From c27e1daa55255416d93e3a019f556f0ca90fd410 Mon Sep 17 00:00:00 2001 From: "Shawn O. Pearce" Date: Tue, 2 Nov 2010 14:12:00 -0700 Subject: [PATCH] Refactor tree entry formatting into a common class Instead of hiding this logic inside of DirCacheTree and the legacy Tree type, pull it into a common place where we can reuse it by creating tree records in a buffer that can be passed directly into the ObjectInserter. This allows us to avoid some copying, as the inserter can be given the internal buffer of the formatter. Because we trust these two callers to feed us records in the proper order, without '/' in the names, and without duplicate names in the same tree, we don't do any validation inside of the formatter itself. To protect themselves from making ordering errors, developers should continue to use DirCache to process edits to source code trees. Change-Id: Idf7f10e736d4a44ccdf8afe060535d7b0554a92f Signed-off-by: Shawn O. Pearce --- .../eclipse/jgit/dircache/DirCacheTree.java | 35 +- .../src/org/eclipse/jgit/lib/FileMode.java | 17 + .../src/org/eclipse/jgit/lib/Tree.java | 11 +- .../org/eclipse/jgit/lib/TreeFormatter.java | 333 ++++++++++++++++++ 4 files changed, 364 insertions(+), 32 deletions(-) create mode 100644 org.eclipse.jgit/src/org/eclipse/jgit/lib/TreeFormatter.java diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheTree.java b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheTree.java index e04b797ab..4d97e7cd8 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheTree.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheTree.java @@ -44,9 +44,9 @@ package org.eclipse.jgit.dircache; -import static org.eclipse.jgit.lib.Constants.OBJECT_ID_LENGTH; +import static org.eclipse.jgit.lib.FileMode.TREE; +import static org.eclipse.jgit.lib.TreeFormatter.entrySize; -import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; import java.nio.ByteBuffer; @@ -55,9 +55,9 @@ import java.util.Comparator; import org.eclipse.jgit.errors.UnmergedPathException; import org.eclipse.jgit.lib.Constants; -import org.eclipse.jgit.lib.FileMode; import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.lib.ObjectInserter; +import org.eclipse.jgit.lib.TreeFormatter; import org.eclipse.jgit.util.MutableInteger; import org.eclipse.jgit.util.RawParseUtils; @@ -315,8 +315,8 @@ public class DirCacheTree { throws UnmergedPathException, IOException { if (id == null) { final int endIdx = cIdx + entrySpan; - final int size = computeSize(cache, cIdx, pathOffset, ow); - final ByteArrayOutputStream out = new ByteArrayOutputStream(size); + final TreeFormatter fmt = new TreeFormatter(computeSize(cache, + cIdx, pathOffset, ow)); int childIdx = 0; int entryIdx = cIdx; @@ -326,27 +326,19 @@ public class DirCacheTree { if (childIdx < childCnt) { final DirCacheTree st = children[childIdx]; if (st.contains(ep, pathOffset, ep.length)) { - FileMode.TREE.copyTo(out); - out.write(' '); - out.write(st.encodedName); - out.write(0); - st.id.copyRawTo(out); - + fmt.append(st.encodedName, TREE, st.id); entryIdx += st.entrySpan; childIdx++; continue; } } - e.getFileMode().copyTo(out); - out.write(' '); - out.write(ep, pathOffset, ep.length - pathOffset); - out.write(0); - out.write(e.idBuffer(), e.idOffset(), OBJECT_ID_LENGTH); + fmt.append(ep, pathOffset, ep.length - pathOffset, e + .getFileMode(), e.idBuffer(), e.idOffset()); entryIdx++; } - id = ow.insert(Constants.OBJ_TREE, out.toByteArray()); + id = fmt.insert(ow); } return id; } @@ -371,9 +363,7 @@ public class DirCacheTree { final int stOffset = pathOffset + st.nameLength() + 1; st.writeTree(cache, entryIdx, stOffset, ow); - size += FileMode.TREE.copyToLength(); - size += st.nameLength(); - size += OBJECT_ID_LENGTH + 2; + size += entrySize(TREE, st.nameLength()); entryIdx += st.entrySpan; childIdx++; @@ -381,10 +371,7 @@ public class DirCacheTree { } } - final FileMode mode = e.getFileMode(); - size += mode.copyToLength(); - size += ep.length - pathOffset; - size += OBJECT_ID_LENGTH + 2; + size += entrySize(e.getFileMode(), ep.length - pathOffset); entryIdx++; } diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/FileMode.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/FileMode.java index 43e4dd9c1..f295f5b72 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/FileMode.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/FileMode.java @@ -222,6 +222,23 @@ public abstract class FileMode { os.write(octalBytes); } + /** + * Copy this mode as a sequence of octal US-ASCII bytes. + * + * The mode is copied as a sequence of octal digits using the US-ASCII + * character encoding. The sequence does not use a leading '0' prefix to + * indicate octal notation. This method is suitable for generation of a mode + * string within a GIT tree object. + * + * @param buf + * buffer to copy the mode to. + * @param ptr + * position within {@code buf} for first digit. + */ + public void copyTo(byte[] buf, int ptr) { + System.arraycopy(octalBytes, 0, buf, ptr, octalBytes.length); + } + /** * @return the number of bytes written by {@link #copyTo(OutputStream)}. */ diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Tree.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Tree.java index 2eb578b88..06ef42997 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Tree.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Tree.java @@ -45,7 +45,6 @@ package org.eclipse.jgit.lib; -import java.io.ByteArrayOutputStream; import java.io.IOException; import java.text.MessageFormat; @@ -614,20 +613,16 @@ public class Tree extends TreeEntry implements Treeish { * the tree cannot be loaded, or its not in a writable state. */ public byte[] format() throws IOException { - ByteArrayOutputStream o = new ByteArrayOutputStream(); + TreeFormatter fmt = new TreeFormatter(); for (TreeEntry e : 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); + fmt.append(e.getNameUTF8(), e.getMode(), id); } - return o.toByteArray(); + return fmt.toByteArray(); } public String toString() { diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/TreeFormatter.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/TreeFormatter.java new file mode 100644 index 000000000..e14e81f6e --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/TreeFormatter.java @@ -0,0 +1,333 @@ +/* + * Copyright (C) 2010, 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 static org.eclipse.jgit.lib.Constants.OBJECT_ID_LENGTH; +import static org.eclipse.jgit.lib.Constants.OBJ_TREE; +import static org.eclipse.jgit.lib.Constants.encode; +import static org.eclipse.jgit.lib.FileMode.GITLINK; +import static org.eclipse.jgit.lib.FileMode.REGULAR_FILE; +import static org.eclipse.jgit.lib.FileMode.TREE; + +import java.io.IOException; + +import org.eclipse.jgit.revwalk.RevBlob; +import org.eclipse.jgit.revwalk.RevCommit; +import org.eclipse.jgit.revwalk.RevTree; +import org.eclipse.jgit.util.TemporaryBuffer; + +/** + * Mutable formatter to construct a single tree object. + * + * This formatter does not process subtrees. Callers must handle creating each + * subtree on their own. + * + * To maintain good performance for bulk operations, this formatter does not + * validate its input. Callers are responsible for ensuring the resulting tree + * object is correctly well formed by writing entries in the correct order. + */ +public class TreeFormatter { + /** + * Compute the size of a tree entry record. + * + * This method can be used to estimate the correct size of a tree prior to + * allocating a formatter. Getting the size correct at allocation time + * ensures the internal buffer is sized correctly, reducing copying. + * + * @param mode + * the mode the entry will have. + * @param nameLen + * the length of the name, in bytes. + * @return the length of the record. + */ + public static int entrySize(FileMode mode, int nameLen) { + return mode.copyToLength() + nameLen + OBJECT_ID_LENGTH + 2; + } + + private byte[] buf; + + private int ptr; + + private TemporaryBuffer.Heap overflowBuffer; + + /** Create an empty formatter with a default buffer size. */ + public TreeFormatter() { + this(8192); + } + + /** + * Create an empty formatter with the specified buffer size. + * + * @param size + * estimated size of the tree, in bytes. Callers can use + * {@link #entrySize(FileMode, int)} to estimate the size of each + * entry in advance of allocating the formatter. + */ + public TreeFormatter(int size) { + buf = new byte[size]; + } + + /** + * Add a link to a submodule commit, mode is {@link #GITLINK}. + * + * @param name + * name of the entry. + * @param commit + * the ObjectId to store in this entry. + */ + public void append(String name, RevCommit commit) { + append(name, GITLINK, commit); + } + + /** + * Add a subtree, mode is {@link #TREE}. + * + * @param name + * name of the entry. + * @param tree + * the ObjectId to store in this entry. + */ + public void append(String name, RevTree tree) { + append(name, TREE, tree); + } + + /** + * Add a regular file, mode is {@link #REGULAR_FILE}. + * + * @param name + * name of the entry. + * @param blob + * the ObjectId to store in this entry. + */ + public void append(String name, RevBlob blob) { + append(name, REGULAR_FILE, blob); + } + + /** + * Append any entry to the tree. + * + * @param name + * name of the entry. + * @param mode + * mode describing the treatment of {@code id}. + * @param id + * the ObjectId to store in this entry. + */ + public void append(String name, FileMode mode, AnyObjectId id) { + append(encode(name), mode, id); + } + + /** + * Append any entry to the tree. + * + * @param name + * name of the entry. The name should be UTF-8 encoded, but file + * name encoding is not a well defined concept in Git. + * @param mode + * mode describing the treatment of {@code id}. + * @param id + * the ObjectId to store in this entry. + */ + public void append(byte[] name, FileMode mode, AnyObjectId id) { + append(name, 0, name.length, mode, id); + } + + /** + * Append any entry to the tree. + * + * @param nameBuf + * buffer holding the name of the entry. The name should be UTF-8 + * encoded, but file name encoding is not a well defined concept + * in Git. + * @param namePos + * first position within {@code nameBuf} of the name data. + * @param nameLen + * number of bytes from {@code nameBuf} to use as the name. + * @param mode + * mode describing the treatment of {@code id}. + * @param id + * the ObjectId to store in this entry. + */ + public void append(byte[] nameBuf, int namePos, int nameLen, FileMode mode, + AnyObjectId id) { + if (fmtBuf(nameBuf, namePos, nameLen, mode)) { + id.copyRawTo(buf, ptr); + ptr += OBJECT_ID_LENGTH; + + } else { + try { + fmtOverflowBuffer(nameBuf, namePos, nameLen, mode); + id.copyRawTo(overflowBuffer); + } catch (IOException badBuffer) { + // This should never occur. + throw new RuntimeException(badBuffer); + } + } + } + + /** + * Append any entry to the tree. + * + * @param nameBuf + * buffer holding the name of the entry. The name should be UTF-8 + * encoded, but file name encoding is not a well defined concept + * in Git. + * @param namePos + * first position within {@code nameBuf} of the name data. + * @param nameLen + * number of bytes from {@code nameBuf} to use as the name. + * @param mode + * mode describing the treatment of {@code id}. + * @param idBuf + * buffer holding the raw ObjectId of the entry. + * @param idPos + * first position within {@code idBuf} to copy the id from. + */ + public void append(byte[] nameBuf, int namePos, int nameLen, FileMode mode, + byte[] idBuf, int idPos) { + if (fmtBuf(nameBuf, namePos, nameLen, mode)) { + System.arraycopy(idBuf, idPos, buf, ptr, OBJECT_ID_LENGTH); + ptr += OBJECT_ID_LENGTH; + + } else { + try { + fmtOverflowBuffer(nameBuf, namePos, nameLen, mode); + overflowBuffer.write(idBuf, idPos, OBJECT_ID_LENGTH); + } catch (IOException badBuffer) { + // This should never occur. + throw new RuntimeException(badBuffer); + } + } + } + + private boolean fmtBuf(byte[] nameBuf, int namePos, int nameLen, + FileMode mode) { + if (buf == null || buf.length < ptr + entrySize(mode, nameLen)) + return false; + + mode.copyTo(buf, ptr); + ptr += mode.copyToLength(); + buf[ptr++] = ' '; + + System.arraycopy(nameBuf, namePos, buf, ptr, nameLen); + ptr += nameLen; + buf[ptr++] = 0; + return true; + } + + private void fmtOverflowBuffer(byte[] nameBuf, int namePos, int nameLen, + FileMode mode) throws IOException { + if (buf != null) { + overflowBuffer = new TemporaryBuffer.Heap(Integer.MAX_VALUE); + overflowBuffer.write(buf, 0, ptr); + buf = null; + } + + mode.copyTo(overflowBuffer); + overflowBuffer.write((byte) ' '); + overflowBuffer.write(nameBuf, namePos, nameLen); + overflowBuffer.write((byte) 0); + } + + /** + * Compute the current tree's ObjectId. + * + * @return computed ObjectId of the tree + */ + public ObjectId getTreeId() { + final ObjectInserter.Formatter fmt = new ObjectInserter.Formatter(); + if (buf != null) + return fmt.idFor(OBJ_TREE, buf, 0, ptr); + + try { + final long len = overflowBuffer.length(); + return fmt.idFor(OBJ_TREE, len, overflowBuffer.openInputStream()); + } catch (IOException err) { + // This should never happen, its read failure on a byte array. + throw new RuntimeException(err); + } + } + + /** + * Insert this tree and obtain its ObjectId. + * + * @param ins + * the inserter to store the tree. + * @return computed ObjectId of the tree + * @throws IOException + * the tree could not be stored. + */ + public ObjectId insert(ObjectInserter ins) throws IOException { + if (buf != null) + return ins.insert(OBJ_TREE, buf, 0, ptr); + + final long len = overflowBuffer.length(); + return ins.insert(OBJ_TREE, len, overflowBuffer.openInputStream()); + } + + /** + * Copy this formatter's buffer into a byte array. + * + * This method is not efficient, as it needs to create a copy of the + * internal buffer in order to supply an array of the correct size to the + * caller. If the buffer is just to pass to an ObjectInserter, consider + * using {@link #insert(ObjectInserter)} instead. + * + * @return a copy of this formatter's buffer. + */ + public byte[] toByteArray() { + if (buf != null) { + byte[] r = new byte[ptr]; + System.arraycopy(buf, 0, r, 0, ptr); + return r; + } + + try { + return overflowBuffer.toByteArray(); + } catch (IOException err) { + // This should never happen, its read failure on a byte array. + throw new RuntimeException(err); + } + } +}