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Support for reading and writing TOML-encoded data via Jackson abstractions.
package com.fasterxml.jackson.dataformat.toml;
import java.io.*;
import com.fasterxml.jackson.core.io.IOContext;
/**
* Optimized Reader that reads UTF-8 encoded content from an input stream.
* Content may come either from a static {@code byte[]} buffer or
* {@link java.io.InputStream}.
*/
public final class UTF8Reader
extends Reader
{
/**
* IO context to use for returning input buffer, iff
* buffer is to be recycled when input ends.
*/
private final IOContext _ioContext;
private InputStream _inputSource;
private final boolean _autoClose;
private byte[] _inputBuffer;
/**
* Pointer to the next available byte (if any), iff less than
* mByteBufferEnd
*/
private int _inputPtr;
/**
* Pointed to the end marker, that is, position one after the last
* valid available byte.
*/
private int _inputEnd;
/**
* Decoded first character of a surrogate pair, if one needs to be buffered
*/
private int _surrogate = -1;
/**
* Total read character count; used for error reporting purposes
*/
private int _charCount = 0;
/**
* Total read byte count; used for error reporting purposes
*/
private int _byteCount = 0;
/*
/**********************************************************************
/* Life-cycle
/**********************************************************************
*/
// Constructor used when caller gives us
private UTF8Reader(IOContext ctxt, InputStream in, boolean autoClose,
byte[] buf, int ptr, int end)
{
super((in == null) ? buf : in);
_ioContext = ctxt;
_inputSource = in;
_inputBuffer = buf;
_inputPtr = ptr;
_inputEnd = end;
_autoClose = autoClose;
}
// Factory method used when dealing with InputStream; will need
// to allocate and manage processing buffers
public static UTF8Reader construct(IOContext ctxt, InputStream in, boolean autoClose)
{
final byte[] buf = ctxt.allocReadIOBuffer();
return new UTF8Reader(ctxt, in, autoClose, buf, 0, 0);
}
// Factory method used when user passes us input in static pre-filled
// input buffer: no InputStream nor buffer recycling used
public static UTF8Reader construct(byte[] buf, int ptr, int len)
{
return new UTF8Reader(null, null, true, buf, ptr, ptr+len);
}
/**
* This method should be called along with (or instead of) normal
* close. After calling this method, no further reads should be tried.
* Method will try to recycle read buffers (if any).
*/
private void freeBuffers()
{
if (_ioContext != null) {
byte[] buf = _inputBuffer;
if (buf != null) {
_inputBuffer = null;
_ioContext.releaseReadIOBuffer(buf);
}
}
}
/*
/**********************************************************************
/* Reader API
/**********************************************************************
*/
@Override
public void close() throws IOException
{
InputStream in = _inputSource;
if (in != null) {
_inputSource = null;
if (_autoClose) {
in.close();
}
}
freeBuffers();
}
private char[] _tmpBuffer = null;
// This method is implemented by the base class, AND it should
//never be called by our code. But let's still implement it bit more
// efficiently just in case
@Override
public int read() throws IOException
{
if (_tmpBuffer == null) {
_tmpBuffer = new char[1];
}
if (read(_tmpBuffer, 0, 1) < 1) {
return -1;
}
return _tmpBuffer[0];
}
@Override
public int read(char[] cbuf) throws IOException {
return read(cbuf, 0, cbuf.length);
}
@Override
public int read(char[] cbuf, int start, int len) throws IOException
{
// Already EOF?
if (_inputBuffer == null) {
return -1;
}
len += start;
int outPtr = start;
// Ok, first; do we have a surrogate from last round?
if (_surrogate >= 0) {
cbuf[outPtr++] = (char) _surrogate;
_surrogate = -1;
// No need to load more, already got one char
// 05-Apr-2021, tatu: but if at the end must return:
if (_inputPtr >= _inputEnd) {
_charCount += 1;
return 1;
}
} else {
// To prevent unnecessary blocking (esp. with network streams),
// we'll only require decoding of a single char
int left = (_inputEnd - _inputPtr);
// 09-Apr-2021, tatu: Not 100% sure this is valid logic for cases
// where content ends with UTF-8 multibyte characters... but
// this has existed in multiple incarnations for over a decade
// so... maybe I thought it all through?
if (left < 4) {
// Need to load more?
if (left < 1 || _inputBuffer[_inputPtr] < 0) {
if (!loadMore(left)) { // (legal) EOF?
return -1;
}
}
}
}
final byte[] buf = _inputBuffer;
int inPtr = _inputPtr;
final int inBufLen = _inputEnd;
main_loop:
while (outPtr < len) {
// At this point we have at least one byte available
int c = (int) buf[inPtr++];
// Let's first do the quickie loop for common case; 7-bit ASCII
if (c >= 0) { // ASCII? can probably loop, then
cbuf[outPtr++] = (char) c; // ok since MSB is never on
// Ok, how many such chars could we safely process without overruns?
// (will combine 2 in-loop comparisons into just one)
int outMax = (len - outPtr); // max output
int inMax = (inBufLen - inPtr); // max input
int inEnd = inPtr + ((inMax < outMax) ? inMax : outMax);
ascii_loop:
while (true) {
if (inPtr >= inEnd) {
break main_loop;
}
c = buf[inPtr++];
if (c < 0) { // or multi-byte
break ascii_loop;
}
cbuf[outPtr++] = (char) c;
}
}
int needed;
// Ok; if we end here, we got multi-byte combination
if ((c & 0xE0) == 0xC0) { // 2 bytes (0x0080 - 0x07FF)
c = (c & 0x1F);
needed = 1;
} else if ((c & 0xF0) == 0xE0) { // 3 bytes (0x0800 - 0xFFFF)
c = (c & 0x0F);
needed = 2;
} else if ((c & 0xF8) == 0xF0) {
// 4 bytes; double-char BS, with surrogates and all...
c = (c & 0x0F);
needed = 3;
} else {
reportInvalidInitial(c & 0xFF, outPtr-start);
// never gets here...
needed = 1;
}
// Do we have enough bytes? If not, let's just push back the
// byte and leave, since we have already gotten at least one
// char decoded. This way we will only block (with read from
// input stream) when absolutely necessary.
if ((inBufLen - inPtr) < needed) {
--inPtr;
break main_loop;
}
int d = (int) buf[inPtr++];
if ((d & 0xC0) != 0x080) {
reportInvalidOther(d & 0xFF, outPtr-start);
}
c = (c << 6) | (d & 0x3F);
if (needed > 1) { // needed == 1 means 2 bytes total
d = buf[inPtr++]; // 3rd byte
if ((d & 0xC0) != 0x080) {
reportInvalidOther(d & 0xFF, outPtr-start);
}
c = (c << 6) | (d & 0x3F);
if (needed > 2) { // 4 bytes? (need surrogates)
d = buf[inPtr++];
if ((d & 0xC0) != 0x080) {
reportInvalidOther(d & 0xFF, outPtr-start);
}
c = (c << 6) | (d & 0x3F);
/* Ugh. Need to mess with surrogates. Ok; let's inline them
* there, then, if there's room: if only room for one,
* need to save the surrogate for the rainy day...
*/
c -= 0x10000; // to normalize it starting with 0x0
cbuf[outPtr++] = (char) (0xD800 + (c >> 10));
// hmmh. can this ever be 0? (not legal, at least?)
c = (0xDC00 | (c & 0x03FF));
// Room for second part?
if (outPtr >= len) { // nope
_surrogate = c;
break main_loop;
}
// sure, let's fall back to normal processing:
}
// Otherwise, should we check that 3-byte chars are
// legal ones (should not expand to surrogates?
// For now, let's not...
/*
else {
if (c >= 0xD800 && c < 0xE000) {
reportInvalid(c, outPtr-start, "(a surrogate character) ");
}
}
*/
}
cbuf[outPtr++] = (char) c;
if (inPtr >= inBufLen) {
break main_loop;
}
}
_inputPtr = inPtr;
len = outPtr - start;
_charCount += len;
return len;
}
/*
/**********************************************************************
/* Internal methods: loading more input
/**********************************************************************
*/
/**
* @param available Number of "unused" bytes in the input buffer
*
* @return True, if enough bytes were read to allow decoding of at least
* one full character; false if EOF was encountered instead.
*/
private boolean loadMore(int available) throws IOException
{
if (_inputSource == null) {
return false;
}
_byteCount += (_inputEnd - available);
// Bytes that need to be moved to the beginning of buffer?
if (available > 0) {
if (_inputPtr > 0) {
for (int i = 0; i < available; ++i) {
_inputBuffer[i] = _inputBuffer[_inputPtr+i];
}
_inputPtr = 0;
_inputEnd = available;
}
} else {
// Ok; here we can actually reasonably expect an EOF,
// so let's do a separate read right away:
int count = readBytes();
if (count < 1) {
freeBuffers(); // recycle eagerly
if (count < 0) { // -1
return false;
}
// 0 count is no good; let's err out
reportStrangeStream();
}
}
// We now have at least one byte... and that allows us to
// calculate exactly how many bytes we need!
@SuppressWarnings("cast")
int c = (int) _inputBuffer[_inputPtr];
if (c >= 0) { // single byte (ascii) char... cool, can return
return true;
}
// Ok, a multi-byte char, let's check how many bytes we'll need:
int needed;
if ((c & 0xE0) == 0xC0) { // 2 bytes (0x0080 - 0x07FF)
needed = 2;
} else if ((c & 0xF0) == 0xE0) { // 3 bytes (0x0800 - 0xFFFF)
needed = 3;
} else if ((c & 0xF8) == 0xF0) {
// 4 bytes; double-char BS, with surrogates and all...
needed = 4;
} else {
reportInvalidInitial(c & 0xFF, 0);
// never gets here... but compiler whines without this:
needed = 1;
}
// And then we'll just need to load up to that many bytes;
// if an EOF is hit, that'll be an error. But we need not do
// actual decoding here, just load enough bytes.
while ((_inputPtr + needed) > _inputEnd) {
int count = readBytesAt(_inputEnd);
if (count < 1) {
if (count < 0) { // -1, EOF... no good!
freeBuffers();
reportUnexpectedEOF(_inputEnd, needed);
}
// 0 count is no good; let's err out
reportStrangeStream();
}
}
return true;
}
protected final int readBytes() throws IOException
{
_inputPtr = 0;
_inputEnd = 0;
if (_inputSource != null) {
int count = _inputSource.read(_inputBuffer, 0, _inputBuffer.length);
if (count > 0) {
_inputEnd = count;
}
return count;
}
return -1;
}
protected final int readBytesAt(int offset) throws IOException
{
// shouldn't modify mBytePtr, assumed to be 'offset'
if (_inputSource != null) {
int count = _inputSource.read(_inputBuffer, offset, _inputBuffer.length - offset);
if (count > 0) {
_inputEnd += count;
}
return count;
}
return -1;
}
/*
/**********************************************************************
/* Internal methods: error reporting
/**********************************************************************
*/
private void reportInvalidInitial(int mask, int offset) throws IOException
{
// input (byte) ptr has been advanced by one, by now:
int bytePos = _byteCount + _inputPtr - 1;
int charPos = _charCount + offset + 1;
throw new CharConversionException("Invalid UTF-8 start byte 0x"+Integer.toHexString(mask)
+" (at char #"+charPos+", byte #"+bytePos+")");
}
private void reportInvalidOther(int mask, int offset)
throws IOException
{
int bytePos = _byteCount + _inputPtr - 1;
int charPos = _charCount + offset;
throw new CharConversionException("Invalid UTF-8 middle byte 0x"+Integer.toHexString(mask)
+" (at char #"+charPos+", byte #"+bytePos+")");
}
private void reportUnexpectedEOF(int gotBytes, int needed)
throws IOException
{
int bytePos = _byteCount + gotBytes;
int charPos = _charCount;
throw new CharConversionException("Unexpected EOF in the middle of a multi-byte char: got "
+gotBytes+", needed "+needed +", at char #"+charPos+", byte #"+bytePos+")");
}
protected void reportBounds(char[] cbuf, int start, int len) throws IOException {
throw new ArrayIndexOutOfBoundsException("read(buf,"+start+","+len+"), cbuf["+cbuf.length+"]");
}
protected void reportStrangeStream() throws IOException {
throw new IOException("Strange I/O stream, returned 0 bytes on read");
}
}