Add getchaintxstats RPC

Author: sipa

src/rpc/blockchain.cpp

@@ -1415,10 +1415,76 @@ UniValue reconsiderblock(const JSONRPCRequest& request)
     return NullUniValue;
 }
 
+UniValue getchaintxstats(const JSONRPCRequest& request)
+{
+    if (request.fHelp || request.params.size() > 2)
+        throw std::runtime_error(
+            "getchaintxstats ( nblocks blockhash )\n"
+            "\nCompute statistics about the total number and rate of transactions in the chain.\n"
+            "\nArguments:\n"
+            "1. nblocks      (numeric, optional) Size of the window in number of blocks (default: one month).\n"
+            "2. \"blockhash\"  (string, optional) The hash of the block that ends the window.\n"
+            "\nResult:\n"
+            "{\n"
+            "  \"time\": xxxxx,        (numeric) The timestamp for the statistics in UNIX format.\n"
+            "  \"txcount\": xxxxx,     (numeric) The total number of transactions in the chain up to that point.\n"
+            "  \"txrate\": x.xx,       (numeric) The average rate of transactions per second in the window.\n"
+            "}\n"
+            "\nExamples:\n"
+            + HelpExampleCli("getchaintxstats", "")
+            + HelpExampleRpc("getchaintxstats", "2016")
+        );
+
+    const CBlockIndex* pindex;
+    int blockcount = 30 * 24 * 60 * 60 / Params().GetConsensus().nPowTargetSpacing; // By default: 1 month
+
+    if (request.params.size() > 0 && !request.params[0].isNull()) {
+        blockcount = request.params[0].get_int();
+    }
+
+    bool havehash = request.params.size() > 1 && !request.params[1].isNull();
+    uint256 hash;
+    if (havehash) {
+        hash = uint256S(request.params[1].get_str());
+    }
+
+    {
+        LOCK(cs_main);
+        if (havehash) {
+            auto it = mapBlockIndex.find(hash);
+            if (it == mapBlockIndex.end()) {
+                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
+            }
+            pindex = it->second;
+            if (!chainActive.Contains(pindex)) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, "Block is not in main chain");
+            }
+        } else {
+            pindex = chainActive.Tip();
+        }
+    }
+
+    if (blockcount < 1 || blockcount >= pindex->nHeight) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid block count: should be between 1 and the block's height");
+    }
+
+    const CBlockIndex* pindexPast = pindex->GetAncestor(pindex->nHeight - blockcount);
+    int nTimeDiff = pindex->GetMedianTimePast() - pindexPast->GetMedianTimePast();
+    int nTxDiff = pindex->nChainTx - pindexPast->nChainTx;
+
+    UniValue ret(UniValue::VOBJ);
+    ret.push_back(Pair("time", (int64_t)pindex->nTime));
+    ret.push_back(Pair("txcount", (int64_t)pindex->nChainTx));
+    ret.push_back(Pair("txrate", ((double)nTxDiff) / nTimeDiff));
+
+    return ret;
+}
+
 static const CRPCCommand commands[] =
 { //  category              name                      actor (function)         okSafe argNames
   //  --------------------- ------------------------  -----------------------  ------ ----------
     { "blockchain",         "getblockchaininfo",      &getblockchaininfo,      true,  {} },
+    { "blockchain",         "getchaintxstats",        &getchaintxstats,        true,  {"nblocks", "blockhash"} },
     { "blockchain",         "getbestblockhash",       &getbestblockhash,       true,  {} },
     { "blockchain",         "getblockcount",          &getblockcount,          true,  {} },
     { "blockchain",         "getblock",               &getblock,               true,  {"blockhash","verbose"} },

src/rpc/client.cpp

@@ -79,6 +79,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "listunspent", 2, "addresses" },
     { "getblock", 1, "verbose" },
     { "getblockheader", 1, "verbose" },
+    { "getchaintxstats", 0, "nblocks" },
     { "gettransaction", 1, "include_watchonly" },
     { "getrawtransaction", 1, "verbose" },
     { "createrawtransaction", 0, "inputs" },