Add opts.cache and share cache between all core sessions (#18)

* Add `opts.cache` and share cache between all core sessions

* Trigger Actions

* Allow overriding session cache

* Pass cache opt to namespaces

Co-authored-by: Andrew Osheroff <andrewosh@gmail.com>

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 sandbox
 coverage
+package-lock.json

index.js

@@ -3,6 +3,7 @@ const safetyCatch = require('safety-catch')
 const crypto = require('hypercore-crypto')
 const sodium = require('sodium-universal')
 const Hypercore = require('hypercore')
+const Xache = require('xache')
 const b4a = require('b4a')
 
 const [NS] = crypto.namespace('corestore', 1)
@@ -20,6 +21,7 @@ module.exports = class Corestore extends EventEmitter {
     this.storage = Hypercore.defaultStorage(storage, { lock: PRIMARY_KEY_FILE_NAME })
     this.cores = opts._cores || new Map()
     this.primaryKey = null
+    this.cache = !!opts.cache
 
     this._keyStorage = null
     this._primaryKey = opts.primaryKey
@@ -175,6 +177,7 @@ module.exports = class Corestore extends EventEmitter {
       encryptionKey: opts.encryptionKey || null,
       userData,
       auth,
+      cache: opts.cache,
       createIfMissing: !opts._discoveryKey,
       keyPair: keyPair && keyPair.publicKey
         ? {
@@ -224,6 +227,11 @@ module.exports = class Corestore extends EventEmitter {
 
   get (opts = {}) {
     opts = validateGetOptions(opts)
+
+    if (opts.cache !== false) {
+      opts.cache = opts.cache === true || (this.cache && !opts.cache) ? defaultCache() : opts.cache
+    }
+
     const core = new Hypercore(null, {
       ...opts,
       name: null,
@@ -279,6 +287,7 @@ module.exports = class Corestore extends EventEmitter {
     return new Corestore(this.storage, {
       primaryKey: this._opening.then(() => this.primaryKey),
       namespace: generateNamespace(this._namespace, name),
+      cache: this.cache,
       _opening: this._opening,
       _cores: this.cores,
       _streams: this._replicationStreams,
@@ -355,6 +364,10 @@ function deriveSeed (primaryKey, namespace, name) {
   return out
 }
 
+function defaultCache () {
+  return new Xache({ maxSize: 65536, maxAge: 0 })
+}
+
 function isStream (s) {
   return typeof s === 'object' && s && typeof s.pipe === 'function'
 }

package.json

@@ -30,6 +30,7 @@
     "hypercore": "next",
     "hypercore-crypto": "^3.2.1",
     "safety-catch": "^1.0.1",
-    "sodium-universal": "^3.0.4"
+    "sodium-universal": "^3.0.4",
+    "xache": "^1.1.0"
   }
 }

test/all.js

@@ -1,4 +1,4 @@
-const { test, configure } = require('brittle')
+const test = require('brittle')
 const crypto = require('hypercore-crypto')
 const ram = require('random-access-memory')
 const os = require('os')
@@ -8,8 +8,6 @@ const sodium = require('sodium-universal')
 
 const Corestore = require('..')
 
-configure({ serial: true })
-
 test('basic get with caching', async function (t) {
   const store = new Corestore(ram)
   const core1a = store.get({ name: 'core-1' })

test/cache.js

@@ -0,0 +1,46 @@
+const test = require('brittle')
+const RAM = require('random-access-memory')
+
+const Corestore = require('..')
+
+test('core cache', async function (t) {
+  const store = new Corestore(RAM, { cache: true })
+
+  const core = store.get({ name: 'core' })
+  await core.append(['a', 'b', 'c'])
+
+  const p = core.get(0)
+  const q = core.get(0)
+
+  t.is(await p, await q)
+})
+
+test('clear cache on truncate', async function (t) {
+  const store = new Corestore(RAM, { cache: true })
+
+  const core = store.get({ name: 'core' })
+  await core.append(['a', 'b', 'c'])
+
+  const p = core.get(0)
+
+  await core.truncate(0)
+  await core.append('d')
+
+  const q = core.get(0)
+
+  t.alike(await p, Buffer.from('a'))
+  t.alike(await q, Buffer.from('d'))
+})
+
+test('core cache on namespace', async function (t) {
+  const store = new Corestore(RAM, { cache: true })
+  const ns1 = store.namespace('test-namespace-1')
+
+  const c1 = store.get({ name: 'test-core' })
+  const c2 = ns1.get({ name: 'test-core' })
+
+  await Promise.all([c1.ready(), c2.ready()])
+
+  t.ok(c1.cache)
+  t.ok(c2.cache)
+})