libresilient: run fetch and alt-fetch in parallel

config.json

@@ -1,18 +1,28 @@
 {
-    "plugins": [{
-        "name": "fetch"
-    },
+  "plugins": [
     {
-        "name": "cache"
+      "name": "any-of",
+      "uses": [
+        {
+          "name": "fetch"
+        },
+        {
+          "name": "delay",
+          "defaultDelay": 5000,
+          "uses": [
+            {
+              "name": "alt-fetch",
+              "endpoints": ["https://deltachat.github.io/deltachat-pages/"]
+            }
+          ]
+        }
+      ]
     },
     {
-        "name": "alt-fetch",
-        "endpoints": [
-            "https://deltachat.github.io/deltachat-pages/"
-        ]
+      "name": "cache"
     }
-    ],
-    "stillLoadingTimeout": 0,
-    "loggedComponents": ["service-worker", "fetch", "cache", "alt-fetch"]
+  ],
+  "defaultPluginTimeout": 300000,
+  "stillLoadingTimeout": 0,
+  "loggedComponents": ["service-worker", "fetch", "cache", "alt-fetch"]
 }
-

plugins/any-of/index.js

@@ -0,0 +1,59 @@
+/* ========================================================================= *\
+|* === Any-of: running multiple plugins simultaneously                   === *|
+\* ========================================================================= */
+
+/**
+ * this plugin does not implement any push method
+ */
+
+// no polluting of the global namespace please
+(function(LRPC){
+    // this never changes
+    const pluginName = "any-of"
+    LRPC.set(pluginName, (LR, init={})=>{
+
+        /*
+         * plugin config settings
+         */
+
+        // sane defaults
+        let defaultConfig = {
+            // list of plugins to run simultaneously
+            uses: [{
+                    name: "alt-fetch"
+                },{
+                    name: "gun-ipfs"
+                }]
+        }
+
+        // merge the defaults with settings from LibResilientConfig
+        let config = {...defaultConfig, ...init}
+
+        // reality check: if no wrapped plugin configured, complain
+        if (config.uses.length < 1) {
+            throw new Error("No wrapped plugins configured!")
+        }
+
+        /**
+         * getting content using Promise.any() on all configured wrapped plugins
+         */
+        let fetchContent = (url, init={}) => {
+            LR.log(pluginName, `using: [${config.uses.map(p=>p.name).join(', ')}]!`)
+            return Promise.any(
+                config.uses.map(p=>p.fetch(url, init))
+            )
+        }
+
+        // and add ourselves to it
+        // with some additional metadata
+        return {
+            name: pluginName,
+            description: `Running simultaneously: [${config.uses.map(p=>p.name).join(', ')}]`,
+            version: 'COMMIT_UNKNOWN',
+            fetch: fetchContent,
+            uses: config.uses
+        }
+
+    })
+// done with not polluting the global namespace
+})(LibResilientPluginConstructors)

plugins/delay/index.js

@@ -0,0 +1,86 @@
+/* ========================================================================= *\
+|* === Delay plugin                                                      === *|
+\* ========================================================================= */
+
+/**
+ * this plugin does not implement any push method
+ */
+
+// no polluting of the global namespace please
+(function(LRPC){
+    // this never changes
+    const pluginName = "delay"
+    LRPC.set(pluginName, (LR, init={})=>{
+
+        /*
+         * plugin config settings
+         */
+
+        // sane defaults
+        let defaultConfig = {
+            // array of two-element arrays
+            // ["/regex_match/", <slowdown in ms>]
+            // first match wins
+            delay: [],
+
+            // default delay, in ms
+            defaultDelay: 1000,
+
+            // plugin to wrap, regular fetch by default
+            uses: [{
+                name: "fetch"
+            }]
+        }
+
+        // merge the defaults with settings from init
+        let config = {...defaultConfig, ...init}
+
+        // reality check: if no wrapped plugin configured, or more than one, complain
+        if (config.uses.length != 1) {
+            throw new Error(`Expected exactly one plugin to wrap, but ${config.uses.length} configured.`)
+        }
+
+        /**
+        * getting content using regular HTTP(S) fetch()
+        */
+        let fetchContent = (url, init={}) => {
+            LR.log(pluginName, `delayed retrieval: ${url}`)
+            // we really want to make fetch happen, Regina!
+            // TODO: this change should *probably* be handled on the Service Worker level
+            init.cache = 'reload'
+
+            // establish the default delay
+            let impose_delay = config.defaultDelay
+            LR.log(pluginName, `default delay: ${impose_delay}`)
+
+            // see if we have any specific delay rule that matches
+            // first match wins
+            for (sp of config.delay) {
+                LR.log(pluginName, `checking delay rule: ${sp}`)
+                let re = new RegExp(sp[0])
+                if (url.search(re) > -1) {
+                    LR.log(pluginName, `delay rule matched: ${sp[0]}, delay set to: ${sp[1]}`)
+                    impose_delay = sp[1]
+                    break;
+                }
+            }
+
+            // wait a bit and run the first wrapped plugin's fetch()
+            return promiseTimeout(impose_delay, true)[0]
+                .then(() => {
+                    return config.uses[0].fetch(url, init)
+                })
+        }
+
+        // return the plugin
+        return {
+            name: pluginName,
+            description: 'Configurable delay!',
+            version: 'COMMIT_UNKNOWN',
+            fetch: fetchContent,
+            uses: config.uses
+        }
+
+    })
+// done with not polluting the global namespace
+})(LibResilientPluginConstructors)