src/journal/mmap-cache.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2012 Lennart Poettering
   8 ***/
   9
  10 #include <stdbool.h>
  11 #include <sys/stat.h>
  12
  13 /* One context per object type, plus one of the header, plus one "additional" one */
  14 #define MMAP_CACHE_MAX_CONTEXTS 9
  15
  16 typedef struct MMapCache MMapCache;
  17 typedef struct MMapFileDescriptor MMapFileDescriptor;
  18
  19 MMapCache* mmap_cache_new(void);
  20 MMapCache* mmap_cache_ref(MMapCache *m);
  21 MMapCache* mmap_cache_unref(MMapCache *m);
  22
  23 int mmap_cache_get(
  24         MMapCache *m,
  25         MMapFileDescriptor *f,
  26         int prot,
  27         unsigned context,
  28         bool keep_always,
  29         uint64_t offset,
  30         size_t size,
  31         struct stat *st,
  32         void **ret,
  33         size_t *ret_size);
  34 MMapFileDescriptor * mmap_cache_add_fd(MMapCache *m, int fd);
  35 void mmap_cache_free_fd(MMapCache *m, MMapFileDescriptor *f);
  36
  37 unsigned mmap_cache_get_hit(MMapCache *m);
  38 unsigned mmap_cache_get_missed(MMapCache *m);
  39
  40 bool mmap_cache_got_sigbus(MMapCache *m, MMapFileDescriptor *f);