in src/main/java/org/apache/commons/codec/binary/BaseNCodecInputStream.java [158:206]
public int read(final byte[] array, final int offset, final int len) throws IOException {
Objects.requireNonNull(array, "array");
if (offset < 0 || len < 0) {
throw new IndexOutOfBoundsException();
}
if (offset > array.length || offset + len > array.length) {
throw new IndexOutOfBoundsException();
}
if (len == 0) {
return 0;
}
int readLen = 0;
/*
Rationale for while-loop on (readLen == 0):
-----
Base32.readResults() usually returns > 0 or EOF (-1). In the
rare case where it returns 0, we just keep trying.
This is essentially an undocumented contract for InputStream
implementors that want their code to work properly with
java.io.InputStreamReader, since the latter hates it when
InputStream.read(byte[]) returns a zero. Unfortunately our
readResults() call must return 0 if a large amount of the data
being decoded was non-base32, so this while-loop enables proper
interop with InputStreamReader for that scenario.
-----
This is a fix for CODEC-101
*/
// Attempt to read the request length
while (readLen < len) {
if (!baseNCodec.hasData(context)) {
// Obtain more data.
// buf is reused across calls to read to avoid repeated allocations
final int c = in.read(buf);
if (doEncode) {
baseNCodec.encode(buf, 0, c, context);
} else {
baseNCodec.decode(buf, 0, c, context);
}
}
final int read = baseNCodec.readResults(array, offset + readLen, len - readLen, context);
if (read < 0) {
// Return the amount read or EOF
return readLen != 0 ? readLen : -1;
}
readLen += read;
}
return readLen;
}