chaindb: refactor writes and pruning.

lib/chain/chaindb.js

@@ -40,7 +40,6 @@ var DUMMY = new Buffer([0]);
  *   C[addr-hash][hash][index] -> dummy (coin by address)
  *   W+T[witaddr-hash][hash] -> dummy (tx by address)
  *   W+C[witaddr-hash][hash][index] -> dummy (coin by address)
- *   q[height] -> block hash to be pruned
  */
 
 var layout = {
@@ -69,9 +68,6 @@ var layout = {
   u: function u(hash) {
     return pair(0x75, hash);
   },
-  q: function q(height) {
-    return ipair(0x71, height);
-  },
   T: function T(address, hash) {
     var len = address.length;
     var key;
@@ -228,11 +224,11 @@ ChainDB.prototype._open = co(function* open() {
 
   yield this.db.checkVersion('V', 1);
 
-  state = yield this.db.get(layout.R);
+  state = yield this.getState();
 
   if (state) {
     // Grab the chainstate if we have one.
-    this.state = ChainState.fromRaw(state);
+    this.state = state;
   } else {
     // Otherwise write the genesis block.
     // (We assume this database is fresh).
@@ -482,7 +478,7 @@ ChainDB.prototype.getBoth = co(function* getBoth(block) {
     if (hash == null)
       height = -1;
 
-    return [hash, height];
+    return new BlockPair(hash, height);
   }
 
   height = yield this.getHeight(hash);
@@ -490,7 +486,7 @@ ChainDB.prototype.getBoth = co(function* getBoth(block) {
   if (height === -1)
     hash = null;
 
-  return [hash, height];
+  return new BlockPair(hash, height);
 });
 
 /**
@@ -554,26 +550,39 @@ ChainDB.prototype.get = co(function* get(hash) {
  */
 
 ChainDB.prototype.save = co(function* save(entry, block, view) {
+  this.start();
+  try {
+    yield this._save(entry, block, view);
+  } catch (e) {
+    this.drop();
+    throw e;
+  }
+  yield this.commit();
+});
+
+/**
+ * Save an entry without a batch.
+ * @private
+ * @param {ChainEntry} entry
+ * @param {Block} block
+ * @param {CoinView?} view
+ * @returns {Promise}
+ */
+
+ChainDB.prototype._save = co(function* save(entry, block, view) {
   var hash = block.hash();
   var height = new Buffer(4);
 
   height.writeUInt32LE(entry.height, 0, true);
 
-  this.start();
-
   this.put(layout.h(hash), height);
   this.put(layout.e(hash), entry.toRaw());
 
   this.cacheHash.set(entry.hash, entry);
 
   if (!view) {
-    try {
+    yield this.saveBlock(block);
-      yield this.saveBlock(block);
+    return;
-    } catch (e) {
-      this.drop();
-      throw e;
-    }
-    return yield this.commit();
   }
 
   this.cacheHeight.set(entry.height, entry);
@@ -581,16 +590,9 @@ ChainDB.prototype.save = co(function* save(entry, block, view) {
   this.put(layout.n(entry.prevBlock), hash);
   this.put(layout.H(entry.height), hash);
 
-  try {
+  yield this.saveBlock(block, view);
-    yield this.saveBlock(block, view);
-  } catch (e) {
-    this.drop();
-    throw e;
-  }
 
   this.put(layout.R, this.pending.commit(hash));
-
-  yield this.commit();
 });
 
 /**
@@ -602,19 +604,50 @@ ChainDB.prototype.getTip = function getTip() {
   return this.get(this.state.hash);
 };
 
+/**
+ * Retrieve the tip entry from the tip record.
+ * @returns {Promise} - Returns {@link ChainEntry}.
+ */
+
+ChainDB.prototype.getState = co(function* getState() {
+  var data = yield this.db.get(layout.R);
+
+  if (!data)
+    return;
+
+  return ChainState.fromRaw(data);
+});
+
 /**
  * Reconnect the block to the chain.
  * @param {ChainEntry} entry
  * @param {Block} block
  * @param {CoinView} view
- * @returns {Promise} -
+ * @returns {Promise}
- * Returns [Error, {@link ChainEntry}, {@link Block}].
  */
 
 ChainDB.prototype.reconnect = co(function* reconnect(entry, block, view) {
-  var hash = block.hash();
-
   this.start();
+  try {
+    yield this._reconnect(entry, block, view);
+  } catch (e) {
+    this.drop();
+    throw e;
+  }
+  yield this.commit();
+});
+
+/**
+ * Reconnect block without a batch.
+ * @private
+ * @param {ChainEntry} entry
+ * @param {Block} block
+ * @param {CoinView} view
+ * @returns {Promise}
+ */
+
+ChainDB.prototype._reconnect = co(function* reconnect(entry, block, view) {
+  var hash = block.hash();
 
   this.put(layout.n(entry.prevBlock), hash);
   this.put(layout.H(entry.height), hash);
@@ -622,31 +655,46 @@ ChainDB.prototype.reconnect = co(function* reconnect(entry, block, view) {
   this.cacheHash.set(entry.hash, entry);
   this.cacheHeight.set(entry.height, entry);
 
-  try {
+  yield this.connectBlock(block, view);
-    yield this.connectBlock(block, view);
-  } catch (e) {
-    this.drop();
-    throw e;
-  }
 
   this.put(layout.R, this.pending.commit(hash));
 
-  yield this.commit();
-
   return block;
 });
 
 /**
  * Disconnect block from the chain.
  * @param {ChainEntry} entry
- * @returns {Promise} -
+ * @returns {Promise}
- * Returns [Error, {@link ChainEntry}, {@link Block}].
  */
 
 ChainDB.prototype.disconnect = co(function* disconnect(entry) {
   var block;
 
   this.start();
+
+  try {
+    block = yield this._disconnect(entry);
+  } catch (e) {
+    this.drop();
+    throw e;
+  }
+
+  yield this.commit();
+
+  return block;
+});
+
+/**
+ * Disconnect block without a batch.
+ * @private
+ * @param {ChainEntry} entry
+ * @returns {Promise}
+ */
+
+ChainDB.prototype._disconnect = co(function* disconnect(entry) {
+  var block;
+
   this.del(layout.n(entry.prevBlock));
   this.del(layout.H(entry.height));
 
@@ -654,33 +702,18 @@ ChainDB.prototype.disconnect = co(function* disconnect(entry) {
 
   if (this.options.spv) {
     this.put(layout.R, this.pending.commit(entry.prevBlock));
-    yield this.commit();
     return entry.toHeaders();
   }
 
-  try {
+  block = yield this.getBlock(entry.hash);
-    block = yield this.getBlock(entry.hash);
-  } catch (e) {
-    this.drop();
-    throw e;
-  }
 
-  if (!block) {
+  if (!block)
-    this.drop();
     throw new Error('Block not found.');
-  }
 
-  try {
+  yield this.disconnectBlock(block);
-    yield this.disconnectBlock(block);
-  } catch (e) {
-    this.drop();
-    throw e;
-  }
 
   this.put(layout.R, this.pending.commit(entry.prevBlock));
 
-  yield this.commit();
-
   return block;
 });
 
@@ -782,14 +815,8 @@ ChainDB.prototype.reset = co(function* reset(block) {
  */
 
 ChainDB.prototype.has = co(function* has(block) {
-  var items, hash;
+  var item = yield this.getBoth(block);
-
+  return item.hash != null;
-  checkHash(block);
-
-  items = yield this.getBoth(block);
-  hash = items[0];
-
-  return hash != null;
 });
 
 /**
@@ -802,16 +829,14 @@ ChainDB.prototype.has = co(function* has(block) {
 
 ChainDB.prototype.saveBlock = co(function* saveBlock(block, view) {
   if (this.options.spv)
-    return block;
+    return;
 
   this.put(layout.b(block.hash()), block.toRaw());
 
   if (!view)
-    return block;
+    return;
 
   yield this.connectBlock(block, view);
-
-  return block;
 });
 
 /**
@@ -844,12 +869,12 @@ ChainDB.prototype.connectBlock = co(function* connectBlock(block, view) {
   var hashes, address, hash, coins, raw;
 
   if (this.options.spv)
-    return block;
+    return;
 
   // Genesis block's coinbase is unspendable.
   if (this.chain.isGenesis(block)) {
     this.pending.connect(block);
-    return block;
+    return;
   }
 
   this.pending.connect(block);
@@ -927,8 +952,6 @@ ChainDB.prototype.connectBlock = co(function* connectBlock(block, view) {
     this.put(layout.u(block.hash()), undo.render());
 
   yield this.pruneBlock(block);
-
-  return block;
 });
 
 /**
@@ -942,7 +965,7 @@ ChainDB.prototype.disconnectBlock = co(function* disconnectBlock(block) {
   var hashes, address, hash, coins, raw;
 
   if (this.options.spv)
-    return block;
+    return;
 
   view = yield this.getUndoView(block);
 
@@ -1021,8 +1044,6 @@ ChainDB.prototype.disconnectBlock = co(function* disconnectBlock(block) {
   }
 
   this.del(layout.u(block.hash()));
-
-  return block;
 });
 
 /**
@@ -1464,22 +1485,19 @@ ChainDB.prototype.getUndoView = co(function* getUndoView(block) {
  */
 
 ChainDB.prototype.getBlock = co(function* getBlock(hash) {
-  var items = yield this.getBoth(hash);
+  var item = yield this.getBoth(hash);
   var height, data, block;
 
-  hash = items[0];
+  if (!item.hash)
-  height = items[1];
-
-  if (!hash)
     return;
 
-  data = yield this.db.get(layout.b(hash));
+  data = yield this.db.get(layout.b(item.hash));
 
   if (!data)
     return;
 
   block = Block.fromRaw(data);
-  block.setHeight(height);
+  block.setHeight(item.height);
 
   return block;
 });
@@ -1519,7 +1537,7 @@ ChainDB.prototype.hasCoins = function hasCoins(hash) {
  */
 
 ChainDB.prototype.pruneBlock = co(function* pruneBlock(block) {
-  var futureHeight, key, hash;
+  var height, hash;
 
   if (this.options.spv)
     return;
@@ -1527,21 +1545,16 @@ ChainDB.prototype.pruneBlock = co(function* pruneBlock(block) {
   if (!this.prune)
     return;
 
-  if (block.height <= this.network.block.pruneAfterHeight)
+  height = block.height - this.keepBlocks;
+
+  if (height <= this.network.block.pruneAfterHeight)
     return;
 
-  futureHeight = block.height + this.keepBlocks;
+  hash = yield this.getHash(height);
-
-  this.put(layout.q(futureHeight), block.hash());
-
-  key = layout.q(block.height);
-
-  hash = yield this.db.get(key);
 
   if (!hash)
     return;
 
-  this.del(key);
   this.del(layout.b(hash));
   this.del(layout.u(hash));
 });
@@ -1654,6 +1667,11 @@ function checkHash(hash) {
     'Must pass in height or hash.');
 }
 
+function BlockPair(hash, height) {
+  this.hash = hash;
+  this.height = height;
+}
+
 /*
  * Expose
  */