ESM: Added Zlib ops and created a Zlib library.

src/core/operations/RawInflate.mjs

@@ -0,0 +1,105 @@
+/**
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import Utils from "../Utils";
+import {INFLATE_BUFFER_TYPE} from "../lib/Zlib";
+import rawinflate from "zlibjs/bin/rawinflate.min";
+
+const Zlib = rawinflate.Zlib;
+
+const RAW_BUFFER_TYPE_LOOKUP = {
+    "Adaptive": Zlib.RawInflate.BufferType.ADAPTIVE,
+    "Block":    Zlib.RawInflate.BufferType.BLOCK,
+};
+
+/**
+ * Raw Inflate operation
+ */
+class RawInflate extends Operation {
+
+    /**
+     * RawInflate constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Raw Inflate";
+        this.module = "Compression";
+        this.description = "Decompresses data which has been compressed using the deflate algorithm with no headers.";
+        this.inputType = "byteArray";
+        this.outputType = "byteArray";
+        this.args = [
+            {
+                name: "Start index",
+                type: "number",
+                value: 0
+            },
+            {
+                name: "Initial output buffer size",
+                type: "number",
+                value: 0
+            },
+            {
+                name: "Buffer expansion type",
+                type: "option",
+                value: INFLATE_BUFFER_TYPE
+            },
+            {
+                name: "Resize buffer after decompression",
+                type: "boolean",
+                value: false
+            },
+            {
+                name: "Verify result",
+                type: "boolean",
+                value: false
+            }
+        ];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        // Deal with character encoding issues
+        input = Utils.strToByteArray(Utils.byteArrayToUtf8(input));
+        const inflate = new Zlib.RawInflate(input, {
+                index: args[0],
+                bufferSize: args[1],
+                bufferType: RAW_BUFFER_TYPE_LOOKUP[args[2]],
+                resize: args[3],
+                verify: args[4]
+            }),
+            result = Array.prototype.slice.call(inflate.decompress());
+
+        // Raw Inflate somethimes messes up and returns nonsense like this:
+        // ]....]....]....]....]....]....]....]....]....]....]....]....]....]...
+        // e.g. Input data of [8b, 1d, dc, 44]
+        // Look for the first two square brackets:
+        if (result.length > 158 && result[0] === 93 && result[5] === 93) {
+            // If the first two square brackets are there, check that the others
+            // are also there. If they are, throw an error. If not, continue.
+            let valid = false;
+            for (let i = 0; i < 155; i += 5) {
+                if (result[i] !== 93) {
+                    valid = true;
+                }
+            }
+
+            if (!valid) {
+                throw "Error: Unable to inflate data";
+            }
+        }
+        // This seems to be the easiest way...
+        return result;
+    }
+
+}
+
+export default RawInflate;