net.sourceforge.plantuml.brotli.BitReader Maven / Gradle / Ivy
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// THIS FILE HAS BEEN GENERATED BY A PREPROCESSOR.
/* +=======================================================================
* |
* | PlantUML : a free UML diagram generator
* |
* +=======================================================================
*
* (C) Copyright 2009-2024, Arnaud Roques
*
* Project Info: https://plantuml.com
*
* If you like this project or if you find it useful, you can support us at:
*
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*
*
* PlantUML is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* PlantUML distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see
* No-op if there are at least 36 bytes present after current position.
*
*
* After encountering the end of the input stream, 64 additional zero bytes are
* copied to the buffer.
*/
static void readMoreInput(State s) {
if (s.halfOffset > HALF_WATERLINE) {
doReadMoreInput(s);
}
}
static void doReadMoreInput(State s) {
if (s.endOfStreamReached != 0) {
if (halfAvailable(s) >= -2) {
return;
}
throw new BrotliRuntimeException("No more input");
}
int readOffset = s.halfOffset << LOG_HALF_SIZE;
int bytesInBuffer = CAPACITY - readOffset;
// Move unused bytes to the head of the buffer.
Utils.copyBytesWithin(s.byteBuffer, 0, readOffset, CAPACITY);
s.halfOffset = 0;
while (bytesInBuffer < CAPACITY) {
int spaceLeft = CAPACITY - bytesInBuffer;
int len = Utils.readInput(s.input, s.byteBuffer, bytesInBuffer, spaceLeft);
// EOF is -1 in Java, but 0 in C#.
if (len <= 0) {
s.endOfStreamReached = 1;
s.tailBytes = bytesInBuffer;
bytesInBuffer += HALF_SIZE - 1;
break;
}
bytesInBuffer += len;
}
bytesToNibbles(s, bytesInBuffer);
}
static void checkHealth(State s, int endOfStream) {
if (s.endOfStreamReached == 0) {
return;
}
int byteOffset = (s.halfOffset << LOG_HALF_SIZE) + ((s.bitOffset + 7) >> 3) - BYTENESS;
if (byteOffset > s.tailBytes) {
throw new BrotliRuntimeException("Read after end");
}
if (CHECK_UNUSED_BYTES_AFTER_END && (endOfStream != 0) && (byteOffset != s.tailBytes)) {
throw new BrotliRuntimeException("Unused bytes after end");
}
}
static void fillBitWindow(State s) {
if (s.bitOffset >= HALF_BITNESS) {
// Same as doFillBitWindow. JVM fails to inline it.
if (BITNESS == 64) {
s.accumulator64 = ((long) s.intBuffer[s.halfOffset++] << HALF_BITNESS)
| (s.accumulator64 >>> HALF_BITNESS);
} else {
s.accumulator32 = ((int) s.shortBuffer[s.halfOffset++] << HALF_BITNESS)
| (s.accumulator32 >>> HALF_BITNESS);
}
s.bitOffset -= HALF_BITNESS;
}
}
private static void doFillBitWindow(State s) {
if (BITNESS == 64) {
s.accumulator64 = ((long) s.intBuffer[s.halfOffset++] << HALF_BITNESS) | (s.accumulator64 >>> HALF_BITNESS);
} else {
s.accumulator32 = ((int) s.shortBuffer[s.halfOffset++] << HALF_BITNESS)
| (s.accumulator32 >>> HALF_BITNESS);
}
s.bitOffset -= HALF_BITNESS;
}
static int peekBits(State s) {
if (BITNESS == 64) {
return (int) (s.accumulator64 >>> s.bitOffset);
} else {
return s.accumulator32 >>> s.bitOffset;
}
}
static int readFewBits(State s, int n) {
int val = peekBits(s) & ((1 << n) - 1);
s.bitOffset += n;
return val;
}
static int readBits(State s, int n) {
if (HALF_BITNESS >= 24) {
return readFewBits(s, n);
} else {
return (n <= 16) ? readFewBits(s, n) : readManyBits(s, n);
}
}
private static int readManyBits(State s, int n) {
int low = readFewBits(s, 16);
doFillBitWindow(s);
return low | (readFewBits(s, n - 16) << 16);
}
static void initBitReader(State s) {
s.byteBuffer = new byte[BUFFER_SIZE];
if (BITNESS == 64) {
s.accumulator64 = 0;
s.intBuffer = new int[HALF_BUFFER_SIZE];
} else {
s.accumulator32 = 0;
s.shortBuffer = new short[HALF_BUFFER_SIZE];
}
s.bitOffset = BITNESS;
s.halfOffset = HALVES_CAPACITY;
s.endOfStreamReached = 0;
prepare(s);
}
private static void prepare(State s) {
readMoreInput(s);
checkHealth(s, 0);
doFillBitWindow(s);
doFillBitWindow(s);
}
static void reload(State s) {
if (s.bitOffset == BITNESS) {
prepare(s);
}
}
static void jumpToByteBoundary(State s) {
int padding = (BITNESS - s.bitOffset) & 7;
if (padding != 0) {
int paddingBits = readFewBits(s, padding);
if (paddingBits != 0) {
throw new BrotliRuntimeException("Corrupted padding bits");
}
}
}
static int halfAvailable(State s) {
int limit = HALVES_CAPACITY;
if (s.endOfStreamReached != 0) {
limit = (s.tailBytes + (HALF_SIZE - 1)) >> LOG_HALF_SIZE;
}
return limit - s.halfOffset;
}
static void copyBytes(State s, byte[] data, int offset, int length) {
if ((s.bitOffset & 7) != 0) {
throw new BrotliRuntimeException("Unaligned copyBytes");
}
// Drain accumulator.
while ((s.bitOffset != BITNESS) && (length != 0)) {
data[offset++] = (byte) peekBits(s);
s.bitOffset += 8;
length--;
}
if (length == 0) {
return;
}
// Get data from shadow buffer with "sizeof(int)" granularity.
int copyNibbles = Math.min(halfAvailable(s), length >> LOG_HALF_SIZE);
if (copyNibbles > 0) {
int readOffset = s.halfOffset << LOG_HALF_SIZE;
int delta = copyNibbles << LOG_HALF_SIZE;
System.arraycopy(s.byteBuffer, readOffset, data, offset, delta);
offset += delta;
length -= delta;
s.halfOffset += copyNibbles;
}
if (length == 0) {
return;
}
// Read tail bytes.
if (halfAvailable(s) > 0) {
// length = 1..3
fillBitWindow(s);
while (length != 0) {
data[offset++] = (byte) peekBits(s);
s.bitOffset += 8;
length--;
}
checkHealth(s, 0);
return;
}
// Now it is possible to copy bytes directly.
while (length > 0) {
int len = Utils.readInput(s.input, data, offset, length);
if (len == -1) {
throw new BrotliRuntimeException("Unexpected end of input");
}
offset += len;
length -= len;
}
}
/**
* Translates bytes to halves (int/short).
*/
static void bytesToNibbles(State s, int byteLen) {
byte[] byteBuffer = s.byteBuffer;
int halfLen = byteLen >> LOG_HALF_SIZE;
if (BITNESS == 64) {
int[] intBuffer = s.intBuffer;
for (int i = 0; i < halfLen; ++i) {
intBuffer[i] = ((byteBuffer[i * 4] & 0xFF)) | ((byteBuffer[(i * 4) + 1] & 0xFF) << 8)
| ((byteBuffer[(i * 4) + 2] & 0xFF) << 16) | ((byteBuffer[(i * 4) + 3] & 0xFF) << 24);
}
} else {
short[] shortBuffer = s.shortBuffer;
for (int i = 0; i < halfLen; ++i) {
shortBuffer[i] = (short) ((byteBuffer[i * 2] & 0xFF) | ((byteBuffer[(i * 2) + 1] & 0xFF) << 8));
}
}
}
}