in src/main/java/org/apache/commons/codec/binary/Base32.java [543:636]
void encode(final byte[] input, int inPos, final int inAvail, final Context context) {
// package protected for access from I/O streams
if (context.eof) {
return;
}
// inAvail < 0 is how we're informed of EOF in the underlying data we're
// encoding.
if (inAvail < 0) {
context.eof = true;
if (0 == context.modulus && lineLength == 0) {
return; // no leftovers to process and not using chunking
}
final byte[] buffer = ensureBufferSize(encodeSize, context);
final int savedPos = context.pos;
switch (context.modulus) { // % 5
case 0:
break;
case 1: // Only 1 octet; take top 5 bits then remainder
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 3) & MASK_5_BITS]; // 8-1*5 = 3
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 2) & MASK_5_BITS]; // 5-3=2
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
break;
case 2: // 2 octets = 16 bits to use
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 11) & MASK_5_BITS]; // 16-1*5 = 11
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 6) & MASK_5_BITS]; // 16-2*5 = 6
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 1) & MASK_5_BITS]; // 16-3*5 = 1
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 4) & MASK_5_BITS]; // 5-1 = 4
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
break;
case 3: // 3 octets = 24 bits to use
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 19) & MASK_5_BITS]; // 24-1*5 = 19
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 14) & MASK_5_BITS]; // 24-2*5 = 14
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 9) & MASK_5_BITS]; // 24-3*5 = 9
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 4) & MASK_5_BITS]; // 24-4*5 = 4
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 1) & MASK_5_BITS]; // 5-4 = 1
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
buffer[context.pos++] = pad;
break;
case 4: // 4 octets = 32 bits to use
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 27) & MASK_5_BITS]; // 32-1*5 = 27
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 22) & MASK_5_BITS]; // 32-2*5 = 22
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 17) & MASK_5_BITS]; // 32-3*5 = 17
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 12) & MASK_5_BITS]; // 32-4*5 = 12
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 7) & MASK_5_BITS]; // 32-5*5 = 7
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 2) & MASK_5_BITS]; // 32-6*5 = 2
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea << 3) & MASK_5_BITS]; // 5-2 = 3
buffer[context.pos++] = pad;
break;
default:
throw new IllegalStateException("Impossible modulus " + context.modulus);
}
context.currentLinePos += context.pos - savedPos; // keep track of current line position
// if currentPos == 0 we are at the start of a line, so don't add CRLF
if (lineLength > 0 && context.currentLinePos > 0) { // add chunk separator if required
System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
context.pos += lineSeparator.length;
}
} else {
for (int i = 0; i < inAvail; i++) {
final byte[] buffer = ensureBufferSize(encodeSize, context);
context.modulus = (context.modulus + 1) % BYTES_PER_UNENCODED_BLOCK;
int b = input[inPos++];
if (b < 0) {
b += 256;
}
context.lbitWorkArea = (context.lbitWorkArea << 8) + b; // BITS_PER_BYTE
if (0 == context.modulus) { // we have enough bytes to create our output
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 35) & MASK_5_BITS];
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 30) & MASK_5_BITS];
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 25) & MASK_5_BITS];
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 20) & MASK_5_BITS];
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 15) & MASK_5_BITS];
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 10) & MASK_5_BITS];
buffer[context.pos++] = encodeTable[(int) (context.lbitWorkArea >> 5) & MASK_5_BITS];
buffer[context.pos++] = encodeTable[(int) context.lbitWorkArea & MASK_5_BITS];
context.currentLinePos += BYTES_PER_ENCODED_BLOCK;
if (lineLength > 0 && lineLength <= context.currentLinePos) {
System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
context.pos += lineSeparator.length;
context.currentLinePos = 0;
}
}
}
}
}