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Diffstat (limited to 'core/deflator.js')
-rw-r--r-- | core/deflator.js | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/core/deflator.js b/core/deflator.js new file mode 100644 index 0000000..ad3d0fb --- /dev/null +++ b/core/deflator.js @@ -0,0 +1,79 @@ +/* + * noVNC: HTML5 VNC client + * Copyright (C) 2020 The noVNC Authors + * Licensed under MPL 2.0 (see LICENSE.txt) + * + * See README.md for usage and integration instructions. + */ + +import { deflateInit, deflate } from "../vendor/pako/lib/zlib/deflate.js"; +import { Z_FULL_FLUSH } from "../vendor/pako/lib/zlib/deflate.js"; +import ZStream from "../vendor/pako/lib/zlib/zstream.js"; + +export default class Deflator { + constructor() { + this.strm = new ZStream(); + this.chunkSize = 1024 * 10 * 10; + this.outputBuffer = new Uint8Array(this.chunkSize); + this.windowBits = 5; + + deflateInit(this.strm, this.windowBits); + } + + deflate(inData) { + this.strm.input = inData; + this.strm.avail_in = this.strm.input.length; + this.strm.next_in = 0; + this.strm.output = this.outputBuffer; + this.strm.avail_out = this.chunkSize; + this.strm.next_out = 0; + + let lastRet = deflate(this.strm, Z_FULL_FLUSH); + let outData = new Uint8Array(this.strm.output.buffer, 0, this.strm.next_out); + + if (lastRet < 0) { + throw new Error("zlib deflate failed"); + } + + if (this.strm.avail_in > 0) { + // Read chunks until done + + let chunks = [outData]; + let totalLen = outData.length; + do { + this.strm.output = new Uint8Array(this.chunkSize); + this.strm.next_out = 0; + this.strm.avail_out = this.chunkSize; + + lastRet = deflate(this.strm, Z_FULL_FLUSH); + + if (lastRet < 0) { + throw new Error("zlib deflate failed"); + } + + let chunk = new Uint8Array(this.strm.output.buffer, 0, this.strm.next_out); + totalLen += chunk.length; + chunks.push(chunk); + } while (this.strm.avail_in > 0); + + // Combine chunks into a single data + + let newData = new Uint8Array(totalLen); + let offset = 0; + + for (let i = 0; i < chunks.length; i++) { + newData.set(chunks[i], offset); + offset += chunks[i].length; + } + + outData = newData; + } + + this.strm.input = null; + this.strm.avail_in = 0; + this.strm.next_in = 0; + + return outData; + } + +} |