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