Decompressing just the start of a block of compressed data #75
Description
For a project I wanted to synchronously extract just the initial 4 KB of text from the start of some compressed data, render that quickly for the user, and then (separately) decompress the entire data asynchronously.
Here is a little hack that does just that. eg, for inserting into lzma-d.js:
/** returns up to max_bytes of decompressed data */
function decompresschunk(byte_arr, max_bytes) {
var this$static = {};
this$static.d = $LZMAByteArrayDecompressor({}, byte_arr);
while ($processChunk(this$static.d.chunker) && this$static.d.chunker.outBytesProcessed[0] < max_bytes);
if (this$static.d.chunker.alive)
$Flush_0(this$static.d.chunker.decoder.m_OutWindow);
return decode($toByteArray(this$static.d.output));
}