Merge #9045: Hash P2P messages as they are received instead of at process-time

fe1dc62 Hash P2P messages as they are received instead of at process-time (Matt Corallo)

src/net.h

@@ -543,6 +543,9 @@ public:
 
 
 class CNetMessage {
+private:
+    mutable CHash256 hasher;
+    mutable uint256 data_hash;
 public:
     bool in_data;                   // parsing header (false) or data (true)
 
@@ -570,6 +573,8 @@ public:
         return (hdr.nMessageSize == nDataPos);
     }
 
+    const uint256& GetMessageHash() const;
+
     void SetVersion(int nVersionIn)
     {
         hdrbuf.SetVersion(nVersionIn);