protected void _writeBinary(
Base64Variant b64variant, byte[] input, int inputPtr, final int inputEnd)
throws IOException, JsonGenerationException {
// Encoding is by chunks of 3 input, 4 output chars, so:
int safeInputEnd = inputEnd - 3;
// Let's also reserve room for possible (and quoted) lf char each round
int safeOutputEnd = _outputEnd - 6;
int chunksBeforeLF = b64variant.getMaxLineLength() >> 2;
// Ok, first we loop through all full triplets of data:
while (inputPtr <= safeInputEnd) {
if (_outputTail > safeOutputEnd) { // need to flush
_flushBuffer();
}
// First, mash 3 bytes into lsb of 32-bit int
int b24 = ((int) input[inputPtr++]) << 8;
b24 |= ((int) input[inputPtr++]) & 0xFF;
b24 = (b24 << 8) | (((int) input[inputPtr++]) & 0xFF);
_outputTail = b64variant.encodeBase64Chunk(b24, _outputBuffer, _outputTail);
if (--chunksBeforeLF <= 0) {
// note: must quote in JSON value
_outputBuffer[_outputTail++] = '\\';
_outputBuffer[_outputTail++] = 'n';
chunksBeforeLF = b64variant.getMaxLineLength() >> 2;
}
}
// And then we may have 1 or 2 leftover bytes to encode
int inputLeft = inputEnd - inputPtr; // 0, 1 or 2
if (inputLeft > 0) { // yes, but do we have room for output?
if (_outputTail > safeOutputEnd) { // don't really need 6 bytes but...
_flushBuffer();
}
int b24 = ((int) input[inputPtr++]) << 16;
if (inputLeft == 2) {
b24 |= (((int) input[inputPtr++]) & 0xFF) << 8;
}
_outputTail = b64variant.encodeBase64Partial(b24, inputLeft, _outputBuffer, _outputTail);
}
}
