Update docs

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@jogogo/mhysa",
-    "version": "2.0.0-alpha.4",
+    "version": "2.0.0-alpha.3",
     "description": "Streams and event emitter utils for Node.js",
     "keywords": [
         "promise",

src/functions/demux.ts

@@ -6,45 +6,36 @@ type DemuxStreams = NodeJS.WritableStream | NodeJS.ReadWriteStream;
 
 export interface DemuxOptions extends DuplexOptions {
     remultiplex?: boolean;
+    purgeIdleInterval?: number;
+    maxIdleTime?: number;
 }
 
 export function demux(
-    pipelineConstructor: (
+    construct: (destKey?: string, chunk?: any) => DemuxStreams,
-        destKey?: string,
-        chunk?: any,
-    ) => DemuxStreams | DemuxStreams[],
     demuxBy: string | ((chunk: any) => string),
     options?: DemuxOptions,
 ): Duplex {
-    return new Demux(pipelineConstructor, demuxBy, options);
+    return new Demux(construct, demuxBy, options);
 }
 
 class Demux extends Duplex {
     private streamsByKey: {
-        [key: string]: DemuxStreams[];
+        [key: string]: { stream: DemuxStreams; lastWrite: number };
     };
     private demuxer: (chunk: any) => string;
-    private pipelineConstructor: (
+    private construct: (destKey?: string, chunk?: any) => DemuxStreams;
-        destKey?: string,
-        chunk?: any,
-    ) => DemuxStreams[];
     private remultiplex: boolean;
     private transform: Transform;
+    private maxIdleTime: number;
     constructor(
-        pipelineConstructor: (
+        construct: (destKey?: string) => DemuxStreams,
-            destKey?: string,
-            chunk?: any,
-        ) => DemuxStreams | DemuxStreams[],
         demuxBy: string | ((chunk: any) => string),
         options: DemuxOptions = {},
     ) {
         super(options);
         this.demuxer =
             typeof demuxBy === "string" ? chunk => chunk[demuxBy] : demuxBy;
-        this.pipelineConstructor = (destKey: string, chunk?: any) => {
+        this.construct = construct;
-            const pipeline = pipelineConstructor(destKey, chunk);
-            return Array.isArray(pipeline) ? pipeline : [pipeline];
-        };
         this.remultiplex =
             options.remultiplex === undefined ? true : options.remultiplex;
         this.streamsByKey = {};
@@ -55,77 +46,74 @@ class Demux extends Duplex {
                 cb(null);
             },
         });
+        this.maxIdleTime = options.maxIdleTime || 600000;
+        const purgeIdleInterval = options.purgeIdleInterval || 600000;
+        setInterval(() => {
+            this._destroyIdle();
+        }, purgeIdleInterval);
 
         this.on("unpipe", () => this._flush());
     }
 
+    private _destroyIdle() {
+        for (let key in this.streamsByKey) {
+            const curTime = Date.now();
+            const pipeline = this.streamsByKey[key];
+
+            if (curTime - pipeline.lastWrite > this.maxIdleTime) {
+                delete this.streamsByKey[key];
+            }
+        }
+    }
     // tslint:disable-next-line
     public _read(size: number) {}
 
     public async _write(chunk: any, encoding: any, cb: any) {
         const destKey = this.demuxer(chunk);
         if (this.streamsByKey[destKey] === undefined) {
-            const newPipelines = this.pipelineConstructor(destKey, chunk);
+            const newPipeline = await this.construct(destKey, chunk);
-            this.streamsByKey[destKey] = newPipelines;
+            this.streamsByKey[destKey] = {
-
+                stream: newPipeline,
-            newPipelines.forEach(newPipeline => {
+                lastWrite: Date.now(),
-                if (this.remultiplex && isReadable(newPipeline)) {
+            };
-                    (newPipeline as NodeJS.ReadWriteStream).pipe(
+            if (this.remultiplex && isReadable(newPipeline)) {
-                        this.transform,
+                (newPipeline as NodeJS.ReadWriteStream).pipe(this.transform);
-                    );
+            } else if (this.remultiplex) {
-                } else if (this.remultiplex) {
+                console.error(
-                    console.error(
+                    `Pipeline construct for ${destKey} does not implement readable interface`,
-                        `Pipeline construct for ${destKey} does not implement readable interface`,
-                    );
-                }
-            });
-        }
-        const pipelines = this.streamsByKey[destKey];
-        const pendingDrains: Array<Promise<any>> = [];
-
-        pipelines.forEach(pipeline => {
-            if (!pipeline.write(chunk, encoding)) {
-                pendingDrains.push(
-                    new Promise(resolve => {
-                        pipeline.once("drain", () => {
-                            resolve();
-                        });
-                    }),
                 );
             }
-        });
+        } else {
-        await Promise.all(pendingDrains);
+            this.streamsByKey[destKey].lastWrite = Date.now();
-        cb();
+        }
+
+        if (!this.streamsByKey[destKey].stream.write(chunk, encoding)) {
+            this.streamsByKey[destKey].stream.once("drain", () => {
+                cb();
+            });
+        } else {
+            cb();
+        }
     }
 
     public _flush() {
-        const pipelines: DemuxStreams[] = [].concat.apply(
+        const pipelines = Object.values(this.streamsByKey);
-            [],
+        let totalEnded = 0;
-            Object.values(this.streamsByKey),
+        pipelines.forEach(({ stream }) => {
-        );
+            stream.once("end", () => {
-        const flushPromises: Array<Promise<void>> = [];
+                totalEnded++;
-        pipelines.forEach(pipeline => {
+                if (pipelines.length === totalEnded) {
-            flushPromises.push(
+                    this.push(null);
-                new Promise(resolve => {
+                    this.emit("end");
-                    pipeline.once("end", () => {
+                }
-                        resolve();
+            });
-                    });
-                }),
-            );
-        });
-        pipelines.forEach(pipeline => pipeline.end());
-        Promise.all(flushPromises).then(() => {
-            this.push(null);
-            this.emit("end");
         });
+        pipelines.forEach(({ stream }) => stream.end());
     }
 
     public _destroy(error: any, cb: (error?: any) => void) {
-        const pipelines: DemuxStreams[] = [].concat.apply(
+        const pipelines = Object.values(this.streamsByKey);
-            [],
+        pipelines.forEach(({ stream }) => (stream as any).destroy());
-            Object.values(this.streamsByKey),
-        );
-        pipelines.forEach(p => (p as any).destroy());
         cb(error);
     }
 }

src/functions/index.ts

@@ -256,11 +256,14 @@ export default function mhysa(defaultOptions?: TransformOptions) {
 
         /**
          * Composes multiple streams together. Writing occurs on first stream, piping occurs from last stream.
-         * @param construct Constructor for new output source. Should return a Writable or ReadWrite stream.
+         * @param {Function} construct Constructor for new output source. Should return a Writable or ReadWrite stream.
-         * @param demuxBy
+         * @param {String | Function} demuxBy
-         * @param demuxBy.key? Key to fetch value from source chunks to demultiplex source.
+         * @param {string} demuxBy.key? Key to fetch value from source chunks to demultiplex source.
-         * @param demuxBy.keyBy? Function to fetch value from source chunks to demultiplex source.
+         * @param {Function} demuxBy.keyBy? Function to fetch value from source chunks to demultiplex source.
-         * @param options Writable stream options
+         * @param {Object} options Demux stream options
+         * @param {boolean} options.remultiplex? If demux should be remultiplexed into a single destination
+         * @param {number} options.purgeIdleInterval? Interval at which a purge for idle pipelines will occur
+         * @param {number} options.maxIdleTime? Min time a demuxed pipeline must be idle for to be purged
          */
         demux: withDefaultOptions(2, demux),
     };

tests/demux.spec.ts

@@ -862,3 +862,39 @@ test.cb("demux() should be 'destroyable'", t => {
     fakeSource.push(input[3]);
     fakeSource.push(input[4]);
 });
+
+test.cb("Should delete idle pipelines", t => {
+    t.plan(5);
+    const input = [
+        { key: "a", visited: [] },
+        { key: "b", visited: [] },
+        { key: "b", visited: [] },
+        { key: "a", visited: [] },
+        { key: "b", visited: [] },
+        { key: "c", visited: [] },
+    ];
+    const construct = sinon.spy((destKey: string) => {
+        const dest = map((chunk: Test) => {
+            chunk.visited.push(1);
+            return chunk;
+        });
+        t.pass();
+
+        return dest;
+    });
+
+    const demuxed = demux(construct, "key", {
+        maxIdleTime: 110,
+        purgeIdleInterval: 110,
+    });
+
+    demuxed.on("data", data => {
+        if (data.key === "c") t.end();
+    });
+
+    for (let i = 0; i < input.length; i++) {
+        setTimeout(() => {
+            demuxed.write(input[i]);
+        }, i * 100);
+    }
+});