First prototype of an offline cache

lib/hk-util.js

@@ -419,9 +419,11 @@ const getHistoryOffset = (Env, channelName, lastKnownHash, _cb) => {
             // fall through to the next block if the offset of the hash in question is not in memory
             if (lastKnownHash && typeof(lkh) !== "number") { return; }
 
+            // If we have a lastKnownHash or we didn't ask for one, we don't need the next blocks
+            waitFor.abort();
+
             // Since last 2 checkpoints
             if (!lastKnownHash) {
-                waitFor.abort();
                 // Less than 2 checkpoints in the history: return everything
                 if (index.cpIndex.length < 2) { return void cb(null, 0); }
                 // Otherwise return the second last checkpoint's index
@@ -436,7 +438,14 @@ const getHistoryOffset = (Env, channelName, lastKnownHash, _cb) => {
                     to reconcile their differences. */
             }
 
-            offset = lkh;
+            // If our lastKnownHash is older than the 2nd to last checkpoint,
+            // only send the last 2 checkpoints and ignore "lkh"
+            if (lkh && index.cpIndex.length >= 2 && lkh < index.cpIndex[0].offset) {
+                return void cb(null, index.cpIndex[0].offset);
+            }
+
+            // Otherwise use our lastKnownHash
+            cb(null, lkh);
         }));
     }).nThen((w) => {
         // skip past this block if the offset is anything other than -1

www/common/outer/async-store.js

@@ -10,6 +10,7 @@ define([
     '/common/common-realtime.js',
     '/common/common-messaging.js',
     '/common/pinpad.js',
+    '/common/outer/cache-store.js',
     '/common/outer/sharedfolder.js',
     '/common/outer/cursor.js',
     '/common/outer/onlyoffice.js',
@@ -28,7 +29,7 @@ define([
     '/bower_components/nthen/index.js',
     '/bower_components/saferphore/index.js',
 ], function (Sortify, UserObject, ProxyManager, Migrate, Hash, Util, Constants, Feedback,
-             Realtime, Messaging, Pinpad,
+             Realtime, Messaging, Pinpad, Cache,
              SF, Cursor, OnlyOffice, Mailbox, Profile, Team, Messenger, History,
              NetConfig, AppConfig,
              Crypto, ChainPad, CpNetflux, Listmap, nThen, Saferphore) {
@@ -1590,6 +1591,7 @@ define([
                 Store.leavePad(null, data, function () {});
             };
             var conf = {
+                Cache: Cache,
                 onReady: function (pad) {
                     var padData = pad.metadata || {};
                     channel.data = padData;
@@ -2640,6 +2642,7 @@ define([
                 readOnly: false,
                 validateKey: secret.keys.validateKey || undefined,
                 crypto: Crypto.createEncryptor(secret.keys),
+                Cache: Cache,
                 userName: 'fs',
                 logLevel: 1,
                 ChainPad: ChainPad,

www/common/outer/cache-store.js

@@ -0,0 +1,55 @@
+define([
+    '/bower_components/localforage/dist/localforage.min.js',
+], function (localForage) {
+    var S = {};
+
+    var cache = localForage.createInstance({
+        name: "cp_cache"
+    });
+
+    // id: channel ID or blob ID
+    // returns array of messages
+    S.getChannelCache = function (id, cb) {
+        cache.getItem(id, function (err, obj) {
+            if (err || !obj || !Array.isArray(obj.c)) {
+                return void cb(err || 'EINVAL');
+            }
+            cb(null, obj);
+        });
+    };
+
+    var checkCheckpoints = function (array) {
+        if (!Array.isArray(array)) { return; }
+        var cp = 0;
+        for (var i = array.length - 1; i >= 0; i--) {
+            if (array[i].isCheckpoint) { cp++; }
+            if (cp === 2) {
+                array.splice(0, i);
+                break;
+            }
+        }
+    };
+
+    S.storeCache = function (id, validateKey, val, cb) {
+        cb = cb || function () {};
+        if (!Array.isArray(val) || !validateKey) { return void cb('EINVAL'); }
+        checkCheckpoints(val);
+        cache.setItem(id, {
+            k: validateKey,
+            c: val
+        }, function (err) {
+            cb(err);
+        });
+    };
+
+    S.clearChannel = function (id, cb) {
+        cb = cb || function () {};
+        cache.removeItem(id, cb);
+    };
+
+    S.clear = function () {
+        cache.clear();
+    };
+
+    return S;
+});

www/common/outer/sharedfolder.js

@@ -2,12 +2,13 @@ define([
     '/common/common-hash.js',
     '/common/common-util.js',
     '/common/userObject.js',
+    '/common/outer/cache-store.js',
 
     '/bower_components/nthen/index.js',
     '/bower_components/chainpad-crypto/crypto.js',
     '/bower_components/chainpad-listmap/chainpad-listmap.js',
     '/bower_components/chainpad/chainpad.dist.js',
-], function (Hash, Util, UserObject,
+], function (Hash, Util, UserObject, Cache,
              nThen, Crypto, Listmap, ChainPad) {
     var SF = {};
 
@@ -174,6 +175,7 @@ define([
                 ChainPad: ChainPad,
                 classic: true,
                 network: network,
+                Cache: Cache,
                 metadata: {
                     validateKey: secret.keys.validateKey || undefined,
                     owners: owners

www/common/outer/team.js

@@ -12,6 +12,7 @@ define([
     '/common/common-feedback.js',
     '/common/outer/invitation.js',
     '/common/cryptget.js',
+    '/common/outer/cache-store.js',
 
     '/bower_components/chainpad-listmap/chainpad-listmap.js',
     '/bower_components/chainpad-crypto/crypto.js',
@@ -21,7 +22,7 @@ define([
     '/bower_components/saferphore/index.js',
     '/bower_components/tweetnacl/nacl-fast.min.js',
 ], function (Util, Hash, Constants, Realtime,
-             ProxyManager, UserObject, SF, Roster, Messaging, Feedback, Invite, Crypt,
+             ProxyManager, UserObject, SF, Roster, Messaging, Feedback, Invite, Crypt, Cache,
              Listmap, Crypto, CpNetflux, ChainPad, nThen, Saferphore) {
     var Team = {};
 
@@ -426,6 +427,7 @@ define([
                 channel: secret.channel,
                 crypto: crypto,
                 ChainPad: ChainPad,
+                Cache: Cache,
                 metadata: {
                     validateKey: secret.keys.validateKey || undefined,
                 },
@@ -573,6 +575,7 @@ define([
             logLevel: 1,
             classic: true,
             ChainPad: ChainPad,
+            Cache: Cache,
             owners: [ctx.store.proxy.edPublic]
         };
         nThen(function (waitFor) {