c2911d48ff
Instead of assuming that more-recently modified directories have higher mtime, just look for any mtime changes, up or down. Since we don't want to remember individual mtimes, hash them to obtain a single value. This should help us behave properly in the case when the time jumps backwards during boot: various files might have mtimes that in the future, but we won't care. This fixes the following scenario: We have /etc/systemd/system with T1. T1 is initially far in the past. We have /run/systemd/generator with time T2. The time is adjusted backwards, so T2 will be always in the future for a while. Now the user writes new files to /etc/systemd/system, and T1 is updated to T1'. Nevertheless, T1 < T1' << T2. We would consider our cache to be up-to-date, falsely.
48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
#pragma once
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#include <inttypes.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <string.h>
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#include <sys/types.h>
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#include "time-util.h"
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struct siphash {
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uint64_t v0;
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uint64_t v1;
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uint64_t v2;
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uint64_t v3;
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uint64_t padding;
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size_t inlen;
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};
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void siphash24_init(struct siphash *state, const uint8_t k[static 16]);
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void siphash24_compress(const void *in, size_t inlen, struct siphash *state);
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#define siphash24_compress_byte(byte, state) siphash24_compress((const uint8_t[]) { (byte) }, 1, (state))
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static inline void siphash24_compress_boolean(bool in, struct siphash *state) {
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uint8_t i = in;
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siphash24_compress(&i, sizeof i, state);
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}
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static inline void siphash24_compress_usec_t(usec_t in, struct siphash *state) {
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siphash24_compress(&in, sizeof in, state);
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}
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static inline void siphash24_compress_string(const char *in, struct siphash *state) {
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if (!in)
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return;
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siphash24_compress(in, strlen(in), state);
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}
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uint64_t siphash24_finalize(struct siphash *state);
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uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]);
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static inline uint64_t siphash24_string(const char *s, const uint8_t k[static 16]) {
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return siphash24(s, strlen(s) + 1, k);
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}
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