/*
* 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.dircache;
import java.io.IOException;
import java.util.Arrays;
import org.spearce.jgit.lib.AnyObjectId;
import org.spearce.jgit.lib.FileMode;
import org.spearce.jgit.lib.Repository;
import org.spearce.jgit.lib.WindowCursor;
import org.spearce.jgit.treewalk.AbstractTreeIterator;
import org.spearce.jgit.treewalk.CanonicalTreeParser;
import org.spearce.jgit.treewalk.TreeWalk;
/**
* Updates a {@link DirCache} by adding individual {@link DirCacheEntry}s.
* <p>
* A builder always starts from a clean slate and appends in every single
* <code>DirCacheEntry</code> which the final updated index must have to reflect
* its new content.
* <p>
* For maximum performance applications should add entries in path name order.
* Adding entries out of order is permitted, however a final sorting pass will
* be implicitly performed during {@link #finish()} to correct any out-of-order
* entries. Duplicate detection is also delayed until the sorting is complete.
*
* @see DirCacheEditor
*/
public class DirCacheBuilder extends BaseDirCacheEditor {
private boolean sorted;
/**
* Construct a new builder.
*
* @param dc
* the cache this builder will eventually update.
* @param ecnt
* estimated number of entries the builder will have upon
* completion. This sizes the initial entry table.
*/
protected DirCacheBuilder(final DirCache dc, final int ecnt) {
super(dc, ecnt);
}
/**
* Append one entry into the resulting entry list.
* <p>
* The entry is placed at the end of the entry list. If the entry causes the
* list to now be incorrectly sorted a final sorting phase will be
* automatically enabled within {@link #finish()}.
* <p>
* The internal entry table is automatically expanded if there is
* insufficient space for the new addition.
*
* @param newEntry
* the new entry to add.
*/
public void add(final DirCacheEntry newEntry) {
beforeAdd(newEntry);
fastAdd(newEntry);
}
/**
* Add a range of existing entries from the destination cache.
* <p>
* The entries are placed at the end of the entry list. If any of the
* entries causes the list to now be incorrectly sorted a final sorting
* phase will be automatically enabled within {@link #finish()}.
* <p>
* This method copies from the destination cache, which has not yet been
* updated with this editor's new table. So all offsets into the destination
* cache are not affected by any updates that may be currently taking place
* in this editor.
* <p>
* The internal entry table is automatically expanded if there is
* insufficient space for the new additions.
*
* @param pos
* first entry to copy from the destination cache.
* @param cnt
* number of entries to copy.
*/
public void keep(final int pos, int cnt) {
beforeAdd(cache.getEntry(pos));
fastKeep(pos, cnt);
}
/**
* Recursively add an entire tree into this builder.
* <p>
* If pathPrefix is "a/b" and the tree contains file "c" then the resulting
* DirCacheEntry will have the path "a/b/c".
* <p>
* All entries are inserted at stage 0, therefore assuming that the
* application will not insert any other paths with the same pathPrefix.
*
* @param pathPrefix
* UTF-8 encoded prefix to mount the tree's entries at. If the
* path does not end with '/' one will be automatically inserted
* as necessary.
* @param stage
* stage of the entries when adding them.
* @param db
* repository the tree(s) will be read from during recursive
* traversal. This must be the same repository that the resulting
* DirCache would be written out to (or used in) otherwise the
* caller is simply asking for deferred MissingObjectExceptions.
* @param tree
* the tree to recursively add. This tree's contents will appear
* under <code>pathPrefix</code>. The ObjectId must be that of a
* tree; the caller is responsible for dereferencing a tag or
* commit (if necessary).
* @throws IOException
* a tree cannot be read to iterate through its entries.
*/
public void addTree(final byte[] pathPrefix, final int stage,
final Repository db, final AnyObjectId tree) throws IOException {
final TreeWalk tw = new TreeWalk(db);
tw.reset();
final WindowCursor curs = new WindowCursor();
try {
tw.addTree(new CanonicalTreeParser(pathPrefix, db, tree
.toObjectId(), curs));
} finally {
curs.release();
}
tw.setRecursive(true);
if (tw.next()) {
final DirCacheEntry newEntry = toEntry(stage, tw);
beforeAdd(newEntry);
fastAdd(newEntry);
while (tw.next())
fastAdd(toEntry(stage, tw));
}
}
private DirCacheEntry toEntry(final int stage, final TreeWalk tw) {
final DirCacheEntry e = new DirCacheEntry(tw.getRawPath(), stage);
final AbstractTreeIterator i;
i = tw.getTree(0, AbstractTreeIterator.class);
e.setFileMode(tw.getFileMode(0));
e.setObjectIdFromRaw(i.idBuffer(), i.idOffset());
return e;
}
public void finish() {
if (!sorted)
resort();
replace();
}
private void beforeAdd(final DirCacheEntry newEntry) {
if (FileMode.TREE.equals(newEntry.getRawMode()))
throw bad(newEntry, "Adding subtree not allowed");
if (sorted && entryCnt > 0) {
final DirCacheEntry lastEntry = entries[entryCnt - 1];
final int cr = DirCache.cmp(lastEntry, newEntry);
if (cr > 0) {
// The new entry sorts before the old entry; we are
// no longer sorted correctly. We'll need to redo
// the sorting before we can close out the build.
//
sorted = false;
} else if (cr == 0) {
// Same file path; we can only insert this if the
// stages won't be violated.
//
final int peStage = lastEntry.getStage();
final int dceStage = newEntry.getStage();
if (peStage == dceStage)
throw bad(newEntry, "Duplicate stages not allowed");
if (peStage == 0 || dceStage == 0)
throw bad(newEntry, "Mixed stages not allowed");
if (peStage > dceStage)
sorted = false;
}
}
}
private void resort() {
Arrays.sort(entries, 0, entryCnt, DirCache.ENT_CMP);
for (int entryIdx = 1; entryIdx < entryCnt; entryIdx++) {
final DirCacheEntry pe = entries[entryIdx - 1];
final DirCacheEntry ce = entries[entryIdx];
final int cr = DirCache.cmp(pe, ce);
if (cr == 0) {
// Same file path; we can only allow this if the stages
// are 1-3 and no 0 exists.
//
final int peStage = pe.getStage();
final int ceStage = ce.getStage();
if (peStage == ceStage)
throw bad(ce, "Duplicate stages not allowed");
if (peStage == 0 || ceStage == 0)
throw bad(ce, "Mixed stages not allowed");
}
}
sorted = true;
}
private static IllegalStateException bad(final DirCacheEntry a,
final String msg) {
return new IllegalStateException(msg + ": " + a.getStage() + " "
+ a.getPathString());
}
}