From db78df2fba24a69175ddce30729efcab5c10bcba Mon Sep 17 00:00:00 2001
From: Marcin Rataj <lidel@lidel.org>
Date: Tue, 16 Jul 2019 23:57:10 +0200
Subject: [PATCH] feat: preload webui root CID (#735)

Optimization: preload the root CID to speed up the first time
Web UI is opened. If embedded js-ipfs is used it will trigger
remote (always recursive) preload of entire DAG to one of preload nodes.
This way when embedded node wants to load resource related to webui
it will get it fast from preload nodes.

This is a best-effort version of #682
---
 add-on/src/lib/ipfs-client/index.js | 18 ++++++++++++++++--
 add-on/src/lib/state.js             |  9 ++++++---
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/add-on/src/lib/ipfs-client/index.js b/add-on/src/lib/ipfs-client/index.js
index 41542b53e..c7b69ecae 100644
--- a/add-on/src/lib/ipfs-client/index.js
+++ b/add-on/src/lib/ipfs-client/index.js
@@ -10,6 +10,7 @@ const browser = require('webextension-polyfill')
 const external = require('./external')
 const embedded = require('./embedded')
 const embeddedWithChromeSockets = require('./embedded-chromesockets')
+const { webuiCid } = require('../state')
 
 let client
 
@@ -32,7 +33,7 @@ async function initIpfsClient (opts) {
 
   const instance = await client.init(opts)
   easeApiChanges(instance)
-  _reloadIpfsClientDependents() // async (API is present)
+  _reloadIpfsClientDependents(instance) // async (API is present)
   return instance
 }
 
@@ -53,7 +54,8 @@ function _isWebuiTab (url) {
   return bundled || ipns
 }
 
-async function _reloadIpfsClientDependents () {
+async function _reloadIpfsClientDependents (instance, opts) {
+  // online || offline
   if (browser.tabs && browser.tabs.query) {
     const tabs = await browser.tabs.query({})
     if (tabs) {
@@ -66,6 +68,18 @@ async function _reloadIpfsClientDependents () {
       })
     }
   }
+  // online only
+  if (client && instance) {
+    if (webuiCid && instance.refs) {
+      // Optimization: preload the root CID to speed up the first time
+      // Web UI is opened. If embedded js-ipfs is used it will trigger
+      // remote (always recursive) preload of entire DAG to one of preload nodes.
+      // This way when embedded node wants to load resource related to webui
+      // it will get it fast from preload nodes.
+      log(`preloading webui root at ${webuiCid}`)
+      instance.refs(webuiCid, { recursive: false })
+    }
+  }
 }
 
 const movedFilesApis = ['add', 'addPullStream', 'addReadableStream', 'cat', 'catPullStream', 'catReadableStream', 'get', 'getPullStream', 'getReadableStream']
diff --git a/add-on/src/lib/state.js b/add-on/src/lib/state.js
index 6345727dd..b9fa09503 100644
--- a/add-on/src/lib/state.js
+++ b/add-on/src/lib/state.js
@@ -4,6 +4,10 @@
 const { safeURL } = require('./options')
 const offlinePeerCount = -1
 
+// CID of a 'blessed' Web UI release
+// which should work without setting CORS headers
+const webuiCid = 'QmYTRvKFGhxgBiUreiw7ihn8g95tfJTWDt7aXqDsvAcJse' // v2.4.7
+
 function initState (options) {
   // we store options and some pregenerated values to avoid async storage
   // reads and minimize performance impact on overall browsing experience
@@ -22,12 +26,11 @@ function initState (options) {
   state.gwURLString = state.gwURL.toString()
   delete state.customGatewayUrl
   state.dnslinkPolicy = String(options.dnslinkPolicy) === 'false' ? false : options.dnslinkPolicy
-  // store info about 'blessed' release of Web UI
-  // which should work without setting CORS headers
-  state.webuiCid = 'QmQNHd1suZTktPRhP7DD4nKWG46ZRSxkwHocycHVrK3dYW' // v2.4.6
+  state.webuiCid = webuiCid
   state.webuiRootUrl = `${state.gwURLString}ipfs/${state.webuiCid}/`
   return state
 }
 
 exports.initState = initState
 exports.offlinePeerCount = offlinePeerCount
+exports.webuiCid = webuiCid