| /* |
| * Copyright (C) 2008-2009, Google Inc. |
| * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com> |
| * 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.internal.storage.pack; |
| |
| import static org.eclipse.jgit.lib.Constants.OBJ_OFS_DELTA; |
| import static org.eclipse.jgit.lib.Constants.OBJ_REF_DELTA; |
| import static org.eclipse.jgit.lib.Constants.PACK_SIGNATURE; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.security.MessageDigest; |
| |
| import org.eclipse.jgit.internal.JGitText; |
| import org.eclipse.jgit.lib.Constants; |
| import org.eclipse.jgit.lib.ProgressMonitor; |
| import org.eclipse.jgit.util.NB; |
| |
| /** |
| * Custom output stream to support |
| * {@link org.eclipse.jgit.internal.storage.pack.PackWriter}. |
| */ |
| public final class PackOutputStream extends OutputStream { |
| private static final int BYTES_TO_WRITE_BEFORE_CANCEL_CHECK = 128 * 1024; |
| |
| private final ProgressMonitor writeMonitor; |
| |
| private final OutputStream out; |
| |
| private final PackWriter packWriter; |
| |
| private final MessageDigest md = Constants.newMessageDigest(); |
| |
| private long count; |
| |
| private final byte[] headerBuffer = new byte[32]; |
| |
| private final byte[] copyBuffer = new byte[64 << 10]; |
| |
| private long checkCancelAt; |
| |
| private boolean ofsDelta; |
| |
| /** |
| * Initialize a pack output stream. |
| * <p> |
| * This constructor is exposed to support debugging the JGit library only. |
| * Application or storage level code should not create a PackOutputStream, |
| * instead use {@link org.eclipse.jgit.internal.storage.pack.PackWriter}, |
| * and let the writer create the stream. |
| * |
| * @param writeMonitor |
| * monitor to update on object output progress. |
| * @param out |
| * target stream to receive all object contents. |
| * @param pw |
| * packer that is going to perform the output. |
| */ |
| public PackOutputStream(final ProgressMonitor writeMonitor, |
| final OutputStream out, final PackWriter pw) { |
| this.writeMonitor = writeMonitor; |
| this.out = out; |
| this.packWriter = pw; |
| this.checkCancelAt = BYTES_TO_WRITE_BEFORE_CANCEL_CHECK; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public final void write(int b) throws IOException { |
| count++; |
| out.write(b); |
| md.update((byte) b); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public final void write(byte[] b, int off, int len) |
| throws IOException { |
| while (0 < len) { |
| final int n = Math.min(len, BYTES_TO_WRITE_BEFORE_CANCEL_CHECK); |
| count += n; |
| |
| if (checkCancelAt <= count) { |
| if (writeMonitor.isCancelled()) { |
| throw new IOException( |
| JGitText.get().packingCancelledDuringObjectsWriting); |
| } |
| checkCancelAt = count + BYTES_TO_WRITE_BEFORE_CANCEL_CHECK; |
| } |
| |
| out.write(b, off, n); |
| md.update(b, off, n); |
| |
| off += n; |
| len -= n; |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void flush() throws IOException { |
| out.flush(); |
| } |
| |
| final void writeFileHeader(int version, long objectCount) |
| throws IOException { |
| System.arraycopy(PACK_SIGNATURE, 0, headerBuffer, 0, 4); |
| NB.encodeInt32(headerBuffer, 4, version); |
| NB.encodeInt32(headerBuffer, 8, (int) objectCount); |
| write(headerBuffer, 0, 12); |
| ofsDelta = packWriter.isDeltaBaseAsOffset(); |
| } |
| |
| /** |
| * Write one object. |
| * |
| * If the object was already written, this method does nothing and returns |
| * quickly. This case occurs whenever an object was written out of order in |
| * order to ensure the delta base occurred before the object that needs it. |
| * |
| * @param otp |
| * the object to write. |
| * @throws java.io.IOException |
| * the object cannot be read from the object reader, or the |
| * output stream is no longer accepting output. Caller must |
| * examine the type of exception and possibly its message to |
| * distinguish between these cases. |
| */ |
| public final void writeObject(ObjectToPack otp) throws IOException { |
| packWriter.writeObject(this, otp); |
| } |
| |
| /** |
| * Commits the object header onto the stream. |
| * <p> |
| * Once the header has been written, the object representation must be fully |
| * output, or packing must abort abnormally. |
| * |
| * @param otp |
| * the object to pack. Header information is obtained. |
| * @param rawLength |
| * number of bytes of the inflated content. For an object that is |
| * in whole object format, this is the same as the object size. |
| * For an object that is in a delta format, this is the size of |
| * the inflated delta instruction stream. |
| * @throws java.io.IOException |
| * the underlying stream refused to accept the header. |
| */ |
| @SuppressWarnings("ShortCircuitBoolean") |
| public final void writeHeader(ObjectToPack otp, long rawLength) |
| throws IOException { |
| ObjectToPack b = otp.getDeltaBase(); |
| if (b != null && (b.isWritten() & ofsDelta)) { // Non-short-circuit logic is intentional |
| int n = objectHeader(rawLength, OBJ_OFS_DELTA, headerBuffer); |
| n = ofsDelta(count - b.getOffset(), headerBuffer, n); |
| write(headerBuffer, 0, n); |
| } else if (otp.isDeltaRepresentation()) { |
| int n = objectHeader(rawLength, OBJ_REF_DELTA, headerBuffer); |
| otp.getDeltaBaseId().copyRawTo(headerBuffer, n); |
| write(headerBuffer, 0, n + 20); |
| } else { |
| int n = objectHeader(rawLength, otp.getType(), headerBuffer); |
| write(headerBuffer, 0, n); |
| } |
| } |
| |
| private static final int objectHeader(long len, int type, byte[] buf) { |
| byte b = (byte) ((type << 4) | (len & 0x0F)); |
| int n = 0; |
| for (len >>>= 4; len != 0; len >>>= 7) { |
| buf[n++] = (byte) (0x80 | b); |
| b = (byte) (len & 0x7F); |
| } |
| buf[n++] = b; |
| return n; |
| } |
| |
| private static final int ofsDelta(long diff, byte[] buf, int p) { |
| p += ofsDeltaVarIntLength(diff); |
| int n = p; |
| buf[--n] = (byte) (diff & 0x7F); |
| while ((diff >>>= 7) != 0) |
| buf[--n] = (byte) (0x80 | (--diff & 0x7F)); |
| return p; |
| } |
| |
| private static final int ofsDeltaVarIntLength(long v) { |
| int n = 1; |
| for (; (v >>>= 7) != 0; n++) |
| --v; |
| return n; |
| } |
| |
| /** |
| * Get a temporary buffer writers can use to copy data with. |
| * |
| * @return a temporary buffer writers can use to copy data with. |
| */ |
| public final byte[] getCopyBuffer() { |
| return copyBuffer; |
| } |
| |
| void endObject() { |
| writeMonitor.update(1); |
| } |
| |
| /** |
| * Get total number of bytes written since stream start. |
| * |
| * @return total number of bytes written since stream start. |
| */ |
| public final long length() { |
| return count; |
| } |
| |
| /** @return obtain the current SHA-1 digest. */ |
| final byte[] getDigest() { |
| return md.digest(); |
| } |
| } |