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Merge "Use heap based stack for PackFile deltas"

stable-0.11
Shawn O. Pearce 14 years ago committed by Code Review
parent
680869d779 165358bc99
commit
05ca0c49f9
1 changed files with 167 additions and 98 deletions
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  1. 213
      org.eclipse.jgit/src/org/eclipse/jgit/storage/file/PackFile.java

213
org.eclipse.jgit/src/org/eclipse/jgit/storage/file/PackFile.java
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@ -63,7 +63,6 @@ import java.util.zip.Inflater;
import org.eclipse.jgit.JGitText;
import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.LargeObjectException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.errors.PackInvalidException;
import org.eclipse.jgit.errors.PackMismatchException;
@ -275,11 +274,25 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
return getReverseIdx().findObject(offset);
}
private final void decompress(final long position, final WindowCursor curs,
final byte[] dstbuf, final int dstoff, final int dstsz)
throws IOException, DataFormatException {
if (curs.inflate(this, position, dstbuf, dstoff) != dstsz)
private final byte[] decompress(final long position, final int sz,
final WindowCursor curs) throws IOException, DataFormatException {
byte[] dstbuf;
try {
dstbuf = new byte[sz];
} catch (OutOfMemoryError noMemory) {
// The size may be larger than our heap allows, return null to
// let the caller know allocation isn't possible and it should
// use the large object streaming approach instead.
//
// For example, this can occur when sz is 640 MB, and JRE
// maximum heap size is only 256 MB. Even if the JRE has
// 200 MB free, it cannot allocate a 640 MB byte array.
return null;
}
if (curs.inflate(this, position, dstbuf, 0) != sz)
throw new EOFException(MessageFormat.format(JGitText.get().shortCompressedStreamAt, position));
return dstbuf;
}
final void copyAsIs(PackOutputStream out, LocalObjectToPack src,
@ -608,12 +621,19 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
, getPackFile()));
}
ObjectLoader load(final WindowCursor curs, final long pos)
ObjectLoader load(final WindowCursor curs, long pos)
throws IOException {
try {
final byte[] ib = curs.tempId;
Delta delta = null;
byte[] data = null;
int type = Constants.OBJ_BAD;
boolean cached = false;
SEARCH: for (;;) {
readFully(pos, ib, 0, 20, curs);
int c = ib[0] & 0xff;
final int type = (c >> 4) & 7;
final int typeCode = (c >> 4) & 7;
long sz = c & 15;
int shift = 4;
int p = 1;
@ -623,47 +643,116 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
shift += 7;
}
try {
switch (type) {
switch (typeCode) {
case Constants.OBJ_COMMIT:
case Constants.OBJ_TREE:
case Constants.OBJ_BLOB:
case Constants.OBJ_TAG: {
if (sz < curs.getStreamFileThreshold()) {
byte[] data;
try {
data = new byte[(int) sz];
} catch (OutOfMemoryError tooBig) {
return largeWhole(curs, pos, type, sz, p);
}
decompress(pos + p, curs, data, 0, data.length);
return new ObjectLoader.SmallObject(type, data);
if (sz < curs.getStreamFileThreshold())
data = decompress(pos + p, (int) sz, curs);
if (delta != null) {
type = typeCode;
break SEARCH;
}
return largeWhole(curs, pos, type, sz, p);
if (data != null)
return new ObjectLoader.SmallObject(typeCode, data);
else
return new LargePackedWholeObject(typeCode, sz, pos, p,
this, curs.db);
}
case Constants.OBJ_OFS_DELTA: {
c = ib[p++] & 0xff;
long ofs = c & 127;
long base = c & 127;
while ((c & 128) != 0) {
ofs += 1;
base += 1;
c = ib[p++] & 0xff;
ofs <<= 7;
ofs += (c & 127);
base <<= 7;
base += (c & 127);
}
base = pos - base;
delta = new Delta(delta, pos, (int) sz, p, base);
if (sz != delta.deltaSize)
break SEARCH;
DeltaBaseCache.Entry e = DeltaBaseCache.get(this, base);
if (e != null) {
type = e.type;
data = e.data;
cached = true;
break SEARCH;
}
return loadDelta(pos, p, sz, pos - ofs, curs);
pos = base;
continue SEARCH;
}
case Constants.OBJ_REF_DELTA: {
readFully(pos + p, ib, 0, 20, curs);
long ofs = findDeltaBase(ObjectId.fromRaw(ib));
return loadDelta(pos, p + 20, sz, ofs, curs);
long base = findDeltaBase(ObjectId.fromRaw(ib));
delta = new Delta(delta, pos, (int) sz, p + 20, base);
if (sz != delta.deltaSize)
break SEARCH;
DeltaBaseCache.Entry e = DeltaBaseCache.get(this, base);
if (e != null) {
type = e.type;
data = e.data;
cached = true;
break SEARCH;
}
pos = base;
continue SEARCH;
}
default:
throw new IOException(MessageFormat.format(
JGitText.get().unknownObjectType, type));
JGitText.get().unknownObjectType, typeCode));
}
}
// At this point there is at least one delta to apply to data.
// (Whole objects with no deltas to apply return early above.)
if (data == null)
return delta.large(this, curs);
do {
// Cache only the base immediately before desired object.
if (cached)
cached = false;
else if (delta.next == null)
DeltaBaseCache.store(this, delta.basePos, data, type);
pos = delta.deltaPos;
final byte[] cmds = decompress(pos + delta.hdrLen,
delta.deltaSize, curs);
if (cmds == null) {
data = null; // Discard base in case of OutOfMemoryError
return delta.large(this, curs);
}
final long sz = BinaryDelta.getResultSize(cmds);
if (Integer.MAX_VALUE <= sz)
return delta.large(this, curs);
final byte[] result;
try {
result = new byte[(int) sz];
} catch (OutOfMemoryError tooBig) {
data = null; // Discard base in case of OutOfMemoryError
return delta.large(this, curs);
}
BinaryDelta.apply(data, cmds, result);
data = result;
delta = delta.next;
} while (delta != null);
return new ObjectLoader.SmallObject(type, data);
} catch (DataFormatException dfe) {
CorruptObjectException coe = new CorruptObjectException(
MessageFormat.format(
@ -683,61 +772,41 @@ public class PackFile implements Iterable<PackIndex.MutableEntry> {
return ofs;
}
private ObjectLoader loadDelta(long posSelf, int hdrLen, long sz,
long posBase, WindowCursor curs) throws IOException,
DataFormatException {
if (Integer.MAX_VALUE <= sz)
return largeDelta(posSelf, hdrLen, posBase, curs);
private static class Delta {
/** Child that applies onto this object. */
final Delta next;
byte[] base;
int type;
/** Offset of the delta object. */
final long deltaPos;
DeltaBaseCache.Entry e = DeltaBaseCache.get(this, posBase);
if (e != null) {
base = e.data;
type = e.type;
} else {
ObjectLoader p = load(curs, posBase);
try {
base = p.getCachedBytes(curs.getStreamFileThreshold());
} catch (LargeObjectException tooBig) {
return largeDelta(posSelf, hdrLen, posBase, curs);
}
type = p.getType();
DeltaBaseCache.store(this, posBase, base, type);
}
/** Size of the inflated delta stream. */
final int deltaSize;
final byte[] delta;
try {
delta = new byte[(int) sz];
} catch (OutOfMemoryError tooBig) {
return largeDelta(posSelf, hdrLen, posBase, curs);
}
/** Total size of the delta's pack entry header (including base). */
final int hdrLen;
decompress(posSelf + hdrLen, curs, delta, 0, delta.length);
sz = BinaryDelta.getResultSize(delta);
if (Integer.MAX_VALUE <= sz)
return largeDelta(posSelf, hdrLen, posBase, curs);
/** Offset of the base object this delta applies onto. */
final long basePos;
final byte[] result;
try {
result = new byte[(int) sz];
} catch (OutOfMemoryError tooBig) {
return largeDelta(posSelf, hdrLen, posBase, curs);
Delta(Delta next, long ofs, int sz, int hdrLen, long baseOffset) {
this.next = next;
this.deltaPos = ofs;
this.deltaSize = sz;
this.hdrLen = hdrLen;
this.basePos = baseOffset;
}
BinaryDelta.apply(base, delta, result);
return new ObjectLoader.SmallObject(type, result);
ObjectLoader large(PackFile pack, WindowCursor wc) {
Delta d = this;
while (d.next != null)
d = d.next;
return d.newLargeLoader(pack, wc);
}
private LargePackedWholeObject largeWhole(final WindowCursor curs,
final long pos, final int type, long sz, int p) {
return new LargePackedWholeObject(type, sz, pos, p, this, curs.db);
private ObjectLoader newLargeLoader(PackFile pack, WindowCursor wc) {
return new LargePackedDeltaObject(deltaPos, basePos, hdrLen,
pack, wc.db);
}
private LargePackedDeltaObject largeDelta(long posObj, int hdrLen,
long posBase, WindowCursor wc) {
return new LargePackedDeltaObject(posObj, posBase, hdrLen, this, wc.db);
}
byte[] getDeltaHeader(WindowCursor wc, long pos)

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