1 files changed, 67 insertions, 0 deletions
diff --git a/include/zix/digest.h b/include/zix/digest.h
new file mode 100644
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--- /dev/null
+++ b/include/zix/digest.h
@@ -0,0 +1,67 @@
+/*
+  Copyright 2012-2020 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#ifndef ZIX_DIGEST_H
+#define ZIX_DIGEST_H
+
+#include "zix/common.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+   Return an initial empty digest value.
+*/
+ZIX_CONST_API
+uint32_t
+zix_digest_start(void);
+
+/**
+   Update `hash` to include `buf`, a buffer of `len` bytes.
+
+   This can be used for any size or alignment.
+*/
+ZIX_PURE_API
+uint32_t
+zix_digest_add(uint32_t hash, const void* buf, size_t len);
+
+/**
+   Update `hash` to include `buf`, a 64-bit aligned buffer of `len` bytes.
+
+   Both `buf` and `len` must be evenly divisible by 8 (64 bits).
+*/
+ZIX_PURE_API
+uint32_t
+zix_digest_add_64(uint32_t hash, const void* buf, size_t len);
+
+/**
+   Update `hash` to include `ptr`.
+
+   This hashes the value of the pointer itself, and does not dereference `ptr`.
+*/
+ZIX_CONST_API
+uint32_t
+zix_digest_add_ptr(uint32_t hash, const void* ptr);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* ZIX_DIGEST_H */