuf = _textBuffer.finishCurrentSegment();
                    outPtr = 0;
                }
                outBuf[outPtr++] = c;
            }
            // must be followed by sequence of ints, one minimum
            if (fractLen == 0) {
                reportUnexpectedNumberChar(c, "Decimal point not followed by a digit");
            }
        }

        int expLen = 0;
        if (c == 'e' || c == 'E') { // exponent?
            if (outPtr >= outBuf.length) {
                outBuf = _textBuffer.finishCurrentSegment();
                outPtr = 0;
            }
            outBuf[outPtr++] = c;
            // Not optional, can require that we get one more char
            c = (_inputPtr < _inputEnd) ? _inputBuffer[_inputPtr++]
                : getNextChar("expected a digit for number exponent");
            // Sign indicator?
            if (c == '-' || c == '+') {
                if (outPtr >= outBuf.length) {
                    outBuf = _textBuffer.finishCurrentSegment();
                    outPtr = 0;
                }
                outBuf[outPtr++] = c;
                // Likewise, non optional:
                c = (_inputPtr < _inputEnd) ? _inputBuffer[_inputPtr++]
                    : getNextChar("expected a digit for number exponent");
            }

            exp_loop:
            while (c <= INT_9 && c >= INT_0) {
                ++expLen;
                if (outPtr >= outBuf.length) {
                    outBuf = _textBuffer.finishCurrentSegment();
                    outPtr = 0;
                }
                outBuf[outPtr++] = c;
                if (_inputPtr >= _inputEnd && !_loadMore()) {
                    eof = true;
                    break exp_loop;
                }
                c = _inputBuffer[_inputPtr++];
            }
            // must be followed by sequence of ints, one minimum
            if (expLen == 0) {
                reportUnexpectedNumberChar(c, "Exponent indicator not followed by a digit");
            }
        }

        // Ok; unless we hit end-of-input, need to push last char read back
        if (!eof) {
            --_inputPtr;
            if (_parsingContext.inRoot()) {
                _verifyRootSpace(c);
            }
        }
        _textBuffer.setCurrentLength(outPtr);
        // And there we have it!
        return reset(neg, intLen, fractLen, expLen);
    }

    /**
     * Method called when we have seen one zero, and want to ensure
     * it is not followed by another
     */
    private final char _verifyNoLeadingZeroes() throws IOException
    {
        // Fast case first:
        if (_inputPtr < _inputEnd) {
            char ch = _inputBuffer[_inputPtr];
            // if not followed by a number (probably '.'); return zero as is, to be included
            if (ch < '0' || ch > '9') {
                return '0';
            }
        }
        // and offline the less common case
        return _verifyNLZ2();
    }

    private char _verifyNLZ2() throws IOException
    {
        if (_inputPtr >= _inputEnd && !_loadMore()) {
            return '0';
        }
        char ch = _inputBuffer[_inputPtr];
        if (ch < '0' || ch > '9') {
            return '0';
        }
        if ((_features & FEAT_MASK_LEADING_ZEROS) == 0) {
            reportInvalidNumber("Leading zeroes not allowed");
        }
        // if so, just need to skip either all zeroes (if followed by number); or all but one (if non-number)
        ++_inputPtr; // Leading zero to be skipped
        if (ch == INT_0) {
            while (_inputPtr < _inputEnd || _loadMore()) {
                ch = _inputBuffer[_inputPtr];
                if (ch < '0' || ch > '9') { // followed by non-number; retain one zero
                    return '0';
                }
                ++_inputPtr; // skip previous zero
                if (ch != '0') { // followed by other number; return
                    break;
                }
            }
        }
        return ch;
    }

    /**
     * Method called if expected numeric value (due to leading sign) does not
     * look like a number
     */
    protected JsonToken _handleInvalidNumberStart(int ch, boolean negative) throws IOException
    {
        if (ch == 'I') {
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) {
                    _reportInvalidEOFInValue(JsonToken.VALUE_NUMBER_INT);
                }
            }
            ch = _inputBuffer[_inputPtr++];
            if (ch == 'N') {
                String match = negative ? "-INF" :"+INF";
                _matchToken(match, 3);
                if ((_features & FEAT_MASK_NON_NUM_NUMBERS) != 0) {
                    return resetAsNaN(match, negative ? Double.NEGATIVE_INFINITY : Double.POSITIVE_INFINITY);
                }
                _reportError("Non-standard token '"+match+"': enable JsonParser.Feature.ALLOW_NON_NUMERIC_NUMBERS to allow");
            } else if (ch == 'n') {
                String match = negative ? "-Infinity" :"+Infinity";
                _matchToken(match, 3);
                if ((_features & FEAT_MASK_NON_NUM_NUMBERS) != 0) {
                    return resetAsNaN(match, negative ? Double.NEGATIVE_INFINITY : Double.POSITIVE_INFINITY);
                }
                _reportError("Non-standard token '"+match+"': enable JsonParser.Feature.ALLOW_NON_NUMERIC_NUMBERS to allow");
            }
        }
        reportUnexpectedNumberChar(ch, "expected digit (0-9) to follow minus sign, for valid numeric value");
        return null;
    }

    /**
     * Method called to ensure that a root-value is followed by a space
     * token.
     *<p>
     * NOTE: caller MUST ensure there is at least one character available;
     * and that input pointer is AT given char (not past)
     */
    private final void _verifyRootSpace(int ch) throws IOException
    {
        // caller had pushed it back, before calling; reset
        ++_inputPtr;
        switch (ch) {
        case ' ':
        case '\t':
            return;
        case '\r':
            _skipCR();
            return;
        case '\n':
            ++_currInputRow;
            _currInputRowStart = _inputPtr;
            return;
        }
        _reportMissingRootWS(ch);
    }

    /*
    /**********************************************************
    /* Internal methods, secondary parsing
    /**********************************************************
     */

    protected final String _parseName() throws IOException
    {
        // First: let's try to see if we have a simple name: one that does
        // not cross input buffer boundary, and does not contain escape sequences.
        int ptr = _inputPtr;
        int hash = _hashSeed;
        final int[] codes = _icLatin1;

        while (ptr < _inputEnd) {
            int ch = _inputBuffer[ptr];
            if (ch < codes.length && codes[ch] != 0) {
                if (ch == '"') {
                    int start = _inputPtr;
                    _inputPtr = ptr+1; // to skip the quote
                    return _symbols.findSymbol(_inputBuffer, start, ptr - start, hash);
                }
                break;
            }
            hash = (hash * CharsToNameCanonicalizer.HASH_MULT) + ch;
            ++ptr;
        }
        int start = _inputPtr;
        _inputPtr = ptr;
        return _parseName2(start, hash, INT_QUOTE);
    }

    private String _parseName2(int startPtr, int hash, int endChar) throws IOException
    {
        _textBuffer.resetWithShared(_inputBuffer, startPtr, (_inputPtr - startPtr));

        /* Output pointers; calls will also ensure that the buffer is
         * not shared and has room for at least one more char.
         */
        char[] outBuf = _textBuffer.getCurrentSegment();
        int outPtr = _textBuffer.getCurrentSegmentSize();

        while (true) {
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) {
                    _reportInvalidEOF(" in field name", JsonToken.FIELD_NAME);
                }
            }
            char c = _inputBuffer[_inputPtr++];
            int i = (int) c;
            if (i <= INT_BACKSLASH) {
                if (i == INT_BACKSLASH) {
                    /* Although chars outside of BMP are to be escaped as
                     * an UTF-16 surrogate pair, does that affect decoding?
                     * For now let's assume it does not.
                     */
                    c = _decodeEscaped();
                } else if (i <= endChar) {
                    if (i == endChar) {
                        break;
                    }
                    if (i < INT_SPACE) {
                        _throwUnquotedSpace(i, "name");
                    }
                }
            }
            hash = (hash * CharsToNameCanonicalizer.HASH_MULT) + c;
            // Ok, let's add char to output:
            outBuf[outPtr++] = c;

            // Need more room?
            if (outPtr >= outBuf.length) {
                outBuf = _textBuffer.finishCurrentSegment();
                outPtr = 0;
            }
        }
        _textBuffer.setCurrentLength(outPtr);
        {
            TextBuffer tb = _textBuffer;
            char[] buf = tb.getTextBuffer();
            int start = tb.getTextOffset();
            int len = tb.size();
            return _symbols.findSymbol(buf, start, len, hash);
        }
    }

    /**
     * Method called when we see non-white space character other
     * than double quote, when expecting a field name.
     * In standard mode will just throw an expection; but
     * in non-standard modes may be able to parse name.
     */
    protected String _handleOddName(int i) throws IOException
    {
        // [JACKSON-173]: allow single quotes
        if (i == '\'' && (_features & FEAT_MASK_ALLOW_SINGLE_QUOTES) != 0) {
            return _parseAposName();
        }
        // [JACKSON-69]: allow unquoted names if feature enabled:
        if ((_features & FEAT_MASK_ALLOW_UNQUOTED_NAMES) == 0) {
            _reportUnexpectedChar(i, "was expecting double-quote to start field name");
        }
        final int[] codes = CharTypes.getInputCodeLatin1JsNames();
        final int maxCode = codes.length;

        // Also: first char must be a valid name char, but NOT be number
        boolean firstOk;

        if (i < maxCode) { // identifier, or a number ([Issue#102])
            firstOk = (codes[i] == 0);
        } else {
            firstOk = Character.isJavaIdentifierPart((char) i);
        }
        if (!firstOk) {
            _reportUnexpectedChar(i, "was expecting either valid name character (for unquoted name) or double-quote (for quoted) to start field name");
        }
        int ptr = _inputPtr;
        int hash = _hashSeed;
        final int inputLen = _inputEnd;

        if (ptr < inputLen) {
            do {
                int ch = _inputBuffer[ptr];
                if (ch < maxCode) {
                    if (codes[ch] != 0) {
                        int start = _inputPtr-1; // -1 to bring back first char
                        _inputPtr = ptr;
                        return _symbols.findSymbol(_inputBuffer, start, ptr - start, hash);
                    }
                } else if (!Character.isJavaIdentifierPart((char) ch)) {
                    int start = _inputPtr-1; // -1 to bring back first char
                    _inputPtr = ptr;
                    return _symbols.findSymbol(_inputBuffer, start, ptr - start, hash);
                }
                hash = (hash * CharsToNameCanonicalizer.HASH_MULT) + ch;
                ++ptr;
            } while (ptr < inputLen);
        }
        int start = _inputPtr-1;
        _inputPtr = ptr;
        return _handleOddName2(start, hash, codes);
    }

    protected String _parseAposName() throws IOException
    {
        // Note: mostly copy of_parseFieldName
        int ptr = _inputPtr;
        int hash = _hashSeed;
        final int inputLen = _inputEnd;

        if (ptr < inputLen) {
            final int[] codes = _icLatin1;
            final int maxCode = codes.length;

            do {
                int ch = _inputBuffer[ptr];
                if (ch == '\'') {
                    int start = _inputPtr;
                    _inputPtr = ptr+1; // to skip the quote
                    return _symbols.findSymbol(_inputBuffer, start, ptr - start, hash);
                }
                if (ch < maxCode && codes[ch] != 0) {
                    break;
                }
                hash = (hash * CharsToNameCanonicalizer.HASH_MULT) + ch;
                ++ptr;
            } while (ptr < inputLen);
        }

        int start = _inputPtr;
        _inputPtr = ptr;

        return _parseName2(start, hash, '\'');
    }

    /**
     * Method for handling cases where first non-space character
     * of an expected value token is not legal for standard JSON content.
     */
    protected JsonToken _handleOddValue(int i) throws IOException
    {
        // Most likely an error, unless we are to allow single-quote-strings
        switch (i) {
        case '\'':
            /* Allow single quotes? Unlike with regular Strings, we'll eagerly parse
             * contents; this so that there'sno need to store information on quote char used.
             * Also, no separation to fast/slow parsing; we'll just do
             * one regular (~= slowish) parsing, to keep code simple
             */
            if ((_features & FEAT_MASK_ALLOW_SINGLE_QUOTES) != 0) {
                return _handleApos();
            }
            break;
        case ']':
            /* 28-Mar-2016: [core#116]: If Feature.ALLOW_MISSING_VALUES is enabled
             *   we may allow "missing values", that is, encountering a trailing
             *   comma or closing marker where value would be expected
             */
            if (!_parsingContext.inArray()) {
                break;
            }
            // fall through
        case ',':
            // 11-May-2020, tatu: [core#616] No commas in root level
            if (!_parsingContext.inRoot()) {
                if ((_features & FEAT_MASK_ALLOW_MISSING) != 0) {
                    --_inputPtr;
                    return JsonToken.VALUE_NULL;
                }
            }
            break;
        case 'N':
            _matchToken("NaN", 1);
            if ((_features & FEAT_MASK_NON_NUM_NUMBERS) != 0) {
                return resetAsNaN("NaN", Double.NaN);
            }
            _reportError("Non-standard token 'NaN': enable JsonParser.Feature.ALLOW_NON_NUMERIC_NUMBERS to allow");
            break;
        case 'I':
            _matchToken("Infinity", 1);
            if ((_features & FEAT_MASK_NON_NUM_NUMBERS) != 0) {
                return resetAsNaN("Infinity", Double.POSITIVE_INFINITY);
            }
            _reportError("Non-standard token 'Infinity': enable JsonParser.Feature.ALLOW_NON_NUMERIC_NUMBERS to allow");
            break;
        case '+': // note: '-' is taken as number
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) {
                    _reportInvalidEOFInValue(JsonToken.VALUE_NUMBER_INT);
                }
            }
            return _handleInvalidNumberStart(_inputBuffer[_inputPtr++], false);
        }
        // [core#77] Try to decode most likely token
        if (Character.isJavaIdentifierStart(i)) {
            _reportInvalidToken(""+((char) i), _validJsonTokenList());
        }
        // but if it doesn't look like a token:
        _reportUnexpectedChar(i, "expected a valid value "+_validJsonValueList());
        return null;
    }

    protected JsonToken _handleApos() throws IOException
    {
        char[] outBuf = _textBuffer.emptyAndGetCurrentSegment();
        int outPtr = _textBuffer.getCurrentSegmentSize();

        while (true) {
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) {
                    _reportInvalidEOF(": was expecting closing quote for a string value",
                            JsonToken.VALUE_STRING);
                }
            }
            char c = _inputBuffer[_inputPtr++];
            int i = (int) c;
            if (i <= '\\') {
                if (i == '\\') {
                    /* Although chars outside of BMP are to be escaped as
                     * an UTF-16 surrogate pair, does that affect decoding?
                     * For now let's assume it does not.
                     */
                    c = _decodeEscaped();
                } else if (i <= '\'') {
                    if (i == '\'') {
                        break;
                    }
                    if (i < INT_SPACE) {
                        _throwUnquotedSpace(i, "string value");
                    }
                }
            }
            // Need more room?
            if (outPtr >= outBuf.length) {
                outBuf = _textBuffer.finishCurrentSegment();
                outPtr = 0;
            }
            // Ok, let's add char to output:
            outBuf[outPtr++] = c;
        }
        _textBuffer.setCurrentLength(outPtr);
        return JsonToken.VALUE_STRING;
    }

    private String _handleOddName2(int startPtr, int hash, int[] codes) throws IOException
    {
        _textBuffer.resetWithShared(_inputBuffer, startPtr, (_inputPtr - startPtr));
        char[] outBuf = _textBuffer.getCurrentSegment();
        int outPtr = _textBuffer.getCurrentSegmentSize();
        final int maxCode = codes.length;

        while (true) {
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) { // acceptable for now (will error out later)
                    break;
                }
            }
            char c = _inputBuffer[_inputPtr];
            int i = (int) c;
            if (i < maxCode) {
                if (codes[i] != 0) {
                    break;
                }
            } else if (!Character.isJavaIdentifierPart(c)) {
                break;
            }
            ++_inputPtr;
            hash = (hash * CharsToNameCanonicalizer.HASH_MULT) + i;
            // Ok, let's add char to output:
            outBuf[outPtr++] = c;

            // Need more room?
            if (outPtr >= outBuf.length) {
                outBuf = _textBuffer.finishCurrentSegment();
                outPtr = 0;
            }
        }
        _textBuffer.setCurrentLength(outPtr);
        {
            TextBuffer tb = _textBuffer;
            char[] buf = tb.getTextBuffer();
            int start = tb.getTextOffset();
            int len = tb.size();

            return _symbols.findSymbol(buf, start, len, hash);
        }
    }

    @Override
    protected final void _finishString() throws IOException
    {
        /* First: let's try to see if we have simple String value: one
         * that does not cross input buffer boundary, and does not
         * contain escape sequences.
         */
        int ptr = _inputPtr;
        final int inputLen = _inputEnd;

        if (ptr < inputLen) {
            final int[] codes = _icLatin1;
            final int maxCode = codes.length;

            do {
                int ch = _inputBuffer[ptr];
                if (ch < maxCode && codes[ch] != 0) {
                    if (ch == '"') {
                        _textBuffer.resetWithShared(_inputBuffer, _inputPtr, (ptr-_inputPtr));
                        _inputPtr = ptr+1;
                        // Yes, we got it all
                        return;
                    }
                    break;
                }
                ++ptr;
            } while (ptr < inputLen);
        }

        // Either ran out of input, or bumped into an escape sequence...
        _textBuffer.resetWithCopy(_inputBuffer, _inputPtr, (ptr-_inputPtr));
        _inputPtr = ptr;
        _finishString2();
    }

    protected void _finishString2() throws IOException
    {
        char[] outBuf = _textBuffer.getCurrentSegment();
        int outPtr = _textBuffer.getCurrentSegmentSize();
        final int[] codes = _icLatin1;
        final int maxCode = codes.length;

        while (true) {
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) {
                    _reportInvalidEOF(": was expecting closing quote for a string value",
                            JsonToken.VALUE_STRING);
                }
            }
            char c = _inputBuffer[_inputPtr++];
            int i = (int) c;
            if (i < maxCode && codes[i] != 0) {
                if (i == INT_QUOTE) {
                    break;
                } else if (i == INT_BACKSLASH) {
                    /* Although chars outside of BMP are to be escaped as
                     * an UTF-16 surrogate pair, does that affect decoding?
                     * For now let's assume it does not.
                     */
                    c = _decodeEscaped();
                } else if (i < INT_SPACE) {
                    _throwUnquotedSpace(i, "string value");
                } // anything else?
            }
            // Need more room?
            if (outPtr >= outBuf.length) {
                outBuf = _textBuffer.finishCurrentSegment();
                outPtr = 0;
            }
            // Ok, let's add char to output:
            outBuf[outPtr++] = c;
        }
        _textBuffer.setCurrentLength(outPtr);
    }

    /**
     * Method called to skim through rest of unparsed String value,
     * if it is not needed. This can be done bit faster if contents
     * need not be stored for future access.
     */
    protected final void _skipString() throws IOException
    {
        _tokenIncomplete = false;

        int inPtr = _inputPtr;
        int inLen = _inputEnd;
        char[] inBuf = _inputBuffer;

        while (true) {
            if (inPtr >= inLen) {
                _inputPtr = inPtr;
                if (!_loadMore()) {
                    _reportInvalidEOF(": was expecting closing quote for a string value",
                            JsonToken.VALUE_STRING);
                }
                inPtr = _inputPtr;
                inLen = _inputEnd;
            }
            char c = inBuf[inPtr++];
            int i = (int) c;
            if (i <= INT_BACKSLASH) {
                if (i == INT_BACKSLASH) {
                    // Although chars outside of BMP are to be escaped as an UTF-16 surrogate pair,
                    // does that affect decoding? For now let's assume it does not.
                    _inputPtr = inPtr;
                    /*c = */ _decodeEscaped();
                    inPtr = _inputPtr;
                    inLen = _inputEnd;
                } else if (i <= INT_QUOTE) {
                    if (i == INT_QUOTE) {
                        _inputPtr = inPtr;
                        break;
                    }
                    if (i < INT_SPACE) {
                        _inputPtr = inPtr;
                        _throwUnquotedSpace(i, "string value");
                    }
                }
            }
        }
    }

    /*
    /**********************************************************
    /* Internal methods, other parsing
    /**********************************************************
     */

    /**
     * We actually need to check the character value here
     * (to see if we have \n following \r).
     */
    protected final void _skipCR() throws IOException {
        if (_inputPtr < _inputEnd || _loadMore()) {
            if (_inputBuffer[_inputPtr] == '\n') {
                ++_inputPtr;
            }
        }
        ++_currInputRow;
        _currInputRowStart = _inputPtr;
    }

    private final int _skipColon() throws IOException
    {
        if ((_inputPtr + 4) >= _inputEnd) {
            return _skipColon2(false);
        }
        char c = _inputBuffer[_inputPtr];
        if (c == ':') { // common case, no leading space
            int i = _inputBuffer[++_inputPtr];
            if (i > INT_SPACE) { // nor trailing
                if (i == INT_SLASH || i == INT_HASH) {
                    return _skipColon2(true);
                }
                ++_inputPtr;
                return i;
            }
            if (i == INT_SPACE || i == INT_TAB) {
                i = (int) _inputBuffer[++_inputPtr];
                if (i > INT_SPACE) {
                    if (i == INT_SLASH || i == INT_HASH) {
                        return _skipColon2(true);
                    }
                    ++_inputPtr;
                    return i;
                }
            }
            return _skipColon2(true); // true -> skipped colon
        }
        if (c == ' ' || c == '\t') {
            c = _inputBuffer[++_inputPtr];
        }
        if (c == ':') {
            int i = _inputBuffer[++_inputPtr];
            if (i > INT_SPACE) {
                if (i == INT_SLASH || i == INT_HASH) {
                    return _skipColon2(true);
                }
                ++_inputPtr;
                return i;
            }
            if (i == INT_SPACE || i == INT_TAB) {
                i = (int) _inputBuffer[++_inputPtr];
                if (i > INT_SPACE) {
                    if (i == INT_SLASH || i == INT_HASH) {
                        return _skipColon2(true);
                    }
                    ++_inputPtr;
                    return i;
                }
            }
            return _skipColon2(true);
        }
        return _skipColon2(false);
    }

    private final int _skipColon2(boolean gotColon) throws IOException
    {
        while (_inputPtr < _inputEnd || _loadMore()) {
            int i = (int) _inputBuffer[_inputPtr++];
            if (i > INT_SPACE) {
                if (i == INT_SLASH) {
                    _skipComment();
                    continue;
                }
                if (i == INT_HASH) {
                    if (_skipYAMLComment()) {
                        continue;
                    }
                }
                if (gotColon) {
                    return i;
                }
                if (i != INT_COLON) {
                    _reportUnexpectedChar(i, "was expecting a colon to separate field name and value");
                }
                gotColon = true;
                continue;
            }
            if (i < INT_SPACE) {
                if (i == INT_LF) {
                    ++_currInputRow;
                    _currInputRowStart = _inputPtr;
                } else if (i == INT_CR) {
                    _skipCR();
                } else if (i != INT_TAB) {
                    _throwInvalidSpace(i);
                }
            }
        }
        _reportInvalidEOF(" within/between "+_parsingContext.typeDesc()+" entries",
                null);
        return -1;
    }

    // Variant called when we know there's at least 4 more bytes available
    private final int _skipColonFast(int ptr) throws IOException
    {
        int i = (int) _inputBuffer[ptr++];
        if (i == INT_COLON) { // common case, no leading space
            i = _inputBuffer[ptr++];
            if (i > INT_SPACE) { // nor trailing
                if (i != INT_SLASH && i != INT_HASH) {
                    _inputPtr = ptr;
                    return i;
                }
            } else if (i == INT_SPACE || i == INT_TAB) {
                i = (int) _inputBuffer[ptr++];
                if (i > INT_SPACE) {
                    if (i != INT_SLASH && i != INT_HASH) {
                        _inputPtr = ptr;
                        return i;
                    }
                }
            }
            _inputPtr = ptr-1;
            return _skipColon2(true); // true -> skipped colon
        }
        if (i == INT_SPACE || i == INT_TAB) {
            i = _inputBuffer[ptr++];
        }
        boolean gotColon = (i == INT_COLON);
        if (gotColon) {
            i = _inputBuffer[ptr++];
            if (i > INT_SPACE) {
                if (i != INT_SLASH && i != INT_HASH) {
                    _inputPtr = ptr;
                    return i;
                }
            } else if (i == INT_SPACE || i == INT_TAB) {
                i = (int) _inputBuffer[ptr++];
                if (i > INT_SPACE) {
                    if (i != INT_SLASH && i != INT_HASH) {
                        _inputPtr = ptr;
                        return i;
                    }
                }
            }
        }
        _inputPtr = ptr-1;
        return _skipColon2(gotColon);
    }

    // Primary loop: no reloading, comment handling
    private final int _skipComma(int i) throws IOException
    {
        if (i != INT_COMMA) {
            _reportUnexpectedChar(i, "was expecting comma to separate "+_parsingContext.typeDesc()+" entries");
        }
        while (_inputPtr < _inputEnd) {
            i = (int) _inputBuffer[_inputPtr++];
            if (i > INT_SPACE) {
                if (i == INT_SLASH || i == INT_HASH) {
                    --_inputPtr;
                    return _skipAfterComma2();
                }
                return i;
            }
            if (i < INT_SPACE) {
                if (i == INT_LF) {
                    ++_currInputRow;
                    _currInputRowStart = _inputPtr;
                } else if (i == INT_CR) {
                    _skipCR();
                } else if (i != INT_TAB) {
                    _throwInvalidSpace(i);
                }
            }
        }
        return _skipAfterComma2();
    }

    private final int _skipAfterComma2() throws IOException
    {
        while (_inputPtr < _inputEnd || _loadMore()) {
            int i = (int) _inputBuffer[_inputPtr++];
            if (i > INT_SPACE) {
                if (i == INT_SLASH) {
                    _skipComment();
                    continue;
                }
                if (i == INT_HASH) {
                    if (_skipYAMLComment()) {
                        continue;
                    }
                }
                return i;
            }
            if (i < INT_SPACE) {
                if (i == INT_LF) {
                    ++_currInputRow;
                    _currInputRowStart = _inputPtr;
                } else if (i == INT_CR) {
                    _skipCR();
                } else if (i != INT_TAB) {
                    _throwInvalidSpace(i);
                }
            }
        }
        throw _constructError("Unexpected end-of-input within/between "+_parsingContext.typeDesc()+" entries");
    }

    private final int _skipWSOrEnd() throws IOException
    {
        // Let's handle first character separately since it is likely that
        // it is either non-whitespace; or we have longer run of white space
        if (_inputPtr >= _inputEnd) {
            if (!_loadMore()) {
                return _eofAsNextChar();
            }
        }
        int i = _inputBuffer[_inputPtr++];
        if (i > INT_SPACE) {
            if (i == INT_SLASH || i == INT_HASH) {
                --_inputPtr;
                return _skipWSOrEnd2();
            }
            return i;
        }
        if (i != INT_SPACE) {
            if (i == INT_LF) {
                ++_currInputRow;
                _currInputRowStart = _inputPtr;
            } else if (i == INT_CR) {
                _skipCR();
            } else if (i != INT_TAB) {
                _throwInvalidSpace(i);
            }
        }

        while (_inputPtr < _inputEnd) {
            i = (int) _inputBuffer[_inputPtr++];
            if (i > INT_SPACE) {
                if (i == INT_SLASH || i == INT_HASH) {
                    --_inputPtr;
                    return _skipWSOrEnd2();
                }
                return i;
            }
            if (i != INT_SPACE) {
                if (i == INT_LF) {
                    ++_currInputRow;
                    _currInputRowStart = _inputPtr;
                } else if (i == INT_CR) {
                    _skipCR();
                } else if (i != INT_TAB) {
                    _throwInvalidSpace(i);
                }
            }
        }
        return _skipWSOrEnd2();
    }

    private int _skipWSOrEnd2() throws IOException
    {
        while (true) {
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) { // We ran out of input...
                    return _eofAsNextChar();
                }
            }
            int i = (int) _inputBuffer[_inputPtr++];
            if (i > INT_SPACE) {
                if (i == INT_SLASH) {
                    _skipComment();
                    continue;
                }
                if (i == INT_HASH) {
                    if (_skipYAMLComment()) {
                        continue;
                    }
                }
                return i;
            } else if (i != INT_SPACE) {
                if (i == INT_LF) {
                    ++_currInputRow;
                    _currInputRowStart = _inputPtr;
                } else if (i == INT_CR) {
                    _skipCR();
                } else if (i != INT_TAB) {
                    _throwInvalidSpace(i);
                }
            }
        }
    }

    private void _skipComment() throws IOException
    {
        if ((_features & FEAT_MASK_ALLOW_JAVA_COMMENTS) == 0) {
            _reportUnexpectedChar('/', "maybe a (non-standard) comment? (not recognized as one since Feature 'ALLOW_COMMENTS' not enabled for parser)");
        }
        // First: check which comment (if either) it is:
        if (_inputPtr >= _inputEnd && !_loadMore()) {
            _reportInvalidEOF(" in a comment", null);
        }
        char c = _inputBuffer[_inputPtr++];
        if (c == '/') {
            _skipLine();
        } else if (c == '*') {
            _skipCComment();
        } else {
            _reportUnexpectedChar(c, "was expecting either '*' or '/' for a comment");
        }
    }

    private void _skipCComment() throws IOException
    {
        // Ok: need the matching '*/'
        while ((_inputPtr < _inputEnd) || _loadMore()) {
            int i = (int) _inputBuffer[_inputPtr++];
            if (i <= '*') {
                if (i == '*') { // end?
                    if ((_inputPtr >= _inputEnd) && !_loadMore()) {
                        break;
                    }
                    if (_inputBuffer[_inputPtr] == INT_SLASH) {
                        ++_inputPtr;
                        return;
                    }
                    continue;
                }
                if (i < INT_SPACE) {
                    if (i == INT_LF) {
                        ++_currInputRow;
                        _currInputRowStart = _inputPtr;
                    } else if (i == INT_CR) {
                        _skipCR();
                    } else if (i != INT_TAB) {
                        _throwInvalidSpace(i);
                    }
                }
            }
        }
        _reportInvalidEOF(" in a comment", null);
    }

    private boolean _skipYAMLComment() throws IOException
    {
        if ((_features & FEAT_MASK_ALLOW_YAML_COMMENTS) == 0) {
            return false;
        }
        _skipLine();
        return true;
    }

    private void _skipLine() throws IOException
    {
        // Ok: need to find EOF or linefeed
        while ((_inputPtr < _inputEnd) || _loadMore()) {
            int i = (int) _inputBuffer[_inputPtr++];
            if (i < INT_SPACE) {
                if (i == INT_LF) {
                    ++_currInputRow;
                    _currInputRowStart = _inputPtr;
                    break;
                } else if (i == INT_CR) {
                    _skipCR();
                    break;
                } else if (i != INT_TAB) {
                    _throwInvalidSpace(i);
                }
            }
        }
    }

    @Override
    protected char _decodeEscaped() throws IOException
    {
        if (_inputPtr >= _inputEnd) {
            if (!_loadMore()) {
                _reportInvalidEOF(" in character escape sequence", JsonToken.VALUE_STRING);
            }
        }
        char c = _inputBuffer[_inputPtr++];

        switch ((int) c) {
            // First, ones that are mapped
        case 'b':
            return '\b';
        case 't':
            return '\t';
        case 'n':
            return '\n';
        case 'f':
            return '\f';
        case 'r':
            return '\r';

            // And these are to be returned as they are
        case '"':
        case '/':
        case '\\':
            return c;

        case 'u': // and finally hex-escaped
            break;

        default:
            return _handleUnrecognizedCharacterEscape(c);
        }

        // Ok, a hex escape. Need 4 characters
        int value = 0;
        for (int i = 0; i < 4; ++i) {
            if (_inputPtr >= _inputEnd) {
                if (!_loadMore()) {
                    _reportInvalidEOF(" in character escape sequence", JsonToken.VALUE_STRING);
                }
            }
            int ch = (int) _inputBuffer[_inputPtr++];
            int digit = CharTypes.charToHex(ch);
            if (digit < 0) {
                _reportUnexpectedChar(ch, "expected a hex-digit for character escape sequence");
            }
            value = (value << 4) | digit;
        }
        return (char) value;
    }

    private final void _matchTrue() throws IOException {
        int ptr = _inputPtr;
        if ((ptr + 3) < _inputEnd) {
            final char[] b = _inputBuffer;
            if (b[ptr] == 'r' && b[++ptr] == 'u' && b[++ptr] == 'e') {
                char c = b[++ptr];
                if (c < '0' || c == ']' || c == '}') { // expected/allowed chars
                    _inputPtr = ptr;
                    return;
                }
            }
        }
        // buffer boundary, or problem, offline
        _matchToken("true", 1);
    }

    private final void _matchFalse() throws IOException {
        int ptr = _inputPtr;
        if ((ptr + 4) < _inputEnd) {
            final char[] b = _inputBuffer;
            if (b[ptr] == 'a' && b[++ptr] == 'l' && b[++ptr] == 's' && b[++ptr] == 'e') {
                char c = b[++ptr];
                if (c < '0' || c == ']' || c == '}') { // expected/allowed chars
                    _inputPtr = ptr;
                    return;
                }
            }
        }
        // buffer boundary, or problem, offline
        _matchToken("false", 1);
    }

    private final void _matchNull() throws IOException {
        int ptr = _inputPtr;
        if ((ptr + 3) < _inputEnd) {
            final char[] b = _inputBuffer;
            if (b[ptr] == 'u' && b[++ptr] == 'l' && b[++ptr] == 'l') {
                char c = b[++ptr];
                if (c < '0' || c == ']' || c == '}') { // expected/allowed chars
                    _inputPtr = ptr;
                    return;
                }
            }
        }
        // buffer boundary, or problem, offline
        _matchToken("null", 1);
    }

    /**
     * Helper method for checking whether input matches expected token
     */
    protected final void _matchToken(String matchStr, int i) throws IOException
    {
        final int len = matchStr.length();
        if ((_inputPtr + len) >= _inputEnd) {
            _matchToken2(matchStr, i);
            return;
        }

        do {
            if (_inputBuffer[_inputPtr] != matchStr.charAt(i)) {
                _reportInvalidToken(matchStr.substring(0, i));
            }
            ++_inputPtr;
        } while (++i < len);
        int ch = _inputBuffer[_inputPtr];
        if (ch >= '0' && ch != ']' && ch != '}') { // expected/allowed chars
            _checkMatchEnd(matchStr, i, ch);
        }
    }

    private final void _matchToken2(String matchStr, int i) throws IOException
    {
        final int len = matchStr.length();
        do {
            if (((_inputPtr >= _inputEnd) && !_loadMore())
                ||  (_inputBuffer[_inputPtr] != matchStr.charAt(i))) {
                _reportInvalidToken(matchStr.substring(0, i));
            }
            ++_inputPtr;
        } while (++i < len);
    
        // but let's also ensure we either get EOF, or non-alphanum char...
        if (_inputPtr >= _inputEnd && !_loadMore()) {
            return;
        }
        int ch = _inputBuffer[_inputPtr];
        if (ch >= '0' && ch != ']' && ch != '}') { // expected/allowed chars
            _checkMatchEnd(matchStr, i, ch);
        }
    }

    private final void _checkMatchEnd(String matchStr, int i, int c) throws IOException {
        // but actually only alphanums are problematic
        char ch = (char) c;
        if (Character.isJavaIdentifierPart(ch)) {
            _reportInvalidToken(matchStr.substring(0, i));
        }
    }

    /*
    /**********************************************************
    /* Binary access
    /**********************************************************
     */

    /**
     * Efficient handling for incremental parsing of base64-encoded
     * textual content.
     */
    @SuppressWarnings("resource")
    protected byte[] _decodeBase64(Base64Variant b64variant) throws IOException
    {
        ByteArrayBuilder builder = _getByteArrayBuilder();

        //main_loop:
        while (true) {
            // first, we'll skip preceding white space, if any
            char ch;
            do {
                if (_inputPtr >= _inputEnd) {
                    _loadMoreGuaranteed();
                }
                ch = _inputBuffer[_inputPtr++];
            } while (ch <= INT_SPACE);
            int bits = b64variant.decodeBase64Char(ch);
            if (bits < 0) {
                if (ch == '"') { // reached the end, fair and square?
                    return builder.toByteArray();
                }
                bits = _decodeBase64Escape(b64variant, ch, 0);
                if (bits < 0) { // white space to skip
                    continue;
                }
            }
            int decodedData = bits;

            // then second base64 char; can't get padding yet, nor ws

            if (_inputPtr >= _inputEnd) {
                _loadMoreGuaranteed();
            }
            ch = _inputBuffer[_inputPtr++];
            bits = b64variant.decodeBase64Char(ch);
            if (bits < 0) {
                bits = _decodeBase64Escape(b64variant, ch, 1);
            }
            decodedData = (decodedData << 6) | bits;

            // third base64 char; can be padding, but not ws
            if (_inputPtr >= _inputEnd) {
                _loadMoreGuaranteed();
            }
            ch = _inputBuffer[_inputPtr++];
            bits = b64variant.decodeBase64Char(ch);

            // First branch: can get padding (-> 1 byte)
            if (bits < 0) {
                if (bits != Base64Variant.BASE64_VALUE_PADDING) {
                    // as per [JACKSON-631], could also just be 'missing'  padding
                    if (ch == '"') {
                        decodedData >>= 4;
                        builder.append(decodedData);
                        if (b64variant.usesPadding()) {
                            --_inputPtr; // to keep parser state bit more consistent
                            _handleBase64MissingPadding(b64variant);
                        }
                        return builder.toByteArray();
                    }
                    bits = _decodeBase64Escape(b64variant, ch, 2);
                }
                if (bits == Base64Variant.BASE64_VALUE_PADDING) {
                    // Ok, must get more padding chars, then
                    if (_inputPtr >= _inputEnd) {
                        _loadMoreGuaranteed();
                    }
                    ch = _inputBuffer[_inputPtr++];
                    if (!b64variant.usesPaddingChar(ch)) {
                        if (_decodeBase64Escape(b64variant, ch, 3) != Base64Variant.BASE64_VALUE_PADDING) {
                            throw reportInvalidBase64Char(b64variant, ch, 3, "expected padding character '"+b64variant.getPaddingChar()+"'");
                        }
                    }
                    // Got 12 bits, only need 8, need to shift
                    decodedData >>= 4;
                    builder.append(decodedData);
                    continue;
                }
                // otherwise we got escaped other char, to be processed below
            }
            // Nope, 2 or 3 bytes
            decodedData = (decodedData << 6) | bits;
            // fourth and last base64 char; can be padding, but not ws
            if (_inputPtr >= _inputEnd) {
                _loadMoreGuaranteed();
            }
            ch = _inputBuffer[_inputPtr++];
            bits = b64variant.decodeBase64Char(ch);
            if (bits < 0) {
                if (bits != Base64Variant.BASE64_VALUE_PADDING) {
                    // as per [JACKSON-631], could also just be 'missing'  padding
                    if (ch == '"') {
                        decodedData >>= 2;
                        builder.appendTwoBytes(decodedData);
                        if (b64variant.usesPadding()) {
                            --_inputPtr; // to keep parser state bit more consistent
                            _handleBase64MissingPadding(b64variant);
                        }
                        return builder.toByteArray();
                    }
                    bits = _decodeBase64Escape(b64variant, ch, 3);
                }
                if (bits == Base64Variant.BASE64_VALUE_PADDING) {
                    // With padding we only get 2 bytes; but we have
                    // to shift it a bit so it is identical to triplet
                    // case with partial output.
                    // 3 chars gives 3x6 == 18 bits, of which 2 are
                    // dummies, need to discard:
                    decodedData >>= 2;
                    builder.appendTwoBytes(decodedData);
                    continue;
                }
                // otherwise we got escaped other char, to be processed below
            }
            // otherwise, our triplet is now complete
            decodedData = (decodedData << 6) | bits;
            builder.appendThreeBytes(decodedData);
        }
    }

    /*
    /**********************************************************
    /* Internal methods, location updating (refactored in 2.7)
    /**********************************************************
     */

    @Override
    public JsonLocation getTokenLocation()
    {
        if (_currToken == JsonToken.FIELD_NAME) {
            long total = _currInputProcessed + (_nameStartOffset-1);
            return new JsonLocation(_getSourceReference(),
                    -1L, total, _nameStartRow, _nameStartCol);
        }
        return new JsonLocation(_getSourceReference(),
                -1L, _tokenInputTotal-1, _tokenInputRow, _tokenInputCol);
    }

    @Override
    public JsonLocation getCurrentLocation() {
        final int col = _inputPtr - _currInputRowStart + 1; // 1-based
        return new JsonLocation(_getSourceReference(),
                -1L, _currInputProcessed + _inputPtr,
                _currInputRow, col);
    }

    // @since 2.7
    private final void _updateLocation()
    {
        int ptr = _inputPtr;
        _tokenInputTotal = _currInputProcessed + ptr;
        _tokenInputRow = _currInputRow;
        _tokenInputCol = ptr - _currInputRowStart;
    }

    // @since 2.7
    private final void _updateNameLocation()
    {
        int ptr = _inputPtr;
        _nameStartOffset = ptr;
        _nameStartRow = _currInputRow;
        _nameStartCol = ptr - _currInputRowStart;
    }

    /*
    /**********************************************************
    /* Error reporting
    /**********************************************************
     */

    protected void _reportInvalidToken(String matchedPart) throws IOException {
        _reportInvalidToken(matchedPart, _validJsonTokenList());
    }

    protected void _reportInvalidToken(String matchedPart, String msg) throws IOException
    {
        /* Let's just try to find what appears to be the token, using
         * regular Java identifier character rules. It's just a heuristic,
         * nothing fancy here.
         */
        StringBuilder sb = new StringBuilder(matchedPart);
        while ((_inputPtr < _inputEnd) || _loadMore()) {
            char c = _inputBuffer[_inputPtr];
            if (!Character.isJavaIdentifierPart(c)) {
                break;
            }
            ++_inputPtr;
            sb.append(c);
            if (sb.length() >= MAX_ERROR_TOKEN_LENGTH) {
                sb.append("...");
                break;
            }
        }
        _reportError("Unrecognized token '%s': was expecting %s", sb, msg);
    }

    /*
    /**********************************************************
    /* Internal methods, other
    /**********************************************************
     */

    private void _closeScope(int i) throws JsonParseException {
        if (i == INT_RBRACKET) {
            _updateLocation();
            if (!_parsingContext.inArray()) {
                _reportMismatchedEndMarker(i, '}');
            }
            _parsingContext = _parsingContext.clearAndGetParent();
            _currToken = JsonToken.END_ARRAY;
        }
        if (i == INT_RCURLY) {
            _updateLocation();
            if (!_parsingContext.inObject()) {
                _reportMismatchedEndMarker(i, ']');
            }
            _parsingContext = _parsingContext.clearAndGetParent();
            _currToken = JsonToken.END_OBJECT;
        }
    }
}

com/fasterxml/jackson/core/json/ReaderBasedJsonParser.java

 

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2016-02-03, 29560👍, 1💬