Added basic file transfer

src/cache.c

@@ -10,22 +10,123 @@
 
 int magic_init() {
     magic = magic_open(MAGIC_MIME);
-    magic_load(magic, "/usr/share/misc/magic.mgc");
+    if (magic == NULL) {
+        fprintf(stderr, ERR_STR "Unable to open magic cookie: %s" CLR_STR "\n", strerror(errno));
+        return -1;
+    }
+    if (magic_load(magic, MAGIC_FILE) != 0) {
+        fprintf(stderr, ERR_STR "Unable to load magic cookie: %s" CLR_STR "\n", magic_error(magic));
+        return -2;
+    }
     return 0;
 }
 
 int cache_init() {
-    magic_init();
+    if (magic_init() != 0) {
+        return -1;
+    }
 
+    int shm_id = shmget(SHM_KEY, FILE_CACHE_SIZE * sizeof(cache_entry), IPC_CREAT | IPC_EXCL);
+    if (shm_id < 0) {
+        fprintf(stderr, ERR_STR "Unable to create shared memory: %s" CLR_STR "\n", strerror(errno));
+        return -2;
+    }
+
+    void *shm = shmat(shm_id, NULL, SHM_RDONLY);
+    if (shm == (void *) -1) {
+        fprintf(stderr, ERR_STR "Unable to attach shared memory (ro): %s" CLR_STR "\n", strerror(errno));
+        return -3;
+    }
+    cache = shm;
+
+    void *shm_rw = shmat(shm_id, NULL, 0);
+    if (shm_rw == (void *) -1) {
+        fprintf(stderr, ERR_STR "Unable to attach shared memory (rw): %s" CLR_STR "\n", strerror(errno));
+        return -4;
+    }
+    cache = shm_rw;
+    memset(cache, 0, FILE_CACHE_SIZE * sizeof(cache_entry));
+    // TODO load cache from file
+    shmdt(shm_rw);
+    cache = shm;
+
+    return 0;
+}
+
+int cache_unload() {
+    int shm_id = shmget(SHM_KEY, 0, 0);
+    if (shm_id < 0) {
+        fprintf(stderr, ERR_STR "Unable to create shared memory: %s" CLR_STR "\n", strerror(errno));
+    } else if (shmctl(shm_id, IPC_RMID, NULL) < 0) {
+        fprintf(stderr, ERR_STR "Unable to configure shared memory: %s" CLR_STR "\n", strerror(errno));
+    }
+    shmdt(cache);
+    return 0;
+}
+
+int cache_update_entry(int entry_num, const char *filename) {
+    void *cache_ro = cache;
+    int shm_id = shmget(SHM_KEY, 0, 0);
+    void *shm_rw = shmat(shm_id, NULL, 0);
+    if (shm_rw == (void *) -1) {
+        print(ERR_STR "Unable to attach shared memory (rw): %s" CLR_STR, strerror(errno));
+        return -1;
+    }
+    cache = shm_rw;
+
+    struct stat statbuf;
+    stat(filename, &statbuf);
+    memcpy(&cache[entry_num].meta.stat, &statbuf, sizeof(statbuf));
+
+    strcpy(cache[entry_num].filename, filename);
+    magic_setflags(magic, MAGIC_MIME_TYPE);
+    strcpy(cache[entry_num].meta.type, magic_file(magic, filename));
+    magic_setflags(magic, MAGIC_MIME_ENCODING);
+    strcpy(cache[entry_num].meta.charset, magic_file(magic, filename));
+    cache[entry_num].is_valid_etag = 0;
+    cache[entry_num].is_updating = 0;
+
+    shmdt(shm_rw);
+    cache = cache_ro;
     return 0;
 }
 
 int uri_cache_init(http_uri *uri) {
     if (uri->filename == NULL) {
-        return -1;
+        return 0;
     }
 
+    int i;
+    for (i = 0; i < FILE_CACHE_SIZE; i++) {
+        if (cache[i].filename[0] != 0 && strncmp(cache[i].filename, uri->filename, cache[i].filename_len) == 0) {
+            uri->meta = &cache[i].meta;
+            if (cache[i].is_updating) {
+                return 0;
+            } else {
+                break;
+            }
+        }
+    }
 
+    if (uri->meta == NULL) {
+        for (i = 0; i < FILE_CACHE_SIZE; i++) {
+            if (cache[i].filename[0] == 0) {
+                if (cache_update_entry(i, uri->filename) != 0) {
+                    return -1;
+                }
+                uri->meta = &cache[i].meta;
+                break;
+            }
+        }
+    } else {
+        struct stat statbuf;
+        stat(uri->filename, &statbuf);
+        if (uri->meta->stat.st_mtimensec != statbuf.st_mtimensec) {
+            if (cache_update_entry(i, uri->filename) != 0) {
+                return -1;
+            }
+        }
+    }
 
     return 0;
 }