/*
* Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
*
* 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 Git Development Community 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.spearce.jgit.lib;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.security.MessageDigest;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
import org.spearce.jgit.errors.ObjectWritingException;
/**
* A class for writing loose objects.
*/
public class ObjectWriter {
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");
private final Repository r;
private final byte[] buf;
private final MessageDigest md;
private final Deflater def;
/**
* Construct an Object writer for the specified repository
* @param d
*/
public ObjectWriter(final Repository d) {
r = d;
buf = new byte[8192];
md = Constants.newMessageDigest();
def = new Deflater(r.getConfig().getCore().getCompression());
}
/**
* Write a blob with the specified data
*
* @param b bytes of the blob
* @return SHA-1 of the blob
* @throws IOException
*/
public ObjectId writeBlob(final byte[] b) throws IOException {
return writeBlob(b.length, new ByteArrayInputStream(b));
}
/**
* Write a blob with the data in the specified file
*
* @param f
* a file containing blob data
* @return SHA-1 of the blob
* @throws IOException
*/
public ObjectId writeBlob(final File f) throws IOException {
final FileInputStream is = new FileInputStream(f);
try {
return writeBlob(f.length(), is);
} finally {
is.close();
}
}
/**
* Write a blob with data from a stream
*
* @param len
* number of bytes to consume from the stream
* @param is
* stream with blob data
* @return SHA-1 of the blob
* @throws IOException
*/
public ObjectId writeBlob(final long len, final InputStream is)
throws IOException {
return writeObject(Constants.OBJ_BLOB, len, is, true);
}
/**
* Write a Tree to the object database.
*
* @param t
* Tree
* @return SHA-1 of the tree
* @throws IOException
*/
public ObjectId writeTree(final Tree t) throws IOException {
final ByteArrayOutputStream o = new ByteArrayOutputStream();
final TreeEntry[] items = t.members();
for (int k = 0; k < items.length; k++) {
final TreeEntry e = items[k];
final ObjectId id = e.getId();
if (id == null)
throw new ObjectWritingException("Object at path \""
+ e.getFullName() + "\" does not have an id assigned."
+ " All object ids must be assigned prior"
+ " to writing a tree.");
e.getMode().copyTo(o);
o.write(' ');
o.write(e.getNameUTF8());
o.write(0);
id.copyRawTo(o);
}
return writeCanonicalTree(o.toByteArray());
}
/**
* Write a canonical tree to the object database.
*
* @param b
* the canonical encoding of the tree object.
* @return SHA-1 of the tree
* @throws IOException
*/
public ObjectId writeCanonicalTree(final byte[] b) throws IOException {
return writeTree(b.length, new ByteArrayInputStream(b));
}
private ObjectId writeTree(final long len, final InputStream is)
throws IOException {
return writeObject(Constants.OBJ_TREE, len, is, true);
}
/**
* Write a Commit to the object database
*
* @param c
* Commit to store
* @return SHA-1 of the commit
* @throws IOException
*/
public ObjectId writeCommit(final Commit c) throws IOException {
final ByteArrayOutputStream os = new ByteArrayOutputStream();
String encoding = c.getEncoding();
if (encoding == null)
encoding = Constants.CHARACTER_ENCODING;
final OutputStreamWriter w = new OutputStreamWriter(os, encoding);
os.write(htree);
os.write(' ');
c.getTreeId().copyTo(os);
os.write('\n');
ObjectId[] ps = c.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(c.getAuthor().toExternalString());
w.flush();
os.write('\n');
os.write(hcommitter);
os.write(' ');
w.write(c.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(c.getMessage());
w.flush();
return writeCommit(os.toByteArray());
}
private ObjectId writeTag(final byte[] b) throws IOException {
return writeTag(b.length, new ByteArrayInputStream(b));
}
/**
* Write an annotated Tag to the object database
*
* @param c
* Tag
* @return SHA-1 of the tag
* @throws IOException
*/
public ObjectId writeTag(final Tag c) throws IOException {
final ByteArrayOutputStream os = new ByteArrayOutputStream();
final OutputStreamWriter w = new OutputStreamWriter(os,
Constants.CHARSET);
w.write("object ");
c.getObjId().copyTo(w);
w.write('\n');
w.write("type ");
w.write(c.getType());
w.write("\n");
w.write("tag ");
w.write(c.getTag());
w.write("\n");
w.write("tagger ");
w.write(c.getAuthor().toExternalString());
w.write('\n');
w.write('\n');
w.write(c.getMessage());
w.close();
return writeTag(os.toByteArray());
}
private ObjectId writeCommit(final byte[] b) throws IOException {
return writeCommit(b.length, new ByteArrayInputStream(b));
}
private ObjectId writeCommit(final long len, final InputStream is)
throws IOException {
return writeObject(Constants.OBJ_COMMIT, len, is, true);
}
private ObjectId writeTag(final long len, final InputStream is)
throws IOException {
return writeObject(Constants.OBJ_TAG, len, is, true);
}
/**
* Compute the SHA-1 of a blob without creating an object. This is for
* figuring out if we already have a blob or not.
*
* @param len number of bytes to consume
* @param is stream for read blob data from
* @return SHA-1 of a looked for blob
* @throws IOException
*/
public ObjectId computeBlobSha1(final long len, final InputStream is)
throws IOException {
return writeObject(Constants.OBJ_BLOB, len, is, false);
}
ObjectId writeObject(final int type, long len, final InputStream is,
boolean store) throws IOException {
final File t;
final DeflaterOutputStream deflateStream;
final FileOutputStream fileStream;
ObjectId id = null;
if (store) {
t = File.createTempFile("noz", null, r.getObjectsDirectory());
fileStream = new FileOutputStream(t);
} else {
t = null;
fileStream = null;
}
md.reset();
if (store) {
def.reset();
deflateStream = new DeflaterOutputStream(fileStream, def);
} else
deflateStream = null;
try {
byte[] header;
int n;
header = Constants.encodedTypeString(type);
md.update(header);
if (deflateStream != null)
deflateStream.write(header);
md.update((byte) ' ');
if (deflateStream != null)
deflateStream.write((byte) ' ');
header = Constants.encodeASCII(len);
md.update(header);
if (deflateStream != null)
deflateStream.write(header);
md.update((byte) 0);
if (deflateStream != null)
deflateStream.write((byte) 0);
while (len > 0
&& (n = is.read(buf, 0, (int) Math.min(len, buf.length))) > 0) {
md.update(buf, 0, n);
if (deflateStream != null)
deflateStream.write(buf, 0, n);
len -= n;
}
if (len != 0)
throw new IOException("Input did not match supplied length. "
+ len + " bytes are missing.");
if (deflateStream != null ) {
deflateStream.close();
if (t != null)
t.setReadOnly();
}
id = ObjectId.fromRaw(md.digest());
} finally {
if (id == null && deflateStream != null) {
try {
deflateStream.close();
} finally {
t.delete();
}
}
}
if (t == null)
return id;
if (r.hasObject(id)) {
// Object is already in the repository so remove
// the temporary file.
//
t.delete();
} else {
final File o = r.toFile(id);
if (!t.renameTo(o)) {
// Maybe the directory doesn't exist yet as the object
// directories are always lazily created. Note that we
// try the rename first as the directory likely does exist.
//
o.getParentFile().mkdir();
if (!t.renameTo(o)) {
if (!r.hasObject(id)) {
// The object failed to be renamed into its proper
// location and it doesn't exist in the repository
// either. We really don't know what went wrong, so
// fail.
//
t.delete();
throw new ObjectWritingException("Unable to"
+ " create new object: " + o);
}
}
}
}
return id;
}
}