core/inflator.js

   1 import { inflateInit, inflate, inflateReset } from "../vendor/pako/lib/zlib/inflate.js";
   2 import ZStream from "../vendor/pako/lib/zlib/zstream.js";
   3
   4 export default class Inflate {
   5     constructor() {
   6         this.strm = new ZStream();
   7         this.chunkSize = 1024 * 10 * 10;
   8         this.strm.output = new Uint8Array(this.chunkSize);
   9         this.windowBits = 5;
  10
  11         inflateInit(this.strm, this.windowBits);
  12     }
  13
  14     inflate(data, flush, expected) {
  15         this.strm.input = data;
  16         this.strm.avail_in = this.strm.input.length;
  17         this.strm.next_in = 0;
  18         this.strm.next_out = 0;
  19
  20         // resize our output buffer if it's too small
  21         // (we could just use multiple chunks, but that would cause an extra
  22         // allocation each time to flatten the chunks)
  23         if (expected > this.chunkSize) {
  24             this.chunkSize = expected;
  25             this.strm.output = new Uint8Array(this.chunkSize);
  26         }
  27
  28         this.strm.avail_out = this.chunkSize;
  29
  30         inflate(this.strm, flush);
  31
  32         return new Uint8Array(this.strm.output.buffer, 0, this.strm.next_out);
  33     }
  34
  35     reset() {
  36         inflateReset(this.strm);
  37     }
  38 }