void Buffer::SetPos(int value) {
if ((value >= fileLen) && (stream != NULL) && !CanSeek()) {
// Wanted position is after buffer and the stream
// is not seek-able e.g. network or console,
// thus we have to read the stream manually till
// the wanted position is in sight.
while ((value >= fileLen) && (ReadNextStreamChunk() > 0));
}
if ((value < 0) || (value > fileLen)) {
wprintf(L"--- buffer out of bounds access, position: %d\n", value);
MX_DEBUG_BREAK;
exit(1);
}
if ((value >= bufStart) && (value < (bufStart + bufLen))) { // already in buffer
bufPos = value - bufStart;
} else if (stream != NULL) { // must be swapped in
fseek(stream, value, SEEK_SET);
bufLen = fread(buf, sizeof(unsigned char), bufCapacity, stream);
bufStart = value;
bufPos = 0;
} else {
bufPos = fileLen - bufStart; // make Pos return fileLen
}
}
int Buffer::Read() {
if (bufPos < bufLen) {
return buf[bufPos++];
} else if (GetPos() < fileLen) {
SetPos(GetPos()); // shift buffer start to Pos
return buf[bufPos++];
} else if ((stream != NULL) && !CanSeek() && (ReadNextStreamChunk() > 0)) {
return buf[bufPos++];
} else {
return EoF;
}
}