- /*
- * 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.storage.pack;
-
- import java.io.IOException;
- import java.io.OutputStream;
- import java.security.MessageDigest;
- import java.util.zip.CRC32;
-
- import org.eclipse.jgit.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 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 CRC32 crc = new CRC32();
-
- private final MessageDigest md = Constants.newMessageDigest();
-
- private long count;
-
- private byte[] headerBuffer = new byte[32];
-
- private byte[] copyBuffer;
-
- private long checkCancelAt;
-
- /**
- * 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 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;
- }
-
- @Override
- public void write(final int b) throws IOException {
- count++;
- out.write(b);
- crc.update(b);
- md.update((byte) b);
- }
-
- @Override
- public void write(final 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);
- crc.update(b, off, n);
- md.update(b, off, n);
-
- off += n;
- len -= n;
- }
- }
-
- @Override
- public void flush() throws IOException {
- out.flush();
- }
-
- void writeFileHeader(int version, long objectCount) throws IOException {
- System.arraycopy(Constants.PACK_SIGNATURE, 0, headerBuffer, 0, 4);
- NB.encodeInt32(headerBuffer, 4, version);
- NB.encodeInt32(headerBuffer, 8, (int) objectCount);
- write(headerBuffer, 0, 12);
- }
-
- /**
- * 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 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 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 IOException
- * the underlying stream refused to accept the header.
- */
- public void writeHeader(ObjectToPack otp, long rawLength)
- throws IOException {
- if (otp.isDeltaRepresentation()) {
- if (packWriter.isDeltaBaseAsOffset()) {
- ObjectToPack baseInPack = otp.getDeltaBase();
- if (baseInPack != null && baseInPack.isWritten()) {
- final long start = count;
- int n = encodeTypeSize(Constants.OBJ_OFS_DELTA, rawLength);
- write(headerBuffer, 0, n);
-
- long offsetDiff = start - baseInPack.getOffset();
- n = headerBuffer.length - 1;
- headerBuffer[n] = (byte) (offsetDiff & 0x7F);
- while ((offsetDiff >>= 7) > 0)
- headerBuffer[--n] = (byte) (0x80 | (--offsetDiff & 0x7F));
- write(headerBuffer, n, headerBuffer.length - n);
- return;
- }
- }
-
- int n = encodeTypeSize(Constants.OBJ_REF_DELTA, rawLength);
- otp.getDeltaBaseId().copyRawTo(headerBuffer, n);
- write(headerBuffer, 0, n + Constants.OBJECT_ID_LENGTH);
- } else {
- int n = encodeTypeSize(otp.getType(), rawLength);
- write(headerBuffer, 0, n);
- }
- }
-
- private int encodeTypeSize(int type, long rawLength) {
- long nextLength = rawLength >>> 4;
- headerBuffer[0] = (byte) ((nextLength > 0 ? 0x80 : 0x00) | (type << 4) | (rawLength & 0x0F));
- rawLength = nextLength;
- int n = 1;
- while (rawLength > 0) {
- nextLength >>>= 7;
- headerBuffer[n++] = (byte) ((nextLength > 0 ? 0x80 : 0x00) | (rawLength & 0x7F));
- rawLength = nextLength;
- }
- return n;
- }
-
- /** @return a temporary buffer writers can use to copy data with. */
- public byte[] getCopyBuffer() {
- if (copyBuffer == null)
- copyBuffer = new byte[16 * 1024];
- return copyBuffer;
- }
-
- void endObject() {
- writeMonitor.update(1);
- }
-
- /** @return total number of bytes written since stream start. */
- long length() {
- return count;
- }
-
- /** @return obtain the current CRC32 register. */
- int getCRC32() {
- return (int) crc.getValue();
- }
-
- /** Reinitialize the CRC32 register for a new region. */
- void resetCRC32() {
- crc.reset();
- }
-
- /** @return obtain the current SHA-1 digest. */
- byte[] getDigest() {
- return md.digest();
- }
- }
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