batch concurrent requests for expensive IO and computations

rpc.js

@@ -19,6 +19,7 @@ const getFolderSize = require("get-folder-size");
 const Pins = require("./lib/pins");
 const Meta = require("./lib/metadata");
 const WriteQueue = require("./lib/write-queue");
+const BatchRead = require("./lib/batch-read");
 
 var RPC = module.exports;
 
@@ -231,6 +232,7 @@ var checkSignature = function (signedMsg, signature, publicKey) {
     return Nacl.sign.detached.verify(signedBuffer, signatureBuffer, pubBuffer);
 };
 
+const batchUserPins = BatchRead();
 var loadUserPins = function (Env, publicKey, cb) {
     var session = getSession(Env.Sessions, publicKey);
 
@@ -238,6 +240,7 @@ var loadUserPins = function (Env, publicKey, cb) {
         return cb(session.channels);
     }
 
+    batchUserPins(publicKey, cb, function (done) {
         var ref = {};
         var lineHandler = Pins.createLineHandler(ref, function (label, data) {
             Log.error(label, {
@@ -252,7 +255,8 @@ var loadUserPins = function (Env, publicKey, cb) {
 
             // only put this into the cache if it completes
             session.channels = ref.pins;
-        cb(ref.pins);
+            done(ref.pins); // FIXME no error handling?
+        });
     });
 };
 
@@ -290,45 +294,49 @@ var getUploadSize = function (Env, channel, cb) {
     });
 };
 
+const batchFileSize = BatchRead();
 var getFileSize = function (Env, channel, cb) {
     if (!isValidId(channel)) { return void cb('INVALID_CHAN'); }
-
+    batchFileSize(channel, cb, function (done) {
         if (channel.length === 32) {
             if (typeof(Env.msgStore.getChannelSize) !== 'function') {
-            return cb('GET_CHANNEL_SIZE_UNSUPPORTED');
+                return done('GET_CHANNEL_SIZE_UNSUPPORTED');
             }
 
             return void Env.msgStore.getChannelSize(channel, function (e, size /*:number*/) {
                 if (e) {
-                if (e.code === 'ENOENT') { return void cb(void 0, 0); }
-                return void cb(e.code);
+                    if (e.code === 'ENOENT') { return void done(void 0, 0); }
+                    return void done(e.code);
                 }
-            cb(void 0, size);
+                done(void 0, size);
             });
         }
 
         // 'channel' refers to a file, so you need another API
         getUploadSize(Env, channel, function (e, size) {
-        if (typeof(size) === 'undefined') { return void cb(e); }
-        cb(void 0, size);
+            if (typeof(size) === 'undefined') { return void done(e); }
+            done(void 0, size);
+        });
     });
 };
 
-
+const batchMetadata = BatchRead();
 var getMetadata = function (Env, channel, cb) {
     if (!isValidId(channel)) { return void cb('INVALID_CHAN'); }
 
     if (channel.length !== 32) { return cb("INVALID_CHAN"); }
 
+    batchMetadata(channel, cb, function (done) {
         var ref = {};
         var lineHandler = Meta.createLineHandler(ref, Log.error);
 
         return void Env.msgStore.readChannelMetadata(channel, lineHandler, function (err) {
             if (err) {
                 // stream errors?
-            return void cb(err);
+                return void done(err);
             }
-        cb(void 0, ref.meta);
+            done(void 0, ref.meta);
+        });
     });
 };
 
@@ -470,19 +478,22 @@ var getDeletedPads = function (Env, channels, cb) {
     });
 };
 
+const batchTotalSize = BatchRead();
 var getTotalSize = function (Env, publicKey, cb) {
+    batchTotalSize(publicKey, cb, function (done) {
         var bytes = 0;
         return void getChannelList(Env, publicKey, function (channels) {
-        if (!channels) { return cb('INVALID_PIN_LIST'); } // unexpected
+            if (!channels) { return done('INVALID_PIN_LIST'); } // unexpected
 
             var count = channels.length;
-        if (!count) { cb(void 0, 0); }
+            if (!count) { return void done(void 0, 0); }
 
-        channels.forEach(function (channel) {
+            channels.forEach(function (channel) { // FIXME this might as well be nThen
                 getFileSize(Env, channel, function (e, size) {
                     count--;
                     if (!e) { bytes += size; }
-                if (count === 0) { return cb(void 0, bytes); }
+                    if (count === 0) { return done(void 0, bytes); }
+                });
             });
         });
     });
@@ -1605,7 +1616,9 @@ var writePrivateMessage = function (Env, args, nfwssCtx, cb) {
     });
 };
 
+const batchDiskUsage = BatchRead();
 var getDiskUsage = function (Env, cb) {
+    batchDiskUsage('', cb, function (done) {
         var data = {};
         nThen(function (waitFor) {
             getFolderSize('./', waitFor(function(err, info) {
@@ -1627,10 +1640,14 @@ var getDiskUsage = function (Env, cb) {
                 data.datastore = info;
             }));
         }).nThen(function () {
-        cb (void 0, data);
+            done(void 0, data);
+        });
     });
 };
+
+const batchRegisteredUsers = BatchRead();
 var getRegisteredUsers = function (Env, cb) {
+    batchRegisteredUsers('', cb, function (done) {
         var dir = Env.paths.pin;
         var folders;
         var users = 0;
@@ -1638,7 +1655,7 @@ var getRegisteredUsers = function (Env, cb) {
             Fs.readdir(dir, waitFor(function (err, list) {
                 if (err) {
                     waitFor.abort();
-                return void cb(err);
+                    return void done(err);
                 }
                 folders = list;
             }));
@@ -1651,7 +1668,8 @@ var getRegisteredUsers = function (Env, cb) {
                 }));
             });
         }).nThen(function () {
-        cb(void 0, users);
+            done(void 0, users);
+        });
     });
 };
 var getActiveSessions = function (Env, ctx, cb) {