add: cache (WIP)

src/cache.c

@@ -1,9 +1,86 @@
 #include <cache.h>
 #include <logger.h>
+#include <sql/cache.h>
+#include <models/junction_tag.h>
 
 
 sqlite3 *cache_database;
 
+static char*
+cache_get_value(char *key)
+{
+    sqlite3_stmt *stmt;
+    sqlite3_prepare_v2(cache_database, "SELECT value FROM cache WHERE key=?1;", -1, &stmt, NULL);
+    sqlite3_bind_text(stmt, 1, key, -1, SQLITE_STATIC);
+
+    char *result = NULL;
+
+    while(1)
+    {
+        int s;
+
+        s = sqlite3_step(stmt);
+        if (s == SQLITE_ROW)
+        {
+            const char *found_value = (const char *)sqlite3_column_text(stmt, 0);
+            result = (char*)malloc(sizeof(char) * (strlen(found_value) + 1));
+            strcpy(result, found_value);
+        }
+        else
+        {
+            if (s == SQLITE_DONE)
+            {
+                break;
+            }
+            else
+            {
+                LOGGER_WARNING("failed selecting %s from cache: %s\n", key, sqlite3_errstr(s));
+                break;
+            }
+        }
+    }
+
+    sqlite3_finalize(stmt);
+
+    return result;
+}
+
+static void
+cache_insert_value(char *key, char *value)
+{
+    sqlite3_stmt *stmt;
+    sqlite3_prepare_v2(cache_database, "INSERT INTO cache (key, value, expiration) VALUES (?1, ?2, 0);", -1, &stmt, NULL);
+    sqlite3_bind_text(stmt, 1, key, -1, SQLITE_STATIC);
+    sqlite3_bind_text(stmt, 2, value, -1, SQLITE_STATIC);
+
+    int rc = sqlite3_step(stmt);
+
+    sqlite3_finalize(stmt);
+
+    if(rc != SQLITE_DONE)
+    {
+        LOGGER_WARNING("failed to save %s to cache: %s\n", key, sqlite3_errstr(rc));
+    }
+}
+
+static void
+cache_invalidate(char *key)
+{
+    sqlite3_stmt *stmt;
+    int rc;
+
+    sqlite3_prepare_v2(cache_database, "DELETE FROM cache WHERE key=?1;", -1, &stmt, NULL);
+    sqlite3_bind_text(stmt, 1, key, -1, SQLITE_STATIC);
+
+    rc = sqlite3_step(stmt);
+    sqlite3_finalize(stmt);
+
+    if(rc != SQLITE_DONE)
+    {
+        LOGGER_WARNING("failed to invalidate %s in cache: %s\n", key, sqlite3_errstr(rc));
+    }
+}
+
 void
 cache_init()
 {
@@ -12,6 +89,130 @@ cache_init()
     if(rc)
     {
         LOGGER_CRIT("can't open cache database: %s\n", sqlite3_errmsg(cache_database));
-        return;
+        exit(1);
     }
+
+    char* err_msg;
+    rc = sqlite3_exec(cache_database, (const char *)sql_cache_sql, NULL, NULL, &err_msg);
+    if(rc)
+    {
+        LOGGER_CRIT("couldn't initialize cache (%s)\n", err_msg);
+        exit(1);
+    }
+    LOGGER_DEBUG("cache initalized\n");
+}
+
+void
+cache_free()
+{
+    sqlite3_close(cache_database);
+}
+
+
+
+void
+cache_put_json_schedule(int schedule_id, char *schedule_json)
+{
+    char key[32];
+    sprintf(key, "schedule_json:%d", schedule_id);
+    cache_insert_value(key, schedule_json);
+}
+
+char*
+cache_get_json_schedule(int schedule_id)
+{
+    char key[32];
+    sprintf(key, "schedule_json:%d", schedule_id);
+    return cache_get_value(key);
+}
+
+void
+cache_invalidate_schedule(int schedule_id)
+{
+    char key[32];
+    sprintf(key, "schedule_json:%d", schedule_id);
+    cache_invalidate(key);
+
+    relay_t **relays = relay_get_with_schedule(schedule_id);
+
+    for(int i = 0; relays[i] != NULL; ++i)
+    {
+        cache_invalidate_relay(relays[i]->id);
+    }
+
+    relay_free_list(relays);
+}
+
+
+
+void
+cache_put_json_relay(int relay_id, char *relay_json)
+{
+    char key[32];
+    sprintf(key, "relay_json:%d", relay_id);
+    cache_insert_value(key, relay_json);
+}
+
+char*
+cache_get_json_relay(int relay_id)
+{
+    char key[32];
+    sprintf(key, "relay_json:%d", relay_id);
+    return cache_get_value(key);
+}
+
+void
+cache_invalidate_relay(int relay_id)
+{
+    char key[32];
+    sprintf(key, "relay_json:%d", relay_id);
+    cache_invalidate(key);
+
+    relay_t *relay = relay_get_by_id(relay_id);
+    cache_invalidate_controller(relay->controller_id);
+    relay_free(relay);
+}
+
+
+
+void
+cache_put_json_controller(int controller_id, char *controller_json)
+{
+    char key[32];
+    sprintf(key, "controller_json:%d", controller_id);
+    cache_insert_value(key, controller_json);
+}
+
+char*
+cache_get_json_controller(int controller_id)
+{
+    char key[32];
+    sprintf(key, "controller_json:%d", controller_id);
+    return cache_get_value(key);
+}
+
+void
+cache_invalidate_controller(int controller_id)
+{
+    char key[32];
+    sprintf(key, "controller_json:%d", controller_id);
+    cache_invalidate(key);
+}
+
+void
+cache_invalidate_tagged(int tag_id)
+{
+    int *schedule_ids = junction_tag_get_schedules_for_tag_id(tag_id);
+    for(int i = 0; schedule_ids[i] != 0; ++i)
+    {
+        cache_invalidate_schedule(schedule_ids[i]);
+    }
+    free(schedule_ids);
+
+    int *relay_ids = junction_tag_get_relays_for_tag_id(tag_id);
+    for(int i = 0; relay_ids[i] != 0; ++i)
+    {
+        cache_invalidate_relay(relay_ids[i]);
+    }
+    free(relay_ids);
 }