commit

node_modules/sandwich-stream/dist/sandwich-stream.js

@@ -0,0 +1,185 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+var stream = require('stream');
+
+/*! *****************************************************************************
+Copyright (c) Microsoft Corporation. All rights reserved.
+Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+this file except in compliance with the License. You may obtain a copy of the
+License at http://www.apache.org/licenses/LICENSE-2.0
+
+THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
+WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
+MERCHANTABLITY OR NON-INFRINGEMENT.
+
+See the Apache Version 2.0 License for specific language governing permissions
+and limitations under the License.
+***************************************************************************** */
+
+function __rest(s, e) {
+    var t = {};
+    for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p) && e.indexOf(p) < 0)
+        t[p] = s[p];
+    if (s != null && typeof Object.getOwnPropertySymbols === "function")
+        for (var i = 0, p = Object.getOwnPropertySymbols(s); i < p.length; i++) if (e.indexOf(p[i]) < 0)
+            t[p[i]] = s[p[i]];
+    return t;
+}
+
+/**
+ * Handles Readable streams requests as concatenation through data handling as
+ * well adding tags it each begin, end and between of the streams
+ */
+class SandwichStream extends stream.Readable {
+    /**
+     * Initiates the SandwichStream, you can consider it also passing
+     * ReadableOptions to it
+     *
+     * @param head Pushes this content before all other content
+     * @param tail Pushes this content after all other data has been pushed
+     * @param separator Pushes this content between each stream
+     * @param remaining The other kind of options to be passed to Readable
+     * @example
+     * const ss = new SandwichStream({
+     *     head: 'This at the top\n',
+     *     tail: '\nThis at the bottom',
+     *     separator: '\n --- \n'
+     * });
+     */
+    constructor(_a) {
+        var { head, tail, separator } = _a, remaining = __rest(_a, ["head", "tail", "separator"]);
+        super(remaining);
+        this.streamsActive = false;
+        this.streams = [];
+        this.newStreams = [];
+        this.currentStream = null;
+        this.head = (null !== head && undefined !== head) ? head : null;
+        this.tail = (null !== tail && undefined !== tail) ? tail : null;
+        this.separator = (null !== separator && undefined !== separator) ? separator : null;
+    }
+    /**
+     * Add a new Readable stream in the queue
+     *
+     * @param newStream The Readable stream
+     * @example
+     * sandwichStream.add(streamOne);
+     * sandwichStream.add(streamTwo);
+     * sandwichStream.add(streamThree);
+     * @throws An Error in case that this request was not accepted
+     * @returns This instance of Sandwich Stream
+     */
+    add(newStream) {
+        if (false === this.streamsActive) {
+            this.streams.push(newStream);
+            newStream.on('error', this.subStreamOnError.bind(this));
+        }
+        else {
+            this.newStreams.push(newStream);
+        }
+        return this;
+    }
+    /**
+     * Works in a similar way from the Readable read, only that this one checks
+     * for whether or not a stream is already being handled
+     * @returns This instance of Sandwich Stream
+     */
+    _read() {
+        if (false === this.streamsActive) {
+            this.streamsActive = true;
+            this.pushHead();
+            this.streamNextStream();
+        }
+    }
+    /**
+     * Binds an error thrown from one of the streams being handled
+     *
+     * @param err Error to be bind
+     * @returns This instance of Sandwich Stream
+     */
+    subStreamOnError(err) {
+        this.emit('error', err);
+    }
+    /**
+     * Fetches the next stream to be handled
+     * @returns This instance of Sandwich Stream
+     */
+    streamNextStream() {
+        if (true === this.nextStream()) {
+            this.bindCurrentStreamEvents();
+        }
+        else {
+            this.pushTail();
+            this.push(null);
+        }
+    }
+    /**
+     * Verifies whether or not the stream queue has ended
+     * @returns This instance of Sandwich Stream
+     */
+    nextStream() {
+        const tmp = this.streams.shift();
+        this.currentStream = (undefined !== tmp) ? tmp : null;
+        return null !== this.currentStream;
+    }
+    /**
+     * Once the current stream starts to pass their data, this handles it in a
+     * less complicated way
+     * @returns This instance of Sandwich Stream
+     */
+    bindCurrentStreamEvents() {
+        this.currentStream.on('readable', this.currentStreamOnReadable.bind(this));
+        this.currentStream.on('end', this.currentStreamOnEnd.bind(this));
+    }
+    /**
+     * Handles the data from a current stream once they are being streamed
+     * @returns This instance of Sandwich Stream
+     */
+    currentStreamOnReadable() {
+        const tmp = this.currentStream.read();
+        const data = (undefined !== tmp && null !== tmp) ? tmp : '';
+        this.push(data);
+    }
+    /**
+     * Handles the tagging once a stream is finished
+     * @returns This instance of Sandwich Stream
+     */
+    currentStreamOnEnd() {
+        this.pushSeparator();
+        this.streams.concat(this.newStreams);
+        this.newStreams = [];
+        this.streamNextStream();
+    }
+    /**
+     * Adds the head tag to the Sandwich Stream
+     * @returns This instance of Sandwich Stream
+     */
+    pushHead() {
+        if (null !== this.head) {
+            this.push(this.head);
+        }
+    }
+    /**
+     * Adds the separator tag to the Sandwich Stream
+     * @returns This instance of Sandwich Stream
+     */
+    pushSeparator() {
+        if (0 < this.streams.length && null !== this.separator) {
+            this.push(this.separator);
+        }
+    }
+    /**
+     * Adds the tail tag to the Sandwich Stream
+     * @returns This instance of Sandwich Stream
+     */
+    pushTail() {
+        if (null !== this.tail) {
+            this.push(this.tail);
+        }
+    }
+}
+
+exports.SandwichStream = SandwichStream;
+exports.default = SandwichStream;