Repository: commons-compress Updated Branches: refs/heads/master 3baf454c2 -> 1d66f1208
Working version of deferred block decompression for skipped entries. Project: http://git-wip-us.apache.org/repos/asf/commons-compress/repo Commit: http://git-wip-us.apache.org/repos/asf/commons-compress/commit/a53ab172 Tree: http://git-wip-us.apache.org/repos/asf/commons-compress/tree/a53ab172 Diff: http://git-wip-us.apache.org/repos/asf/commons-compress/diff/a53ab172 Branch: refs/heads/master Commit: a53ab172b2a9b7c1a57be9f8d6dc82977af02bff Parents: deb891f Author: Dawid Weiss <dawid.we...@carrotsearch.com> Authored: Tue Feb 23 16:19:25 2016 +0100 Committer: Stefan Bodewig <bode...@apache.org> Committed: Wed Feb 24 15:42:19 2016 +0100 ---------------------------------------------------------------------- .../compress/archivers/sevenz/SevenZFile.java | 72 +++++++++++--------- 1 file changed, 41 insertions(+), 31 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/commons-compress/blob/a53ab172/src/main/java/org/apache/commons/compress/archivers/sevenz/SevenZFile.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/commons/compress/archivers/sevenz/SevenZFile.java b/src/main/java/org/apache/commons/compress/archivers/sevenz/SevenZFile.java index 90bda16..60ffea8 100644 --- a/src/main/java/org/apache/commons/compress/archivers/sevenz/SevenZFile.java +++ b/src/main/java/org/apache/commons/compress/archivers/sevenz/SevenZFile.java @@ -26,6 +26,7 @@ import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.RandomAccessFile; +import java.util.ArrayList; import java.util.Arrays; import java.util.BitSet; import java.util.LinkedList; @@ -74,9 +75,10 @@ public class SevenZFile implements Closeable { private int currentEntryIndex = -1; private int currentFolderIndex = -1; private InputStream currentFolderInputStream = null; - private InputStream currentEntryInputStream = null; private byte[] password; - + + private ArrayList<InputStream> deferredBlockStreams = new ArrayList<InputStream>(); + static final byte[] sevenZSignature = { (byte)'7', (byte)'z', (byte)0xBC, (byte)0xAF, (byte)0x27, (byte)0x1C }; @@ -809,17 +811,25 @@ public class SevenZFile implements Closeable { private void buildDecodingStream() throws IOException { final int folderIndex = archive.streamMap.fileFolderIndex[currentEntryIndex]; if (folderIndex < 0) { - currentEntryInputStream = new BoundedInputStream( - new ByteArrayInputStream(new byte[0]), 0); + deferredBlockStreams.clear(); + // TODO: previously it'd return an empty stream? + // new BoundedInputStream(new ByteArrayInputStream(new byte[0]), 0); return; } final SevenZArchiveEntry file = archive.files[currentEntryIndex]; if (currentFolderIndex == folderIndex) { + // (COMPRESS-320). + // The current entry is within the same (potentially opened) folder. The + // previous stream has to be fully decoded before we can start reading + // but don't do it eagerly -- if the user skips over the entire folder nothing + // is effectively decompressed. + // need to advance the folder input stream past the current file - drainPreviousEntry(); file.setContentMethods(archive.files[currentEntryIndex - 1].getContentMethods()); } else { + // We're opening a new folder. Discard any queued streams/ folder stream. currentFolderIndex = folderIndex; + deferredBlockStreams.clear(); if (currentFolderInputStream != null) { currentFolderInputStream.close(); currentFolderInputStream = null; @@ -831,26 +841,15 @@ public class SevenZFile implements Closeable { archive.streamMap.packStreamOffsets[firstPackStreamIndex]; currentFolderInputStream = buildDecoderStack(folder, folderOffset, firstPackStreamIndex, file); } - final InputStream fileStream = new BoundedInputStream( - currentFolderInputStream, file.getSize()); + + InputStream fileStream = new BoundedInputStream(currentFolderInputStream, file.getSize()); if (file.getHasCrc()) { - currentEntryInputStream = new CRC32VerifyingInputStream( - fileStream, file.getSize(), file.getCrcValue()); - } else { - currentEntryInputStream = fileStream; + fileStream = new CRC32VerifyingInputStream(fileStream, file.getSize(), file.getCrcValue()); } + deferredBlockStreams.add(fileStream); } - - private void drainPreviousEntry() throws IOException { - if (currentEntryInputStream != null) { - // return value ignored as IOUtils.skip ensures the stream is drained completely - IOUtils.skip(currentEntryInputStream, Long.MAX_VALUE); - currentEntryInputStream.close(); - currentEntryInputStream = null; - } - } - + private InputStream buildDecoderStack(final Folder folder, final long folderOffset, final int firstPackStreamIndex, SevenZArchiveEntry entry) throws IOException { file.seek(folderOffset); @@ -886,13 +885,27 @@ public class SevenZFile implements Closeable { * if an I/O error has occurred */ public int read() throws IOException { - if (currentEntryInputStream == null) { - throw new IllegalStateException("No current 7z entry"); - } - return currentEntryInputStream.read(); + return getCurrentStream().read(); } - /** + private InputStream getCurrentStream() throws IOException { + if (deferredBlockStreams.isEmpty()) { + throw new IllegalStateException("No current 7z entry (call getNextEntry() first)."); + } + + while (deferredBlockStreams.size() > 1) { + // In solid compression mode we need to decompress all leading folder' + // streams to get access to an entry. We defer this until really needed + // so that entire blocks can be skipped without wasting time for decompression. + InputStream stream = deferredBlockStreams.remove(0); + IOUtils.skip(stream, Long.MAX_VALUE); + stream.close(); + } + + return deferredBlockStreams.get(0); + } + + /** * Reads data into an array of bytes. * * @param b the array to write data to @@ -901,7 +914,7 @@ public class SevenZFile implements Closeable { * if an I/O error has occurred */ public int read(byte[] b) throws IOException { - return read(b, 0, b.length); + return read(b, 0, b.length); } /** @@ -915,10 +928,7 @@ public class SevenZFile implements Closeable { * if an I/O error has occurred */ public int read(byte[] b, int off, int len) throws IOException { - if (currentEntryInputStream == null) { - throw new IllegalStateException("No current 7z entry"); - } - return currentEntryInputStream.read(b, off, len); + return getCurrentStream().read(b, off, len); } private static long readUint64(final DataInput in) throws IOException {
