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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 13:40:54 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 13:40:54 +0000 |
commit | 317c0644ccf108aa23ef3fd8358bd66c2840bfc0 (patch) | |
tree | c417b3d25c86b775989cb5ac042f37611b626c8a /src/endianconv.c | |
parent | Initial commit. (diff) | |
download | redis-317c0644ccf108aa23ef3fd8358bd66c2840bfc0.tar.xz redis-317c0644ccf108aa23ef3fd8358bd66c2840bfc0.zip |
Adding upstream version 5:7.2.4.upstream/5%7.2.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/endianconv.c')
-rw-r--r-- | src/endianconv.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/endianconv.c b/src/endianconv.c new file mode 100644 index 0000000..8eb6b22 --- /dev/null +++ b/src/endianconv.c @@ -0,0 +1,129 @@ +/* endinconv.c -- Endian conversions utilities. + * + * This functions are never called directly, but always using the macros + * defined into endianconv.h, this way we define everything is a non-operation + * if the arch is already little endian. + * + * Redis tries to encode everything as little endian (but a few things that need + * to be backward compatible are still in big endian) because most of the + * production environments are little endian, and we have a lot of conversions + * in a few places because ziplists, intsets, zipmaps, need to be endian-neutral + * even in memory, since they are serialized on RDB files directly with a single + * write(2) without other additional steps. + * + * ---------------------------------------------------------------------------- + * + * Copyright (c) 2011-2012, Salvatore Sanfilippo <antirez at gmail dot com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Redis nor the names of its contributors may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + + +#include <stdint.h> + +/* Toggle the 16 bit unsigned integer pointed by *p from little endian to + * big endian */ +void memrev16(void *p) { + unsigned char *x = p, t; + + t = x[0]; + x[0] = x[1]; + x[1] = t; +} + +/* Toggle the 32 bit unsigned integer pointed by *p from little endian to + * big endian */ +void memrev32(void *p) { + unsigned char *x = p, t; + + t = x[0]; + x[0] = x[3]; + x[3] = t; + t = x[1]; + x[1] = x[2]; + x[2] = t; +} + +/* Toggle the 64 bit unsigned integer pointed by *p from little endian to + * big endian */ +void memrev64(void *p) { + unsigned char *x = p, t; + + t = x[0]; + x[0] = x[7]; + x[7] = t; + t = x[1]; + x[1] = x[6]; + x[6] = t; + t = x[2]; + x[2] = x[5]; + x[5] = t; + t = x[3]; + x[3] = x[4]; + x[4] = t; +} + +uint16_t intrev16(uint16_t v) { + memrev16(&v); + return v; +} + +uint32_t intrev32(uint32_t v) { + memrev32(&v); + return v; +} + +uint64_t intrev64(uint64_t v) { + memrev64(&v); + return v; +} + +#ifdef REDIS_TEST +#include <stdio.h> + +#define UNUSED(x) (void)(x) +int endianconvTest(int argc, char *argv[], int flags) { + char buf[32]; + + UNUSED(argc); + UNUSED(argv); + UNUSED(flags); + + snprintf(buf,sizeof(buf),"ciaoroma"); + memrev16(buf); + printf("%s\n", buf); + + snprintf(buf,sizeof(buf),"ciaoroma"); + memrev32(buf); + printf("%s\n", buf); + + snprintf(buf,sizeof(buf),"ciaoroma"); + memrev64(buf); + printf("%s\n", buf); + + return 0; +} +#endif |