public void testSkip() throws IOException {
init(32, 15);
copy(2, 2);
insert("ab");
insert("cd");
copy(4, 4);
copy(0, 2);
insert("efg");
assertValidState();
for (int p = 0; p < data.length; p++) {
byte[] act = new byte[data.length];
System.arraycopy(data, 0, act, 0, p);
DeltaStream in = open();
IO.skipFully(in, p);
assertEquals(data.length - p, in.read(act, p, data.length - p));
assertEquals(-1, in.read());
assertTrue("skipping " + p, Arrays.equals(data, act));
}
// Skip all the way to the end should still recognize EOF.
DeltaStream in = open();
IO.skipFully(in, data.length);
assertEquals(-1, in.read());
assertEquals(0, in.skip(1));
// Skip should not open the base as we move past it, but it
// will open when we need to start copying data from it.
final boolean[] opened = new boolean[1];
in =
new DeltaStream(new ByteArrayInputStream(delta)) {
@Override
protected long getBaseSize() throws IOException {
return base.length;
}
@Override
protected InputStream openBase() throws IOException {
opened[0] = true;
return new ByteArrayInputStream(base);
}
};
IO.skipFully(in, 7);
assertFalse("not yet open", opened[0]);
assertEquals(data[7], in.read());
assertTrue("now open", opened[0]);
}
private void readFrom(final InputStream inStream) throws IOException, CorruptObjectException {
final BufferedInputStream in = new BufferedInputStream(inStream);
final MessageDigest md = Constants.newMessageDigest();
// Read the index header and verify we understand it.
//
final byte[] hdr = new byte[20];
IO.readFully(in, hdr, 0, 12);
md.update(hdr, 0, 12);
if (!is_DIRC(hdr)) throw new CorruptObjectException(JGitText.get().notADIRCFile);
final int ver = NB.decodeInt32(hdr, 4);
boolean extended = false;
if (ver == 3) extended = true;
else if (ver != 2)
throw new CorruptObjectException(
MessageFormat.format(JGitText.get().unknownDIRCVersion, Integer.valueOf(ver)));
entryCnt = NB.decodeInt32(hdr, 8);
if (entryCnt < 0) throw new CorruptObjectException(JGitText.get().DIRCHasTooManyEntries);
snapshot = FileSnapshot.save(liveFile);
int smudge_s = (int) (snapshot.lastModified() / 1000);
int smudge_ns = ((int) (snapshot.lastModified() % 1000)) * 1000000;
// Load the individual file entries.
//
final int infoLength = DirCacheEntry.getMaximumInfoLength(extended);
final byte[] infos = new byte[infoLength * entryCnt];
sortedEntries = new DirCacheEntry[entryCnt];
final MutableInteger infoAt = new MutableInteger();
for (int i = 0; i < entryCnt; i++)
sortedEntries[i] = new DirCacheEntry(infos, infoAt, in, md, smudge_s, smudge_ns);
// After the file entries are index extensions, and then a footer.
//
for (; ; ) {
in.mark(21);
IO.readFully(in, hdr, 0, 20);
if (in.read() < 0) {
// No extensions present; the file ended where we expected.
//
break;
}
in.reset();
md.update(hdr, 0, 8);
IO.skipFully(in, 8);
long sz = NB.decodeUInt32(hdr, 4);
switch (NB.decodeInt32(hdr, 0)) {
case EXT_TREE:
{
if (Integer.MAX_VALUE < sz) {
throw new CorruptObjectException(
MessageFormat.format(
JGitText.get().DIRCExtensionIsTooLargeAt,
formatExtensionName(hdr),
Long.valueOf(sz)));
}
final byte[] raw = new byte[(int) sz];
IO.readFully(in, raw, 0, raw.length);
md.update(raw, 0, raw.length);
tree = new DirCacheTree(raw, new MutableInteger(), null);
break;
}
default:
if (hdr[0] >= 'A' && hdr[0] <= 'Z') {
// The extension is optional and is here only as
// a performance optimization. Since we do not
// understand it, we can safely skip past it, after
// we include its data in our checksum.
//
skipOptionalExtension(in, md, hdr, sz);
} else {
// The extension is not an optimization and is
// _required_ to understand this index format.
// Since we did not trap it above we must abort.
//
throw new CorruptObjectException(
MessageFormat.format(
JGitText.get().DIRCExtensionNotSupportedByThisVersion,
formatExtensionName(hdr)));
}
}
}
readIndexChecksum = md.digest();
if (!Arrays.equals(readIndexChecksum, hdr)) {
throw new CorruptObjectException(JGitText.get().DIRCChecksumMismatch);
}
}