V0.11.2.x add getblockheader rpc command (+small fix for getblock example)

src/rpcblockchain.cpp

@@ -80,6 +80,20 @@ Object blockToJSON(const CBlock& block, const CBlockIndex* blockindex)
 }
 
 
+Object blockHeaderToJSON(const CBlock& block, const CBlockIndex* blockindex)
+{
+    Object result;
+    result.push_back(Pair("version", block.nVersion));
+    if (blockindex->pprev)
+        result.push_back(Pair("previousblockhash", blockindex->pprev->GetBlockHash().GetHex()));
+    result.push_back(Pair("merkleroot", block.hashMerkleRoot.GetHex()));
+    result.push_back(Pair("time", block.GetBlockTime()));
+    result.push_back(Pair("bits", HexBits(block.nBits)));
+    result.push_back(Pair("nonce", (uint64_t)block.nNonce));
+    return result;
+}
+
+
 Value getblockcount(const Array& params, bool fHelp)
 {
     if (fHelp || params.size() != 0)
@@ -261,8 +275,8 @@ Value getblock(const Array& params, bool fHelp)
             "\nResult (for verbose=false):\n"
             "\"data\"             (string) A string that is serialized, hex-encoded data for block 'hash'.\n"
             "\nExamples:\n"
-            + HelpExampleCli("getblock", "\"00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09\"")
-            + HelpExampleRpc("getblock", "\"00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09\"")
+            + HelpExampleCli("getblock", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
+            + HelpExampleRpc("getblock", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
         );
 
     std::string strHash = params[0].get_str();
@@ -292,6 +306,59 @@ Value getblock(const Array& params, bool fHelp)
     return blockToJSON(block, pblockindex);
 }
 
+Value getblockheader(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() < 1 || params.size() > 2)
+        throw runtime_error(
+                "getblockheader \"hash\" ( verbose )\n"
+                "\nIf verbose is false, returns a string that is serialized, hex-encoded data for block 'hash' header.\n"
+                "If verbose is true, returns an Object with information about block <hash> header.\n"
+                "\nArguments:\n"
+                "1. \"hash\"          (string, required) The block hash\n"
+                "2. verbose           (boolean, optional, default=true) true for a json object, false for the hex encoded data\n"
+                "\nResult (for verbose = true):\n"
+                "{\n"
+                "  \"version\" : n,         (numeric) The block version\n"
+                "  \"previousblockhash\" : \"hash\",  (string) The hash of the previous block\n"
+                "  \"merkleroot\" : \"xxxx\", (string) The merkle root\n"
+                "  \"time\" : ttt,          (numeric) The block time in seconds since epoch (Jan 1 1970 GMT)\n"
+                "  \"bits\" : \"1d00ffff\", (string) The bits\n"
+                "  \"nonce\" : n,           (numeric) The nonce\n"
+                "}\n"
+                "\nResult (for verbose=false):\n"
+                "\"data\"             (string) A string that is serialized, hex-encoded data for block 'hash' header.\n"
+                "\nExamples:\n"
+                + HelpExampleCli("getblockheader", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
+                + HelpExampleRpc("getblockheader", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
+                );
+
+    std::string strHash = params[0].get_str();
+    uint256 hash(strHash);
+
+    bool fVerbose = true;
+    if (params.size() > 1)
+        fVerbose = params[1].get_bool();
+
+    if (mapBlockIndex.count(hash) == 0)
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
+
+    CBlock block;
+    CBlockIndex* pblockindex = mapBlockIndex[hash];
+
+    if(!ReadBlockFromDisk(block, pblockindex))
+        throw JSONRPCError(RPC_INTERNAL_ERROR, "Can't read block from disk");
+
+    if (!fVerbose)
+    {
+        CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION);
+        ssBlock << block.GetBlockHeader();
+        std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
+        return strHex;
+    }
+
+    return blockHeaderToJSON(block, pblockindex);
+}
+
 Value gettxoutsetinfo(const Array& params, bool fHelp)
 {
     if (fHelp || params.size() != 0)

src/rpcclient.cpp

@@ -163,6 +163,7 @@ Array RPCConvertValues(const std::string &strMethod, const std::vector<std::stri
     if (strMethod == "listunspent"            && n > 1) ConvertTo<int64_t>(params[1]);
     if (strMethod == "listunspent"            && n > 2) ConvertTo<Array>(params[2]);
     if (strMethod == "getblock"               && n > 1) ConvertTo<bool>(params[1]);
+    if (strMethod == "getblockheader"         && n > 1) ConvertTo<bool>(params[1]);
     if (strMethod == "getrawtransaction"      && n > 1) ConvertTo<int64_t>(params[1]);
     if (strMethod == "createrawtransaction"   && n > 0) ConvertTo<Array>(params[0]);
     if (strMethod == "createrawtransaction"   && n > 1) ConvertTo<Object>(params[1]);

src/rpcserver.cpp

@@ -243,6 +243,7 @@ static const CRPCCommand vRPCCommands[] =
     { "getbestblockhash",       &getbestblockhash,       true,      false,      false },
     { "getblockcount",          &getblockcount,          true,      false,      false },
     { "getblock",               &getblock,               false,     false,      false },
+    { "getblockheader",         &getblockheader,         false,     false,      false },
     { "getblockhash",           &getblockhash,           false,     false,      false },
     { "getdifficulty",          &getdifficulty,          true,      false,      false },
     { "getrawmempool",          &getrawmempool,          true,      false,      false },

src/rpcserver.h

@@ -185,6 +185,7 @@ extern json_spirit::Value settxfee(const json_spirit::Array& params, bool fHelp)
 extern json_spirit::Value getrawmempool(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getblockhash(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value getblock(const json_spirit::Array& params, bool fHelp);
+extern json_spirit::Value getblockheader(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value gettxoutsetinfo(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value gettxout(const json_spirit::Array& params, bool fHelp);
 extern json_spirit::Value verifychain(const json_spirit::Array& params, bool fHelp);