wallet rescan: Add error for SPV mode and excessive depth in pruned mode

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Bcoin Release Notes & Changelog
 
+## vX.Y.Z
+
+### Regtest pruning policy changed
+
+In the old configuration, a pruned node on Regtest would start pruning at height
+1000 and then keep the last 1000 blocks on disk (pruning anything older). This
+has been changed to facilitate testing. The new parameters are
+`pruneAfterHeight: 500, keepBlocks: 288`.
+
 ## v1.0.0
 
 ### Migration

lib/node/http.js

@@ -125,7 +125,9 @@ class HTTP extends Server {
         chain: {
           height: this.chain.height,
           tip: this.chain.tip.rhash(),
-          progress: this.chain.getProgress()
+          progress: this.chain.getProgress(),
+          spv: this.chain.options.spv,
+          prune: this.chain.options.prune
         },
         pool: {
           host: addr.host,

lib/protocol/networks.js

@@ -775,8 +775,8 @@ regtest.block = {
   bip65hash: null,
   bip66height: 1251,
   bip66hash: null,
-  pruneAfterHeight: 1000,
-  keepBlocks: 10000,
+  pruneAfterHeight: 500,
+  keepBlocks: 288,
   maxTipAge: 0xffffffff,
   slowHeight: 0
 };

lib/wallet/client.js

@@ -77,6 +77,10 @@ class WalletClient extends NodeClient {
 
     return super.rescan(start);
   }
+
+  async getInfo() {
+    return (await super.getInfo());
+  }
 }
 
 /*

lib/wallet/http.js

@@ -45,6 +45,7 @@ class HTTP extends Server {
     this.logger = this.options.logger.context('http');
     this.wdb = this.options.node.wdb;
     this.rpc = this.options.node.rpc;
+    this.chain = this.options.node.chain;
 
     this.init();
   }
@@ -190,9 +191,23 @@ class HTTP extends Server {
         return;
       }
 
+      // SPV doesn't have blocks on disk, so rescan is ineffective
+      enforce(!this.options.node.chainInfo.spv, 'Cannot rescan in SPV mode.' +
+        ' Try rewinding blockchain with node `reset` command.');
+
       const valid = Validator.fromRequest(req);
       const height = valid.u32('height');
 
+      // Pruned node can only rescan the blocks it has on disk
+      if (this.options.node.chainInfo.prune) {
+        const tipHeight = await this.options.node.client.getTip();
+        const pruneDepth = this.network.block.keepBlocks;
+        const minHeight = tipHeight.height - pruneDepth;
+
+        enforce(height > minHeight,
+          'Rescan height must be greater than prune height of ' + minHeight);
+      }
+
       res.json(200, { success: true });
 
       await this.wdb.rescan(height);

lib/wallet/node.js

@@ -108,6 +108,12 @@ class WalletNode extends Node {
     await this.http.open();
     await this.handleOpen();
 
+    const clientInfo = await this.client.getInfo();
+    this.chainInfo = {
+      spv: clientInfo.chain.spv,
+      prune: clientInfo.chain.prune
+    };
+
     this.logger.info('Wallet node is loaded.');
   }
 

lib/wallet/nodeclient.js

@@ -211,6 +211,20 @@ class NodeClient extends AsyncEmitter {
       return this.emitAsync('block rescan', entry, txs);
     });
   }
+
+  /**
+   * Get relevant node info for wallet
+   * @returns {Promise}
+   */
+
+  async getInfo() {
+    return Promise.resolve({
+      chain: {
+        spv:this.node.chain.options.spv,
+        prune:this.node.chain.options.prune
+      }
+    });
+  }
 }
 
 /*

lib/wallet/nullclient.js

@@ -162,6 +162,20 @@ class NullClient extends EventEmitter {
   async rescan(start) {
     ;
   }
+
+  /**
+   * Get relevant node info for wallet
+   * @returns {Promise}
+   */
+
+  async getInfo() {
+    return Promise.resolve({
+      chain: {
+        spv: false,
+        prune: false
+      }
+    });
+  }
 }
 
 /*

lib/wallet/plugin.js

@@ -88,6 +88,12 @@ class Plugin extends EventEmitter {
     await this.wdb.open();
     this.rpc.wallet = this.wdb.primary;
     await this.http.open();
+
+    const clientInfo = await this.client.getInfo();
+    this.chainInfo = {
+      spv: clientInfo.chain.spv,
+      prune: clientInfo.chain.prune
+    };
   }
 
   async close() {

lib/wallet/walletdb.js

@@ -195,6 +195,12 @@ class WalletDB extends EventEmitter {
       this.state.height,
       this.state.startHeight);
 
+    const clientInfo = await this.client.getInfo();
+    this.chainInfo = {
+      spv: clientInfo.chain.spv,
+      prune: clientInfo.chain.prune
+    };
+
     const wallet = await this.ensure({
       id: 'primary'
     });
@@ -440,6 +446,16 @@ class WalletDB extends EventEmitter {
 
     assert((height >>> 0) === height, 'WDB: Must pass in a height.');
 
+    // Pruned node can only rescan the blocks it has on disk
+    if (this.chainInfo.prune) {
+      const tipHeight = await this.client.getTip();
+      const pruneDepth = this.network.block.keepBlocks;
+      const minHeight = tipHeight.height - pruneDepth;
+
+      assert(height > minHeight,
+        'Rescan height must be greater than prune height of ' + minHeight);
+    }
+
     this.logger.info(
       'WalletDB is scanning %d blocks.',
       this.state.height - height + 1);

test/prune-test.js

@@ -0,0 +1,64 @@
+/* eslint-env mocha */
+/* eslint prefer-arrow-callback: "off" */
+
+'use strict';
+
+const assert = require('./util/assert');
+const FullNode = require('../lib/node/fullnode');
+const Block = require('../lib/primitives/block');
+
+const node = new FullNode({
+  network: 'regtest',
+  memory: true,
+  plugins: [require('../lib/wallet/plugin')],
+  prune: true
+});
+
+describe('Pruned node', function() {
+  this.timeout(60000);
+
+  it('should open node', async () => {
+    await node.open();
+  });
+
+  it('should indicate prune in getInfo', async () => {
+    assert.strictEqual(true, node.chain.options.prune);
+  });
+
+  it('should generate 1000 blocks', async () => {
+    for (let i = 0; i < 1000; i++) {
+      const block = await node.miner.cpu.mineBlock();
+      assert(block);
+      assert(await node.chain.add(block));
+    }
+    assert.strictEqual(1000, node.chain.height);
+  });
+
+  it('should fail to rescan past prune height', async () => {
+    const pruneHeight = 1000 - 288;
+
+    // This block is not on disk
+    assert.strictEqual(null, await node.getBlock(pruneHeight));
+
+    // Try to rescan it anyway
+    try {
+      await node.plugins.walletdb.wdb.rescan(pruneHeight);
+    } catch(e) {
+      assert.strictEqual(
+        e.message,
+        'Rescan height must be greater than prune height of ' + pruneHeight
+      );
+    }
+  });
+
+  it('should succeed to rescan within prune height', async () => {
+    const pruneHeight = 1000 - 288;
+    // This block *IS* on disk
+    assert((await node.getBlock(pruneHeight + 1)) instanceof Block);
+    await node.plugins.walletdb.wdb.rescan(pruneHeight + 1);
+  });
+
+  it('should cleanup', async () => {
+    await node.close();
+  });
+});