core/inflator.js

   1 /*
   2  * noVNC: HTML5 VNC client
   3  * Copyright (C) 2020 The noVNC Authors
   4  * Licensed under MPL 2.0 (see LICENSE.txt)
   5  *
   6  * See README.md for usage and integration instructions.
   7  */
   8
   9 import { inflateInit, inflate, inflateReset } from "../vendor/pako/lib/zlib/inflate.js";
  10 import ZStream from "../vendor/pako/lib/zlib/zstream.js";
  11
  12 export default class Inflate {
  13     constructor() {
  14         this.strm = new ZStream();
  15         this.chunkSize = 1024 * 10 * 10;
  16         this.strm.output = new Uint8Array(this.chunkSize);
  17         this.windowBits = 5;
  18
  19         inflateInit(this.strm, this.windowBits);
  20     }
  21
  22     inflate(data, expected) {
  23         this.strm.input = data;
  24         this.strm.avail_in = this.strm.input.length;
  25         this.strm.next_in = 0;
  26         this.strm.next_out = 0;
  27
  28         // resize our output buffer if it's too small
  29         // (we could just use multiple chunks, but that would cause an extra
  30         // allocation each time to flatten the chunks)
  31         if (expected > this.chunkSize) {
  32             this.chunkSize = expected;
  33             this.strm.output = new Uint8Array(this.chunkSize);
  34         }
  35
  36         this.strm.avail_out = this.chunkSize;
  37
  38         inflate(this.strm, 0); // Flush argument not used.
  39
  40         if (this.strm.next_out != expected) {
  41             throw new Error("Incomplete zlib block");
  42         }
  43
  44         return new Uint8Array(this.strm.output.buffer, 0, this.strm.next_out);
  45     }
  46
  47     reset() {
  48         inflateReset(this.strm);
  49     }
  50 }