blockchain: remove coin cache

CHANGELOG.md

@@ -44,6 +44,9 @@
 
 - Pool options now has a `--discover` option exposed, and the `--only` node
   option will disable discovery of new nodes.
+- The option for `coin-cache` has been removed, this setting was causing
+  issues during the sync with out-of-memory errors and was making performance
+  worse instead of better.
 
 ### Script changes
 

browser/src/app.js

@@ -61,7 +61,6 @@ const node = new FullNode({
   prune: true,
   network: 'main',
   memory: false,
-  coinCache: 30,
   logConsole: true,
   workers: true,
   workerFile: '/worker.js',

docs/configuration.md

@@ -87,9 +87,6 @@ database and must be passed in consistently.
 - `prune`: Prune from the last 288 blocks (default: false).
 - `checkpoints`: Use checkpoints and getheaders for the initial
   sync (default: true).
-- `coin-cache`: The size (in MB) of the in-memory UTXO cache. By default,
-  there is no UTXO cache enabled. To get a good number of cache hits per
-  block, the coin cache has to be fairly large (60-100mb recommended at least).
 - `index-tx`: Index transactions (enables transaction endpoints in REST api)
   (default: false).
 - `index-address`: Index transactions and utxos by address (default: false).

etc/sample.conf

@@ -37,7 +37,6 @@ log-file: true
 
 prune: false
 checkpoints: true
-coin-cache: 0
 entry-cache: 5000
 index-tx: false
 index-address: false

lib/blockchain/chain.js

@@ -79,9 +79,6 @@ class Chain extends AsyncEmitter {
     if (this.options.checkpoints)
       this.logger.info('Checkpoints are enabled.');
 
-    if (this.options.coinCache)
-      this.logger.info('Coin cache is enabled.');
-
     if (this.options.bip91)
       this.logger.warning('BIP91 enabled. Segsignal will be enforced.');
 
@@ -1535,11 +1532,6 @@ class Chain extends AsyncEmitter {
       block.getSize(),
       block.txs.length,
       elapsed);
-
-    if (this.db.coinCache.capacity > 0) {
-      this.logger.debug('Coin Cache: size=%dmb, items=%d.',
-        this.db.coinCache.size / (1 << 20), this.db.coinCache.items);
-    }
   }
 
   /**
@@ -2687,7 +2679,6 @@ class ChainOptions {
     this.indexAddress = false;
     this.forceFlags = false;
 
-    this.coinCache = 0;
     this.entryCache = 5000;
     this.maxOrphans = 20;
     this.checkpoints = true;
@@ -2786,11 +2777,6 @@ class ChainOptions {
       this.bip148 = options.bip148;
     }
 
-    if (options.coinCache != null) {
-      assert((options.coinCache >>> 0) === options.coinCache);
-      this.coinCache = options.coinCache;
-    }
-
     if (options.entryCache != null) {
       assert((options.entryCache >>> 0) === options.entryCache);
       this.entryCache = options.entryCache;

lib/blockchain/chaindb.js

@@ -47,7 +47,6 @@ class ChainDB {
     this.pending = null;
     this.current = null;
 
-    this.coinCache = new LRU(this.options.coinCache, getSize, BufferMap);
     this.cacheHash = new LRU(this.options.entryCache, null, BufferMap);
     this.cacheHeight = new LRU(this.options.entryCache);
   }
@@ -118,7 +117,6 @@ class ChainDB {
     this.current = this.db.batch();
     this.pending = this.state.clone();
 
-    this.coinCache.start();
     this.cacheHash.start();
     this.cacheHeight.start();
 
@@ -170,7 +168,6 @@ class ChainDB {
     this.current = null;
     this.pending = null;
 
-    this.coinCache.drop();
     this.cacheHash.drop();
     this.cacheHeight.drop();
     this.stateCache.drop();
@@ -192,7 +189,6 @@ class ChainDB {
     } catch (e) {
       this.current = null;
       this.pending = null;
-      this.coinCache.drop();
       this.cacheHash.drop();
       this.cacheHeight.drop();
       throw e;
@@ -209,7 +205,6 @@ class ChainDB {
     this.current = null;
     this.pending = null;
 
-    this.coinCache.commit();
     this.cacheHash.commit();
     this.cacheHeight.commit();
     this.stateCache.commit();
@@ -923,22 +918,12 @@ class ChainDB {
       return null;
 
     const {hash, index} = prevout;
-    const key = prevout.toKey();
-    const state = this.state;
-
-    const cache = this.coinCache.get(key);
-
-    if (cache)
-      return CoinEntry.fromRaw(cache);
 
     const raw = await this.db.get(layout.c.encode(hash, index));
 
     if (!raw)
       return null;
 
-    if (state === this.state)
-      this.coinCache.set(key, raw);
-
     return CoinEntry.fromRaw(raw);
   }
 
@@ -1722,17 +1707,12 @@ class ChainDB {
       for (const [index, coin] of coins.outputs) {
         if (coin.spent) {
           this.del(layout.c.encode(hash, index));
-          if (this.coinCache.capacity > 0)
-            this.coinCache.unpush(Outpoint.toKey(hash, index));
           continue;
         }
 
         const raw = coin.toRaw();
 
         this.put(layout.c.encode(hash, index), raw);
-
-        if (this.coinCache.capacity > 0)
-          this.coinCache.push(Outpoint.toKey(hash, index), raw);
       }
     }
   }
@@ -2281,10 +2261,6 @@ class CacheUpdate {
  * Helpers
  */
 
-function getSize(value) {
-  return value.length + 80;
-}
-
 function fromU32(num) {
   const data = Buffer.allocUnsafe(4);
   data.writeUInt32LE(num, 0, true);

lib/node/fullnode.js

@@ -54,7 +54,6 @@ class FullNode extends Node {
       bip148: this.config.bool('bip148'),
       prune: this.config.bool('prune'),
       checkpoints: this.config.bool('checkpoints'),
-      coinCache: this.config.mb('coin-cache'),
       entryCache: this.config.uint('entry-cache'),
       indexTX: this.config.bool('index-tx'),
       indexAddress: this.config.bool('index-address')