src/basic/io-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <stdbool.h>
   5 #include <stddef.h>
   6 #include <stdint.h>
   7 #include <sys/types.h>
   8 #include <sys/uio.h>
   9
  10 #include "macro.h"
  11 #include "time-util.h"
  12
  13 int flush_fd(int fd);
  14
  15 ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll);
  16 int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll);
  17 int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll);
  18
  19 int pipe_eof(int fd);
  20
  21 int fd_wait_for_event(int fd, int event, usec_t timeout);
  22
  23 ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length);
  24
  25 static inline size_t IOVEC_TOTAL_SIZE(const struct iovec *i, size_t n) {
  26         size_t j, r = 0;
  27
  28         for (j = 0; j < n; j++)
  29                 r += i[j].iov_len;
  30
  31         return r;
  32 }
  33
  34 static inline size_t IOVEC_INCREMENT(struct iovec *i, size_t n, size_t k) {
  35         size_t j;
  36
  37         for (j = 0; j < n; j++) {
  38                 size_t sub;
  39
  40                 if (_unlikely_(k <= 0))
  41                         break;
  42
  43                 sub = MIN(i[j].iov_len, k);
  44                 i[j].iov_len -= sub;
  45                 i[j].iov_base = (uint8_t*) i[j].iov_base + sub;
  46                 k -= sub;
  47         }
  48
  49         return k;
  50 }
  51
  52 static inline bool FILE_SIZE_VALID(uint64_t l) {
  53         /* ftruncate() and friends take an unsigned file size, but actually cannot deal with file sizes larger than
  54          * 2^63 since the kernel internally handles it as signed value. This call allows checking for this early. */
  55
  56         return (l >> 63) == 0;
  57 }
  58
  59 static inline bool FILE_SIZE_VALID_OR_INFINITY(uint64_t l) {
  60
  61         /* Same as above, but allows one extra value: -1 as indication for infinity. */
  62
  63         if (l == (uint64_t) -1)
  64                 return true;
  65
  66         return FILE_SIZE_VALID(l);
  67
  68 }
  69
  70 #define IOVEC_INIT(base, len) { .iov_base = (base), .iov_len = (len) }
  71 #define IOVEC_MAKE(base, len) (struct iovec) IOVEC_INIT(base, len)
  72 #define IOVEC_INIT_STRING(string) IOVEC_INIT((char*) string, strlen(string))
  73 #define IOVEC_MAKE_STRING(string) (struct iovec) IOVEC_INIT_STRING(string)
  74
  75 char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value);
  76 char* set_iovec_string_field_free(struct iovec *iovec, size_t *n_iovec, const char *field, char *value);
  77
  78 struct iovec_wrapper {
  79         struct iovec *iovec;
  80         size_t count;
  81         size_t size_bytes;
  82 };
  83
  84 struct iovec_wrapper *iovw_new(void);
  85 struct iovec_wrapper *iovw_free(struct iovec_wrapper *iovw);
  86 struct iovec_wrapper *iovw_free_free(struct iovec_wrapper *iovw);
  87 void iovw_free_contents(struct iovec_wrapper *iovw, bool free_vectors);
  88 int iovw_put(struct iovec_wrapper *iovw, void *data, size_t len);
  89 int iovw_put_string_field(struct iovec_wrapper *iovw, const char *field, const char *value);
  90 int iovw_put_string_field_free(struct iovec_wrapper *iovw, const char *field, char *value);
  91 void iovw_rebase(struct iovec_wrapper *iovw, char *old, char *new);
  92 size_t iovw_size(struct iovec_wrapper *iovw);