Merge #14298: [REST] improve performance for JSON calls

30973e9844 [REST] improve performance for JSON calls (Antoine Le Calvez)

Pull request description:

  JSON calls do not use the raw data generated for the .bin and .hex calls.

  By moving the raw data creation into the .bin and .hex switch branches, JSON calls' performance is improved.

  Light benchmarking indicates that fetching 2000 JSON headers is ~25% faster, fetching large JSON blocks is ~4% faster.

Tree-SHA512: 433552c89bac2469d041b48a4a991d5443e4026a3ad7dc5621685386029f22826484218642fa5130c268349a55524ecbc4e30d64c867bd6632e0edd24370cf11

1 files changed, 20 insertions, 11 deletions

diff --git a/src/rest.cpp b/src/rest.cpp
index 6ba15172fa..7792844992 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -157,13 +157,13 @@ static bool rest_headers(HTTPRequest* req,
         }
     }
 
-    CDataStream ssHeader(SER_NETWORK, PROTOCOL_VERSION);
-    for (const CBlockIndex *pindex : headers) {
-        ssHeader << pindex->GetBlockHeader();
-    }
-
     switch (rf) {
     case RetFormat::BINARY: {
+        CDataStream ssHeader(SER_NETWORK, PROTOCOL_VERSION);
+        for (const CBlockIndex *pindex : headers) {
+            ssHeader << pindex->GetBlockHeader();
+        }
+
         std::string binaryHeader = ssHeader.str();
         req->WriteHeader("Content-Type", "application/octet-stream");
         req->WriteReply(HTTP_OK, binaryHeader);
@@ -171,6 +171,11 @@ static bool rest_headers(HTTPRequest* req,
     }
 
     case RetFormat::HEX: {
+        CDataStream ssHeader(SER_NETWORK, PROTOCOL_VERSION);
+        for (const CBlockIndex *pindex : headers) {
+            ssHeader << pindex->GetBlockHeader();
+        }
+
         std::string strHex = HexStr(ssHeader.begin(), ssHeader.end()) + "\n";
         req->WriteHeader("Content-Type", "text/plain");
         req->WriteReply(HTTP_OK, strHex);
@@ -224,11 +229,10 @@ static bool rest_block(HTTPRequest* req,
             return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");
     }
 
-    CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
-    ssBlock << block;
-
     switch (rf) {
     case RetFormat::BINARY: {
+        CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssBlock << block;
         std::string binaryBlock = ssBlock.str();
         req->WriteHeader("Content-Type", "application/octet-stream");
         req->WriteReply(HTTP_OK, binaryBlock);
@@ -236,6 +240,8 @@ static bool rest_block(HTTPRequest* req,
     }
 
     case RetFormat::HEX: {
+        CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssBlock << block;
         std::string strHex = HexStr(ssBlock.begin(), ssBlock.end()) + "\n";
         req->WriteHeader("Content-Type", "text/plain");
         req->WriteReply(HTTP_OK, strHex);
@@ -360,11 +366,11 @@ static bool rest_tx(HTTPRequest* req, const std::string& strURIPart)
     if (!GetTransaction(hash, tx, Params().GetConsensus(), hashBlock, true))
         return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");
 
-    CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
-    ssTx << tx;
-
     switch (rf) {
     case RetFormat::BINARY: {
+        CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssTx << tx;
+
         std::string binaryTx = ssTx.str();
         req->WriteHeader("Content-Type", "application/octet-stream");
         req->WriteReply(HTTP_OK, binaryTx);
@@ -372,6 +378,9 @@ static bool rest_tx(HTTPRequest* req, const std::string& strURIPart)
     }
 
     case RetFormat::HEX: {
+        CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
+        ssTx << tx;
+
         std::string strHex = HexStr(ssTx.begin(), ssTx.end()) + "\n";
         req->WriteHeader("Content-Type", "text/plain");
         req->WriteReply(HTTP_OK, strHex);