From 8824331c4b8dbc4a652bdf76e0450e8a1b7b53d1 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Mon, 20 Jun 2016 16:48:17 +1000
Subject: [PATCH] hash/crc: convert to object style accumulator

---
 hash/crc.cpp | 37 ++++++++++++++++++++++++++++---------
 hash/crc.hpp | 16 ++++++++++++++--
 2 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/hash/crc.cpp b/hash/crc.cpp
index 59c3c34b..436771d7 100644
--- a/hash/crc.cpp
+++ b/hash/crc.cpp
@@ -16,25 +16,32 @@
 
 #include "./crc.hpp"
 
-#include "../endian.hpp"
 #include "../debug.hpp"
 
+using util::hash::crc32;
+
 
 ///////////////////////////////////////////////////////////////////////////////
-uint32_t
-util::hash::crc32 (
-    const uint8_t *restrict first,
-    const uint8_t *restrict last
-) noexcept {
+void
+crc32::reset (void)
+{ ; }
+
+
+///////////////////////////////////////////////////////////////////////////////
+void
+crc32::update (const uint8_t *restrict first,
+               const uint8_t *restrict last) noexcept
+{
     CHECK_LE (first, last);
 
-    return crc32 (first, last - first);
+    return update (first, last - first);
 }
 
 
 //-----------------------------------------------------------------------------
-uint32_t
-util::hash::crc32 (const void *restrict, size_t) noexcept {
+void
+crc32::update (const void *restrict, size_t) noexcept
+{
     not_implemented ();
 
     /*
@@ -67,3 +74,15 @@ util::hash::crc32 (const void *restrict, size_t) noexcept {
     }
     */
 }
+
+
+//-----------------------------------------------------------------------------
+void
+crc32::finish (void)
+{ not_implemented (); }
+
+
+//-----------------------------------------------------------------------------
+typename crc32::digest_t
+crc32::digest (void) const
+{ not_implemented (); }
diff --git a/hash/crc.hpp b/hash/crc.hpp
index 6b7b175d..222f0119 100644
--- a/hash/crc.hpp
+++ b/hash/crc.hpp
@@ -23,8 +23,20 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 namespace util { namespace hash {
-    uint32_t crc32 (const void *restrict data, size_t bytes) noexcept;
-    uint32_t crc32 (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
+    class crc32 {
+    public:
+        using digest_t = uint32_t;
+
+        void reset (void);
+
+        void update (const void *restrict data, size_t bytes) noexcept;
+        void update (const uint8_t *restrict first, const uint8_t *restrict last) noexcept;
+
+        void finish (void);
+
+        digest_t digest (void) const;
+    };
+
 } }
 #endif