Add a generic hash API.

Also use this API in framemd5.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

1 files changed, 78 insertions, 0 deletions

diff --git a/libavutil/hash.h b/libavutil/hash.h
new file mode 100644
index 0000000..7ecb3e7
--- /dev/null
+++ b/libavutil/hash.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2013 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_HASH_H
+#define AVUTIL_HASH_H
+
+#include <stdint.h>
+
+struct AVHashContext;
+
+/**
+ * Allocate a hash context for the algorithm specified by name.
+ *
+ * @return  >= 0 for success, a negative error code for failure
+ * @note  The context is not initialized, you must call av_hash_init().
+ */
+int av_hash_alloc(struct AVHashContext **ctx, const char *name);
+
+/**
+ * Get the names of available hash algorithms.
+ *
+ * This function can be used to enumerate the algorithms.
+ *
+ * @param i  index of the hash algorithm, starting from 0
+ * @return   a pointer to a static string or NULL if i is out of range
+ */
+const char *av_hash_names(int i);
+
+/**
+ * Get the name of the algorithm corresponding to the given hash context.
+ */
+const char *av_hash_get_name(const struct AVHashContext *ctx);
+
+/**
+ * Get the size of the resulting hash value in bytes.
+ *
+ * The pointer passed to av_hash_final have space for at least this many bytes.
+ */
+int av_hash_get_size(const struct AVHashContext *ctx);
+
+/**
+ * Initialize or reset a hash context.
+ */
+void av_hash_init(struct AVHashContext *ctx);
+
+/**
+ * Update a hash context with additional data.
+ */
+void av_hash_update(struct AVHashContext *ctx, const uint8_t *src, int len);
+
+/**
+ * Finalize a hash context and compute the actual hash value.
+ */
+void av_hash_final(struct AVHashContext *ctx, uint8_t *dst);
+
+/**
+ * Free hash context.
+ */
+void av_hash_freep(struct AVHashContext **ctx);
+
+#endif /* AVUTIL_HASH_H */