com.groupbyinc.common.jackson.dataformat.cbor.CBORGenerator Maven / Gradle / Ivy
package com.fasterxml.jackson.dataformat.cbor;
import java.io.*;
import java.math.BigDecimal;
import java.math.BigInteger;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.io.*;
import com.fasterxml.jackson.core.json.JsonWriteContext;
import com.fasterxml.jackson.core.base.GeneratorBase;
import static com.fasterxml.jackson.dataformat.cbor.CBORConstants.*;
/**
* {@link JsonGenerator} implementation that writes CBOR encoded content.
*
* @author Tatu Saloranta
*/
public class CBORGenerator extends GeneratorBase
{
/**
* Let's ensure that we have big enough output buffer because of
* safety margins we need for UTF-8 encoding.
*/
final static int BYTE_BUFFER_FOR_OUTPUT = 16000;
/**
* Longest char chunk we will output is chosen so that it is guaranteed to fit
* in an empty buffer even if everything encoded in 3-byte sequences; but also
* fit two full chunks in case of single-byte (ascii) output.
*/
private final static int MAX_LONG_STRING_CHARS = (BYTE_BUFFER_FOR_OUTPUT / 4) - 4;
/**
* This is the worst case length (in bytes) of maximum chunk we ever write.
*/
private final static int MAX_LONG_STRING_BYTES = (MAX_LONG_STRING_CHARS * 3) + 3;
/**
* Enumeration that defines all togglable features for CBOR generator.
*/
public enum Feature implements FormatFeature
{
/**
* Feature that determines whether generator should try to use smallest (size-wise)
* integer representation: if true, will use smallest representation that is enough
* to retain value; if false, will use length indicated by argument type (4-byte
* for int, 8-byte for long and so on).
*/
WRITE_MINIMAL_INTS(true),
/**
* Feature that determines whether CBOR "Self-Describe Tag" (value 55799,
* encoded as 3-byte sequence of 0xD9, 0xD9, 0xF7) should be written
* at the beginnig of document or not.
*
* Default value is false meaning that type tag will not be written
* at the beginning of a new document.
*
* @since 2.5
*/
WRITE_TYPE_HEADER(false),
;
protected final boolean _defaultState;
protected final int _mask;
/**
* Method that calculates bit set (flags) of all features that
* are enabled by default.
*/
public static int collectDefaults() {
int flags = 0;
for (Feature f : values()) {
if (f.enabledByDefault()) {
flags |= f.getMask();
}
}
return flags;
}
private Feature(boolean defaultState) {
_defaultState = defaultState;
_mask = (1 << ordinal());
}
@Override public boolean enabledByDefault() { return _defaultState; }
@Override public boolean enabledIn(int flags) { return (flags & getMask()) != 0; }
@Override public int getMask() { return _mask; }
}
/**
* To simplify certain operations, we require output buffer length
* to allow outputting of contiguous 256 character UTF-8 encoded String
* value. Length of the longest UTF-8 code point (from Java char) is 3 bytes,
* and we need both initial token byte and single-byte end marker
* so we get following value.
*
* Note: actually we could live with shorter one; absolute minimum would
* be for encoding 64-character Strings.
*/
private final static int MIN_BUFFER_LENGTH = (3 * 256) + 2;
private final static long MIN_INT_AS_LONG = (long) Integer.MIN_VALUE;
private final static long MAX_INT_AS_LONG = (long) Integer.MAX_VALUE;
/*
/**********************************************************
/* Configuration
/**********************************************************
*/
final protected IOContext _ioContext;
final protected OutputStream _out;
/**
* Bit flag composed of bits that indicate which
* {@link CBORGenerator.Feature}s
* are enabled.
*/
protected int _formatFeatures;
protected boolean _cfgMinimalInts;
/*
/**********************************************************
/* Output buffering
/**********************************************************
*/
/**
* Intermediate buffer in which contents are buffered before
* being written using {@link #_out}.
*/
protected byte[] _outputBuffer;
/**
* Pointer to the next available byte in {@link #_outputBuffer}
*/
protected int _outputTail = 0;
/**
* Offset to index after the last valid index in {@link #_outputBuffer}.
* Typically same as length of the buffer.
*/
protected final int _outputEnd;
/**
* Intermediate buffer in which characters of a String are copied
* before being encoded.
*/
protected char[] _charBuffer;
protected final int _charBufferLength;
/**
* Let's keep track of how many bytes have been output, may prove useful
* when debugging. This does not include bytes buffered in
* the output buffer, just bytes that have been written using underlying
* stream writer.
*/
protected int _bytesWritten;
/*
/**********************************************************
/* Shared String detection
/**********************************************************
*/
/**
* Flag that indicates whether the output buffer is recycable (and
* needs to be returned to recycler once we are done) or not.
*/
protected boolean _bufferRecyclable;
/*
/**********************************************************
/* Life-cycle
/**********************************************************
*/
public CBORGenerator(IOContext ctxt, int jsonFeatures, int formatFeatures,
ObjectCodec codec, OutputStream out)
{
super(jsonFeatures, codec);
_formatFeatures = formatFeatures;
_cfgMinimalInts = Feature.WRITE_MINIMAL_INTS.enabledIn(formatFeatures);
_ioContext = ctxt;
_out = out;
_bufferRecyclable = true;
_outputBuffer = ctxt.allocWriteEncodingBuffer(BYTE_BUFFER_FOR_OUTPUT);
_outputEnd = _outputBuffer.length;
_charBuffer = ctxt.allocConcatBuffer();
_charBufferLength = _charBuffer.length;
// let's just sanity check to prevent nasty odd errors
if (_outputEnd < MIN_BUFFER_LENGTH) {
throw new IllegalStateException("Internal encoding buffer length ("+_outputEnd
+") too short, must be at least "+MIN_BUFFER_LENGTH);
}
}
/**
* Alternative constructor that may be used to feed partially initialized content.
*
* @param outputBuffer Buffer to use for output before flushing to the underlying stream
* @param offset Offset pointing past already buffered content; that is, number of bytes of valid content
* to output, within buffer.
*/
public CBORGenerator(IOContext ctxt, int jsonFeatures, int formatFeatures,
ObjectCodec codec, OutputStream out, byte[] outputBuffer, int offset, boolean bufferRecyclable)
{
super(jsonFeatures, codec);
_formatFeatures = formatFeatures;
_cfgMinimalInts = Feature.WRITE_MINIMAL_INTS.enabledIn(formatFeatures);
_ioContext = ctxt;
_out = out;
_bufferRecyclable = bufferRecyclable;
_outputTail = offset;
_outputBuffer = outputBuffer;
_outputEnd = _outputBuffer.length;
_charBuffer = ctxt.allocConcatBuffer();
_charBufferLength = _charBuffer.length;
// let's just sanity check to prevent nasty odd errors
if (_outputEnd < MIN_BUFFER_LENGTH) {
throw new IllegalStateException("Internal encoding buffer length ("+_outputEnd
+") too short, must be at least "+MIN_BUFFER_LENGTH);
}
}
/*
/**********************************************************
/* Versioned
/**********************************************************
*/
@Override
public Version version() {
return PackageVersion.VERSION;
}
/*
/**********************************************************
/* Capability introspection
/**********************************************************
*/
@Override
public boolean canWriteBinaryNatively() {
return true;
}
/*
/**********************************************************
/* Overridden methods, configuration
/**********************************************************
*/
/**
* No way (or need) to indent anything, so let's block any attempts.
* (should we throw an exception instead?)
*/
@Override
public JsonGenerator useDefaultPrettyPrinter() {
return this;
}
/**
* No way (or need) to indent anything, so let's block any attempts.
* (should we throw an exception instead?)
*/
@Override
public JsonGenerator setPrettyPrinter(PrettyPrinter pp) {
return this;
}
@Override
public Object getOutputTarget() {
return _out;
}
@Override
public int getOutputBuffered() {
return _outputTail;
}
// public JsonParser overrideStdFeatures(int values, int mask)
@Override
public int getFormatFeatures() {
return _formatFeatures;
}
@Override
public JsonGenerator overrideFormatFeatures(int values, int mask) {
_formatFeatures = (_formatFeatures & ~mask) | (values & mask);
return this;
}
/*
/**********************************************************
/* Overridden methods, write methods
/**********************************************************
*/
/* And then methods overridden to make final, streamline some
* aspects...
*/
@Override
public final void writeFieldName(String name) throws IOException
{
if (_writeContext.writeFieldName(name) == JsonWriteContext.STATUS_EXPECT_VALUE) {
_reportError("Can not write a field name, expecting a value");
}
_writeString(name);
}
@Override
public final void writeFieldName(SerializableString name) throws IOException
{
// Object is a value, need to verify it's allowed
if (_writeContext.writeFieldName(name.getValue()) == JsonWriteContext.STATUS_EXPECT_VALUE) {
_reportError("Can not write a field name, expecting a value");
}
byte[] raw = name.asUnquotedUTF8();
final int len = raw.length;
if (len == 0) {
_writeByte(BYTE_EMPTY_STRING);
return;
}
_writeLengthMarker(PREFIX_TYPE_TEXT, len);
_writeBytes(raw, 0, len);
}
@Override
public final void writeStringField(String fieldName, String value) throws IOException
{
if (_writeContext.writeFieldName(fieldName) == JsonWriteContext.STATUS_EXPECT_VALUE) {
_reportError("Can not write a field name, expecting a value");
}
_writeString(fieldName);
// inlined from 'writeString()'
if (value == null) {
writeNull();
return;
}
_verifyValueWrite("write String value");
_writeString(value);
}
/*
/**********************************************************
/* Extended API, configuration
/**********************************************************
*/
public CBORGenerator enable(Feature f) {
_formatFeatures |= f.getMask();
if (f == Feature.WRITE_MINIMAL_INTS) {
_cfgMinimalInts = true;
}
return this;
}
public CBORGenerator disable(Feature f) {
_formatFeatures &= ~f.getMask();
if (f == Feature.WRITE_MINIMAL_INTS) {
_cfgMinimalInts = false;
}
return this;
}
public final boolean isEnabled(Feature f) {
return (_formatFeatures & f.getMask()) != 0;
}
public CBORGenerator configure(Feature f, boolean state) {
if (state) {
enable(f);
} else {
disable(f);
}
return this;
}
/*
/**********************************************************
/* Extended API, CBOR-specific encoded output
/**********************************************************
*/
/**
* Method for writing out an explicit CBOR Tag.
*
* @param tagId Positive integer (0 or higher)
*
* @since 2.5
*/
public void writeTag(int tagId) throws IOException
{
if (tagId < 0) {
throw new IllegalArgumentException("Can not write negative tag ids ("+tagId+")");
}
_writeLengthMarker(PREFIX_TYPE_TAG, tagId);
}
/*
/**********************************************************
/* Extended API, raw bytes (by-passing encoder)
/**********************************************************
*/
/**
* Method for directly inserting specified byte in output at
* current position.
*
* NOTE: only use this method if you really know what you are doing.
*/
public void writeRaw(byte b) throws IOException {
_writeByte(b);
}
/**
* Method for directly inserting specified bytes in output at
* current position.
*
* NOTE: only use this method if you really know what you are doing.
*/
public void writeBytes(byte[] data, int offset, int len) throws IOException {
_writeBytes(data, offset, len);
}
/*
/**********************************************************
/* Output method implementations, structural
/**********************************************************
*/
@Override
public final void writeStartArray() throws IOException
{
_verifyValueWrite("start an array");
_writeContext = _writeContext.createChildArrayContext();
_writeByte(BYTE_ARRAY_INDEFINITE);
}
// TODO: implement this for CBOR
/*
* Unlike with JSON, this method can use slightly optimized version
* since CBOR has a variant that allows embedding length in array
* start marker. But it mostly (or only?) makes sense for small
* arrays, cases where length marker fits within type marker byte;
* otherwise we might as well just use "indefinite" notation.
*/
@Override
public void writeStartArray(int size) throws IOException {
_verifyValueWrite("start an array");
_writeContext = _writeContext.createChildArrayContext();
/*
if (size >= 31 || size < 0) {
_writeByte(BYTE_ARRAY_INDEFINITE);
} else {
}
*/
_writeByte(BYTE_ARRAY_INDEFINITE);
}
@Override
public final void writeEndArray() throws IOException
{
if (!_writeContext.inArray()) {
_reportError("Current context not an ARRAY but "+_writeContext.getTypeDesc());
}
_writeByte(BYTE_BREAK);
_writeContext = _writeContext.getParent();
}
@Override
public final void writeStartObject() throws IOException
{
_verifyValueWrite("start an object");
_writeContext = _writeContext.createChildObjectContext();
_writeByte(BYTE_OBJECT_INDEFINITE);
}
@Override
public final void writeEndObject() throws IOException
{
if (!_writeContext.inObject()) {
_reportError("Current context not an object but "+_writeContext.getTypeDesc());
}
_writeContext = _writeContext.getParent();
_writeByte(BYTE_BREAK);
}
/*
/**********************************************************
/* Output method implementations, textual
/**********************************************************
*/
@Override
public void writeString(String text) throws IOException,JsonGenerationException
{
if (text == null) {
writeNull();
return;
}
_verifyValueWrite("write String value");
_writeString(text);
}
@Override
public final void writeString(SerializableString sstr) throws IOException
{
_verifyValueWrite("write String value");
byte[] raw = sstr.asUnquotedUTF8();
final int len = raw.length;
if (len == 0) {
_writeByte(BYTE_EMPTY_STRING);
return;
}
_writeLengthMarker(PREFIX_TYPE_TEXT, len);
_writeBytes(raw, 0, len);
}
@Override
public void writeString(char[] text, int offset, int len) throws IOException
{
_verifyValueWrite("write String value");
if (len == 0) {
_writeByte(BYTE_EMPTY_STRING);
return;
}
_writeString(text, offset, len);
}
@Override
public void writeRawUTF8String(byte[] raw, int offset, int len) throws IOException
{
_verifyValueWrite("write String value");
if (len == 0) {
_writeByte(BYTE_EMPTY_STRING);
return;
}
_writeLengthMarker(PREFIX_TYPE_TEXT, len);
_writeBytes(raw, 0, len);
}
@Override
public final void writeUTF8String(byte[] text, int offset, int len) throws IOException
{
// Since no escaping is needed, same as 'writeRawUTF8String'
writeRawUTF8String(text, offset, len);
}
/*
/**********************************************************
/* Output method implementations, unprocessed ("raw")
/**********************************************************
*/
@Override
public void writeRaw(String text) throws IOException {
throw _notSupported();
}
@Override
public void writeRaw(String text, int offset, int len) throws IOException {
throw _notSupported();
}
@Override
public void writeRaw(char[] text, int offset, int len) throws IOException {
throw _notSupported();
}
@Override
public void writeRaw(char c) throws IOException {
throw _notSupported();
}
@Override
public void writeRawValue(String text) throws IOException {
throw _notSupported();
}
@Override
public void writeRawValue(String text, int offset, int len) throws IOException {
throw _notSupported();
}
@Override
public void writeRawValue(char[] text, int offset, int len) throws IOException {
throw _notSupported();
}
/*
/**********************************************************
/* Output method implementations, base64-encoded binary
/**********************************************************
*/
@Override
public void writeBinary(Base64Variant b64variant, byte[] data, int offset, int len) throws IOException
{
if (data == null) {
writeNull();
return;
}
_verifyValueWrite("write Binary value");
_writeLengthMarker(PREFIX_TYPE_BYTES, len);
_writeBytes(data, offset, len);
}
@Override
public int writeBinary(InputStream data, int dataLength)
throws IOException
{
/* 28-Mar-2014, tatu: Theoretically we could implement encoder that uses
* chunking to output binary content of unknown (a priori) length.
* But for no let's require knowledge of length, for simplicity: may be
* revisited in future.
*/
if (dataLength < 0) {
throw new UnsupportedOperationException("Must pass actual length for CBOR encoded data");
}
_verifyValueWrite("write Binary value");
int missing;
_writeLengthMarker(PREFIX_TYPE_BYTES, dataLength);
missing = _writeBytes(data, dataLength);
if (missing > 0) {
_reportError("Too few bytes available: missing "+missing+" bytes (out of "+dataLength+")");
}
return dataLength;
}
@Override
public int writeBinary(Base64Variant b64variant, InputStream data, int dataLength)
throws IOException
{
return writeBinary(data, dataLength);
}
/*
/**********************************************************
/* Output method implementations, primitive
/**********************************************************
*/
@Override
public void writeBoolean(boolean state) throws IOException
{
_verifyValueWrite("write boolean value");
if (state) {
_writeByte(BYTE_TRUE);
} else {
_writeByte(BYTE_FALSE);
}
}
@Override
public void writeNull() throws IOException
{
_verifyValueWrite("write null value");
_writeByte(BYTE_NULL);
}
@Override
public void writeNumber(int i) throws IOException
{
_verifyValueWrite("write number");
int marker;
if (i < 0) {
i = -i - 1;
marker = PREFIX_TYPE_INT_NEG;
} else {
marker = PREFIX_TYPE_INT_POS;
}
_ensureRoomForOutput(5);
byte b0;
if (_cfgMinimalInts) {
if (i < 24) {
_outputBuffer[_outputTail++] = (byte) (marker + i);
return;
}
if (i <= 0xFF) {
_outputBuffer[_outputTail++] = (byte) (marker + 24);
_outputBuffer[_outputTail++] = (byte) i;
return;
}
b0 = (byte) i;
i >>= 8;
if (i <= 0xFF) {
_outputBuffer[_outputTail++] = (byte) (marker + 25);
_outputBuffer[_outputTail++] = (byte) i;
_outputBuffer[_outputTail++] = b0;
return;
}
} else {
b0 = (byte) i;
i >>= 8;
}
_outputBuffer[_outputTail++] = (byte) (marker + 26);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
_outputBuffer[_outputTail++] = b0;
}
@Override
public void writeNumber(long l) throws IOException
{
if (_cfgMinimalInts) {
// First: maybe 32 bits is enough?
if (l <= MAX_INT_AS_LONG && l >= MIN_INT_AS_LONG) {
writeNumber((int) l);
return;
}
}
_verifyValueWrite("write number");
_ensureRoomForOutput(9);
if (l < 0L) {
l += 1;
l = -l;
_outputBuffer[_outputTail++] = (PREFIX_TYPE_INT_NEG + 27);
} else {
_outputBuffer[_outputTail++] = (PREFIX_TYPE_INT_POS + 27);
}
int i = (int) (l >> 32);
_outputBuffer[_outputTail++] = (byte) (i >> 24);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
i = (int) l;
_outputBuffer[_outputTail++] = (byte) (i >> 24);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
}
@Override
public void writeNumber(BigInteger v) throws IOException
{
if (v == null) {
writeNull();
return;
}
_verifyValueWrite("write number");
/* Supported by using type tags, as per spec: major type for tag '6';
* 5 LSB either 2 for positive bignum or 3 for negative bignum.
* And then byte sequence that encode variable length integer.
*/
if (v.signum() < 0) {
_writeByte(BYTE_TAG_BIGNUM_NEG);
v = v.negate();
} else {
_writeByte(BYTE_TAG_BIGNUM_POS);
}
byte[] data = v.toByteArray();
final int len = data.length;
_writeLengthMarker(PREFIX_TYPE_BYTES, len);
_writeBytes(data, 0, len);
}
@Override
public void writeNumber(double d) throws IOException
{
_verifyValueWrite("write number");
_ensureRoomForOutput(11);
/* 17-Apr-2010, tatu: could also use 'doubleToIntBits', but it seems more accurate to use
* exact representation; and possibly faster. However, if there are cases
* where collapsing of NaN was needed (for non-Java clients), this can
* be changed
*/
long l = Double.doubleToRawLongBits(d);
_outputBuffer[_outputTail++] = BYTE_FLOAT64;
int i = (int) (l >> 32);
_outputBuffer[_outputTail++] = (byte) (i >> 24);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
i = (int) l;
_outputBuffer[_outputTail++] = (byte) (i >> 24);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
}
@Override
public void writeNumber(float f) throws IOException
{
// Ok, now, we needed token type byte plus 5 data bytes (7 bits each)
_ensureRoomForOutput(6);
_verifyValueWrite("write number");
/* 17-Apr-2010, tatu: could also use 'floatToIntBits', but it seems more accurate to use
* exact representation; and possibly faster. However, if there are cases
* where collapsing of NaN was needed (for non-Java clients), this can
* be changed
*/
int i = Float.floatToRawIntBits(f);
_outputBuffer[_outputTail++] = BYTE_FLOAT32;
_outputBuffer[_outputTail++] = (byte) (i >> 24);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
}
@Override
public void writeNumber(BigDecimal dec) throws IOException
{
if (dec == null) {
writeNull();
return;
}
_verifyValueWrite("write number");
/* Supported by using type tags, as per spec: major type for tag '6';
* 5 LSB 4.
* And then a two-int array, with mantissa and exponent
*/
_writeByte(BYTE_TAG_BIGFLOAT);
_writeByte(BYTE_ARRAY_2_ELEMENTS);
int scale = dec.scale();
_writeIntValue(scale);
/* Hmmmh. Specification suggest use of regular integer for mantissa.
* But... it may or may not fit. Let's try to do that, if it works;
* if not, use byte array.
*/
BigInteger unscaled = dec.unscaledValue();
byte[] data = unscaled.toByteArray();
if (data.length <= 4) {
int v = data[0]; // let it be sign extended on purpose
for (int i = 1; i < data.length; ++i) {
v = (v << 8) + (data[i] & 0xFF);
}
_writeIntValue(v);
} else if (data.length <= 8) {
long v = data[0]; // let it be sign extended on purpose
for (int i = 1; i < data.length; ++i) {
v = (v << 8) + (data[i] & 0xFF);
}
_writeLongValue(v);
} else {
final int len = data.length;
_writeLengthMarker(PREFIX_TYPE_BYTES, len);
_writeBytes(data, 0, len);
}
}
@Override
public void writeNumber(String encodedValue) throws IOException,JsonGenerationException, UnsupportedOperationException
{
// just write as a String -- CBOR does not require schema, so databinding
// on receiving end should be able to coerce it appropriately
writeString(encodedValue);
}
/*
/**********************************************************
/* Implementations for other methods
/**********************************************************
*/
@Override
protected final void _verifyValueWrite(String typeMsg) throws IOException
{
int status = _writeContext.writeValue();
if (status == JsonWriteContext.STATUS_EXPECT_NAME) {
_reportError("Can not "+typeMsg+", expecting field name");
}
}
/*
/**********************************************************
/* Low-level output handling
/**********************************************************
*/
@Override
public final void flush() throws IOException
{
_flushBuffer();
if (isEnabled(JsonGenerator.Feature.FLUSH_PASSED_TO_STREAM)) {
_out.flush();
}
}
@Override
public void close() throws IOException
{
// First: let's see that we still have buffers...
if (_outputBuffer != null
&& isEnabled(JsonGenerator.Feature.AUTO_CLOSE_JSON_CONTENT)) {
while (true) {
JsonStreamContext ctxt = getOutputContext();
if (ctxt.inArray()) {
writeEndArray();
} else if (ctxt.inObject()) {
writeEndObject();
} else {
break;
}
}
}
// boolean wasClosed = _closed;
super.close();
_flushBuffer();
if (_ioContext.isResourceManaged() || isEnabled(JsonGenerator.Feature.AUTO_CLOSE_TARGET)) {
_out.close();
} else {
// If we can't close it, we should at least flush
_out.flush();
}
// Internal buffer(s) generator has can now be released as well
_releaseBuffers();
}
/*
/**********************************************************
/* Internal methods: low-level text output
/**********************************************************
*/
protected final void _writeString(String name) throws IOException
{
int len = name.length();
if (len == 0) {
_writeByte(BYTE_EMPTY_STRING);
return;
}
// Actually, let's not bother with copy for shortest strings
if (len <= MAX_SHORT_STRING_CHARS) {
_ensureSpace(MAX_SHORT_STRING_BYTES); // can afford approximate length
int actual = _encode(_outputTail+1, name, len);
final byte[] buf = _outputBuffer;
int ix = _outputTail;
if (actual < MAX_SHORT_STRING_CHARS) { // fits in prefix byte
buf[ix++] = (byte) (PREFIX_TYPE_TEXT + actual);
_outputTail = ix + actual;
return;
}
// no, have to move. Blah.
System.arraycopy(buf, ix+1, buf, ix+2, actual);
buf[ix++] = BYTE_STRING_1BYTE_LEN;
buf[ix++] = (byte) actual;
_outputTail = ix+actual;
return;
}
char[] cbuf = _charBuffer;
if (len > cbuf.length) {
_charBuffer = cbuf = new char[Math.max(_charBuffer.length + 32, len)];
}
name.getChars(0, len, cbuf, 0);
_writeString(cbuf, 0, len);
}
private final static int MAX_SHORT_STRING_CHARS = 23;
private final static int MAX_SHORT_STRING_BYTES = 23 * 3 + 2; // in case it's > 23 bytes
private final static int MAX_MEDIUM_STRING_CHARS = 255;
private final static int MAX_MEDIUM_STRING_BYTES = 255 * 3 + 3; // in case it's > 255 bytes
protected final void _ensureSpace(int needed) throws IOException {
if ((_outputTail + needed + 3) > _outputEnd) {
_flushBuffer();
}
}
protected final void _writeString(char[] text, int offset, int len) throws IOException
{
if (len <= MAX_SHORT_STRING_CHARS) { // possibly short strings (not necessarily)
_ensureSpace(MAX_SHORT_STRING_BYTES); // can afford approximate length
int actual = _encode(_outputTail+1, text, offset, offset+len);
final byte[] buf = _outputBuffer;
int ix = _outputTail;
if (actual < MAX_SHORT_STRING_CHARS) { // fits in prefix byte
buf[ix++] = (byte) (PREFIX_TYPE_TEXT + actual);
_outputTail = ix + actual;
return;
}
// no, have to move. Blah.
System.arraycopy(buf, ix+1, buf, ix+2, actual);
buf[ix++] = BYTE_STRING_1BYTE_LEN;
buf[ix++] = (byte) actual;
_outputTail = ix+actual;
return;
}
if (len <= MAX_MEDIUM_STRING_CHARS) {
_ensureSpace(MAX_MEDIUM_STRING_BYTES); // short enough, can approximate
int actual = _encode(_outputTail+2, text, offset, offset+len);
final byte[] buf = _outputBuffer;
int ix = _outputTail;
if (actual < MAX_MEDIUM_STRING_CHARS) { // fits as expected
buf[ix++] = BYTE_STRING_1BYTE_LEN;
buf[ix++] = (byte) actual;
_outputTail = ix + actual;
return;
}
// no, have to move. Blah.
System.arraycopy(buf, ix+2, buf, ix+3, actual);
buf[ix++] = BYTE_STRING_2BYTE_LEN;
buf[ix++] = (byte) (actual >> 8);
buf[ix++] = (byte) actual;
_outputTail = ix+actual;
return;
}
if (len <= MAX_LONG_STRING_CHARS) { // no need to chunk yet
// otherwise, long but single chunk
_ensureSpace(MAX_LONG_STRING_BYTES); // calculate accurate length to avoid extra flushing
int ix = _outputTail;
int actual = _encode(ix+3, text, offset, offset+len);
final byte[] buf = _outputBuffer;
buf[ix++] = BYTE_STRING_2BYTE_LEN;
buf[ix++] = (byte) (actual >> 8);
buf[ix++] = (byte) actual;
_outputTail = ix+actual;
return;
}
_writeChunkedString(text, offset, len);
}
protected final void _writeChunkedString(char[] text, int offset, int len) throws IOException
{
// need to use a marker first
_writeByte(BYTE_STRING_INDEFINITE);
while (len > MAX_LONG_STRING_CHARS) {
_ensureSpace(MAX_LONG_STRING_BYTES); // marker and single-byte length?
int ix = _outputTail;
int actual = _encode(_outputTail+3, text, offset, offset+MAX_LONG_STRING_CHARS);
final byte[] buf = _outputBuffer;
buf[ix++] = BYTE_STRING_2BYTE_LEN;
buf[ix++] = (byte) (actual >> 8);
buf[ix++] = (byte) actual;
_outputTail = ix+actual;
offset += MAX_LONG_STRING_CHARS;
len -= MAX_LONG_STRING_CHARS;
}
// and for the last chunk, just use recursion
if (len > 0) {
_writeString(text, offset, len);
}
// plus end marker
_writeByte(BYTE_BREAK);
}
/*
/**********************************************************
/* Internal methods, UTF-8 encoding
/**********************************************************
*/
/**
* Helper method called when the whole character sequence is known to
* fit in the output buffer regardless of UTF-8 expansion.
*/
private final int _encode(int outputPtr, char[] str, int i, int end)
{
// First: let's see if it's all ASCII: that's rather fast
final byte[] outBuf = _outputBuffer;
final int outputStart = outputPtr;
do {
int c = str[i];
if (c > 0x7F) {
return _shortUTF8Encode2(str, i, end, outputPtr, outputStart);
}
outBuf[outputPtr++] = (byte) c;
} while (++i < end);
return outputPtr - outputStart;
}
/**
* Helper method called when the whole character sequence is known to
* fit in the output buffer, but not all characters are single-byte (ASCII)
* characters.
*/
private final int _shortUTF8Encode2(char[] str, int i, int end,
int outputPtr, int outputStart)
{
final byte[] outBuf = _outputBuffer;
while (i < end) {
int c = str[i++];
if (c <= 0x7F) {
outBuf[outputPtr++] = (byte) c;
continue;
}
// Nope, multi-byte:
if (c < 0x800) { // 2-byte
outBuf[outputPtr++] = (byte) (0xc0 | (c >> 6));
outBuf[outputPtr++] = (byte) (0x80 | (c & 0x3f));
continue;
}
// 3 or 4 bytes (surrogate)
// Surrogates?
if (c < SURR1_FIRST || c > SURR2_LAST) { // nope, regular 3-byte character
outBuf[outputPtr++] = (byte) (0xe0 | (c >> 12));
outBuf[outputPtr++] = (byte) (0x80 | ((c >> 6) & 0x3f));
outBuf[outputPtr++] = (byte) (0x80 | (c & 0x3f));
continue;
}
// Yup, a surrogate pair
if (c > SURR1_LAST) { // must be from first range; second won't do
_throwIllegalSurrogate(c);
}
// ... meaning it must have a pair
if (i >= end) {
_throwIllegalSurrogate(c);
}
c = _convertSurrogate(c, str[i++]);
if (c > 0x10FFFF) { // illegal in JSON as well as in XML
_throwIllegalSurrogate(c);
}
outBuf[outputPtr++] = (byte) (0xf0 | (c >> 18));
outBuf[outputPtr++] = (byte) (0x80 | ((c >> 12) & 0x3f));
outBuf[outputPtr++] = (byte) (0x80 | ((c >> 6) & 0x3f));
outBuf[outputPtr++] = (byte) (0x80 | (c & 0x3f));
}
return (outputPtr - outputStart);
}
private final int _encode(int outputPtr, String str, int len)
{
final byte[] outBuf = _outputBuffer;
final int outputStart = outputPtr;
for (int i = 0; i < len; ++i) {
int c = str.charAt(i);
if (c > 0x7F) {
return _encode2(i, outputPtr, str, len, outputStart);
}
outBuf[outputPtr++] = (byte) c;
}
return (outputPtr - outputStart);
}
private final int _encode2(int i, int outputPtr, String str, int len,
int outputStart)
{
final byte[] outBuf = _outputBuffer;
// no; non-ASCII stuff, slower loop
while (i < len) {
int c = str.charAt(i++);
if (c <= 0x7F) {
outBuf[outputPtr++] = (byte) c;
continue;
}
// Nope, multi-byte:
if (c < 0x800) { // 2-byte
outBuf[outputPtr++] = (byte) (0xc0 | (c >> 6));
outBuf[outputPtr++] = (byte) (0x80 | (c & 0x3f));
continue;
}
// 3 or 4 bytes (surrogate)
// Surrogates?
if (c < SURR1_FIRST || c > SURR2_LAST) { // nope, regular 3-byte character
outBuf[outputPtr++] = (byte) (0xe0 | (c >> 12));
outBuf[outputPtr++] = (byte) (0x80 | ((c >> 6) & 0x3f));
outBuf[outputPtr++] = (byte) (0x80 | (c & 0x3f));
continue;
}
// Yup, a surrogate pair
if (c > SURR1_LAST) { // must be from first range; second won't do
_throwIllegalSurrogate(c);
}
// ... meaning it must have a pair
if (i >= len) {
_throwIllegalSurrogate(c);
}
c = _convertSurrogate(c, str.charAt(i++));
if (c > 0x10FFFF) { // illegal in JSON as well as in XML
_throwIllegalSurrogate(c);
}
outBuf[outputPtr++] = (byte) (0xf0 | (c >> 18));
outBuf[outputPtr++] = (byte) (0x80 | ((c >> 12) & 0x3f));
outBuf[outputPtr++] = (byte) (0x80 | ((c >> 6) & 0x3f));
outBuf[outputPtr++] = (byte) (0x80 | (c & 0x3f));
}
return (outputPtr - outputStart);
}
/**
* Method called to calculate UTF codepoint, from a surrogate pair.
*/
private int _convertSurrogate(int firstPart, int secondPart)
{
// Ok, then, is the second part valid?
if (secondPart < SURR2_FIRST || secondPart > SURR2_LAST) {
throw new IllegalArgumentException("Broken surrogate pair: first char 0x"+Integer.toHexString(firstPart)+", second 0x"+Integer.toHexString(secondPart)+"; illegal combination");
}
return 0x10000 + ((firstPart - SURR1_FIRST) << 10) + (secondPart - SURR2_FIRST);
}
private void _throwIllegalSurrogate(int code)
{
if (code > 0x10FFFF) { // over max?
throw new IllegalArgumentException("Illegal character point (0x"+Integer.toHexString(code)+") to output; max is 0x10FFFF as per RFC 4627");
}
if (code >= SURR1_FIRST) {
if (code <= SURR1_LAST) { // Unmatched first part (closing without second part?)
throw new IllegalArgumentException("Unmatched first part of surrogate pair (0x"+Integer.toHexString(code)+")");
}
throw new IllegalArgumentException("Unmatched second part of surrogate pair (0x"+Integer.toHexString(code)+")");
}
// should we ever get this?
throw new IllegalArgumentException("Illegal character point (0x"+Integer.toHexString(code)+") to output");
}
/*
/**********************************************************
/* Internal methods, writing bytes
/**********************************************************
*/
private final void _ensureRoomForOutput(int needed) throws IOException {
if ((_outputTail + needed) >= _outputEnd) {
_flushBuffer();
}
}
private final void _writeIntValue(int i) throws IOException
{
int marker;
if (i < 0) {
i += 1;
i = -1;
marker = PREFIX_TYPE_INT_NEG;
} else {
marker = PREFIX_TYPE_INT_POS;
}
_writeLengthMarker(marker, i);
}
private final void _writeLongValue(long l) throws IOException
{
_ensureRoomForOutput(9);
if (l < 0) {
l += 1;
l = -1;
_outputBuffer[_outputTail++] = (PREFIX_TYPE_INT_NEG + 27);
} else {
_outputBuffer[_outputTail++] = (PREFIX_TYPE_INT_POS + 27);
}
int i = (int) (l >> 32);
_outputBuffer[_outputTail++] = (byte) (i >> 24);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
i = (int) l;
_outputBuffer[_outputTail++] = (byte) (i >> 24);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
}
private final void _writeLengthMarker(int majorType, int i) throws IOException
{
_ensureRoomForOutput(5);
if (i < 24) {
_outputBuffer[_outputTail++] = (byte) (majorType + i);
return;
}
if (i <= 0xFF) {
_outputBuffer[_outputTail++] = (byte) (majorType + 24);
_outputBuffer[_outputTail++] = (byte) i;
return;
}
final byte b0 = (byte) i;
i >>= 8;
if (i <= 0xFF) {
_outputBuffer[_outputTail++] = (byte) (majorType + 25);
_outputBuffer[_outputTail++] = (byte) i;
_outputBuffer[_outputTail++] = b0;
return;
}
_outputBuffer[_outputTail++] = (byte) (majorType + 26);
_outputBuffer[_outputTail++] = (byte) (i >> 16);
_outputBuffer[_outputTail++] = (byte) (i >> 8);
_outputBuffer[_outputTail++] = (byte) i;
_outputBuffer[_outputTail++] = b0;
}
private final void _writeByte(byte b) throws IOException
{
if (_outputTail >= _outputEnd) {
_flushBuffer();
}
_outputBuffer[_outputTail++] = b;
}
/*
private final void _writeBytes(byte b1, byte b2) throws IOException
{
if ((_outputTail + 1) >= _outputEnd) {
_flushBuffer();
}
_outputBuffer[_outputTail++] = b1;
_outputBuffer[_outputTail++] = b2;
}
*/
private final void _writeBytes(byte[] data, int offset, int len) throws IOException
{
if (len == 0) {
return;
}
if ((_outputTail + len) >= _outputEnd) {
_writeBytesLong(data, offset, len);
return;
}
// common case, non-empty, fits in just fine:
System.arraycopy(data, offset, _outputBuffer, _outputTail, len);
_outputTail += len;
}
private final int _writeBytes(InputStream in, int bytesLeft) throws IOException
{
while (bytesLeft > 0) {
int room = _outputEnd - _outputTail;
if (room <= 0) {
_flushBuffer();
room = _outputEnd - _outputTail;
}
int count = in.read(_outputBuffer, _outputTail, room);
if (count < 0) {
break;
}
_outputTail += count;
bytesLeft -= count;
}
return bytesLeft;
}
private final void _writeBytesLong(byte[] data, int offset, int len) throws IOException
{
if (_outputTail >= _outputEnd) {
_flushBuffer();
}
while (true) {
int currLen = Math.min(len, (_outputEnd - _outputTail));
System.arraycopy(data, offset, _outputBuffer, _outputTail, currLen);
_outputTail += currLen;
if ((len -= currLen) == 0) {
break;
}
offset += currLen;
_flushBuffer();
}
}
/*
/**********************************************************
/* Internal methods, buffer handling
/**********************************************************
*/
@Override
protected void _releaseBuffers()
{
byte[] buf = _outputBuffer;
if (buf != null && _bufferRecyclable) {
_outputBuffer = null;
_ioContext.releaseWriteEncodingBuffer(buf);
}
char[] cbuf = _charBuffer;
if (cbuf != null) {
_charBuffer = null;
_ioContext.releaseConcatBuffer(cbuf);
}
}
protected final void _flushBuffer() throws IOException
{
if (_outputTail > 0) {
_bytesWritten += _outputTail;
_out.write(_outputBuffer, 0, _outputTail);
_outputTail = 0;
}
}
/*
/**********************************************************
/* Internal methods, error reporting
/**********************************************************
*/
protected UnsupportedOperationException _notSupported() {
return new UnsupportedOperationException();
}
}