Document cached hash state, used for incremental hashing.

src/core/model/hash-fnv.h

@@ -96,7 +96,7 @@ private:
   };
   //@{
   /**
-   * Cache last hash value, for incremental hashing
+   * Cache last hash value, for incremental hashing.
    */
   uint32_t m_hash32;
   uint64_t m_hash64;

src/core/model/hash-murmur3.h

@@ -98,15 +98,17 @@ private:
     SEED = 0x8BADF00D  // Ate bad food
   };
   //@{
-  /**
-   * Cache last hash value, and total bytes hashed,
+  /** 
+   * Cache last hash value, and total bytes hashed (needed to finalize),
    * for incremental hashing
    */
   uint32_t m_hash32;
   uint32_t m_size32;
-  uint64_t m_hash64[2];  // murmur3 produces 128-bit hash
+  /** murmur3 produces 128-bit hash and state; we use just the first 64-bits. */
+  uint64_t m_hash64[2];  
   uint64_t m_size64;
   //@}
+      
 };  // class Murmur3
 
 }  // namespace Function