Merge #8020: Use SipHash-2-4 for various non-cryptographic hashes

a68ec21 Use SipHash-2-4 for address relay selection (Pieter Wuille)
8cc9cfe Switch CTxMempool::mapTx to use a hash index for txids (Pieter Wuille)
382c871 Use SipHash-2-4 for CCoinsCache index (Pieter Wuille)
0b1295b Add SipHash-2-4 primitives to hash (Pieter Wuille)

1 files changed, 13 insertions, 5 deletions

diff --git a/src/uint256.h b/src/uint256.h
index bcdb6dd7c2..dd8432d74c 100644
--- a/src/uint256.h
+++ b/src/uint256.h
@@ -83,6 +83,19 @@ public:
         return sizeof(data);
     }
 
+    uint64_t GetUint64(int pos) const
+    {
+        const uint8_t* ptr = data + pos * 8;
+        return ((uint64_t)ptr[0]) | \
+               ((uint64_t)ptr[1]) << 8 | \
+               ((uint64_t)ptr[2]) << 16 | \
+               ((uint64_t)ptr[3]) << 24 | \
+               ((uint64_t)ptr[4]) << 32 | \
+               ((uint64_t)ptr[5]) << 40 | \
+               ((uint64_t)ptr[6]) << 48 | \
+               ((uint64_t)ptr[7]) << 56;
+    }
+
     template<typename Stream>
     void Serialize(Stream& s, int nType, int nVersion) const
     {
@@ -127,11 +140,6 @@ public:
     {
         return ReadLE64(data);
     }
-
-    /** A more secure, salted hash function.
-     * @note This hash is not stable between little and big endian.
-     */
-    uint64_t GetHash(const uint256& salt) const;
 };
 
 /* uint256 from const char *.