Added Bzip2 compression support

src/core/operations/Bzip2Compress.mjs

@@ -0,0 +1,74 @@
+/**
+ * @author Matt C [me@mitt.dev]
+ * @copyright Crown Copyright 2019
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import OperationError from "../errors/OperationError";
+import Bzip2 from "libbzip2-wasm";
+
+/**
+ * Bzip2 Compress operation
+ */
+class Bzip2Compress extends Operation {
+
+    /**
+     * Bzip2Compress constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Bzip2 Compress";
+        this.module = "Compression";
+        this.description = "yeet";
+        this.infoURL = "https://en.wikipedia.org/wiki/Bzip2";
+        this.inputType = "ArrayBuffer";
+        this.outputType = "File";
+        this.args = [
+            {
+                name: "Block size (100s of kb)",
+                type: "number",
+                value: 9
+            },
+            {
+                name: "Work factor",
+                type: "number",
+                value: 30
+            },
+            {
+                name: "Compressed filename",
+                type: "string",
+                value: "compressed.bz2"
+            }
+        ];
+    }
+
+    /**
+     * @param {ArrayBuffer} input
+     * @param {Object[]} args
+     * @returns {File}
+     */
+    run(input, args) {
+        const [blockSize, workFactor, filename] = args;
+        if (input.byteLength <= 0) {
+            throw new OperationError("Please provide an input.");
+        }
+        if (ENVIRONMENT_IS_WORKER()) self.sendStatusMessage("Loading Bzip2...");
+        return new Promise((resolve, reject) => {
+            Bzip2().then(bzip2 => {
+                if (ENVIRONMENT_IS_WORKER()) self.sendStatusMessage("Compressing data...");
+                const inpArray = new Uint8Array(input);
+                const bzip2cc = bzip2.compressBZ2(inpArray, blockSize, workFactor);
+                if (bzip2cc.error !== 0) {
+                    reject(new OperationError(bzip2cc.error_msg));
+                } else {
+                    resolve(new File([bzip2cc.output], filename));
+                }
+            });
+        });
+    }
+
+}
+
+export default Bzip2Compress;