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| author | Albert Esteve <aesteve@redhat.com> | 2023-10-02 08:57:03 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2023-10-04 18:15:06 -0400 |
| commit | a6ceee591acdb9c9c772bf59544a57891308222e (patch) | |
| tree | 79cadd8681bb2324c370cf64b17b2b2e3855df31 /util/uuid.c | |
| parent | 70f88436aa5a8aeddd33e4d06270146af5d5bb52 (diff) | |
| download | focaccia-qemu-a6ceee591acdb9c9c772bf59544a57891308222e.tar.gz focaccia-qemu-a6ceee591acdb9c9c772bf59544a57891308222e.zip | |
util/uuid: add a hash function
Add hash function to uuid module using the djb2 hash algorithm. Add a couple simple unit tests for the hash function, checking collisions for similar UUIDs. Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Albert Esteve <aesteve@redhat.com> Message-Id: <20231002065706.94707-2-aesteve@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'util/uuid.c')
| -rw-r--r-- | util/uuid.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/util/uuid.c b/util/uuid.c index b1108dde78..d71aa79e5e 100644 --- a/util/uuid.c +++ b/util/uuid.c @@ -116,3 +116,17 @@ QemuUUID qemu_uuid_bswap(QemuUUID uuid) bswap16s(&uuid.fields.time_high_and_version); return uuid; } + +/* djb2 hash algorithm */ +uint32_t qemu_uuid_hash(const void *uuid) +{ + QemuUUID *qid = (QemuUUID *) uuid; + uint32_t h = 5381; + int i; + + for (i = 0; i < ARRAY_SIZE(qid->data); i++) { + h = (h << 5) + h + qid->data[i]; + } + + return h; +} |