ESM: Ported Bzip2, Diff and Tar operations

src/core/operations/Tar.mjs

@@ -0,0 +1,139 @@
+/**
+ * @author tlwr [toby@toby.codes]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import Utils from "../Utils";
+
+/**
+ * Tar operation
+ */
+class Tar extends Operation {
+
+    /**
+     * Tar constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Tar";
+        this.module = "Compression";
+        this.description = "Packs the input into a tarball.<br><br>No support for multiple files at this time.";
+        this.inputType = "byteArray";
+        this.outputType = "File";
+        this.args = [
+            {
+                "name": "Filename",
+                "type": "string",
+                "value": "file.txt"
+            }
+        ];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const Tarball = function() {
+            this.bytes = new Array(512);
+            this.position = 0;
+        };
+
+        Tarball.prototype.addEmptyBlock = function() {
+            const filler = new Array(512);
+            filler.fill(0);
+            this.bytes = this.bytes.concat(filler);
+        };
+
+        Tarball.prototype.writeBytes = function(bytes) {
+            const self = this;
+
+            if (this.position + bytes.length > this.bytes.length) {
+                this.addEmptyBlock();
+            }
+
+            Array.prototype.forEach.call(bytes, function(b, i) {
+                if (typeof b.charCodeAt !== "undefined") {
+                    b = b.charCodeAt();
+                }
+
+                self.bytes[self.position] = b;
+                self.position += 1;
+            });
+        };
+
+        Tarball.prototype.writeEndBlocks = function() {
+            const numEmptyBlocks = 2;
+            for (let i = 0; i < numEmptyBlocks; i++) {
+                this.addEmptyBlock();
+            }
+        };
+
+        const fileSize = input.length.toString(8).padStart(11, "0");
+        const currentUnixTimestamp = Math.floor(Date.now() / 1000);
+        const lastModTime = currentUnixTimestamp.toString(8).padStart(11, "0");
+
+        const file = {
+            fileName: Utils.padBytesRight(args[0], 100),
+            fileMode: Utils.padBytesRight("0000664", 8),
+            ownerUID: Utils.padBytesRight("0", 8),
+            ownerGID: Utils.padBytesRight("0", 8),
+            size: Utils.padBytesRight(fileSize, 12),
+            lastModTime: Utils.padBytesRight(lastModTime, 12),
+            checksum: "        ",
+            type: "0",
+            linkedFileName: Utils.padBytesRight("", 100),
+            USTARFormat: Utils.padBytesRight("ustar", 6),
+            version: "00",
+            ownerUserName: Utils.padBytesRight("", 32),
+            ownerGroupName: Utils.padBytesRight("", 32),
+            deviceMajor: Utils.padBytesRight("", 8),
+            deviceMinor: Utils.padBytesRight("", 8),
+            fileNamePrefix: Utils.padBytesRight("", 155),
+        };
+
+        let checksum = 0;
+        for (const key in file) {
+            const bytes = file[key];
+            Array.prototype.forEach.call(bytes, function(b) {
+                if (typeof b.charCodeAt !== "undefined") {
+                    checksum += b.charCodeAt();
+                } else {
+                    checksum += b;
+                }
+            });
+        }
+        checksum = Utils.padBytesRight(checksum.toString(8).padStart(7, "0"), 8);
+        file.checksum = checksum;
+
+        const tarball = new Tarball();
+        tarball.writeBytes(file.fileName);
+        tarball.writeBytes(file.fileMode);
+        tarball.writeBytes(file.ownerUID);
+        tarball.writeBytes(file.ownerGID);
+        tarball.writeBytes(file.size);
+        tarball.writeBytes(file.lastModTime);
+        tarball.writeBytes(file.checksum);
+        tarball.writeBytes(file.type);
+        tarball.writeBytes(file.linkedFileName);
+        tarball.writeBytes(file.USTARFormat);
+        tarball.writeBytes(file.version);
+        tarball.writeBytes(file.ownerUserName);
+        tarball.writeBytes(file.ownerGroupName);
+        tarball.writeBytes(file.deviceMajor);
+        tarball.writeBytes(file.deviceMinor);
+        tarball.writeBytes(file.fileNamePrefix);
+        tarball.writeBytes(Utils.padBytesRight("", 12));
+        tarball.writeBytes(input);
+        tarball.writeEndBlocks();
+
+        return new File([new Uint8Array(tarball.bytes)], args[0]);
+    }
+
+}
+
+export default Tar;