Add ETag calculation

src/cache.c

@@ -21,6 +21,74 @@ int magic_init() {
     return 0;
 }
 
+void cache_process_term() {
+    cache_continue = 0;
+}
+
+int cache_process() {
+    signal(SIGINT, cache_process_term);
+    signal(SIGTERM, cache_process_term);
+
+    int shm_id = shmget(SHM_KEY, FILE_CACHE_SIZE * sizeof(cache_entry), 0);
+    if (shm_id < 0) {
+        fprintf(stderr, ERR_STR "Unable to create shared memory: %s" CLR_STR "\n", strerror(errno));
+        return -1;
+    }
+    shmdt(cache);
+    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 -2;
+    }
+    cache = shm_rw;
+
+    mkdir("/var/necronda-server", 0655);
+
+    FILE *cache_file = fopen("/var/necronda-server/cache", "rb");
+    fread(cache, sizeof(cache_entry), FILE_CACHE_SIZE , cache_file);
+    fclose(cache_file);
+
+    for (int i = 0; i < FILE_CACHE_SIZE; i++) {
+        cache[i].is_updating = 0;
+    }
+
+    FILE *file;
+    char buf[16384];
+    unsigned long read;
+    int compress;
+    SHA_CTX ctx;
+    unsigned char hash[SHA_DIGEST_LENGTH];
+    while (cache_continue) {
+        for (int i = 0; i < FILE_CACHE_SIZE; i++) {
+            if (cache[i].filename[0] != 0 && cache[i].meta.etag[0] == 0 && !cache[i].is_updating) {
+                cache[i].is_updating = 1;
+                SHA1_Init(&ctx);
+                file = fopen(cache[i].filename, "rb");
+                compress = strncmp(cache[i].meta.type, "text/", 5) == 0;
+                while ((read = fread(buf, 1, sizeof(buf), file)) > 0) {
+                    SHA1_Update(&ctx, buf, read);
+                    if (compress) {
+                        // TODO compress text/* files
+                    }
+                }
+                SHA1_Final(hash, &ctx);
+                memset(cache[i].meta.etag, 0, sizeof(cache[i].meta.etag));
+                for (int j = 0; j < SHA_DIGEST_LENGTH; j++) {
+                    sprintf(cache[i].meta.etag + j * 2, "%02x", hash[j]);
+                }
+                fclose(file);
+                cache[i].is_updating = 0;
+            }
+        }
+
+        cache_file = fopen("/var/necronda-server/cache", "wb");
+        fwrite(cache, sizeof(cache_entry), FILE_CACHE_SIZE , cache_file);
+        fclose(cache_file);
+        sleep(1);
+    }
+    return 0;
+}
+
 int cache_init() {
     if (magic_init() != 0) {
         return -1;
@@ -46,10 +114,26 @@ int cache_init() {
     }
     cache = shm_rw;
     memset(cache, 0, FILE_CACHE_SIZE * sizeof(cache_entry));
-    // TODO load cache from file
     shmdt(shm_rw);
     cache = shm;
 
+    pid_t pid = fork();
+    if (pid == 0) {
+        // child
+        if (cache_process() == 0) {
+            return 1;
+        } else {
+            return -6;
+        }
+    } else if (pid > 0) {
+        // parent
+        fprintf(stderr, "Started child process with PID %i as cache-updater\n", pid);
+        children[0] = pid;
+    } else {
+        fprintf(stderr, ERR_STR "Unable to create child process: %s" CLR_STR "\n", strerror(errno));
+        return -5;
+    }
+
     return 0;
 }
 
@@ -80,10 +164,20 @@ int cache_update_entry(int entry_num, const char *filename) {
 
     strcpy(cache[entry_num].filename, filename);
     magic_setflags(magic, MAGIC_MIME_TYPE);
-    strcpy(cache[entry_num].meta.type, magic_file(magic, filename));
+    const char *type = magic_file(magic, filename);
+    char type_new[24];
+    sprintf(type_new, "%s", type);
+    if (strncmp(type, "text/plain", 10) == 0) {
+        if (strncmp(filename + strlen(filename) - 4, ".css", 4) == 0) {
+            sprintf(type_new, "text/css");
+        } else if (strncmp(filename + strlen(filename) - 3, ".js", 3) == 0) {
+            sprintf(type_new, "text/javascript");
+        }
+    }
+    strcpy(cache[entry_num].meta.type, type_new);
     magic_setflags(magic, MAGIC_MIME_ENCODING);
     strcpy(cache[entry_num].meta.charset, magic_file(magic, filename));
-    cache[entry_num].is_valid_etag = 0;
+    memset(cache[entry_num].meta.etag, 0, sizeof(cache[entry_num].meta.etag));
     cache[entry_num].is_updating = 0;
 
     shmdt(shm_rw);
@@ -98,7 +192,8 @@ int uri_cache_init(http_uri *uri) {
 
     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) {
+        if (cache[i].filename[0] != 0 && strlen(cache[i].filename) == strlen(uri->filename) &&
+            strcmp(cache[i].filename, uri->filename) == 0) {
             uri->meta = &cache[i].meta;
             if (cache[i].is_updating) {
                 return 0;