From 218d4ce7616e07b1d580c8b1022c52656a8058b7 Mon Sep 17 00:00:00 2001
From: HDegroote <75906619+HDegroote@users.noreply.github.com>
Date: Mon, 24 Jun 2024 15:08:51 +0200
Subject: [PATCH] Expose maxCacheSize opt (for system db) (#156)

* Expose maxCacheSize opt (for system db)

* 0 default

* Make SystemView's 'checkout' non-positional

* Cleaner opts definition in SystemView

* Bugfix: use correct maxCacheSize for SystemView.checkout

* reformat multiline opts

* checkout takes optional maxCacheSize

---------

Co-authored-by: Christophe Diederichs <chm-diederichs@protonmail.com>
---
 index.js      | 34 +++++++++++++++++++++++++++++-----
 lib/system.js | 13 +++++++++----
 test/basic.js | 15 +++++++++++++++
 3 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/index.js b/index.js
index b6e040b8..4757fd1d 100644
--- a/index.js
+++ b/index.js
@@ -131,6 +131,8 @@ module.exports = class Autobase extends ReadyResource {
     this.system = null
     this.version = -1
 
+    this.maxCacheSize = handlers.maxCacheSize || 0 // 0 means the hyperbee default cache size will be used
+
     const {
       ackInterval = DEFAULT_ACK_INTERVAL,
       ackThreshold = DEFAULT_ACK_THRESHOLD
@@ -150,7 +152,13 @@ module.exports = class Autobase extends ReadyResource {
 
     this._waiting = new SignalPromise()
 
-    this.system = new SystemView(this._viewStore.get({ name: '_system', exclusive: true }))
+    const sysCore = this._viewStore.get({ name: '_system', exclusive: true })
+
+    this.system = new SystemView(sysCore, {
+      checkout: 0,
+      maxCacheSize: this.maxCacheSize
+    })
+
     this.view = this._hasOpen ? this._handlers.open(this._viewStore, this) : null
 
     this.ready().catch(safetyCatch)
@@ -316,7 +324,11 @@ module.exports = class Autobase extends ReadyResource {
       return { bootstrap, system: null, heads: [] }
     }
 
-    const system = new SystemView(core, length)
+    const system = new SystemView(core, {
+      checkout: length,
+      maxCacheSize: this.maxCacheSize
+    })
+
     await system.ready()
 
     if (system.version > this.maxSupportedVersion) {
@@ -406,7 +418,11 @@ module.exports = class Autobase extends ReadyResource {
     const core = this.store.get({ key, encryptionKey, isBlockKey: true }).batch({ checkout: length, session: false })
 
     const base = this
-    const system = new SystemView(core, length)
+    const system = new SystemView(core, {
+      checkout: length,
+      maxCacheSize: this.maxCacheSize
+    })
+
     await system.ready()
 
     const indexerCores = []
@@ -1551,7 +1567,11 @@ module.exports = class Autobase extends ReadyResource {
         await core.get(length - 1, { timeout })
       }
 
-      const system = new SystemView(core.session(), length)
+      const system = new SystemView(core.session(), {
+        checkout: length,
+        maxCacheSize: this.maxCacheSize
+      })
+
       await system.ready()
 
       if (system.version > this.maxSupportedVersion) {
@@ -1670,7 +1690,11 @@ module.exports = class Autobase extends ReadyResource {
       return
     }
 
-    const system = new SystemView(core, length)
+    const system = new SystemView(core, {
+      checkout: length,
+      maxCacheSize: this.maxCacheSize
+    })
+
     await system.ready()
 
     const opened = []
diff --git a/lib/system.js b/lib/system.js
index 30b1b711..6cc68418 100644
--- a/lib/system.js
+++ b/lib/system.js
@@ -12,12 +12,13 @@ const DIGEST = subs.sub(b4a.from([0]))
 const MEMBERS = subs.sub(b4a.from([1]))
 
 module.exports = class SystemView extends ReadyResource {
-  constructor (core, checkout = 0) {
+  constructor (core, { checkout = 0, maxCacheSize = 0 } = {}) {
     super()
 
     this.core = core
+
     // sessions is a workaround for batches not having sessions atm...
-    this.db = new Hyperbee(core, { keyEncoding: 'binary', extension: false, checkout, sessions: typeof core.session === 'function' })
+    this.db = new Hyperbee(core, { keyEncoding: 'binary', extension: false, checkout, sessions: typeof core.session === 'function', maxCacheSize })
 
     this.version = -1 // set version in apply
     this.members = 0
@@ -67,8 +68,12 @@ module.exports = class SystemView extends ReadyResource {
     }
   }
 
-  async checkout (length) {
-    const checkout = new SystemView(this.core.session(), length)
+  async checkout (length, { maxCacheSize = this.db.maxCacheSize } = {}) {
+    const checkout = new SystemView(this.core.session(), {
+      checkout: length,
+      maxCacheSize
+    })
+
     await checkout.ready()
 
     return checkout
diff --git a/test/basic.js b/test/basic.js
index be94550a..f63ffc0e 100644
--- a/test/basic.js
+++ b/test/basic.js
@@ -1616,6 +1616,21 @@ test('basic - writer adds a writer while being removed', async t => {
   t.is(binfo.isRemoved, true)
 })
 
+test('basic - maxCacheSize opt', async t => {
+  const [store] = await createStores(1, t)
+  const base = new Autobase(store.namespace('with-cache'), null, { maxCacheSize: 10 })
+  await base.ready()
+  t.is(base.maxCacheSize, 10, 'maxCacheSize set')
+  t.is(base.system.db.maxCacheSize, 10, 'maxCacheSize applied to sys db')
+})
+
+test('basic - maxCacheSize has 0 default', async t => {
+  const [store] = await createStores(1, t)
+  const base = new Autobase(store.namespace('with-cache'))
+  await base.ready()
+  t.is(base.maxCacheSize, 0, 'maxCacheSize default 0')
+})
+
 // todo: this test is hard, probably have to rely on ff to recover
 test.skip('basic - writer adds a writer while being removed', async t => {
   const { bases } = await create(4, t, { apply: applyWithRemove })