optimization: removed superfluous code from shdict_store. (#1956)

avoid setting the key_len, key_data and value_len fields since they
already have the same values when replacing the value data.

Author: Miniwoffer

src/ngx_http_lua_shdict.c

@@ -1426,8 +1426,6 @@ ngx_http_lua_ffi_shdict_store(ngx_shm_zone_t *zone, int op, u_char *key,
             ngx_queue_remove(&sd->queue);
             ngx_queue_insert_head(&ctx->sh->lru_queue, &sd->queue);
 
-            sd->key_len = (u_short) key_len;
-
             if (exptime > 0) {
                 tp = ngx_timeofday();
                 sd->expires = (uint64_t) tp->sec * 1000 + tp->msec
@@ -1439,14 +1437,11 @@ ngx_http_lua_ffi_shdict_store(ngx_shm_zone_t *zone, int op, u_char *key,
 
             sd->user_flags = user_flags;
 
-            sd->value_len = (uint32_t) str_value_len;
-
             dd("setting value type to %d", value_type);
 
             sd->value_type = (uint8_t) value_type;
 
-            p = ngx_copy(sd->data, key, key_len);
-            ngx_memcpy(p, str_value_buf, str_value_len);
+            ngx_memcpy(sd->data + key_len, str_value_buf, str_value_len);
 
             ngx_shmtx_unlock(&ctx->shpool->mutex);