diff options
Diffstat (limited to 'java/org/brotli/dec/Decode.java')
| -rw-r--r-- | java/org/brotli/dec/Decode.java | 84 |
1 files changed, 45 insertions, 39 deletions
diff --git a/java/org/brotli/dec/Decode.java b/java/org/brotli/dec/Decode.java index 4a1ded6..9e3d43b 100644 --- a/java/org/brotli/dec/Decode.java +++ b/java/org/brotli/dec/Decode.java @@ -25,10 +25,10 @@ final class Decode { private static final int COPY_UNCOMPRESSED = 5; private static final int INSERT_LOOP = 6; private static final int COPY_LOOP = 7; - private static final int COPY_WRAP_BUFFER = 8; - private static final int TRANSFORM = 9; - private static final int FINISHED = 10; - private static final int CLOSED = 11; + private static final int TRANSFORM = 8; + private static final int FINISHED = 9; + private static final int CLOSED = 10; + private static final int INIT_WRITE = 11; private static final int WRITE = 12; private static final int DEFAULT_CODE_LENGTH = 8; @@ -550,9 +550,7 @@ final class Decode { private static void readNextMetablockHeader(State s) { if (s.inputEnd != 0) { s.nextRunningState = FINISHED; - s.bytesToWrite = s.pos; - s.bytesWritten = 0; - s.runningState = WRITE; + s.runningState = INIT_WRITE; return; } // TODO: Reset? Do we need this? @@ -674,9 +672,7 @@ final class Decode { s.pos += chunkLength; if (s.pos == s.ringBufferSize) { s.nextRunningState = COPY_UNCOMPRESSED; - s.bytesToWrite = s.ringBufferSize; - s.bytesWritten = 0; - s.runningState = WRITE; + s.runningState = INIT_WRITE; return; } @@ -686,12 +682,12 @@ final class Decode { private static int writeRingBuffer(State s) { int toWrite = Math.min(s.outputLength - s.outputUsed, - s.bytesToWrite - s.bytesWritten); + s.ringBufferBytesReady - s.ringBufferBytesWritten); if (toWrite != 0) { - System.arraycopy(s.ringBuffer, s.bytesWritten, s.output, + System.arraycopy(s.ringBuffer, s.ringBufferBytesWritten, s.output, s.outputOffset + s.outputUsed, toWrite); s.outputUsed += toWrite; - s.bytesWritten += toWrite; + s.ringBufferBytesWritten += toWrite; } if (s.outputUsed < s.outputLength) { @@ -712,6 +708,15 @@ final class Decode { return group; } + // Returns offset in ringBuffer that should trigger WRITE when filled. + private static int calculateFence(State s) { + int result = s.ringBufferSize; + if (s.isEager != 0) { + result = Math.min(result, s.ringBufferBytesWritten + s.outputLength - s.outputUsed); + } + return result; + } + /** * Actual decompress implementation. */ @@ -722,6 +727,7 @@ final class Decode { if (s.runningState == CLOSED) { throw new IllegalStateException("Can't decompress after close"); } + int fence = calculateFence(s); int ringBufferMask = s.ringBufferSize - 1; byte[] ringBuffer = s.ringBuffer; @@ -734,6 +740,7 @@ final class Decode { } readNextMetablockHeader(s); /* Ring-buffer would be reallocated here. */ + fence = calculateFence(s); ringBufferMask = s.ringBufferSize - 1; ringBuffer = s.ringBuffer; continue; @@ -787,12 +794,11 @@ final class Decode { BitReader.fillBitWindow(s); ringBuffer[s.pos] = (byte) readSymbol(s.hGroup0, s.literalTree, s); + s.pos++; s.j++; - if (s.pos++ == ringBufferMask) { + if (s.pos >= fence) { s.nextRunningState = INSERT_LOOP; - s.bytesToWrite = s.ringBufferSize; - s.bytesWritten = 0; - s.runningState = WRITE; + s.runningState = INIT_WRITE; break; } } @@ -813,12 +819,11 @@ final class Decode { prevByte1 = readSymbol( s.hGroup0, s.hGroup0[literalTreeIndex], s); ringBuffer[s.pos] = (byte) prevByte1; + s.pos++; s.j++; - if (s.pos++ == ringBufferMask) { + if (s.pos >= fence) { s.nextRunningState = INSERT_LOOP; - s.bytesToWrite = s.ringBufferSize; - s.bytesWritten = 0; - s.runningState = WRITE; + s.runningState = INIT_WRITE; break; } } @@ -868,7 +873,6 @@ final class Decode { s.maxDistance = s.maxBackwardDistance; } - s.copyDst = s.pos; if (s.distance > s.maxDistance) { s.runningState = TRANSFORM; continue; @@ -907,12 +911,11 @@ final class Decode { ringBuffer[s.pos] = ringBuffer[(s.pos - s.distance) & ringBufferMask]; s.metaBlockLength--; + s.pos++; s.j++; - if (s.pos++ == ringBufferMask) { + if (s.pos >= fence) { s.nextRunningState = COPY_LOOP; - s.bytesToWrite = s.ringBufferSize; - s.bytesWritten = 0; - s.runningState = WRITE; + s.runningState = INIT_WRITE; break; } } @@ -933,16 +936,13 @@ final class Decode { int transformIdx = wordId >>> shift; offset += wordIdx * s.copyLength; if (transformIdx < Transform.NUM_TRANSFORMS) { - int len = Transform.transformDictionaryWord(ringBuffer, s.copyDst, + int len = Transform.transformDictionaryWord(ringBuffer, s.pos, Dictionary.getData(), offset, s.copyLength, transformIdx); - s.copyDst += len; s.pos += len; s.metaBlockLength -= len; - if (s.copyDst >= s.ringBufferSize) { - s.nextRunningState = COPY_WRAP_BUFFER; - s.bytesToWrite = s.ringBufferSize; - s.bytesWritten = 0; - s.runningState = WRITE; + if (s.pos >= fence) { + s.nextRunningState = MAIN_LOOP; + s.runningState = INIT_WRITE; continue; } } else { @@ -954,11 +954,6 @@ final class Decode { s.runningState = MAIN_LOOP; continue; - case COPY_WRAP_BUFFER: - Utils.copyBytesWithin(ringBuffer, 0, s.ringBufferSize, s.copyDst); - s.runningState = MAIN_LOOP; - continue; - case READ_METADATA: while (s.metaBlockLength > 0) { BitReader.readMoreInput(s); @@ -975,6 +970,10 @@ final class Decode { copyUncompressedData(s); continue; + case INIT_WRITE: + s.ringBufferBytesReady = Math.min(s.pos, s.ringBufferSize); + s.runningState = WRITE; + // fall through case WRITE: if (writeRingBuffer(s) == 0) { // Output buffer is full. @@ -983,7 +982,14 @@ final class Decode { if (s.pos >= s.maxBackwardDistance) { s.maxDistance = s.maxBackwardDistance; } - s.pos &= ringBufferMask; + // Wrap the ringBuffer. + if (s.pos >= s.ringBufferSize) { + if (s.pos > s.ringBufferSize) { + Utils.copyBytesWithin(ringBuffer, 0, s.ringBufferSize, s.pos); + } + s.pos &= ringBufferMask; + s.ringBufferBytesWritten = 0; + } s.runningState = s.nextRunningState; continue; |