@Override
protected int readChunk(long pos, byte[] buf, int offset, int len, byte[] checksum)
throws IOException {
boolean eof = false;
if (needChecksum()) {
try {
long checksumPos = getChecksumFilePos(pos);
if (checksumPos != sums.getPos()) {
sums.seek(checksumPos);
}
sums.readFully(checksum);
} catch (EOFException e) {
eof = true;
}
len = bytesPerSum;
}
if (pos != datas.getPos()) {
datas.seek(pos);
}
int nread = readFully(datas, buf, offset, len);
if (eof && nread > 0) {
throw new ChecksumException("Checksum error: " + file + " at " + pos, pos);
}
return nread;
}
@Override
protected int readChunk(long pos, byte[] buf, int offset, int len, byte[] checksum)
throws IOException {
boolean eof = false;
if (needChecksum()) {
assert checksum != null; // we have a checksum buffer
assert checksum.length % CHECKSUM_SIZE == 0; // it is sane length
assert len >= bytesPerSum; // we must read at least one chunk
final int checksumsToRead =
Math.min(
len / bytesPerSum, // number of checksums based on len to read
checksum.length / CHECKSUM_SIZE); // size of checksum buffer
long checksumPos = getChecksumFilePos(pos);
if (checksumPos != sums.getPos()) {
sums.seek(checksumPos);
}
int sumLenRead = sums.read(checksum, 0, CHECKSUM_SIZE * checksumsToRead);
if (sumLenRead >= 0 && sumLenRead % CHECKSUM_SIZE != 0) {
throw new ChecksumException(
"Checksum file not a length multiple of checksum size "
+ "in "
+ file
+ " at "
+ pos
+ " checksumpos: "
+ checksumPos
+ " sumLenread: "
+ sumLenRead,
pos);
}
if (sumLenRead <= 0) { // we're at the end of the file
eof = true;
} else {
// Adjust amount of data to read based on how many checksum chunks we read
len = Math.min(len, bytesPerSum * (sumLenRead / CHECKSUM_SIZE));
}
}
if (pos != datas.getPos()) {
datas.seek(pos);
}
int nread = readFully(datas, buf, offset, len);
if (eof && nread > 0) {
throw new ChecksumException("Checksum error: " + file + " at " + pos, pos);
}
return nread;
}
@Override
public synchronized int available() throws IOException {
long remaining = end - underLyingStream.getPos();
if (remaining > Integer.MAX_VALUE) {
return Integer.MAX_VALUE;
}
return (int) remaining;
}
@Override
public long tell() throws IOException {
return stream.getPos();
}