ESM: Added Zlib ops and created a Zlib library.

src/core/operations/Gzip.mjs

@@ -0,0 +1,85 @@
+/**
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import {COMPRESSION_TYPE, ZLIB_COMPRESSION_TYPE_LOOKUP} from "../lib/Zlib";
+import zlibAndGzip from "zlibjs/bin/zlib_and_gzip.min";
+
+const Zlib = zlibAndGzip.Zlib;
+
+/**
+ * Gzip operation
+ */
+class Gzip extends Operation {
+
+    /**
+     * Gzip constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Gzip";
+        this.module = "Compression";
+        this.description = "Compresses data using the deflate algorithm with gzip headers.";
+        this.inputType = "byteArray";
+        this.outputType = "byteArray";
+        this.args = [
+            {
+                name: "Compression type",
+                type: "option",
+                value: COMPRESSION_TYPE
+            },
+            {
+                name: "Filename (optional)",
+                type: "string",
+                value: ""
+            },
+            {
+                name: "Comment (optional)",
+                type: "string",
+                value: ""
+            },
+            {
+                name: "Include file checksum",
+                type: "boolean",
+                value: false
+            }
+        ];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const filename = args[1],
+            comment = args[2],
+            options = {
+                deflateOptions: {
+                    compressionType: ZLIB_COMPRESSION_TYPE_LOOKUP[args[0]]
+                },
+                flags: {
+                    fhcrc: args[3]
+                }
+            };
+
+        if (filename.length) {
+            options.flags.fname = true;
+            options.filename = filename;
+        }
+        if (comment.length) {
+            options.flags.fcommenct = true;
+            options.comment = comment;
+        }
+
+        const gzip = new Zlib.Gzip(input, options);
+        return Array.prototype.slice.call(gzip.compress());
+    }
+
+}
+
+export default Gzip;