tools/lib/api/fd/array.c

   1 /*
   2  * Copyright (C) 2014, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
   3  *
   4  * Released under the GPL v2. (and only v2, not any later version)
   5  */
   6 #include "array.h"
   7 #include <errno.h>
   8 #include <fcntl.h>
   9 #include <poll.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12
  13 void fdarray__init(struct fdarray *fda, int nr_autogrow)
  14 {
  15         fda->entries     = NULL;
  16         fda->priv        = NULL;
  17         fda->nr          = fda->nr_alloc = 0;
  18         fda->nr_autogrow = nr_autogrow;
  19 }
  20
  21 int fdarray__grow(struct fdarray *fda, int nr)
  22 {
  23         void *priv;
  24         int nr_alloc = fda->nr_alloc + nr;
  25         size_t psize = sizeof(fda->priv[0]) * nr_alloc;
  26         size_t size  = sizeof(struct pollfd) * nr_alloc;
  27         struct pollfd *entries = realloc(fda->entries, size);
  28
  29         if (entries == NULL)
  30                 return -ENOMEM;
  31
  32         priv = realloc(fda->priv, psize);
  33         if (priv == NULL) {
  34                 free(entries);
  35                 return -ENOMEM;
  36         }
  37
  38         fda->nr_alloc = nr_alloc;
  39         fda->entries  = entries;
  40         fda->priv     = priv;
  41         return 0;
  42 }
  43
  44 struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
  45 {
  46         struct fdarray *fda = calloc(1, sizeof(*fda));
  47
  48         if (fda != NULL) {
  49                 if (fdarray__grow(fda, nr_alloc)) {
  50                         free(fda);
  51                         fda = NULL;
  52                 } else {
  53                         fda->nr_autogrow = nr_autogrow;
  54                 }
  55         }
  56
  57         return fda;
  58 }
  59
  60 void fdarray__exit(struct fdarray *fda)
  61 {
  62         free(fda->entries);
  63         free(fda->priv);
  64         fdarray__init(fda, 0);
  65 }
  66
  67 void fdarray__delete(struct fdarray *fda)
  68 {
  69         fdarray__exit(fda);
  70         free(fda);
  71 }
  72
  73 int fdarray__add(struct fdarray *fda, int fd, short revents)
  74 {
  75         int pos = fda->nr;
  76
  77         if (fda->nr == fda->nr_alloc &&
  78             fdarray__grow(fda, fda->nr_autogrow) < 0)
  79                 return -ENOMEM;
  80
  81         fda->entries[fda->nr].fd     = fd;
  82         fda->entries[fda->nr].events = revents;
  83         fda->nr++;
  84         return pos;
  85 }
  86
  87 int fdarray__filter(struct fdarray *fda, short revents,
  88                     void (*entry_destructor)(struct fdarray *fda, int fd, void *arg),
  89                     void *arg)
  90 {
  91         int fd, nr = 0;
  92
  93         if (fda->nr == 0)
  94                 return 0;
  95
  96         for (fd = 0; fd < fda->nr; ++fd) {
  97                 if (fda->entries[fd].revents & revents) {
  98                         if (entry_destructor)
  99                                 entry_destructor(fda, fd, arg);
 100
 101                         continue;
 102                 }
 103
 104                 if (fd != nr) {
 105                         fda->entries[nr] = fda->entries[fd];
 106                         fda->priv[nr]    = fda->priv[fd];
 107                 }
 108
 109                 ++nr;
 110         }
 111
 112         return fda->nr = nr;
 113 }
 114
 115 int fdarray__poll(struct fdarray *fda, int timeout)
 116 {
 117         return poll(fda->entries, fda->nr, timeout);
 118 }
 119
 120 int fdarray__fprintf(struct fdarray *fda, FILE *fp)
 121 {
 122         int fd, printed = fprintf(fp, "%d [ ", fda->nr);
 123
 124         for (fd = 0; fd < fda->nr; ++fd)
 125                 printed += fprintf(fp, "%s%d", fd ? ", " : "", fda->entries[fd].fd);
 126
 127         return printed + fprintf(fp, " ]");
 128 }