package com.fasterxml.jackson.core.json.async;

import java.io.*;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.base.ParserBase;
import com.fasterxml.jackson.core.io.IOContext;
import com.fasterxml.jackson.core.json.JsonReadContext;
import com.fasterxml.jackson.core.sym.ByteQuadsCanonicalizer;
import com.fasterxml.jackson.core.util.ByteArrayBuilder;

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

Intermediate base class for non-blocking JSON parsers.
/**
 * Intermediate base class for non-blocking JSON parsers.
 */
public abstract class NonBlockingJsonParserBase
    extends ParserBase
{
    /*
    /**********************************************************************
    /* Major state constants
    /**********************************************************************
     */

    
State right after parser has been constructed, before seeing the first byte
to handle possible (but optional) BOM.
/**
     * State right after parser has been constructed, before seeing the first byte
     * to handle possible (but optional) BOM.
     */
    protected final static int MAJOR_INITIAL = 0;

    
State right after parser a root value has been
finished, but next token has not yet been recognized.
/**
     * State right after parser a root value has been
     * finished, but next token has not yet been recognized.
     */
    protected final static int MAJOR_ROOT = 1;

    protected final static int MAJOR_OBJECT_FIELD_FIRST = 2;
    protected final static int MAJOR_OBJECT_FIELD_NEXT = 3;

    protected final static int MAJOR_OBJECT_VALUE = 4;

    protected final static int MAJOR_ARRAY_ELEMENT_FIRST = 5;
    protected final static int MAJOR_ARRAY_ELEMENT_NEXT = 6;

    
State after non-blocking input source has indicated that no more input
is forthcoming AND we have exhausted all the input
/**
     * State after non-blocking input source has indicated that no more input
     * is forthcoming AND we have exhausted all the input
     */
    protected final static int MAJOR_CLOSED = 7;

    /*
    /**********************************************************************
    /* Minor state constants
    /**********************************************************************
     */

    
State in which part of (UTF-8) BOM has been detected, but not yet completely.
/**
     * State in which part of (UTF-8) BOM has been detected, but not yet completely.
     */
    protected final static int MINOR_ROOT_BOM = 1;

    
State between root-level value, waiting for at least one white-space
character as separator
/**
     * State between root-level value, waiting for at least one white-space
     * character as separator
     */
    protected final static int MINOR_ROOT_NEED_SEPARATOR = 2;

    
State between root-level value, having processed at least one white-space
character, and expecting either more, start of a value, or end of input
stream.
/**
     * State between root-level value, having processed at least one white-space
     * character, and expecting either more, start of a value, or end of input
     * stream.
     */
    protected final static int MINOR_ROOT_GOT_SEPARATOR = 3;

    // state before field name itself, waiting for quote (or unquoted name)
    protected final static int MINOR_FIELD_LEADING_WS = 4;
    // state before field name, expecting comma (or closing curly), then field name
    protected final static int MINOR_FIELD_LEADING_COMMA = 5;

    // State within regular (double-quoted) field name
    protected final static int MINOR_FIELD_NAME = 7;
    // State within regular (double-quoted) field name, within escape (having
    // encountered either just backslash, or backslash and 'u' and 0 - 3 hex digits,
    protected final static int MINOR_FIELD_NAME_ESCAPE = 8;

    protected final static int MINOR_FIELD_APOS_NAME = 9;
    protected final static int MINOR_FIELD_UNQUOTED_NAME = 10;

    protected final static int MINOR_VALUE_LEADING_WS = 12;
    protected final static int MINOR_VALUE_EXPECTING_COMMA = 13;
    protected final static int MINOR_VALUE_EXPECTING_COLON = 14;
    protected final static int MINOR_VALUE_WS_AFTER_COMMA = 15;

    protected final static int MINOR_VALUE_TOKEN_NULL = 16;
    protected final static int MINOR_VALUE_TOKEN_TRUE = 17;
    protected final static int MINOR_VALUE_TOKEN_FALSE = 18;

    protected final static int MINOR_VALUE_TOKEN_NON_STD = 19;

    protected final static int MINOR_NUMBER_MINUS = 23;
    protected final static int MINOR_NUMBER_ZERO = 24; // zero as first, possibly trimming multiple
    protected final static int MINOR_NUMBER_MINUSZERO = 25; // "-0" (and possibly more zeroes) receive
    protected final static int MINOR_NUMBER_INTEGER_DIGITS = 26;

    protected final static int MINOR_NUMBER_FRACTION_DIGITS = 30;
    protected final static int MINOR_NUMBER_EXPONENT_MARKER = 31;
    protected final static int MINOR_NUMBER_EXPONENT_DIGITS = 32;

    protected final static int MINOR_VALUE_STRING = 40;
    protected final static int MINOR_VALUE_STRING_ESCAPE = 41;
    protected final static int MINOR_VALUE_STRING_UTF8_2 = 42;
    protected final static int MINOR_VALUE_STRING_UTF8_3 = 43;
    protected final static int MINOR_VALUE_STRING_UTF8_4 = 44;
    protected final static int MINOR_VALUE_APOS_STRING = 45;

    
Special state at which point decoding of a non-quoted token has encountered
a problem; that is, either not matching fully (like "truf" instead of "true",
at "tru"), or not having trailing separator (or end of input), like "trueful".
Attempt is made, then, to decode likely full input token to report suitable
error.
/**
     * Special state at which point decoding of a non-quoted token has encountered
     * a problem; that is, either not matching fully (like "truf" instead of "true",
     * at "tru"), or not having trailing separator (or end of input), like "trueful".
     * Attempt is made, then, to decode likely full input token to report suitable
     * error.
     */
    protected final static int MINOR_VALUE_TOKEN_ERROR = 50;

    protected final static int MINOR_COMMENT_LEADING_SLASH = 51;
    protected final static int MINOR_COMMENT_CLOSING_ASTERISK = 52;
    protected final static int MINOR_COMMENT_C = 53;
    protected final static int MINOR_COMMENT_CPP = 54;
    protected final static int MINOR_COMMENT_YAML = 55;
    
    /*
    /**********************************************************************
    /* Helper objects, symbols (field names)
    /**********************************************************************
     */

    
Symbol table that contains field names encountered so far
/**
     * Symbol table that contains field names encountered so far
     */
    final protected ByteQuadsCanonicalizer _symbols;

    
Temporary buffer used for name parsing.
/**
     * Temporary buffer used for name parsing.
     */
    protected int[] _quadBuffer = new int[8];

    protected int _quadLength;

    protected int _quad1;

    protected int _pending32;

    protected int _pendingBytes;

    protected int _quoted32;

    protected int _quotedDigits;

    /*
    /**********************************************************************
    /* Additional parsing state
    /**********************************************************************
     */

    
Current main decoding state within logical tree
/**
     * Current main decoding state within logical tree
     */
    protected int _majorState;

    
Value of _majorState after completing a scalar value /**
     * Value of {@link #_majorState} after completing a scalar value
     */
    protected int _majorStateAfterValue;

    
Additional indicator within state; contextually relevant for just that state
/**
     * Additional indicator within state; contextually relevant for just that state
     */
    protected int _minorState;

    
Secondary minor state indicator used during decoding of escapes and/or
multi-byte Unicode characters
/**
     * Secondary minor state indicator used during decoding of escapes and/or
     * multi-byte Unicode characters
     */
    protected int _minorStateAfterSplit;

    
Flag that is sent when calling application indicates that there will
be no more input to parse.
/**
     * Flag that is sent when calling application indicates that there will
     * be no more input to parse.
     */
    protected boolean _endOfInput = false;

    /*
    /**********************************************************************
    /* Additional parsing state: non-standard tokens
    /**********************************************************************
     */

    protected final static int NON_STD_TOKEN_NAN = 0;

    protected final static int NON_STD_TOKEN_INFINITY = 1;
    protected final static int NON_STD_TOKEN_PLUS_INFINITY = 2;
    protected final static int NON_STD_TOKEN_MINUS_INFINITY = 3;

    protected final static String[] NON_STD_TOKENS = new String[] {
            "NaN",
            "Infinity", "+Infinity", "-Infinity",
    };

    protected final static double[] NON_STD_TOKEN_VALUES = new double[] {
            Double.NaN,
            Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY,
    };
    
    
When tokenizing non-standard ("odd") tokens, this is the type to consider;
also works as index to actual textual representation.
/**
     * When tokenizing non-standard ("odd") tokens, this is the type to consider;
     * also works as index to actual textual representation.
     */
    protected int _nonStdTokenType;

    /*
    /**********************************************************************
    /* Location tracking, additional
    /**********************************************************************
     */

    
Since we are fed content that may or may not start at zero offset, we need
to keep track of the first byte within that buffer, to be able to calculate
logical offset within input "stream"
/**
     * Since we are fed content that may or may not start at zero offset, we need
     * to keep track of the first byte within that buffer, to be able to calculate
     * logical offset within input "stream"
     */
    protected int _currBufferStart = 0;
    
    
Alternate row tracker, used to keep track of position by `\r` marker
(whereas _currInputRow tracks `\n`). Used to simplify
tracking of linefeeds, assuming that input typically uses various
linefeed combinations (`\r`, `\n` or `\r\n`) consistently, in which
case we can simply choose max of two row candidates.
/**
     * Alternate row tracker, used to keep track of position by `\r` marker
     * (whereas <code>_currInputRow</code> tracks `\n`). Used to simplify
     * tracking of linefeeds, assuming that input typically uses various
     * linefeed combinations (`\r`, `\n` or `\r\n`) consistently, in which
     * case we can simply choose max of two row candidates.
     */
    protected int _currInputRowAlt = 1;
    
    /*
    /**********************************************************************
    /* Life-cycle
    /**********************************************************************
     */

    public NonBlockingJsonParserBase(IOContext ctxt, int parserFeatures,
            ByteQuadsCanonicalizer sym)
    {
        super(ctxt, parserFeatures);
        _symbols = sym;
        _currToken = null;
        _majorState = MAJOR_INITIAL;
        _majorStateAfterValue = MAJOR_ROOT;
    }

    @Override
    public ObjectCodec getCodec() {
        return null;
    }

    @Override
    public void setCodec(ObjectCodec c) {
        throw new UnsupportedOperationException("Can not use ObjectMapper with non-blocking parser");
    }

    
Since:
2.9/**
     * @since 2.9
     */
    @Override
    public boolean canParseAsync() { return true; }

    /*
    /**********************************************************
    /* Test support
    /**********************************************************
     */

    protected ByteQuadsCanonicalizer symbolTableForTests() {
        return _symbols;
    }

    /*
    /**********************************************************
    /* Abstract methods from JsonParser
    /**********************************************************
     */

    @Override
    public abstract int releaseBuffered(OutputStream out) throws IOException;

    @Override
    protected void _releaseBuffers() throws IOException
    {
        super._releaseBuffers();
        // Merge found symbols, if any:
        _symbols.release();
        // any other temp buffers?
    }

    @Override
    public Object getInputSource() {
        // since input is "pushed", to traditional source...
        return null;
    }

    @Override
    protected void _closeInput() throws IOException {
        // 30-May-2017, tatu: Seems like this is the most certain way to prevent
        //    further decoding... not the optimal place, but due to inheritance
        //    hierarchy most convenient.
        _currBufferStart = 0;
        _inputEnd = 0;
    }

    /*
    /**********************************************************************
    /* Overridden methods
    /**********************************************************************
     */

    @Override
    public boolean hasTextCharacters()
    {
        if (_currToken == JsonToken.VALUE_STRING) {
            // yes; is or can be made available efficiently as char[]
            return _textBuffer.hasTextAsCharacters();
        }
        if (_currToken == JsonToken.FIELD_NAME) {
            // not necessarily; possible but:
            return _nameCopied;
        }
        // other types, no benefit from accessing as char[]
        return false;
    }

    @Override
    public JsonLocation getCurrentLocation()
    {
        int col = _inputPtr - _currInputRowStart + 1; // 1-based
        // Since we track CR and LF separately, max should gives us right answer
        int row = Math.max(_currInputRow, _currInputRowAlt);
        return new JsonLocation(_getSourceReference(),
                _currInputProcessed + (_inputPtr - _currBufferStart), -1L, // bytes, chars
                row, col);
    }

    @Override
    public JsonLocation getTokenLocation()
    {
        return new JsonLocation(_getSourceReference(),
                _tokenInputTotal, -1L, _tokenInputRow, _tokenInputCol);
    }

    /*
    /**********************************************************************
    /* Public API, access to token information, text
    /**********************************************************************
     */

    
Method for accessing textual representation of the current event; if no current event (before first call to ParserMinimalBase.nextToken, or after encountering end-of-input), returns null. Method can be called for any event. /**
     * 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 String getText() throws IOException
    {
        if (_currToken == JsonToken.VALUE_STRING) {
            return _textBuffer.contentsAsString();
        }
        return _getText2(_currToken);
    }

    protected final String _getText2(JsonToken t)
    {
        if (t == null) {
            return null;
        }
        switch (t.id()) {
        case ID_NOT_AVAILABLE:
            return null;
        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 // since 2.8
    public int getText(Writer writer) throws IOException
    {
        JsonToken t = _currToken;
        if (t == JsonToken.VALUE_STRING) {
            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);
            }
            if (t == JsonToken.NOT_AVAILABLE) {
                _reportError("Current token not available: can not call this method");
            }
            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 String getValueAsString() throws IOException
    {
        if (_currToken == JsonToken.VALUE_STRING) {
            return _textBuffer.contentsAsString();
        }
        if (_currToken == JsonToken.FIELD_NAME) {
            return getCurrentName();
        }
        return super.getValueAsString(null);
    }
    
    // @since 2.1
    @Override
    public String getValueAsString(String defValue) throws IOException
    {
        if (_currToken == JsonToken.VALUE_STRING) {
            return _textBuffer.contentsAsString();
        }
        if (_currToken == JsonToken.FIELD_NAME) {
            return getCurrentName();
        }
        return super.getValueAsString(defValue);
    }

    @Override
    public 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:
                // fall through
            case ID_NUMBER_INT:
            case ID_NUMBER_FLOAT:
                return _textBuffer.getTextBuffer();
                
            default:
                return _currToken.asCharArray();
            }
        }
        return null;
    }

    @Override
    public 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:
                // fall through
            case ID_NUMBER_INT:
            case ID_NUMBER_FLOAT:
                return _textBuffer.size();
                
            default:
                return _currToken.asCharArray().length;
            }
        }
        return 0;
    }

    @Override
    public 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:
                // fall through
            case ID_NUMBER_INT:
            case ID_NUMBER_FLOAT:
                return _textBuffer.getTextOffset();
            default:
            }
        }
        return 0;
    }

    /*
    /**********************************************************************
    /* Public API, access to token information, binary
    /**********************************************************************
     */

    @Override
    public byte[] getBinaryValue(Base64Variant b64variant) throws IOException
    {
        if (_currToken != JsonToken.VALUE_STRING) {
            _reportError("Current token (%s) not VALUE_STRING or VALUE_EMBEDDED_OBJECT, can not access as binary",
                    _currToken);
        }
        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
    {
        byte[] b = getBinaryValue(b64variant);
        out.write(b);
        return b.length;
    }

    @Override
    public Object getEmbeddedObject() throws IOException
    {
        if (_currToken == JsonToken.VALUE_EMBEDDED_OBJECT ) {
            return _binaryValue;
        }
        return null;
    }

    /*
    /**********************************************************************
    /* Handling of nested scope, state
    /**********************************************************************
     */

    protected final JsonToken _startArrayScope() throws IOException
    {
        _parsingContext = _parsingContext.createChildArrayContext(-1, -1);
        _majorState = MAJOR_ARRAY_ELEMENT_FIRST;
        _majorStateAfterValue = MAJOR_ARRAY_ELEMENT_NEXT;
        return (_currToken = JsonToken.START_ARRAY);
    }

    protected final JsonToken _startObjectScope() throws IOException
    {
        _parsingContext = _parsingContext.createChildObjectContext(-1, -1);
        _majorState = MAJOR_OBJECT_FIELD_FIRST;
        _majorStateAfterValue = MAJOR_OBJECT_FIELD_NEXT;
        return (_currToken = JsonToken.START_OBJECT);
    }

    protected final JsonToken _closeArrayScope() throws IOException
    {
        if (!_parsingContext.inArray()) {
            _reportMismatchedEndMarker(']', '}');
        }
        JsonReadContext ctxt = _parsingContext.getParent();
        _parsingContext = ctxt;
        int st;
        if (ctxt.inObject()) {
            st = MAJOR_OBJECT_FIELD_NEXT;
        } else if (ctxt.inArray()) {
            st = MAJOR_ARRAY_ELEMENT_NEXT;
        } else {
            st = MAJOR_ROOT;
        }
        _majorState = st;
        _majorStateAfterValue = st;
        return (_currToken = JsonToken.END_ARRAY);
    }

    protected final JsonToken _closeObjectScope() throws IOException
    {
        if (!_parsingContext.inObject()) {
            _reportMismatchedEndMarker('}', ']');
        }
        JsonReadContext ctxt = _parsingContext.getParent();
        _parsingContext = ctxt;
        int st;
        if (ctxt.inObject()) {
            st = MAJOR_OBJECT_FIELD_NEXT;
        } else if (ctxt.inArray()) {
            st = MAJOR_ARRAY_ELEMENT_NEXT;
        } else {
            st = MAJOR_ROOT;
        }
        _majorState = st;
        _majorStateAfterValue = st;
        return (_currToken = JsonToken.END_OBJECT);
    }

    /*
    /**********************************************************
    /* Internal methods, symbol (name) handling
    /**********************************************************
     */

    protected final String _findName(int q1, int lastQuadBytes) throws JsonParseException
    {
        q1 = _padLastQuad(q1, lastQuadBytes);
        // Usually we'll find it from the canonical symbol table already
        String name = _symbols.findName(q1);
        if (name != null) {
            return name;
        }
        // If not, more work. We'll need add stuff to buffer
        _quadBuffer[0] = q1;
        return _addName(_quadBuffer, 1, lastQuadBytes);
    }

    protected final String _findName(int q1, int q2, int lastQuadBytes) throws JsonParseException
    {
        q2 = _padLastQuad(q2, lastQuadBytes);
        // Usually we'll find it from the canonical symbol table already
        String name = _symbols.findName(q1, q2);
        if (name != null) {
            return name;
        }
        // If not, more work. We'll need add stuff to buffer
        _quadBuffer[0] = q1;
        _quadBuffer[1] = q2;
        return _addName(_quadBuffer, 2, lastQuadBytes);
    }

    protected final String _findName(int q1, int q2, int q3, int lastQuadBytes) throws JsonParseException
    {
        q3 = _padLastQuad(q3, lastQuadBytes);
        String name = _symbols.findName(q1, q2, q3);
        if (name != null) {
            return name;
        }
        int[] quads = _quadBuffer;
        quads[0] = q1;
        quads[1] = q2;
        quads[2] = _padLastQuad(q3, lastQuadBytes);
        return _addName(quads, 3, lastQuadBytes);
    }

    
This is the main workhorse method used when we take a symbol
table miss. It needs to demultiplex individual bytes, decode
multi-byte chars (if any), and then construct Name instance
and add it to the symbol table.
/**
     * This is the main workhorse method used when we take a symbol
     * table miss. It needs to demultiplex individual bytes, decode
     * multi-byte chars (if any), and then construct Name instance
     * and add it to the symbol table.
     */
    protected final String _addName(int[] quads, int qlen, int lastQuadBytes) throws JsonParseException
    {
        /* Ok: must decode UTF-8 chars. No other validation is
         * needed, since unescaping has been done earlier as necessary
         * (as well as error reporting for unescaped control chars)
         */
        // 4 bytes per quad, except last one maybe less
        int byteLen = (qlen << 2) - 4 + lastQuadBytes;

        /* And last one is not correctly aligned (leading zero bytes instead
         * need to shift a bit, instead of trailing). Only need to shift it
         * for UTF-8 decoding; need revert for storage (since key will not
         * be aligned, to optimize lookup speed)
         */
        int lastQuad;

        if (lastQuadBytes < 4) {
            lastQuad = quads[qlen-1];
            // 8/16/24 bit left shift
            quads[qlen-1] = (lastQuad << ((4 - lastQuadBytes) << 3));
        } else {
            lastQuad = 0;
        }

        // Need some working space, TextBuffer works well:
        char[] cbuf = _textBuffer.emptyAndGetCurrentSegment();
        int cix = 0;

        for (int ix = 0; ix < byteLen; ) {
            int ch = quads[ix >> 2]; // current quad, need to shift+mask
            int byteIx = (ix & 3);
            ch = (ch >> ((3 - byteIx) << 3)) & 0xFF;
            ++ix;

            if (ch > 127) { // multi-byte
                int needed;
                if ((ch & 0xE0) == 0xC0) { // 2 bytes (0x0080 - 0x07FF)
                    ch &= 0x1F;
                    needed = 1;
                } else if ((ch & 0xF0) == 0xE0) { // 3 bytes (0x0800 - 0xFFFF)
                    ch &= 0x0F;
                    needed = 2;
                } else if ((ch & 0xF8) == 0xF0) { // 4 bytes; double-char with surrogates and all...
                    ch &= 0x07;
                    needed = 3;
                } else { // 5- and 6-byte chars not valid xml chars
                    _reportInvalidInitial(ch);
                    needed = ch = 1; // never really gets this far
                }
                if ((ix + needed) > byteLen) {
                    _reportInvalidEOF(" in field name", JsonToken.FIELD_NAME);
                }
                
                // Ok, always need at least one more:
                int ch2 = quads[ix >> 2]; // current quad, need to shift+mask
                byteIx = (ix & 3);
                ch2 = (ch2 >> ((3 - byteIx) << 3));
                ++ix;
                
                if ((ch2 & 0xC0) != 0x080) {
                    _reportInvalidOther(ch2);
                }
                ch = (ch << 6) | (ch2 & 0x3F);
                if (needed > 1) {
                    ch2 = quads[ix >> 2];
                    byteIx = (ix & 3);
                    ch2 = (ch2 >> ((3 - byteIx) << 3));
                    ++ix;
                    
                    if ((ch2 & 0xC0) != 0x080) {
                        _reportInvalidOther(ch2);
                    }
                    ch = (ch << 6) | (ch2 & 0x3F);
                    if (needed > 2) { // 4 bytes? (need surrogates on output)
                        ch2 = quads[ix >> 2];
                        byteIx = (ix & 3);
                        ch2 = (ch2 >> ((3 - byteIx) << 3));
                        ++ix;
                        if ((ch2 & 0xC0) != 0x080) {
                            _reportInvalidOther(ch2 & 0xFF);
                        }
                        ch = (ch << 6) | (ch2 & 0x3F);
                    }
                }
                if (needed > 2) { // surrogate pair? once again, let's output one here, one later on
                    ch -= 0x10000; // to normalize it starting with 0x0
                    if (cix >= cbuf.length) {
                        cbuf = _textBuffer.expandCurrentSegment();
                    }
                    cbuf[cix++] = (char) (0xD800 + (ch >> 10));
                    ch = 0xDC00 | (ch & 0x03FF);
                }
            }
            if (cix >= cbuf.length) {
                cbuf = _textBuffer.expandCurrentSegment();
            }
            cbuf[cix++] = (char) ch;
        }

        // Ok. Now we have the character array, and can construct the String
        String baseName = new String(cbuf, 0, cix);
        // And finally, un-align if necessary
        if (lastQuadBytes < 4) {
            quads[qlen-1] = lastQuad;
        }
        return _symbols.addName(baseName, quads, qlen);
    }

    
Helper method needed to fix [jackson-core#148], masking of 0x00 character
/**
     * Helper method needed to fix [jackson-core#148], masking of 0x00 character
     */
    protected final static int _padLastQuad(int q, int bytes) {
        return (bytes == 4) ? q : (q | (-1 << (bytes << 3)));
    }

    /*
    /**********************************************************************
    /* Internal methods, state changes
    /**********************************************************************
     */
    
    
Helper method called at point when all input has been exhausted and
input feeder has indicated no more input will be forthcoming.
/**
     * Helper method called at point when all input has been exhausted and
     * input feeder has indicated no more input will be forthcoming.
     */
    protected final JsonToken _eofAsNextToken() throws IOException {
        _majorState = MAJOR_CLOSED;
        if (!_parsingContext.inRoot()) {
            _handleEOF();
        }
        close();
        return (_currToken = null);
    }

    protected final JsonToken _fieldComplete(String name) throws IOException
    {
        _majorState = MAJOR_OBJECT_VALUE;
        _parsingContext.setCurrentName(name);
        return (_currToken = JsonToken.FIELD_NAME);
    }

    protected final JsonToken _valueComplete(JsonToken t) throws IOException
    {
        _majorState = _majorStateAfterValue;
        _currToken = t;
        return t;
    }

    protected final JsonToken _valueCompleteInt(int value, String asText) throws IOException
    {
        _textBuffer.resetWithString(asText);
        _intLength = asText.length();
        _numTypesValid = NR_INT; // to force parsing
        _numberInt = value;
        _majorState = _majorStateAfterValue;
        JsonToken t = JsonToken.VALUE_NUMBER_INT;
        _currToken = t;
        return t;
    }

    @SuppressWarnings("deprecation")
    protected final JsonToken _valueNonStdNumberComplete(int type) throws IOException
    {
        String tokenStr = NON_STD_TOKENS[type];
        _textBuffer.resetWithString(tokenStr);
        if (!isEnabled(Feature.ALLOW_NON_NUMERIC_NUMBERS)) {
            _reportError("Non-standard token '%s': enable JsonParser.Feature.ALLOW_NON_NUMERIC_NUMBERS to allow",
                    tokenStr);
        }
        _intLength = 0;
        _numTypesValid = NR_DOUBLE;
        _numberDouble = NON_STD_TOKEN_VALUES[type];
        _majorState = _majorStateAfterValue;
        return (_currToken = JsonToken.VALUE_NUMBER_FLOAT);
    }

    protected final String _nonStdToken(int type) {
        return NON_STD_TOKENS[type];
    }

    /*
    /**********************************************************************
    /* Internal methods, error reporting, related
    /**********************************************************************
     */

    protected final void _updateTokenLocation()
    {
        _tokenInputRow = Math.max(_currInputRow, _currInputRowAlt);
        final int ptr = _inputPtr;
        _tokenInputCol = ptr - _currInputRowStart;
        _tokenInputTotal = _currInputProcessed + (ptr - _currBufferStart);
    }

    protected void _reportInvalidChar(int c) throws JsonParseException {
        // Either invalid WS or illegal UTF-8 start char
        if (c < INT_SPACE) {
            _throwInvalidSpace(c);
        }
        _reportInvalidInitial(c);
    }

    protected void _reportInvalidInitial(int mask) throws JsonParseException {
        _reportError("Invalid UTF-8 start byte 0x"+Integer.toHexString(mask));
    }

    protected void _reportInvalidOther(int mask, int ptr) throws JsonParseException {
        _inputPtr = ptr;
        _reportInvalidOther(mask);
    }

    protected void _reportInvalidOther(int mask) throws JsonParseException {
        _reportError("Invalid UTF-8 middle byte 0x"+Integer.toHexString(mask));
    }
}