Initial commit - full huishou project

node_modules/crc32-stream/lib/deflate-crc32-stream.js

@@ -0,0 +1,40 @@
+import { DeflateRaw } from "zlib";
+import crc32 from "crc-32";
+
+export default class DeflateCRC32Stream extends DeflateRaw {
+  constructor(options) {
+    super(options);
+    this.checksum = Buffer.allocUnsafe(4);
+    this.checksum.writeInt32BE(0, 0);
+    this.rawSize = 0;
+    this.compressedSize = 0;
+  }
+  push(chunk, encoding) {
+    if (chunk) {
+      this.compressedSize += chunk.length;
+    }
+    return super.push(chunk, encoding);
+  }
+  _transform(chunk, encoding, callback) {
+    if (chunk) {
+      this.checksum = crc32.buf(chunk, this.checksum) >>> 0;
+      this.rawSize += chunk.length;
+    }
+    super._transform(chunk, encoding, callback);
+  }
+  digest(encoding) {
+    const checksum = Buffer.allocUnsafe(4);
+    checksum.writeUInt32BE(this.checksum >>> 0, 0);
+    return encoding ? checksum.toString(encoding) : checksum;
+  }
+  hex() {
+    return this.digest("hex").toUpperCase();
+  }
+  size(compressed = false) {
+    if (compressed) {
+      return this.compressedSize;
+    } else {
+      return this.rawSize;
+    }
+  }
+}