From 93c6ff845e63a15aaabc73455985af72246eb5cb Mon Sep 17 00:00:00 2001
From: Braydon Fuller <courier@braydon.com>
Date: Fri, 5 Apr 2019 17:11:18 -0700
Subject: [PATCH] indexer: fix, simplify and rewrite indexer base

- Write indexer state and index atomically.
- Simplify chain state with current height.
- Roll forward to best height.
- Synchronize the index with the chain with common method `sync` for
  the events 'connect', 'disconnect' and 'reset'. This will prevent
  any of the events from conflicting with each other.
- Fix the chain rollback and reset.
- Make sure blocks are connected in the correct order.
- Improve logging to log similar to chain.
---
 lib/indexer/addrindexer.js |  22 +-
 lib/indexer/indexer.js     | 738 ++++++++++++++++---------------------
 lib/indexer/records.js     |  69 ----
 lib/indexer/txindexer.js   |  12 +-
 lib/node/fullnode.js       |   6 +
 test/indexer-test.js       |  16 +-
 6 files changed, 338 insertions(+), 525 deletions(-)

diff --git a/lib/indexer/addrindexer.js b/lib/indexer/addrindexer.js
index 1f7d13fb..0572a88b 100644
--- a/lib/indexer/addrindexer.js
+++ b/lib/indexer/addrindexer.js
@@ -127,7 +127,6 @@ class AddrIndexer extends Indexer {
    */
 
   async indexBlock(entry, block, view) {
-    const b = this.db.batch();
     const height = entry.height;
 
     for (let i = 0; i < block.txs.length; i++) {
@@ -136,15 +135,17 @@ class AddrIndexer extends Indexer {
 
       for (const addr of tx.getAddresses(view)) {
         const prefix = addr.getPrefix();
+
+        if (prefix < 0)
+          continue;
+
         const addrHash = addr.getHash();
         const count = new Count(height, i);
 
-        b.put(layout.A.encode(prefix, addrHash, height, i, hash), null);
-        b.put(layout.a.encode(prefix, addrHash, hash), count.toRaw());
+        this.put(layout.A.encode(prefix, addrHash, height, i, hash), null);
+        this.put(layout.a.encode(prefix, addrHash, hash), count.toRaw());
       }
     }
-
-    return b.write();
   }
 
   /**
@@ -156,7 +157,6 @@ class AddrIndexer extends Indexer {
    */
 
   async unindexBlock(entry, block, view) {
-    const b = this.db.batch();
     const height = entry.height;
 
     for (let i = 0; i < block.txs.length; i++) {
@@ -165,13 +165,15 @@ class AddrIndexer extends Indexer {
 
       for (const addr of tx.getAddresses(view)) {
         const prefix = addr.getPrefix();
+
+        if (prefix < 0)
+          continue;
+
         const addrHash = addr.getHash();
-        b.del(layout.A.encode(prefix, addrHash, height, i, hash));
-        b.del(layout.a.encode(prefix, addrHash, hash));
+        this.del(layout.A.encode(prefix, addrHash, height, i, hash));
+        this.del(layout.a.encode(prefix, addrHash, hash));
       }
     }
-
-    return b.write();
   }
 
   /**
diff --git a/lib/indexer/indexer.js b/lib/indexer/indexer.js
index dc7a5c35..702d5a4a 100644
--- a/lib/indexer/indexer.js
+++ b/lib/indexer/indexer.js
@@ -9,17 +9,13 @@
 const assert = require('assert');
 const path = require('path');
 const fs = require('bfile');
+const bio = require('bufio');
 const EventEmitter = require('events');
-const {Lock} = require('bmutex');
 const Logger = require('blgr');
 const Network = require('../protocol/network');
+const util = require('../utils/util');
 const layout = require('./layout');
-const records = require('./records');
-
-const {
-  ChainState,
-  BlockMeta
-} = records;
+const {BlockMeta} = require('./records');
 
 /**
  * Indexer
@@ -27,13 +23,12 @@ const {
  * @extends EventEmitter
  * @property {IndexerDB} db
  * @property {Number} height
- * @property {ChainState} state
  * @emits Indexer#chain tip
  */
 
 class Indexer extends EventEmitter {
   /**
-   * Create a index db.
+   * Create an indexer.
    * @constructor
    * @param {String} module
    * @param {Object} options
@@ -53,103 +48,72 @@ class Indexer extends EventEmitter {
     this.chain = this.options.chain;
 
     this.db = null;
-    this.rescanning = false;
-
-    this.state = new ChainState();
+    this.batch = null;
+    this.syncing = false;
     this.height = 0;
-
-    this.lock = new Lock();
   }
 
   /**
-   * Bind to chain events.
-   * @private
+   * Start a new batch write.
+   * @returns {Batch}
    */
 
-  bind() {
-    this.chain.on('connect', async (entry, block, view) => {
-      if (this.rescanning)
-        return;
-
-      try {
-        await this.addBlock(entry, block, view);
-      } catch (e) {
-        this.emit('error', e);
-      }
-    });
-
-    this.chain.on('disconnect', async (entry, block, view) => {
-      if (this.rescanning)
-        return;
-
-      try {
-        await this.removeBlock(entry, block, view);
-      } catch (e) {
-        this.emit('error', e);
-      }
-    });
-
-    this.chain.on('reset', async (tip) => {
-      try {
-        await this.resetChain(tip);
-      } catch (e) {
-        this.emit('error', e);
-      }
-    });
+  start() {
+    assert(this.batch === null, 'Already started.');
+    this.batch = this.db.batch();
+    return this.batch;
   }
 
   /**
-   * Ensure prefix directory (prefix/index).
+   * Put key and value to the current batch.
+   * @param {String} key
+   * @param {Buffer} value
+   */
+
+  put(key, value) {
+    this.batch.put(key, value);
+  }
+
+  /**
+   * Delete key from the current batch.
+   * @param {String} key
+   */
+
+  del(key) {
+    this.batch.del(key);
+  }
+
+  /**
+   * Commit the current batch.
    * @returns {Promise}
    */
 
-  async ensure() {
-    if (fs.unsupported)
-      return undefined;
-
-    if (this.options.memory)
-      return undefined;
-
-    return fs.mkdirp(this.options.prefix);
+  async commit() {
+    await this.batch.write();
+    this.batch = null;
   }
 
   /**
-   * Open the indexdb, wait for the database to load.
+   * Open the indexer, open the database,
+   * initialize height, and bind to events.
    * @returns {Promise}
    */
 
   async open() {
+    this.logger.info('Indexer is loading.');
+
     await this.ensure();
     await this.db.open();
     await this.db.verify(layout.V.encode(), 'index', 0);
-
     await this.verifyNetwork();
 
+    // Initialize the indexed height.
+    const data = await this.db.get(layout.R.encode());
+    if (data)
+      this.height = bio.readU32(data, 0);
+
+    // Bind to chain events.
     this.bind();
-
-    await this.sync();
-  }
-
-  /**
-   * Verify network.
-   * @returns {Promise}
-   */
-
-  async verifyNetwork() {
-    const raw = await this.db.get(layout.O.encode());
-
-    if (!raw) {
-      const b = this.db.batch();
-      b.put(layout.O.encode(), fromU32(this.network.magic));
-      return b.write();
-    }
-
-    const magic = raw.readUInt32LE(0, true);
-
-    if (magic !== this.network.magic)
-      throw new Error('Network mismatch for Indexer.');
-
-    return undefined;
   }
 
   /**
@@ -162,68 +126,69 @@ class Indexer extends EventEmitter {
   }
 
   /**
-   * Sync state with server on every connect.
+   * Ensure prefix directory (prefix/index).
    * @returns {Promise}
    */
 
-  async sync() {
-    const unlock = await this.lock.lock();
-    try {
-      this.logger.info('Resyncing from server...');
-      await this.syncState();
-      await this.syncChain();
-    } finally {
-      unlock();
-    }
+  async ensure() {
+    if (fs.unsupported)
+      return;
+
+    if (this.options.memory)
+      return;
+
+    await fs.mkdirp(this.options.prefix);
   }
 
   /**
-   * Initialize and write initial sync state.
+   * Verify network of index.
    * @returns {Promise}
    */
 
-  async syncState() {
-    const cache = await this.getState();
+  async verifyNetwork() {
+    let raw = await this.db.get(layout.O.encode());
 
-    if (cache) {
-      this.state = cache;
-      this.height = cache.height;
-
-      this.logger.info(
-        'Indexer loaded (height=%d, start=%d).',
-        this.state.height,
-        this.state.startHeight);
-      return undefined;
+    if (!raw) {
+      raw = bio.write(4).writeU32(this.network.magic).render();
+      await this.db.put(layout.O.encode(), raw);
+      return;
     }
 
-    this.logger.info('Initializing database state from server.');
+    const magic = bio.readU32(raw, 0);
 
-    const b = this.db.batch();
-    const hashes = await this.chain.getHashes();
+    if (magic !== this.network.magic)
+      throw new Error('Indexer: Network mismatch.');
+  }
 
-    let tip = null;
+  /**
+   * Bind to chain events.
+   * @private
+   */
 
-    for (let height = 0; height < hashes.length; height++) {
-      const hash = hashes[height];
-      const meta = new BlockMeta(hash, height);
-      b.put(layout.h.encode(height), meta.toHash());
-      tip = meta;
-    }
+  bind() {
+    this.chain.on('connect', async (entry, block, view) => {
+      try {
+        await this.sync(entry, block, view);
+      } catch (e) {
+        this.emit('error', e);
+      }
+    });
 
-    assert(tip);
+    this.chain.on('disconnect', async (entry, block, view) => {
+      try {
+        await this.sync(entry, block, view);
+      } catch (e) {
+        this.emit('error', e);
+      }
+    });
 
-    const state = this.state.clone();
-    state.startHeight = 0;
-    state.height = tip.height;
-
-    b.put(layout.R.encode(), state.toRaw());
-
-    await b.write();
-
-    this.state = state;
-    this.height = state.height;
-
-    return undefined;
+    this.chain.on('reset', async (tip) => {
+      try {
+        await this.sync(tip);
+      } catch (e) {
+        this.emit('error', e);
+      }
+    });
   }
 
   /**
@@ -244,179 +209,13 @@ class Indexer extends EventEmitter {
     return entry;
   }
 
-  /**
-   * Connect and sync with the chain server.
-   * @private
-   * @returns {Promise}
-   */
-
-  async syncChain() {
-    let height = this.state.height;
-
-    this.logger.info('Syncing state from height %d.', height);
-
-    // A re-org when we're offline might
-    // leave chain in a different state.
-    // Scan chain backwards until we
-    // find a known 'good' height.
-    for (;;) {
-      const tip = await this.getBlock(height);
-      assert(tip);
-
-      if (await this.getEntry(tip.hash))
-        break;
-
-      assert(height !== 0);
-      height -= 1;
-    }
-
-    // Start scan from last indexed OR
-    // last known 'good' height whichever
-    // is lower, because `scan` scans from
-    // low to high blocks
-    if (this.state.startHeight < height)
-      height = this.state.startHeight;
-
-    return this._rescan(height);
-  }
-
-  /**
-   * Rescan a block.
-   * @private
-   * @param {ChainEntry} entry
-   * @param {TX[]} txs
-   * @returns {Promise}
-   */
-
-  async rescanBlock(entry, block, view) {
-    this.logger.spam('Rescanning block: %d.', entry.height);
-
-    if (!this.rescanning) {
-      this.logger.warning('Unsolicited rescan block: %d.', entry.height);
-      return;
-    }
-
-    if (entry.height % 1000 === 0)
-      this.logger.debug('Rescanned block: %d.', entry.height);
-
-    if (entry.height > this.state.height + 1) {
-      this.logger.warning('Rescan block too high: %d.', entry.height);
-      return;
-    }
-
-    try {
-      await this._addBlock(entry, block, view);
-    } catch (e) {
-      this.emit('error', e);
-      throw e;
-    }
-  }
-
-  /**
-   * Force a rescan.
-   * @param {Number} height
-   * @returns {Promise}
-   */
-
-  async rescan(height) {
-    const unlock = await this.lock.lock();
-    try {
-      return await this._rescan(height);
-    } finally {
-      unlock();
-    }
-  }
-
-  /**
-   * Rescan blockchain from a given height.
-   * @private
-   * @param {Number} height
-   * @returns {Promise}
-   */
-
-  async _rescan(height) {
-    assert((height >>> 0) === height, 'Must pass in a height.');
-
-    await this.rollback(height);
-
-    const tip = this.state.height;
-
-    this.logger.debug('Rescanning from %d to %d', height, tip);
-
-    this.rescanning = true;
-
-    for (let i = height; ; i++) {
-      const entry = await this.chain.getEntry(i);
-      if (!entry)
-        break;
-
-      const block = await this.chain.getBlock(entry.hash);
-      assert(block);
-
-      const view = await this.chain.getBlockView(block);
-      assert(view);
-
-      await this.rescanBlock(entry, block, view);
-    }
-
-    this.rescanning = false;
-  }
-
-  /**
-   * Get the best block hash.
-   * @returns {Promise}
-   */
-
-  async getState() {
-    const data = await this.db.get(layout.R.encode());
-
-    if (!data)
-      return null;
-
-    return ChainState.fromRaw(data);
-  }
-
-  /**
-   * Sync the current chain state to tip.
-   * @param {BlockMeta} tip
-   * @returns {Promise}
-   */
-
-  async setTip(tip) {
-    const b = this.db.batch();
-    const state = this.state.clone();
-
-    if (tip.height < state.height) {
-      // Hashes ahead of our new tip
-      // that we need to delete.
-      while (state.height !== tip.height) {
-        b.del(layout.h.encode(state.height));
-        state.height -= 1;
-      }
-    } else if (tip.height > state.height) {
-      assert(tip.height === state.height + 1, 'Bad chain sync.');
-      state.height += 1;
-    }
-
-    state.startHeight = tip.height;
-
-    // Save tip and state.
-    b.put(layout.h.encode(tip.height), tip.toHash());
-    b.put(layout.R.encode(), state.toRaw());
-
-    await b.write();
-
-    this.state = state;
-    this.height = state.height;
-  }
-
   /**
    * Get a index block meta.
    * @param {Hash} hash
    * @returns {Promise}
    */
 
-  async getBlock(height) {
+  async getBlockMeta(height) {
     const data = await this.db.get(layout.h.encode(height));
 
     if (!data)
@@ -430,59 +229,157 @@ class Indexer extends EventEmitter {
   }
 
   /**
-   * Get index tip.
-   * @param {Hash} hash
+   * Sync with the chain.
+   * @param {ChainEntry} entry
+   * @param {Block} block
+   * @param {CoinView} view
    * @returns {Promise}
    */
 
-  async getTip() {
-    const tip = await this.getBlock(this.state.height);
+  async sync(entry, block, view) {
+    if (this.syncing)
+      return;
 
-    if (!tip)
-      throw new Error('Indexer: Tip not found!');
+    this.syncing = true;
 
-    return tip;
+    const connected = await this._syncBlock(entry, block, view);
+
+    if (connected) {
+      this.syncing = false;
+    } else {
+      (async () => {
+        await this._syncChain(entry);
+        this.syncing = false;
+      })();
+    }
   }
 
   /**
-   * Sync with chain height.
+   * Sync with the chain with a block.
+   * @private
+   * @param {ChainEntry} entry
+   * @param {Block} block
+   * @param {CoinView} view
+   * @returns {Promise}
+   */
+
+  async _syncBlock(entry, block, view) {
+    // In the case that the next block is being
+    // connected or the current block disconnected
+    // use the block and view being passed directly,
+    // instead of reading that information again.
+    if (entry && block && view) {
+      if (entry.height === this.height + 1) {
+        await this._addBlock(entry, block, view);
+        return true;
+      } else if (entry.height === this.height) {
+        await this._removeBlock(entry, block, view);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Sync with the chain.
+   * @private
+   * @param {ChainEntry} entry
+   * @returns {Promise}
+   */
+
+  async _syncChain(entry) {
+    let height = this.height;
+
+    // In the case that the indexer has never
+    // started, sync to the best height.
+    if (!height) {
+      await this._rollforward();
+      return;
+    }
+
+    // Check for a re-org that might
+    // leave chain in a different state.
+    // Scan chain backwards until we
+    // find a common height.
+    for (;;) {
+      const tip = await this.getBlockMeta(height);
+      assert(tip);
+
+      if (await this.getEntry(tip.hash))
+        break;
+
+      assert(height !== 0);
+      height -= 1;
+    }
+
+    // In the case that the chain is reset
+    // the entry will be less than the
+    // current height.
+    if (entry && entry.height < height)
+      height = entry.height;
+
+    if (height < this.height) {
+      await this._rollback(height);
+      await this._rollforward();
+    } else {
+      await this._rollforward();
+    }
+  }
+
+  /**
+   * Scan blockchain to the best chain height.
+   * @private
+   * @returns {Promise}
+   */
+
+  async _rollforward() {
+    this.logger.info('Indexing to best height.');
+
+    for (let i = this.height + 1; ; i++) {
+      const entry = await this.getEntry(i);
+      if (!entry)
+        break;
+
+      const block = await this.chain.getBlock(entry.hash);
+      assert(block);
+
+      const view = await this.chain.getBlockView(block);
+      assert(view);
+
+      await this._addBlock(entry, block, view);
+    }
+  }
+
+  /**
+   * Rollback to a given chain height.
    * @param {Number} height
    * @returns {Promise}
    */
 
-  async rollback(height) {
-    if (height > this.state.height)
-      throw new Error('Indexer: Cannot rollback to the future.');
-
-    if (height === this.state.height) {
-      this.logger.info('Rolled back to same height (%d).', height);
+  async _rollback(height) {
+    if (height > this.height) {
+      this.logger.warning(
+        'Ignoring rollback to future height (%d).',
+        height);
       return;
     }
 
-    this.logger.info(
-      'Rolling back %d Indexer blocks to height %d.',
-      this.state.height - height, height);
+    this.logger.info('Rolling back to height %d.', height);
 
-    const tip = await this.getBlock(height);
-    assert(tip);
+    while (this.height > height) {
+      const tip = await this.getBlockMeta(this.height);
+      assert(tip);
 
-    await this.revert(tip.height);
-    await this.setTip(tip);
-  }
+      const entry = await this.chain.getEntry(tip.hash);
+      assert(entry);
 
-  /**
-   * Add a block's transactions and write the new best hash.
-   * @param {ChainEntry} entry
-   * @param {Block} block
-   * @returns {Promise}
-   */
+      const block = await this.chain.getBlock(entry.hash);
+      assert(block);
 
-  async addBlock(entry, block, view) {
-    const unlock = await this.lock.lock();
-    try {
-      return await this._addBlock(entry, block, view);
-    } finally {
-      unlock();
+      const view = await this.chain.getBlockView(block);
+      assert(view);
+
+      await this._removeBlock(entry, block, view);
     }
   }
 
@@ -497,34 +394,31 @@ class Indexer extends EventEmitter {
   async _addBlock(entry, block, view) {
     assert(block.hasRaw(), 'Expected raw data for block.');
 
+    const start = util.bench();
+
+    if (entry.height !== this.height + 1)
+      throw new Error('Indexer: Can not add block.');
+
     const tip = BlockMeta.fromEntry(entry);
 
-    if (tip.height >= this.network.block.slowHeight && !this.rescanning)
-      this.logger.debug('Adding block: %d.', tip.height);
-
-    this.logger.spam('Adding block: %d.', entry.height);
-
-    if (tip.height === this.state.height) {
-      // We let blocks of the same height
-      // through specifically for rescans:
-      // we always want to rescan the last
-      // block since the state may have
-      // updated before the block was fully
-      // processed (in the case of a crash).
-      this.logger.warning('Already saw Indexer block (%d).', tip.height);
-    } else if (tip.height !== this.state.startHeight + 1) {
-      await this._rescan(this.state.height);
-      return;
-    }
-
-    this.logger.spam('Indexing block: %d.', entry.height);
+    // Start the batch write.
+    this.start();
 
+    // Call the implemented indexer to add to
+    // the batch write.
     await this.indexBlock(entry, block, view);
 
-    // Sync the state to the new tip.
-    await this.setTip(tip);
+    // Sync the height to the new tip.
+    const height = await this._setTip(tip);
 
-    return;
+    // Commit the write batch to disk.
+    await this.commit();
+
+    // Update height _after_ successful commit.
+    this.height = height;
+
+    // Log the current indexer status.
+    this.logStatus(start, block, entry);
   }
 
   /**
@@ -551,32 +445,6 @@ class Indexer extends EventEmitter {
     ;
   }
 
-  /**
-   * Revert db to an older state.
-   * @param {Number} target
-   * @returns {Promise}
-   */
-
-  async revert(target) {
-    ;
-  }
-
-  /**
-   * Unconfirm a block's transactions
-   * and write the new best hash (SPV version).
-   * @param {ChainEntry} entry
-   * @returns {Promise}
-   */
-
-  async removeBlock(entry, block, view) {
-    const unlock = await this.lock.lock();
-    try {
-      return await this._removeBlock(entry, block, view);
-    } finally {
-      unlock();
-    }
-  }
-
   /**
    * Unconfirm a block's transactions.
    * @private
@@ -585,63 +453,94 @@ class Indexer extends EventEmitter {
    */
 
   async _removeBlock(entry, block, view) {
+    const start = util.bench();
+
+    if (entry.height !== this.height)
+      throw new Error('Indexer: Can not remove block.');
+
     const tip = BlockMeta.fromEntry(entry);
 
-    this.logger.spam('Removing block: %d.', entry.height);
-
-    if (tip.height === 0)
-      throw new Error('Indexer: Bad disconnection (genesis block).');
-
-    if (tip.height > this.state.height) {
-      this.logger.warning(
-        'Indexer is disconnecting high blocks (%d).',
-        tip.height);
-      return;
-    }
-
-    if (tip.height !== this.state.height)
-      throw new Error('Indexer: Bad disconnection (height mismatch).');
-
-    this.logger.spam('Unindexing block: %d.', entry.height);
+    // Start the batch write.
+    this.start();
 
+    // Call the implemented indexer to add to
+    // the batch write.
     await this.unindexBlock(entry, block, view);
 
-    const prev = await this.getBlock(tip.height - 1);
+    const prev = await this.getBlockMeta(tip.height - 1);
     assert(prev);
 
-    // Sync the state to the previous tip.
-    await this.setTip(prev);
+    // Sync the height to the previous tip.
+    const height = await this._setTip(prev);
 
-    return;
+    // Commit the write batch to disk.
+    await this.commit();
+
+    // Update height _after_ successful commit.
+    this.height = height;
+
+    // Log the current indexer status.
+    this.logStatus(start, block, entry);
   }
 
   /**
-   * Handle a chain reset.
-   * @param {ChainEntry} entry
+   * Update the current height to tip.
+   * @param {BlockMeta} tip
    * @returns {Promise}
    */
 
-  async resetChain(entry) {
-    const unlock = await this.lock.lock();
-    try {
-      return await this._resetChain(entry);
-    } finally {
-      unlock();
+  async _setTip(tip) {
+    if (tip.height < this.height) {
+      assert(tip.height === this.height - 1);
+      this.del(layout.h.encode(this.height));
+    } else if (tip.height > this.height) {
+      assert(tip.height === this.height + 1);
     }
+
+    // Add to batch write to save tip and height.
+    this.put(layout.h.encode(tip.height), tip.toHash());
+
+    const raw = bio.write(4).writeU32(tip.height).render();
+    this.put(layout.R.encode(), raw);
+
+    return tip.height;
   }
 
   /**
-   * Handle a chain reset without a lock.
+   * Test whether the indexer has reached its slow height.
    * @private
-   * @param {ChainEntry} entry
-   * @returns {Promise}
+   * @returns {Boolean}
    */
 
-  async _resetChain(entry) {
-    if (entry.height > this.state.height)
-      throw new Error('Indexer: Bad reset height.');
+  isSlow() {
+    if (this.height === 1 || this.height % 20 === 0)
+      return true;
 
-    return this.rollback(entry.height);
+    if (this.height >= this.network.block.slowHeight)
+      return true;
+
+    return false;
+  }
+
+  /**
+   * Log the current indexer status.
+   * @private
+   * @param {Array} start
+   * @param {Block} block
+   * @param {ChainEntry} entry
+   */
+
+  logStatus(start, block, entry) {
+    if (!this.isSlow())
+      return;
+
+    const elapsed = util.bench(start);
+
+    this.logger.info(
+      'Block (%d) added to indexer (txs=%d time=%d).',
+      entry.height,
+      block.txs.length,
+      elapsed);
   }
 }
 
@@ -664,7 +563,6 @@ class IndexOptions {
     this.logger = Logger.global;
     this.blocks = null;
     this.chain = null;
-    this.indexers = null;
 
     this.prefix = null;
     this.location = null;
@@ -737,7 +635,7 @@ class IndexOptions {
   }
 
   /**
-   * Instantiate chain options from object.
+   * Instantiate indexer options from object.
    * @param {Object} options
    * @returns {IndexOptions}
    */
@@ -747,22 +645,6 @@ class IndexOptions {
   }
 }
 
-/*
- * Helpers
- */
-
-/**
- * fromU32
- * read a 4 byte Uint32LE
- * @param {Number} num number
- * @returns {Buffer} buffer
- */
-function fromU32(num) {
-  const data = Buffer.allocUnsafe(4);
-  data.writeUInt32LE(num, 0, true);
-  return data;
-}
-
 /*
  * Expose
  */
diff --git a/lib/indexer/records.js b/lib/indexer/records.js
index 3e67e843..7db64b94 100644
--- a/lib/indexer/records.js
+++ b/lib/indexer/records.js
@@ -14,74 +14,6 @@ const bio = require('bufio');
 const util = require('../utils/util');
 const consensus = require('../protocol/consensus');
 
-/**
- * Chain State
- * @alias module:indexer.ChainState
- */
-
-class ChainState {
-  /**
-   * Create a chain state.
-   * @constructor
-   */
-
-  constructor() {
-    this.startHeight = 0;
-    this.height = 0;
-  }
-
-  /**
-   * Clone the state.
-   * @returns {ChainState}
-   */
-
-  clone() {
-    const state = new ChainState();
-    state.startHeight = this.startHeight;
-    state.height = this.height;
-    return state;
-  }
-
-  /**
-   * Inject properties from serialized data.
-   * @private
-   * @param {Buffer} data
-   */
-
-  fromRaw(data) {
-    const br = bio.read(data);
-
-    this.startHeight = br.readU32();
-    this.height = br.readU32();
-
-    return this;
-  }
-
-  /**
-   * Instantiate chain state from serialized data.
-   * @param {Buffer} data
-   * @returns {ChainState}
-   */
-
-  static fromRaw(data) {
-    return new this().fromRaw(data);
-  }
-
-  /**
-   * Serialize the chain state.
-   * @returns {Buffer}
-   */
-
-  toRaw() {
-    const bw = bio.write(8);
-
-    bw.writeU32(this.startHeight);
-    bw.writeU32(this.height);
-
-    return bw.render();
-  }
-}
-
 /**
  * Block Meta
  * @alias module:indexer.BlockMeta
@@ -215,7 +147,6 @@ class BlockMeta {
  * Expose
  */
 
-exports.ChainState = ChainState;
 exports.BlockMeta = BlockMeta;
 
 module.exports = exports;
diff --git a/lib/indexer/txindexer.js b/lib/indexer/txindexer.js
index 8821fc30..82746f51 100644
--- a/lib/indexer/txindexer.js
+++ b/lib/indexer/txindexer.js
@@ -129,8 +129,6 @@ class TXIndexer extends Indexer {
    */
 
   async indexBlock(entry, block, view) {
-    const b = this.db.batch();
-
     for (let i = 0; i < block.txs.length; i++) {
       const tx = block.txs[i];
 
@@ -146,10 +144,8 @@ class TXIndexer extends Indexer {
         length: size
       });
 
-      b.put(layout.t.encode(hash), txrecord.toRaw());
+      this.put(layout.t.encode(hash), txrecord.toRaw());
     }
-
-    return b.write();
   }
 
   /**
@@ -161,15 +157,11 @@ class TXIndexer extends Indexer {
    */
 
   async unindexBlock(entry, block, view) {
-    const b = this.db.batch();
-
     for (let i = 0; i < block.txs.length; i++) {
       const tx = block.txs[i];
       const hash = tx.hash();
-      b.del(layout.t.encode(hash));
+      this.del(layout.t.encode(hash));
     }
-
-    return b.write();
   }
 
   /**
diff --git a/lib/node/fullnode.js b/lib/node/fullnode.js
index 4e6747d4..73e973f8 100644
--- a/lib/node/fullnode.js
+++ b/lib/node/fullnode.js
@@ -410,6 +410,12 @@ class FullNode extends Node {
    */
 
   startSync() {
+    if (this.txindex)
+      this.txindex.sync();
+
+    if (this.addrindex)
+      this.addrindex.sync();
+
     return this.pool.startSync();
   }
 
diff --git a/test/indexer-test.js b/test/indexer-test.js
index 90f3cc65..839bc3cd 100644
--- a/test/indexer-test.js
+++ b/test/indexer-test.js
@@ -90,8 +90,8 @@ describe('Indexer', function() {
       }
 
       assert.strictEqual(chain.height, 10);
-      assert.strictEqual(txindexer.state.startHeight, 10);
-      assert.strictEqual(addrindexer.state.startHeight, 10);
+      assert.strictEqual(txindexer.height, 10);
+      assert.strictEqual(addrindexer.height, 10);
     });
 
     it('should get txs by address', async () => {
@@ -172,8 +172,8 @@ describe('Indexer', function() {
       }
 
       assert.strictEqual(chain.height, 20);
-      assert.strictEqual(txindexer.state.startHeight, 20);
-      assert.strictEqual(addrindexer.state.startHeight, 20);
+      assert.strictEqual(txindexer.height, 20);
+      assert.strictEqual(addrindexer.height, 20);
 
       const hashes = await addrindexer.getHashesByAddress(miner.getAddress());
       assert.strictEqual(hashes.length, 20);
@@ -187,8 +187,8 @@ describe('Indexer', function() {
     it('should handle indexing a reorg', async () => {
       await reorg(chain, cpu, 10);
 
-      assert.strictEqual(txindexer.state.startHeight, 31);
-      assert.strictEqual(addrindexer.state.startHeight, 31);
+      assert.strictEqual(txindexer.height, 31);
+      assert.strictEqual(addrindexer.height, 31);
 
       const hashes = await addrindexer.getHashesByAddress(miner.getAddress());
       assert.strictEqual(hashes.length, 31);
@@ -269,9 +269,9 @@ describe('Indexer', function() {
         'getnewaddress', ['default']);
 
       const blocks = await nclient.execute(
-        'generatetoaddress', [120, coinbase]);
+        'generatetoaddress', [150, coinbase]);
 
-      assert.equal(blocks.length, 120);
+      assert.equal(blocks.length, 150);
 
       // Send to the vector addresses for several blocks.
       for (let i = 0; i < 10; i++) {