| /* |
| * Copyright (C) 2008-2009, Google Inc. |
| * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com> |
| * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org> |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package org.eclipse.jgit.lib; |
| |
| import java.io.EOFException; |
| import java.io.File; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.io.RandomAccessFile; |
| import java.nio.MappedByteBuffer; |
| import java.nio.channels.FileChannel.MapMode; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.Iterator; |
| import java.util.zip.CRC32; |
| import java.util.zip.CheckedOutputStream; |
| import java.util.zip.DataFormatException; |
| |
| import org.eclipse.jgit.errors.CorruptObjectException; |
| import org.eclipse.jgit.errors.PackInvalidException; |
| import org.eclipse.jgit.errors.PackMismatchException; |
| import org.eclipse.jgit.util.IO; |
| import org.eclipse.jgit.util.NB; |
| import org.eclipse.jgit.util.RawParseUtils; |
| |
| /** |
| * A Git version 2 pack file representation. A pack file contains Git objects in |
| * delta packed format yielding high compression of lots of object where some |
| * objects are similar. |
| */ |
| public class PackFile implements Iterable<PackIndex.MutableEntry> { |
| /** Sorts PackFiles to be most recently created to least recently created. */ |
| public static Comparator<PackFile> SORT = new Comparator<PackFile>() { |
| public int compare(final PackFile a, final PackFile b) { |
| return b.packLastModified - a.packLastModified; |
| } |
| }; |
| |
| private final File idxFile; |
| |
| private final File packFile; |
| |
| final int hash; |
| |
| private RandomAccessFile fd; |
| |
| long length; |
| |
| private int activeWindows; |
| |
| private int activeCopyRawData; |
| |
| private int packLastModified; |
| |
| private volatile boolean invalid; |
| |
| private byte[] packChecksum; |
| |
| private PackIndex loadedIdx; |
| |
| private PackReverseIndex reverseIdx; |
| |
| /** |
| * Construct a reader for an existing, pre-indexed packfile. |
| * |
| * @param idxFile |
| * path of the <code>.idx</code> file listing the contents. |
| * @param packFile |
| * path of the <code>.pack</code> file holding the data. |
| */ |
| public PackFile(final File idxFile, final File packFile) { |
| this.idxFile = idxFile; |
| this.packFile = packFile; |
| this.packLastModified = (int) (packFile.lastModified() >> 10); |
| |
| // Multiply by 31 here so we can more directly combine with another |
| // value in WindowCache.hash(), without doing the multiply there. |
| // |
| hash = System.identityHashCode(this) * 31; |
| length = Long.MAX_VALUE; |
| } |
| |
| private synchronized PackIndex idx() throws IOException { |
| if (loadedIdx == null) { |
| if (invalid) |
| throw new PackInvalidException(packFile); |
| |
| try { |
| final PackIndex idx = PackIndex.open(idxFile); |
| |
| if (packChecksum == null) |
| packChecksum = idx.packChecksum; |
| else if (!Arrays.equals(packChecksum, idx.packChecksum)) |
| throw new PackMismatchException("Pack checksum mismatch"); |
| |
| loadedIdx = idx; |
| } catch (IOException e) { |
| invalid = true; |
| throw e; |
| } |
| } |
| return loadedIdx; |
| } |
| |
| final PackedObjectLoader resolveBase(final WindowCursor curs, final long ofs) |
| throws IOException { |
| return reader(curs, ofs); |
| } |
| |
| /** @return the File object which locates this pack on disk. */ |
| public File getPackFile() { |
| return packFile; |
| } |
| |
| /** |
| * Determine if an object is contained within the pack file. |
| * <p> |
| * For performance reasons only the index file is searched; the main pack |
| * content is ignored entirely. |
| * </p> |
| * |
| * @param id |
| * the object to look for. Must not be null. |
| * @return true if the object is in this pack; false otherwise. |
| * @throws IOException |
| * the index file cannot be loaded into memory. |
| */ |
| public boolean hasObject(final AnyObjectId id) throws IOException { |
| return idx().hasObject(id); |
| } |
| |
| /** |
| * Get an object from this pack. |
| * |
| * @param curs |
| * temporary working space associated with the calling thread. |
| * @param id |
| * the object to obtain from the pack. Must not be null. |
| * @return the object loader for the requested object if it is contained in |
| * this pack; null if the object was not found. |
| * @throws IOException |
| * the pack file or the index could not be read. |
| */ |
| public PackedObjectLoader get(final WindowCursor curs, final AnyObjectId id) |
| throws IOException { |
| final long offset = idx().findOffset(id); |
| return 0 < offset ? reader(curs, offset) : null; |
| } |
| |
| /** |
| * Close the resources utilized by this repository |
| */ |
| public void close() { |
| UnpackedObjectCache.purge(this); |
| WindowCache.purge(this); |
| synchronized (this) { |
| loadedIdx = null; |
| reverseIdx = null; |
| } |
| } |
| |
| /** |
| * Provide iterator over entries in associated pack index, that should also |
| * exist in this pack file. Objects returned by such iterator are mutable |
| * during iteration. |
| * <p> |
| * Iterator returns objects in SHA-1 lexicographical order. |
| * </p> |
| * |
| * @return iterator over entries of associated pack index |
| * |
| * @see PackIndex#iterator() |
| */ |
| public Iterator<PackIndex.MutableEntry> iterator() { |
| try { |
| return idx().iterator(); |
| } catch (IOException e) { |
| return Collections.<PackIndex.MutableEntry> emptyList().iterator(); |
| } |
| } |
| |
| /** |
| * Obtain the total number of objects available in this pack. This method |
| * relies on pack index, giving number of effectively available objects. |
| * |
| * @return number of objects in index of this pack, likewise in this pack |
| * @throws IOException |
| * the index file cannot be loaded into memory. |
| */ |
| long getObjectCount() throws IOException { |
| return idx().getObjectCount(); |
| } |
| |
| /** |
| * Search for object id with the specified start offset in associated pack |
| * (reverse) index. |
| * |
| * @param offset |
| * start offset of object to find |
| * @return object id for this offset, or null if no object was found |
| * @throws IOException |
| * the index file cannot be loaded into memory. |
| */ |
| ObjectId findObjectForOffset(final long offset) throws IOException { |
| return getReverseIdx().findObject(offset); |
| } |
| |
| final UnpackedObjectCache.Entry readCache(final long position) { |
| return UnpackedObjectCache.get(this, position); |
| } |
| |
| final void saveCache(final long position, final byte[] data, final int type) { |
| UnpackedObjectCache.store(this, position, data, type); |
| } |
| |
| final byte[] decompress(final long position, final int totalSize, |
| final WindowCursor curs) throws DataFormatException, IOException { |
| final byte[] dstbuf = new byte[totalSize]; |
| if (curs.inflate(this, position, dstbuf, 0) != totalSize) |
| throw new EOFException("Short compressed stream at " + position); |
| return dstbuf; |
| } |
| |
| final void copyRawData(final PackedObjectLoader loader, |
| final OutputStream out, final byte buf[], final WindowCursor curs) |
| throws IOException { |
| final long objectOffset = loader.objectOffset; |
| final long dataOffset = loader.dataOffset; |
| final int cnt = (int) (findEndOffset(objectOffset) - dataOffset); |
| final PackIndex idx = idx(); |
| |
| if (idx.hasCRC32Support()) { |
| final CRC32 crc = new CRC32(); |
| int headerCnt = (int) (dataOffset - objectOffset); |
| while (headerCnt > 0) { |
| final int toRead = Math.min(headerCnt, buf.length); |
| readFully(objectOffset, buf, 0, toRead, curs); |
| crc.update(buf, 0, toRead); |
| headerCnt -= toRead; |
| } |
| final CheckedOutputStream crcOut = new CheckedOutputStream(out, crc); |
| copyToStream(dataOffset, buf, cnt, crcOut, curs); |
| final long computed = crc.getValue(); |
| |
| final ObjectId id = findObjectForOffset(objectOffset); |
| final long expected = idx.findCRC32(id); |
| if (computed != expected) |
| throw new CorruptObjectException("Object at " + dataOffset |
| + " in " + getPackFile() + " has bad zlib stream"); |
| } else { |
| try { |
| curs.inflateVerify(this, dataOffset); |
| } catch (DataFormatException dfe) { |
| final CorruptObjectException coe; |
| coe = new CorruptObjectException("Object at " + dataOffset |
| + " in " + getPackFile() + " has bad zlib stream"); |
| coe.initCause(dfe); |
| throw coe; |
| } |
| copyToStream(dataOffset, buf, cnt, out, curs); |
| } |
| } |
| |
| boolean supportsFastCopyRawData() throws IOException { |
| return idx().hasCRC32Support(); |
| } |
| |
| boolean invalid() { |
| return invalid; |
| } |
| |
| private void readFully(final long position, final byte[] dstbuf, |
| int dstoff, final int cnt, final WindowCursor curs) |
| throws IOException { |
| if (curs.copy(this, position, dstbuf, dstoff, cnt) != cnt) |
| throw new EOFException(); |
| } |
| |
| private void copyToStream(long position, final byte[] buf, long cnt, |
| final OutputStream out, final WindowCursor curs) |
| throws IOException, EOFException { |
| while (cnt > 0) { |
| final int toRead = (int) Math.min(cnt, buf.length); |
| readFully(position, buf, 0, toRead, curs); |
| position += toRead; |
| cnt -= toRead; |
| out.write(buf, 0, toRead); |
| } |
| } |
| |
| synchronized void beginCopyRawData() throws IOException { |
| if (++activeCopyRawData == 1 && activeWindows == 0) |
| doOpen(); |
| } |
| |
| synchronized void endCopyRawData() { |
| if (--activeCopyRawData == 0 && activeWindows == 0) |
| doClose(); |
| } |
| |
| synchronized boolean beginWindowCache() throws IOException { |
| if (++activeWindows == 1) { |
| if (activeCopyRawData == 0) |
| doOpen(); |
| return true; |
| } |
| return false; |
| } |
| |
| synchronized boolean endWindowCache() { |
| final boolean r = --activeWindows == 0; |
| if (r && activeCopyRawData == 0) |
| doClose(); |
| return r; |
| } |
| |
| private void doOpen() throws IOException { |
| try { |
| if (invalid) |
| throw new PackInvalidException(packFile); |
| fd = new RandomAccessFile(packFile, "r"); |
| length = fd.length(); |
| onOpenPack(); |
| } catch (IOException ioe) { |
| openFail(); |
| throw ioe; |
| } catch (RuntimeException re) { |
| openFail(); |
| throw re; |
| } catch (Error re) { |
| openFail(); |
| throw re; |
| } |
| } |
| |
| private void openFail() { |
| activeWindows = 0; |
| activeCopyRawData = 0; |
| invalid = true; |
| doClose(); |
| } |
| |
| private void doClose() { |
| if (fd != null) { |
| try { |
| fd.close(); |
| } catch (IOException err) { |
| // Ignore a close event. We had it open only for reading. |
| // There should not be errors related to network buffers |
| // not flushed, etc. |
| } |
| fd = null; |
| } |
| } |
| |
| ByteArrayWindow read(final long pos, int size) throws IOException { |
| if (length < pos + size) |
| size = (int) (length - pos); |
| final byte[] buf = new byte[size]; |
| IO.readFully(fd.getChannel(), pos, buf, 0, size); |
| return new ByteArrayWindow(this, pos, buf); |
| } |
| |
| ByteWindow mmap(final long pos, int size) throws IOException { |
| if (length < pos + size) |
| size = (int) (length - pos); |
| |
| MappedByteBuffer map; |
| try { |
| map = fd.getChannel().map(MapMode.READ_ONLY, pos, size); |
| } catch (IOException ioe1) { |
| // The most likely reason this failed is the JVM has run out |
| // of virtual memory. We need to discard quickly, and try to |
| // force the GC to finalize and release any existing mappings. |
| // |
| System.gc(); |
| System.runFinalization(); |
| map = fd.getChannel().map(MapMode.READ_ONLY, pos, size); |
| } |
| |
| if (map.hasArray()) |
| return new ByteArrayWindow(this, pos, map.array()); |
| return new ByteBufferWindow(this, pos, map); |
| } |
| |
| private void onOpenPack() throws IOException { |
| final PackIndex idx = idx(); |
| final byte[] buf = new byte[20]; |
| |
| IO.readFully(fd.getChannel(), 0, buf, 0, 12); |
| if (RawParseUtils.match(buf, 0, Constants.PACK_SIGNATURE) != 4) |
| throw new IOException("Not a PACK file."); |
| final long vers = NB.decodeUInt32(buf, 4); |
| final long packCnt = NB.decodeUInt32(buf, 8); |
| if (vers != 2 && vers != 3) |
| throw new IOException("Unsupported pack version " + vers + "."); |
| |
| if (packCnt != idx.getObjectCount()) |
| throw new PackMismatchException("Pack object count mismatch:" |
| + " pack " + packCnt |
| + " index " + idx.getObjectCount() |
| + ": " + getPackFile()); |
| |
| IO.readFully(fd.getChannel(), length - 20, buf, 0, 20); |
| if (!Arrays.equals(buf, packChecksum)) |
| throw new PackMismatchException("Pack checksum mismatch:" |
| + " pack " + ObjectId.fromRaw(buf).name() |
| + " index " + ObjectId.fromRaw(idx.packChecksum).name() |
| + ": " + getPackFile()); |
| } |
| |
| private PackedObjectLoader reader(final WindowCursor curs, |
| final long objOffset) throws IOException { |
| long pos = objOffset; |
| int p = 0; |
| final byte[] ib = curs.tempId; |
| readFully(pos, ib, 0, 20, curs); |
| int c = ib[p++] & 0xff; |
| final int typeCode = (c >> 4) & 7; |
| long dataSize = c & 15; |
| int shift = 4; |
| while ((c & 0x80) != 0) { |
| c = ib[p++] & 0xff; |
| dataSize += (c & 0x7f) << shift; |
| shift += 7; |
| } |
| pos += p; |
| |
| switch (typeCode) { |
| case Constants.OBJ_COMMIT: |
| case Constants.OBJ_TREE: |
| case Constants.OBJ_BLOB: |
| case Constants.OBJ_TAG: |
| return new WholePackedObjectLoader(this, pos, objOffset, typeCode, |
| (int) dataSize); |
| |
| case Constants.OBJ_OFS_DELTA: { |
| readFully(pos, ib, 0, 20, curs); |
| p = 0; |
| c = ib[p++] & 0xff; |
| long ofs = c & 127; |
| while ((c & 128) != 0) { |
| ofs += 1; |
| c = ib[p++] & 0xff; |
| ofs <<= 7; |
| ofs += (c & 127); |
| } |
| return new DeltaOfsPackedObjectLoader(this, pos + p, objOffset, |
| (int) dataSize, objOffset - ofs); |
| } |
| case Constants.OBJ_REF_DELTA: { |
| readFully(pos, ib, 0, 20, curs); |
| return new DeltaRefPackedObjectLoader(this, pos + ib.length, |
| objOffset, (int) dataSize, ObjectId.fromRaw(ib)); |
| } |
| default: |
| throw new IOException("Unknown object type " + typeCode + "."); |
| } |
| } |
| |
| private long findEndOffset(final long startOffset) |
| throws IOException, CorruptObjectException { |
| final long maxOffset = length - 20; |
| return getReverseIdx().findNextOffset(startOffset, maxOffset); |
| } |
| |
| private synchronized PackReverseIndex getReverseIdx() throws IOException { |
| if (reverseIdx == null) |
| reverseIdx = new PackReverseIndex(idx()); |
| return reverseIdx; |
| } |
| } |