Add a generic hash API.

Also use this API in framemd5.

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

1 files changed, 154 insertions, 0 deletions

diff --git a/libavutil/hash.c b/libavutil/hash.c
new file mode 100644
index 0000000000..481010dee8
--- /dev/null
+++ b/libavutil/hash.c
@@ -0,0 +1,154 @@
+/*
+ * 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
+ */
+#include <stdint.h>
+#include "hash.h"
+
+#include "adler32.h"
+#include "crc.h"
+#include "md5.h"
+#include "murmur3.h"
+#include "sha.h"
+
+#include "avstring.h"
+#include "error.h"
+#include "intreadwrite.h"
+#include "mem.h"
+
+enum hashtype {
+    MD5,
+    MURMUR3,
+    SHA160,
+    SHA224,
+    SHA256,
+    CRC32,
+    ADLER32,
+    NUM_HASHES
+};
+
+typedef struct AVHashContext {
+    void *ctx;
+    enum hashtype type;
+    const AVCRC *crctab;
+    uint32_t crc;
+} AVHashContext;
+
+struct {
+    const char *name;
+    int size;
+} hashdesc[] = {
+    [MD5]     = {"MD5",     16},
+    [MURMUR3] = {"murmur3", 16},
+    [SHA160]  = {"SHA160",  20},
+    [SHA224]  = {"SHA240",  28},
+    [SHA256]  = {"SHA256",  32},
+    [CRC32]   = {"CRC32",    4},
+    [ADLER32] = {"adler32",  4},
+};
+
+const char *av_hash_names(int i)
+{
+    if (i < 0 || i >= NUM_HASHES) return NULL;
+    return hashdesc[i].name;
+}
+
+const char *av_hash_get_name(const AVHashContext *ctx)
+{
+    return hashdesc[ctx->type].name;
+}
+
+int av_hash_get_size(const AVHashContext *ctx)
+{
+    return hashdesc[ctx->type].size;
+}
+
+int av_hash_alloc(AVHashContext **ctx, const char *name)
+{
+    AVHashContext *res;
+    int i;
+    *ctx = NULL;
+    for (i = 0; i < NUM_HASHES; i++)
+        if (av_strcasecmp(name, hashdesc[i].name) == 0)
+            break;
+    if (i >= NUM_HASHES) return AVERROR(EINVAL);
+    res = av_mallocz(sizeof(*res));
+    if (!res) return AVERROR(ENOMEM);
+    res->type = i;
+    switch (i) {
+    case MD5:     res->ctx = av_md5_alloc(); break;
+    case MURMUR3: res->ctx = av_murmur3_alloc(); break;
+    case SHA160:
+    case SHA224:
+    case SHA256:  res->ctx = av_sha_alloc(); break;
+    case CRC32:   res->crctab = av_crc_get_table(AV_CRC_32_IEEE); break;
+    case ADLER32: break;
+    }
+    if (i != ADLER32 && i != CRC32 && !res->ctx) {
+        av_free(res);
+        return AVERROR(ENOMEM);
+    }
+    *ctx = res;
+    return 0;
+}
+
+void av_hash_init(AVHashContext *ctx)
+{
+    switch (ctx->type) {
+    case MD5:     av_md5_init(ctx->ctx); break;
+    case MURMUR3: av_murmur3_init(ctx->ctx); break;
+    case SHA160:  av_sha_init(ctx->ctx, 160); break;
+    case SHA224:  av_sha_init(ctx->ctx, 224); break;
+    case SHA256:  av_sha_init(ctx->ctx, 256); break;
+    case CRC32:
+    case ADLER32: ctx->crc = 0; break;
+    }
+}
+
+void av_hash_update(AVHashContext *ctx, const uint8_t *src, int len)
+{
+    switch (ctx->type) {
+    case MD5:     av_md5_update(ctx->ctx, src, len); break;
+    case MURMUR3: av_murmur3_update(ctx->ctx, src, len); break;
+    case SHA160:
+    case SHA224:
+    case SHA256:  av_sha_update(ctx->ctx, src, len); break;
+    case CRC32:   ctx->crc = av_crc(ctx->crctab, ctx->crc, src, len); break;
+    case ADLER32: ctx->crc = av_adler32_update(ctx->crc, src, len); break;
+    }
+}
+
+void av_hash_final(AVHashContext *ctx, uint8_t *dst)
+{
+    switch (ctx->type) {
+    case MD5:     av_md5_final(ctx->ctx, dst); break;
+    case MURMUR3: av_murmur3_final(ctx->ctx, dst); break;
+    case SHA160:
+    case SHA224:
+    case SHA256:  av_sha_final(ctx->ctx, dst); break;
+    case CRC32:
+    case ADLER32: AV_WL32(dst, ctx->crc); break;
+    }
+}
+
+void av_hash_freep(AVHashContext **ctx)
+{
+    if (*ctx)
+        av_freep(&(*ctx)->ctx);
+    av_freep(ctx);
+}