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author | Michele Papalini <micpapal+fdio@cisco.com> | 2017-02-24 08:00:33 +0000 |
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committer | Gerrit Code Review <gerrit@fd.io> | 2017-02-24 08:00:33 +0000 |
commit | 4df7f4cc98b6288177df256e1db70ddc3f7d00db (patch) | |
tree | 55e71277b419e4830ae641868ab8e751c8b86972 /libparc/parc/algol/parc_HashCode.c | |
parent | f28308bd99381ef5f1e178e2e1f870f245e35873 (diff) | |
parent | ec688b4723a041044226358bcd4dd6e2da39da49 (diff) |
Merge "Initial commit: cframework. Longbow and Libparc" into cframework/master
Diffstat (limited to 'libparc/parc/algol/parc_HashCode.c')
-rwxr-xr-x | libparc/parc/algol/parc_HashCode.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/libparc/parc/algol/parc_HashCode.c b/libparc/parc/algol/parc_HashCode.c new file mode 100755 index 00000000..8554429c --- /dev/null +++ b/libparc/parc/algol/parc_HashCode.c @@ -0,0 +1,49 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + */ +#include <config.h> + +#include <parc/algol/parc_HashCode.h> + +#if PARCHashCodeSize == 64 +static const PARCHashCode _fnv1a_prime = 0x00000100000001B3ULL; +const PARCHashCode parcHashCode_InitialValue = 0xCBF29CE484222325ULL; +#else +static const PARCHashCode _fnv1a_prime = 0x01000193; +const PARCHashCode parcHashCode_InitialValue = 0x811C9DC5; +#endif + +PARCHashCode +parcHashCode_HashImpl(const uint8_t *memory, size_t length, PARCHashCode initialValue) +{ + // Standard FNV 64-bit prime: see http://www.isthe.com/chongo/tech/comp/fnv/#FNV-param + + PARCHashCode hash = initialValue; + + for (size_t i = 0; i < length; i++) { + hash = hash ^ memory[i]; + hash = hash * _fnv1a_prime; + } + + return hash; +} + +PARCHashCode +parcHashCode_HashHashCode(PARCHashCode initialValue, PARCHashCode update) +{ + return parcHashCode_HashImpl((uint8_t *) &update, sizeof(PARCHashCode), initialValue); +} |