From 24e705b26569ad443b6247c29880e1131fc55bb2 Mon Sep 17 00:00:00 2001
From: Braydon Fuller <braydon@bitpay.com>
Date: Thu, 9 Jul 2015 16:45:30 -0400
Subject: [PATCH] Get blocks by height.

---
 integration/index.js | 22 +++++++++++++-
 src/bitcoindjs.cc    | 72 ++++++++++++++++++++++++--------------------
 2 files changed, 60 insertions(+), 34 deletions(-)

diff --git a/integration/index.js b/integration/index.js
index 04849e6c..f7cbe53c 100644
--- a/integration/index.js
+++ b/integration/index.js
@@ -45,7 +45,7 @@ describe('Basic Functionality', function() {
     });
   });
 
-  describe('will get correct block data', function() {
+  describe('get blocks by hash', function() {
 
     blockData.forEach(function(data) {
       var block = bitcore.Block.fromString(data);
@@ -58,4 +58,24 @@ describe('Basic Functionality', function() {
     });
   });
 
+  describe('get blocks by height', function() {
+
+    var knownHeights = [
+      [0, '000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f'],
+      [1, '00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048'],
+      [100000,'000000000003ba27aa200b1cecaad478d2b00432346c3f1f3986da1afd33e506'],
+      [314159, '00000000000000001bb82a7f5973618cfd3185ba1ded04dd852a653f92a27c45']
+    ];
+
+    knownHeights.forEach(function(data) {
+      it('block at height ' + data[0], function(done) {
+        bitcoind.getBlock(data[0], function(err, response) {
+          var block = bitcore.Block.fromBuffer(response);
+          block.hash.should.equal(data[1]);
+          done();
+        });
+      });
+    });
+  });
+
 });
diff --git a/src/bitcoindjs.cc b/src/bitcoindjs.cc
index 0c0c6bc5..a62f3d06 100644
--- a/src/bitcoindjs.cc
+++ b/src/bitcoindjs.cc
@@ -837,46 +837,52 @@ static void
 async_get_block(uv_work_t *req) {
   async_block_data* data = static_cast<async_block_data*>(req->data);
 
+  CBlockIndex* pblockindex;
   std::string strHash = data->hash;
   uint256 hash(strHash);
 
-  if (mapBlockIndex.count(hash) == 0) {
-    data->err_msg = std::string("Block not found.");
+  if (data->height != -1) {
+    pblockindex = chainActive[data->height];
   } else {
-
-    CBlockIndex* pblockindex = mapBlockIndex[hash];
-
-    const CDiskBlockPos& pos = pblockindex->GetBlockPos();
-
-    // We can read directly from the file, and pass that, we don't need to
-    // deserialize the entire block only for it to then be serialized
-    // and then deserialized again in JavaScript
-
-    // Open history file to read
-    CAutoFile filein(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION);
-    if (filein.IsNull()) {
-      data->err_msg = std::string("ReadBlockFromDisk: OpenBlockFile failed");
+    if (mapBlockIndex.count(hash) == 0) {
+      data->err_msg = std::string("Block not found.");
       return;
+    } else {
+      pblockindex = mapBlockIndex[hash];
     }
-
-    // Get the actual file, seeked position and rewind a uint32_t
-    FILE* blockFile = filein.release();
-    long int filePos = ftell(blockFile);
-    fseek(blockFile, filePos - sizeof(uint32_t), SEEK_SET);
-
-    // Read the size of the block
-    uint32_t size = 0;
-    fread(&size, sizeof(uint32_t), 1, blockFile);
-
-    // Read block
-    char* buffer = (char *)malloc(sizeof(char) * size);
-    fread((void *)buffer, sizeof(char), size, blockFile);
-    fclose(blockFile);
-
-    data->buffer = buffer;
-    data->size = size;
-    data->cblock_index = pblockindex;
   }
+
+  const CDiskBlockPos& pos = pblockindex->GetBlockPos();
+
+  // We can read directly from the file, and pass that, we don't need to
+  // deserialize the entire block only for it to then be serialized
+  // and then deserialized again in JavaScript
+
+  // Open history file to read
+  CAutoFile filein(OpenBlockFile(pos, true), SER_DISK, CLIENT_VERSION);
+  if (filein.IsNull()) {
+    data->err_msg = std::string("ReadBlockFromDisk: OpenBlockFile failed");
+    return;
+  }
+
+  // Get the actual file, seeked position and rewind a uint32_t
+  FILE* blockFile = filein.release();
+  long int filePos = ftell(blockFile);
+  fseek(blockFile, filePos - sizeof(uint32_t), SEEK_SET);
+
+  // Read the size of the block
+  uint32_t size = 0;
+  fread(&size, sizeof(uint32_t), 1, blockFile);
+
+  // Read block
+  char* buffer = (char *)malloc(sizeof(char) * size);
+  fread((void *)buffer, sizeof(char), size, blockFile);
+  fclose(blockFile);
+
+  data->buffer = buffer;
+  data->size = size;
+  data->cblock_index = pblockindex;
+
 }
 
 static void