Add subscription feed fetching, clean up a bit

[blerg.git] / database / subscription.c

diff --git a/database/subscription.c b/database/subscription.c
index e6ae94a..d67d31f 100644 (file)
--- a/database/subscription.c
+++ b/database/subscription.c
@@ -1,7 +1,12 @@
+/* Blerg is (C) 2011 The Dominion of Awesome, and is distributed under a
+ * BSD-style license.  Please see the COPYING file for details.
+ */
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <fcntl.h>
+#include <sys/mman.h>
+#include <stdlib.h>
 #include <stdio.h>
+#include <fcntl.h>
 #include <string.h>
 #include "subscription.h"
 #include "stringbucket.h"
@@ -41,14 +46,14 @@ void subscription_notify_add_item(char *to, void *stuff) {
        char filename[512];
 
        snprintf(filename, 512, "%s/%s/subscription_feed", DATA_PATH, to);
-       int fd = open(filename, O_WRONLY | O_APPEND | O_CREAT);
-       write(fd, stuff, sizeof(struct subscription_record));
+       int fd = open(filename, O_WRONLY | O_APPEND | O_CREAT, 0600);
+       write(fd, stuff, sizeof(struct blergref));
        close(fd);
 }
 
 int subscription_notify(const char *author, uint64_t record) {
        char filename[512];
-       struct subscription_record r;
+       struct blergref r;
 
        strncpy(r.author, author, 32);
        r.record = record;
@@ -58,3 +63,68 @@ int subscription_notify(const char *author, uint64_t record) {
        stringbucket_iterate(sb, subscription_notify_add_item, &r);
        stringbucket_close(sb);
 }
+
+struct blergref * subscription_list(const char *author, uint64_t offset, int *count, int direction) {
+       char filename[512];
+       struct stat st;
+       struct blergref * slist;
+       struct blergref * retlist;
+       uint64_t n_subscription_records;
+
+       if (!valid_name(author))
+               return NULL;
+
+       snprintf(filename, 512, "%s/%s/subscription_feed", DATA_PATH, author);
+
+       int feed_fd = open(filename, O_RDONLY);
+       if (feed_fd == -1) {
+               perror("Could not open subscription feed");
+               goto subscription_list_map_failed;
+       }
+
+       fstat(feed_fd, &st);
+       if (st.st_size == 0) {
+               close(feed_fd);
+               goto subscription_list_map_failed;
+       }
+       n_subscription_records = st.st_size / sizeof(struct blergref);
+       if (*count > n_subscription_records - offset)
+               *count = n_subscription_records - offset;
+       if (offset > n_subscription_records) {
+               fprintf(stderr, "Cannot access subscription record beyond end\n");
+               goto subscription_list_map_failed;
+               close(feed_fd);
+               return NULL;
+       }
+
+       slist = (struct blergref *) mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, feed_fd, 0);
+       if (slist == MAP_FAILED) {
+               perror("Could not mmap tag_file");
+               goto subscription_list_map_failed;
+       }
+       retlist = (struct blergref *) malloc(sizeof(struct blergref) * *count);
+       if (retlist == NULL) {
+               perror("Could not allocate memory for subscription feed list");
+               goto subscription_list_malloc_failed;
+       }
+       
+       switch(direction) {
+       case 1:
+               memcpy(retlist, slist + offset, sizeof(struct blergref) * *count);
+               break;
+       case -1:
+               memcpy(retlist, slist + (n_subscription_records - *count - offset), sizeof(struct blergref) * *count);
+       }
+
+       munmap(slist, st.st_size);
+       close(feed_fd);
+       return retlist;
+
+subscription_list_malloc_failed:
+       munmap(slist, st.st_size);
+subscription_list_map_failed:
+       close(feed_fd);
+subscription_list_open_failed:
+       *count = 0;
+       return NULL;
+}