/*
* Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
* Copyright (C) 2009, Google Inc.
* 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.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.text.MessageFormat;
import org.eclipse.jgit.JGitText;
import org.eclipse.jgit.errors.ObjectWritingException;
/**
* Inserts objects into an existing {@code ObjectDatabase}.
* <p>
* An inserter is not thread-safe. Individual threads should each obtain their
* own unique inserter instance, or must arrange for locking at a higher level
* to ensure the inserter is in use by no more than one thread at a time.
* <p>
* Objects written by an inserter may not be immediately visible for reading
* after the insert method completes. Callers must invoke either
* {@link #release()} or {@link #flush()} prior to updating references or
* otherwise making the returned ObjectIds visible to other code.
*/
public abstract class ObjectInserter {
private static final byte[] htree = Constants.encodeASCII("tree");
private static final byte[] hparent = Constants.encodeASCII("parent");
private static final byte[] hauthor = Constants.encodeASCII("author");
private static final byte[] hcommitter = Constants.encodeASCII("committer");
private static final byte[] hencoding = Constants.encodeASCII("encoding");
/** An inserter that can be used for formatting and id generation only. */
public static class Formatter extends ObjectInserter {
@Override
public ObjectId insert(int objectType, long length, InputStream in)
throws IOException {
throw new UnsupportedOperationException();
}
@Override
public void flush() throws IOException {
// Do nothing.
}
@Override
public void release() {
// Do nothing.
}
}
/** Digest to compute the name of an object. */
private final MessageDigest digest;
/** Temporary working buffer for streaming data through. */
private byte[] tempBuffer;
/** Create a new inserter for a database. */
protected ObjectInserter() {
digest = Constants.newMessageDigest();
}
/** @return a temporary byte array for use by the caller. */
protected byte[] buffer() {
if (tempBuffer == null)
tempBuffer = new byte[8192];
return tempBuffer;
}
/** @return digest to help compute an ObjectId */
protected MessageDigest digest() {
digest.reset();
return digest;
}
/**
* Compute the name of an object, without inserting it.
*
* @param type
* type code of the object to store.
* @param data
* complete content of the object.
* @return the name of the object.
*/
public ObjectId idFor(int type, byte[] data) {
return idFor(type, data, 0, data.length);
}
/**
* Compute the name of an object, without inserting it.
*
* @param type
* type code of the object to store.
* @param data
* complete content of the object.
* @param off
* first position within {@code data}.
* @param len
* number of bytes to copy from {@code data}.
* @return the name of the object.
*/
public ObjectId idFor(int type, byte[] data, int off, int len) {
MessageDigest md = digest();
md.update(Constants.encodedTypeString(type));
md.update((byte) ' ');
md.update(Constants.encodeASCII(len));
md.update((byte) 0);
md.update(data, off, len);
return ObjectId.fromRaw(md.digest());
}
/**
* Compute the name of an object, without inserting it.
*
* @param objectType
* type code of the object to store.
* @param length
* number of bytes to scan from {@code in}.
* @param in
* stream providing the object content. The caller is responsible
* for closing the stream.
* @return the name of the object.
* @throws IOException
* the source stream could not be read.
*/
public ObjectId idFor(int objectType, long length, InputStream in)
throws IOException {
MessageDigest md = digest();
md.update(Constants.encodedTypeString(objectType));
md.update((byte) ' ');
md.update(Constants.encodeASCII(length));
md.update((byte) 0);
byte[] buf = buffer();
while (length > 0) {
int n = in.read(buf, 0, (int) Math.min(length, buf.length));
if (n < 0)
throw new EOFException("Unexpected end of input");
md.update(buf, 0, n);
length -= n;
}
return ObjectId.fromRaw(md.digest());
}
/**
* Insert a single object into the store, returning its unique name.
*
* @param type
* type code of the object to store.
* @param data
* complete content of the object.
* @return the name of the object.
* @throws IOException
* the object could not be stored.
*/
public ObjectId insert(final int type, final byte[] data)
throws IOException {
return insert(type, data, 0, data.length);
}
/**
* Insert a single object into the store, returning its unique name.
*
* @param type
* type code of the object to store.
* @param data
* complete content of the object.
* @param off
* first position within {@code data}.
* @param len
* number of bytes to copy from {@code data}.
* @return the name of the object.
* @throws IOException
* the object could not be stored.
*/
public ObjectId insert(int type, byte[] data, int off, int len)
throws IOException {
return insert(type, len, new ByteArrayInputStream(data, off, len));
}
/**
* Insert a single object into the store, returning its unique name.
*
* @param objectType
* type code of the object to store.
* @param length
* number of bytes to copy from {@code in}.
* @param in
* stream providing the object content. The caller is responsible
* for closing the stream.
* @return the name of the object.
* @throws IOException
* the object could not be stored, or the source stream could
* not be read.
*/
public abstract ObjectId insert(int objectType, long length, InputStream in)
throws IOException;
/**
* Make all inserted objects visible.
* <p>
* The flush may take some period of time to make the objects available to
* other threads.
*
* @throws IOException
* the flush could not be completed; objects inserted thus far
* are in an indeterminate state.
*/
public abstract void flush() throws IOException;
/**
* Release any resources used by this inserter.
* <p>
* An inserter that has been released can be used again, but may need to be
* released after the subsequent usage.
*/
public abstract void release();
/**
* Format a Tree in canonical format.
*
* @param tree
* the tree object to format
* @return canonical encoding of the tree object.
* @throws IOException
* the tree cannot be loaded, or its not in a writable state.
*/
public final byte[] format(Tree tree) throws IOException {
ByteArrayOutputStream o = new ByteArrayOutputStream();
for (TreeEntry e : tree.members()) {
ObjectId id = e.getId();
if (id == null)
throw new ObjectWritingException(MessageFormat.format(JGitText
.get().objectAtPathDoesNotHaveId, e.getFullName()));
e.getMode().copyTo(o);
o.write(' ');
o.write(e.getNameUTF8());
o.write(0);
id.copyRawTo(o);
}
return o.toByteArray();
}
/**
* Format a Commit in canonical format.
*
* @param commit
* the commit object to format
* @return canonical encoding of the commit object.
* @throws UnsupportedEncodingException
* the commit's chosen encoding isn't supported on this JVM.
*/
public final byte[] format(Commit commit)
throws UnsupportedEncodingException {
String encoding = commit.getEncoding();
if (encoding == null)
encoding = Constants.CHARACTER_ENCODING;
ByteArrayOutputStream os = new ByteArrayOutputStream();
OutputStreamWriter w = new OutputStreamWriter(os, encoding);
try {
os.write(htree);
os.write(' ');
commit.getTreeId().copyTo(os);
os.write('\n');
ObjectId[] ps = commit.getParentIds();
for (int i = 0; i < ps.length; ++i) {
os.write(hparent);
os.write(' ');
ps[i].copyTo(os);
os.write('\n');
}
os.write(hauthor);
os.write(' ');
w.write(commit.getAuthor().toExternalString());
w.flush();
os.write('\n');
os.write(hcommitter);
os.write(' ');
w.write(commit.getCommitter().toExternalString());
w.flush();
os.write('\n');
if (!encoding.equals(Constants.CHARACTER_ENCODING)) {
os.write(hencoding);
os.write(' ');
os.write(Constants.encodeASCII(encoding));
os.write('\n');
}
os.write('\n');
w.write(commit.getMessage());
w.flush();
} catch (IOException err) {
// This should never occur, the only way to get it above is
// for the ByteArrayOutputStream to throw, but it doesn't.
//
throw new RuntimeException(err);
}
return os.toByteArray();
}
/**
* Format a Tag in canonical format.
*
* @param tag
* the tag object to format
* @return canonical encoding of the tag object.
*/
public final byte[] format(Tag tag) {
ByteArrayOutputStream os = new ByteArrayOutputStream();
OutputStreamWriter w = new OutputStreamWriter(os, Constants.CHARSET);
try {
w.write("object ");
tag.getObjId().copyTo(w);
w.write('\n');
w.write("type ");
w.write(tag.getType());
w.write("\n");
w.write("tag ");
w.write(tag.getTag());
w.write("\n");
w.write("tagger ");
w.write(tag.getAuthor().toExternalString());
w.write('\n');
w.write('\n');
w.write(tag.getMessage());
w.close();
} catch (IOException err) {
// This should never occur, the only way to get it above is
// for the ByteArrayOutputStream to throw, but it doesn't.
//
throw new RuntimeException(err);
}
return os.toByteArray();
}
}