database/subscription.c

   1 /* Blerg is (C) 2011 The Dominion of Awesome, and is distributed under a
   2  * BSD-style license.  Please see the COPYING file for details.
   3  */
   4 #include <sys/types.h>
   5 #include <sys/stat.h>
   6 #include <sys/mman.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9 #include <stdio.h>
  10 #include <fcntl.h>
  11 #include <string.h>
  12 #include "subscription.h"
  13 #include "stringbucket.h"
  14 #include "util.h"
  15 #include "config.h"
  16 #include "configuration.h"
  17
  18 int subscription_add(const char *from, const char *to) {
  19         char filename[FILENAME_MAX];
  20         struct stringbucket * sb;
  21
  22         snprintf(filename, FILENAME_MAX, "%s/%s/subscriptions", blergconf.data_path, from);
  23         sb = stringbucket_open(filename);
  24         stringbucket_add(sb, to);
  25         stringbucket_close(sb);
  26
  27         snprintf(filename, FILENAME_MAX, "%s/%s/subscribers", blergconf.data_path, to);
  28         sb = stringbucket_open(filename);
  29         stringbucket_add(sb, from);
  30         stringbucket_close(sb);
  31
  32         return 1;
  33 }
  34
  35 int subscription_remove(const char *from, const char *to) {
  36         char filename[FILENAME_MAX];
  37         struct stringbucket * sb;
  38
  39         snprintf(filename, FILENAME_MAX, "%s/%s/subscriptions", blergconf.data_path, from);
  40         sb = stringbucket_open(filename);
  41         stringbucket_delete(sb, to);
  42         stringbucket_close(sb);
  43
  44         snprintf(filename, FILENAME_MAX, "%s/%s/subscribers", blergconf.data_path, to);
  45         sb = stringbucket_open(filename);
  46         stringbucket_delete(sb, from);
  47         stringbucket_close(sb);
  48
  49         return 1;
  50 }
  51
  52 void subscription_notify_add_item(char *to, void *stuff) {
  53         char filename[FILENAME_MAX];
  54
  55         snprintf(filename, FILENAME_MAX, "%s/%s/subscription_feed", blergconf.data_path, to);
  56         int fd = open(filename, O_WRONLY | O_APPEND | O_CREAT, 0600);
  57         write(fd, stuff, sizeof(struct blergref));
  58         close(fd);
  59 }
  60
  61 int subscription_notify(const char *author, uint64_t record) {
  62         char filename[FILENAME_MAX];
  63         struct blergref r;
  64
  65         strncpy(r.author, author, 32);
  66         r.record = record;
  67
  68         snprintf(filename, FILENAME_MAX, "%s/%s/subscribers", blergconf.data_path, author);
  69         struct stringbucket * sb = stringbucket_open(filename);
  70         stringbucket_iterate(sb, subscription_notify_add_item, &r);
  71         stringbucket_close(sb);
  72
  73         return 1;
  74 }
  75
  76 struct blergref * subscription_list(const char *author, uint64_t offset, int *count, int direction) {
  77         char filename[FILENAME_MAX];
  78         struct stat st;
  79         struct blergref * slist;
  80         struct blergref * retlist;
  81         uint64_t n_subscription_records;
  82
  83         if (!valid_name(author))
  84                 return NULL;
  85
  86         snprintf(filename, FILENAME_MAX, "%s/%s/subscription_feed", blergconf.data_path, author);
  87
  88         int feed_fd = open(filename, O_RDONLY);
  89         if (feed_fd == -1) {
  90                 perror("Could not open subscription feed");
  91                 goto subscription_list_open_failed;
  92         }
  93
  94         fstat(feed_fd, &st);
  95         if (st.st_size == 0) {
  96                 fprintf(stderr, "Feed is empty\n");
  97                 goto subscription_list_map_failed;
  98         }
  99         n_subscription_records = st.st_size / sizeof(struct blergref);
 100         if (*count > n_subscription_records - offset)
 101                 *count = n_subscription_records - offset;
 102         if (offset > n_subscription_records) {
 103                 fprintf(stderr, "Cannot access subscription record beyond end\n");
 104                 goto subscription_list_map_failed;
 105                 close(feed_fd);
 106                 return NULL;
 107         }
 108
 109         slist = (struct blergref *) mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, feed_fd, 0);
 110         if (slist == MAP_FAILED) {
 111                 perror("Could not mmap tag_file");
 112                 goto subscription_list_map_failed;
 113         }
 114         retlist = (struct blergref *) malloc(sizeof(struct blergref) * *count);
 115         if (retlist == NULL) {
 116                 perror("Could not allocate memory for subscription feed list");
 117                 goto subscription_list_malloc_failed;
 118         }
 119
 120         switch(direction) {
 121         case 1:
 122                 memcpy(retlist, slist + offset, sizeof(struct blergref) * *count);
 123                 break;
 124         case -1:
 125                 memcpy(retlist, slist + (n_subscription_records - *count - offset), sizeof(struct blergref) * *count);
 126         }
 127
 128         munmap(slist, st.st_size);
 129         close(feed_fd);
 130         return retlist;
 131
 132 subscription_list_malloc_failed:
 133         munmap(slist, st.st_size);
 134 subscription_list_map_failed:
 135         close(feed_fd);
 136 subscription_list_open_failed:
 137         *count = 0;
 138         return NULL;
 139 }
 140
 141 int is_subscribed(const char *from, const char *to) {
 142         char filename[FILENAME_MAX];
 143         struct stringbucket * sb;
 144         int ret = 0;
 145
 146         snprintf(filename, FILENAME_MAX, "%s/%s/subscriptions", blergconf.data_path, from);
 147         sb = stringbucket_open(filename);
 148         if (stringbucket_find(sb, to) != -1)
 149                 ret = 1;
 150         stringbucket_close(sb);
 151
 152         return ret;
 153 }
 154
 155 int subscription_count_items(const char *user) {
 156         char filename[FILENAME_MAX];
 157         struct stat st;
 158
 159         if (!valid_name(user))
 160                 return -1;
 161
 162         snprintf(filename, FILENAME_MAX, "%s/%s/subscription_feed", blergconf.data_path, user);
 163
 164         if (access(filename, R_OK) != 0)
 165                 return 0;
 166         stat(filename, &st);
 167         return st.st_size / sizeof(struct blergref);
 168 }