public final void update(int i) {
int b0 = (i >> 24) & 0xff;
int b1 = (i >> 16) & 0xff;
int b2 = (i >> 8) & 0xff;
int b3 = i & 0xff;
crc.update(b0);
crc.update(b1);
crc.update(b2);
crc.update(b3);
// com.oddlabs.tt.util.ChecksumLogger.log(i);
}
/**
* Reads up to {@code byteCount} bytes of data from the underlying input stream, storing it into
* {@code buffer}, starting at offset {@code byteOffset}. The checksum is updated with the bytes
* read. Returns the number of bytes actually read or {@code -1} if arrived at the end of the
* filtered stream while reading the data.
*
* @throws IOException if this stream is closed or some I/O error occurs.
*/
@Override
public int read(byte[] buffer, int byteOffset, int byteCount) throws IOException {
int bytesRead = in.read(buffer, byteOffset, byteCount);
if (bytesRead != -1) {
check.update(buffer, byteOffset, bytesRead);
}
return bytesRead;
}
/**
* Reads one byte of data from the underlying input stream and updates the checksum with the byte
* data.
*
* @return {@code -1} at the end of the stream, a single byte value otherwise.
* @throws IOException if an {@code IOException} occurs.
*/
@Override
public int read() throws IOException {
int x = in.read();
if (x != -1) {
check.update(x);
}
return x;
}
/**
* Reads up to n bytes of data from the underlying input stream, storing it into {@code buf},
* starting at offset {@code off}. The checksum is updated with the bytes read.
*
* @param buf the byte array in which to store the bytes read.
* @param off the initial position in {@code buf} to store the bytes read from this stream.
* @param nbytes the maximum number of bytes to store in {@code buf}.
* @return the number of bytes actually read or {@code -1} if arrived at the end of the filtered
* stream while reading the data.
* @throws IOException if this stream is closed or some I/O error occurs.
*/
@Override
public int read(byte[] buf, int off, int nbytes) throws IOException {
int x = in.read(buf, off, nbytes);
if (x != -1) {
check.update(buf, off, x);
}
return x;
}
@Override
public int read(byte b[], int off, int len) throws IOException {
int bytesRead = super.read(b, off, len);
log.trace("{} bytes read from {}", bytesRead, in);
if (bytesRead != -1) {
totalBytesRead += bytesRead;
for (Checksum checksum : checksums) {
checksum.update(b, off, bytesRead);
}
}
return bytesRead;
}
/**
* Skip up to n bytes of data on the underlying input stream. Any skipped bytes are added to the
* running checksum value.
*
* @param nbytes the number of bytes to skip.
* @throws IOException if this stream is closed or another I/O error occurs.
* @return the number of bytes skipped.
*/
@Override
public long skip(long nbytes) throws IOException {
if (nbytes < 1) {
return 0;
}
long skipped = 0;
byte[] b = new byte[2048];
int x, v;
while (skipped != nbytes) {
x = in.read(b, 0, (v = (int) (nbytes - skipped)) > b.length ? b.length : v);
if (x == -1) {
return skipped;
}
check.update(b, 0, x);
skipped += x;
}
return skipped;
}
