Merge pull request #249 from kleetus/feature/getNextBlockHash

Next Block Hash Bindings

Author: Braydon Fuller

integration/regtest.js

@@ -430,4 +430,20 @@ describe('Daemon Binding Functionality', function() {
       best.should.equal(bestblock);
     });
   });
+
+  describe('get next block hash', function() {
+    it('will get next block hash', function() {
+      var nextBlockHash = bitcoind.getNextBlockHash(blockHashes[0]);
+      nextBlockHash.should.equal(blockHashes[1]);
+      var nextnextBlockHash = bitcoind.getNextBlockHash(nextBlockHash);
+      nextnextBlockHash.should.equal(blockHashes[2]);
+    });
+
+    it('will get a null response if the tip hash is provided', function() {
+      var bestBlockHash = bitcoind.getBestBlockHash();
+      var nextBlockHash = bitcoind.getNextBlockHash(bestBlockHash);
+      should.not.exist(nextBlockHash);
+    });
+  });
+
 });

lib/services/bitcoind.js

@@ -228,6 +228,10 @@ Bitcoin.prototype.getBestBlockHash = function() {
   return bindings.getBestBlockHash();
 };
 
+Bitcoin.prototype.getNextBlockHash = function(hash) {
+  return bindings.getNextBlockHash(hash);
+};
+
 Bitcoin.prototype.getTxOutSetInfo = function() {
   return bindings.getTxOutSetInfo();
 };

src/libbitcoind.cc

@@ -2,7 +2,7 @@
  * bitcoind.js - a binding for node.js which links to libbitcoind.so/dylib.
  * Copyright (c) 2015, BitPay (MIT License)
  *
- * bitcoindjs.cc:
+ * libbitcoind.cc:
  *   A bitcoind node.js binding.
  */
 
@@ -91,7 +91,7 @@ init(Handle<Object>);
 
 /**
  * Private Global Variables
- * Used only by bitcoindjs functions.
+ * Used only by bitcoind functions.
  */
 static std::vector<CDataStream> txmon_messages;
 static uv_async_t txmon_async;
@@ -236,6 +236,28 @@ NAN_METHOD(GetBestBlockHash) {
   }
 }
 
+NAN_METHOD(GetNextBlockHash) {
+
+  if (args.Length() < 1 || !args[0]->IsString()) {
+    return NanThrowError("Usage: bitcoind.getNextBlockHash(blockhash)");
+  }
+
+  CBlockIndex* pblockindex;
+  v8::String::Utf8Value param1(args[0]->ToString());
+  std::string *hash = new std::string(*param1);
+  uint256 shash = uint256S(*hash);
+  pblockindex = mapBlockIndex[shash];
+  CBlockIndex* pnextblockindex = chainActive.Next(pblockindex);
+  if (pnextblockindex) {
+    uint256 nexthash = pnextblockindex->GetBlockHash();
+    std::string rethash = nexthash.ToString();
+    NanReturnValue(NanNew<String>(rethash));
+  } else {
+    NanReturnValue(NanNull());
+  }
+
+}
+
 /**
  * IsSynced()
  * bitcoind.isSynced()
@@ -914,7 +936,7 @@ NAN_METHOD(GetBlock) {
       || (!args[0]->IsString() && !args[0]->IsNumber())
       || !args[1]->IsFunction()) {
     return NanThrowError(
-      "Usage: bitcoindjs.getBlock([blockhash,blockheight], callback)");
+      "Usage: bitcoind.getBlock([blockhash,blockheight], callback)");
   }
 
   async_block_data *req = new async_block_data();
@@ -1177,7 +1199,7 @@ NAN_METHOD(GetTransactionWithBlockInfo) {
       || !args[1]->IsBoolean()
       || !args[2]->IsFunction()) {
     return NanThrowError(
-      "Usage: bitcoindjs.getTransactionWithBlockInfo(txid, queryMempool, callback)");
+      "Usage: bitcoind.getTransactionWithBlockInfo(txid, queryMempool, callback)");
   }
 
   String::Utf8Value txid_(args[0]->ToString());
@@ -1307,15 +1329,15 @@ async_get_tx_and_info_after(uv_work_t *r) {
 
 /**
  * IsSpent()
- * bitcoindjs.isSpent()
+ * bitcoind.isSpent()
  * Determine if an outpoint is spent
  */
 NAN_METHOD(IsSpent) {
   NanScope();
 
   if (args.Length() > 2) {
     return NanThrowError(
-      "Usage: bitcoindjs.isSpent(txid, outputIndex)");
+      "Usage: bitcoind.isSpent(txid, outputIndex)");
   }
 
   String::Utf8Value arg(args[0]->ToString());
@@ -1341,7 +1363,7 @@ NAN_METHOD(IsSpent) {
 
 /**
  * GetBlockIndex()
- * bitcoindjs.getBlockIndex()
+ * bitcoind.getBlockIndex()
  * Get index information about a block by hash including:
  * - the total amount of work (expected number of hashes) in the chain up to
  *   and including this block.
@@ -1423,7 +1445,7 @@ NAN_METHOD(IsMainChain) {
 
 /**
  * GetInfo()
- * bitcoindjs.getInfo()
+ * bitcoind.getInfo()
  * Get miscellaneous information
  */
 
@@ -1432,7 +1454,7 @@ NAN_METHOD(GetInfo) {
 
   if (args.Length() > 0) {
     return NanThrowError(
-      "Usage: bitcoindjs.getInfo()");
+      "Usage: bitcoind.getInfo()");
   }
 
   Local<Object> obj = NanNew<Object>();
@@ -1482,7 +1504,7 @@ NAN_METHOD(EstimateFee) {
 
 /**
  * Send Transaction
- * bitcoindjs.sendTransaction()
+ * bitcoind.sendTransaction()
  * Will add a transaction to the mempool and broadcast to connected peers.
  * @param {string} - The serialized hex string of the transaction.
  * @param {boolean} - Skip absurdly high fee checks
@@ -1637,7 +1659,7 @@ set_cooked(void) {
 
 /**
  * Init()
- * Initialize the singleton object known as bitcoindjs.
+ * Initialize the singleton object known as bitcoind.
  */
 
 extern "C" void
@@ -1664,6 +1686,7 @@ init(Handle<Object> target) {
   NODE_SET_METHOD(target, "isSynced", IsSynced);
   NODE_SET_METHOD(target, "getTxOutSetInfo", GetTxOutSetInfo);
   NODE_SET_METHOD(target, "getBestBlockHash", GetBestBlockHash);
+  NODE_SET_METHOD(target, "getNextBlockHash", GetNextBlockHash);
 
 }
 

src/libbitcoind.h

@@ -38,3 +38,4 @@ NAN_METHOD(SyncPercentage);
 NAN_METHOD(IsSynced);
 NAN_METHOD(GetTxOutSetInfo);
 NAN_METHOD(GetBestBlockHash);
+NAN_METHOD(GetNextBlockHash);

test/services/bitcoind.unit.js

@@ -410,6 +410,7 @@ describe('Bitcoin Service', function() {
       ['addMempoolUncheckedTransaction', 1],
       ['getTxOutSetInfo', 0],
       ['getBestBlockHash', 0],
+      ['getNextBlockHash', 1],
       ['getInfo', 0]
     ];