diff options
Diffstat (limited to 'src/org/tukaani/xz/LZMAOutputStream.java')
| -rw-r--r-- | src/org/tukaani/xz/LZMAOutputStream.java | 58 |
1 files changed, 45 insertions, 13 deletions
diff --git a/src/org/tukaani/xz/LZMAOutputStream.java b/src/org/tukaani/xz/LZMAOutputStream.java index 298e1ed..a9f1918 100644 --- a/src/org/tukaani/xz/LZMAOutputStream.java +++ b/src/org/tukaani/xz/LZMAOutputStream.java @@ -30,7 +30,8 @@ public class LZMAOutputStream extends FinishableOutputStream { private final int props; private final boolean useEndMarker; - private long uncompressedSize = 0; + private final long expectedUncompressedSize; + private long currentUncompressedSize = 0; private boolean finished = false; private IOException exception = null; @@ -38,12 +39,19 @@ public class LZMAOutputStream extends FinishableOutputStream { private final byte[] tempBuf = new byte[1]; private LZMAOutputStream(OutputStream out, LZMA2Options options, - boolean useHeader, boolean useEndMarker) + boolean useHeader, boolean useEndMarker, + long expectedUncompressedSize) throws IOException { if (out == null) throw new NullPointerException(); + // -1 indicates unknown and >= 0 are for known sizes. + if (expectedUncompressedSize < -1) + throw new IllegalArgumentException( + "Invalid expected input size (less than -1)"); + this.useEndMarker = useEndMarker; + this.expectedUncompressedSize = expectedUncompressedSize; this.out = out; rc = new RangeEncoderToStream(out); @@ -70,22 +78,31 @@ public class LZMAOutputStream extends FinishableOutputStream { props = (options.getPb() * 5 + options.getLp()) * 9 + options.getLc(); if (useHeader) { + // Props byte stores lc, lp, and pb. out.write(props); + // Dictionary size is stored as a 32-bit unsigned little endian + // integer. for (int i = 0; i < 4; ++i) { out.write(dictSize & 0xFF); dictSize >>>= 8; } + // Uncompressed size is stored as a 64-bit unsigned little endian + // integer. The max value (-1 in two's complement) indicates + // unknown size. for (int i = 0; i < 8; ++i) - out.write(0xFF); + out.write((int)(expectedUncompressedSize >>> (8 * i)) & 0xFF); } } /** * Creates a new compressor for the legacy .lzma file format. - * The files will always use the end of stream marker and thus - * will not have the uncompressed size stored in the header. + * <p> + * If the uncompressed size of the input data is known, it will be stored + * in the .lzma header and no end of stream marker will be used. Otherwise + * the header will indicate unknown uncompressed size and the end of stream + * marker will be used. * <p> * Note that a preset dictionary cannot be used in .lzma files but * it can be used for raw LZMA streams. @@ -96,18 +113,22 @@ public class LZMAOutputStream extends FinishableOutputStream { * @param options LZMA compression options; the same class * is used here as is for LZMA2 * + * @param inputSize uncompressed size of the data to be compressed; + * use <code>-1</code> when unknown + * * @throws IOException may be thrown from <code>out</code> */ - public LZMAOutputStream(OutputStream out, LZMA2Options options) + public LZMAOutputStream(OutputStream out, LZMA2Options options, + long inputSize) throws IOException { - this(out, options, true, true); + this(out, options, true, inputSize == -1, inputSize); } /** * Creates a new compressor for raw LZMA (also known as LZMA1) stream. * <p> * Raw LZMA streams can be encoded with or without end of stream marker. - * When decompressing the stream, one must if the end marker was used + * When decompressing the stream, one must know if the end marker was used * and tell it to the decompressor. If the end marker wasn't used, the * decompressor will also need to know the uncompressed size. * @@ -124,7 +145,7 @@ public class LZMAOutputStream extends FinishableOutputStream { */ public LZMAOutputStream(OutputStream out, LZMA2Options options, boolean useEndMarker) throws IOException { - this(out, options, false, useEndMarker); + this(out, options, false, useEndMarker, -1); } /** @@ -142,7 +163,7 @@ public class LZMAOutputStream extends FinishableOutputStream { * the end of stream marker. */ public long getUncompressedSize() { - return uncompressedSize; + return currentUncompressedSize; } public void write(int b) throws IOException { @@ -160,7 +181,12 @@ public class LZMAOutputStream extends FinishableOutputStream { if (finished) throw new XZIOException("Stream finished or closed"); - uncompressedSize += len; + if (expectedUncompressedSize != -1 + && expectedUncompressedSize - currentUncompressedSize < len) + throw new XZIOException("Expected uncompressed input size (" + + expectedUncompressedSize + " bytes) was exceeded"); + + currentUncompressedSize += len; try { while (len > 0) { @@ -190,9 +216,15 @@ public class LZMAOutputStream extends FinishableOutputStream { if (exception != null) throw exception; - lz.setFinishing(); - try { + if (expectedUncompressedSize != -1 + && expectedUncompressedSize != currentUncompressedSize) + throw new XZIOException("Expected uncompressed size (" + + expectedUncompressedSize + ") doesn't equal " + + "the number of bytes written to the stream (" + + currentUncompressedSize + ")"); + + lz.setFinishing(); lzma.encodeForLZMA1(); if (useEndMarker) |