From 8a53cb0b9d6a6c780c3458a2c3801409c2e3b0ca Mon Sep 17 00:00:00 2001
From: Gavin Andresen <gavinandresen@gmail.com>
Date: Fri, 23 Dec 2011 16:26:38 -0500
Subject: [PATCH] New RPC commands: getblockhash and getblock

---
 src/bitcoinrpc.cpp | 120 +++++++++++++++++++++++++++++++++++----------
 src/main.h         |   1 -
 2 files changed, 94 insertions(+), 27 deletions(-)

diff --git a/src/bitcoinrpc.cpp b/src/bitcoinrpc.cpp
index c1e8ef76..09be73af 100644
--- a/src/bitcoinrpc.cpp
+++ b/src/bitcoinrpc.cpp
@@ -72,6 +72,37 @@ void PrintConsole(const std::string &format, ...)
     fprintf(stdout, "%s", buffer);
 }
 
+double GetDifficulty(const CBlockIndex* blockindex = NULL)
+{
+    // Floating point number that is a multiple of the minimum difficulty,
+    // minimum difficulty = 1.0.
+    if (blockindex == NULL)
+    {
+        if (pindexBest == NULL)
+            return 1.0;
+        else
+            blockindex = pindexBest;
+    }
+
+    int nShift = (blockindex->nBits >> 24) & 0xff;
+
+    double dDiff =
+        (double)0x0000ffff / (double)(blockindex->nBits & 0x00ffffff);
+
+    while (nShift < 29)
+    {
+        dDiff *= 256.0;
+        nShift++;
+    }
+    while (nShift > 29)
+    {
+        dDiff /= 256.0;
+        nShift--;
+    }
+
+    return dDiff;
+}
+
 
 int64 AmountFromValue(const Value& value)
 {
@@ -112,6 +143,28 @@ string AccountFromValue(const Value& value)
     return strAccount;
 }
 
+Object blockToJSON(const CBlock& block, const CBlockIndex* blockindex)
+{
+    Object result;
+    result.push_back(Pair("hash", block.GetHash().GetHex()));
+    result.push_back(Pair("blockcount", blockindex->nHeight));
+    result.push_back(Pair("version", block.nVersion));
+    result.push_back(Pair("merkleroot", block.hashMerkleRoot.GetHex()));
+    result.push_back(Pair("time", (boost::int64_t)block.GetBlockTime()));
+    result.push_back(Pair("nonce", (boost::uint64_t)block.nNonce));
+    result.push_back(Pair("difficulty", GetDifficulty(blockindex)));
+    Array txhashes;
+    BOOST_FOREACH (const CTransaction&tx, block.vtx)
+        txhashes.push_back(tx.GetHash().GetHex());
+    result.push_back(Pair("tx", txhashes));
+
+    if (blockindex->pprev)
+        result.push_back(Pair("hashprevious", blockindex->pprev->GetBlockHash().GetHex()));
+    if (blockindex->pnext)
+        result.push_back(Pair("hashnext", blockindex->pnext->GetBlockHash().GetHex()));
+    return result;
+}
+
 
 
 ///
@@ -217,32 +270,6 @@ Value getconnectioncount(const Array& params, bool fHelp)
 }
 
 
-double GetDifficulty()
-{
-    // Floating point number that is a multiple of the minimum difficulty,
-    // minimum difficulty = 1.0.
-
-    if (pindexBest == NULL)
-        return 1.0;
-    int nShift = (pindexBest->nBits >> 24) & 0xff;
-
-    double dDiff =
-        (double)0x0000ffff / (double)(pindexBest->nBits & 0x00ffffff);
-
-    while (nShift < 29)
-    {
-        dDiff *= 256.0;
-        nShift++;
-    }
-    while (nShift > 29)
-    {
-        dDiff /= 256.0;
-        nShift--;
-    }
-
-    return dDiff;
-}
-
 Value getdifficulty(const Array& params, bool fHelp)
 {
     if (fHelp || params.size() != 0)
@@ -1892,6 +1919,44 @@ Value getmemorypool(const Array& params, bool fHelp)
     }
 }
 
+Value getblockhash(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() != 1)
+        throw runtime_error(
+            "getblockhash <index>\n"
+            "Returns hash of block in best-block-chain at <index>.");
+
+    int nHeight = params[0].get_int();
+    if (nHeight < 0 || nHeight > nBestHeight)
+        throw runtime_error("Block number out of range.");
+
+    CBlock block;
+    CBlockIndex* pblockindex = mapBlockIndex[hashBestChain];
+    while (pblockindex->nHeight > nHeight)
+        pblockindex = pblockindex->pprev;
+    return pblockindex->phashBlock->GetHex();
+}
+
+Value getblock(const Array& params, bool fHelp)
+{
+    if (fHelp || params.size() != 1)
+        throw runtime_error(
+            "getblock <hash>\n"
+            "Returns details of a block with given block-hash.");
+
+    std::string strHash = params[0].get_str();
+    uint256 hash(strHash);
+
+    if (mapBlockIndex.count(hash) == 0)
+        throw JSONRPCError(-5, "Block not found");
+
+    CBlock block;
+    CBlockIndex* pblockindex = mapBlockIndex[hash];
+    block.ReadFromDisk(pblockindex, true);
+
+    return blockToJSON(block, pblockindex);
+}
+
 
 
 
@@ -1940,6 +2005,8 @@ pair<string, rpcfn_type> pCallTable[] =
     make_pair("sendfrom",               &sendfrom),
     make_pair("sendmany",               &sendmany),
     make_pair("addmultisigaddress",     &addmultisigaddress),
+    make_pair("getblock",               &getblock),
+    make_pair("getblockhash",           &getblockhash),
     make_pair("gettransaction",         &gettransaction),
     make_pair("listtransactions",       &listtransactions),
     make_pair("signmessage",            &signmessage),
@@ -2565,6 +2632,7 @@ int CommandLineRPC(int argc, char *argv[])
         if (strMethod == "listreceivedbyaccount"  && n > 0) ConvertTo<boost::int64_t>(params[0]);
         if (strMethod == "listreceivedbyaccount"  && n > 1) ConvertTo<bool>(params[1]);
         if (strMethod == "getbalance"             && n > 1) ConvertTo<boost::int64_t>(params[1]);
+        if (strMethod == "getblockhash"           && n > 0) ConvertTo<boost::int64_t>(params[0]);
         if (strMethod == "move"                   && n > 2) ConvertTo<double>(params[2]);
         if (strMethod == "move"                   && n > 3) ConvertTo<boost::int64_t>(params[3]);
         if (strMethod == "sendfrom"               && n > 2) ConvertTo<double>(params[2]);
diff --git a/src/main.h b/src/main.h
index d613d284..a7c16828 100644
--- a/src/main.h
+++ b/src/main.h
@@ -25,7 +25,6 @@ class CAddress;
 class CInv;
 class CRequestTracker;
 class CNode;
-class CBlockIndex;
 
 static const int CLIENT_VERSION = 59900;
 static const bool VERSION_IS_BETA = true;