Optimization [Performance: commit takes long time with many devices](#…

…154)

Avoid copy in compare/ diffs

CHANGELOG.md

@@ -5,6 +5,8 @@ Expected: January 2025
 
 ### New features
 
+* Optimization [Performance: commit takes long time with many devices](https://github.com/clicon/clixon-controller/issues/154)
+  * Avoid copy in compare/diff
 * Show device state
   * New CLI show device state command
   * See [CLI show state does not return device state (config false) data](https://github.com/clicon/clixon-controller/issues/143)

src/controller_backend.c

@@ -504,13 +504,13 @@ controller_reset(clixon_handle h,
 
     if ((nsc = xml_nsctx_init(NULL, CONTROLLER_NAMESPACE)) == NULL)
         goto done;
-    if ((ret = xmldb_get0(h, "running", YB_MODULE, nsc, xpath, 1, 0, &xtop, NULL, NULL)) < 0)
+    if ((ret = xmldb_get_cache(h, "running", YB_MODULE, &xtop, NULL, NULL)) < 0)
         goto done;
     if (ret == 0){
         clixon_err(OE_DB, 0, "Error when reading from running_db, unknown error");
         goto done;
     }
-    if ((xse = xpath_first(xtop, 0, "processes/services/enabled")) != NULL){
+    if ((xse = xpath_first(xtop, 0, "%s", xpath)) != NULL){
         if (strcmp(xml_body(xse), "true") == 0)
             if (clixon_process_operation(h, ACTION_PROCESS, PROC_OP_START, 0) < 0)
                 goto done;
@@ -519,8 +519,6 @@ controller_reset(clixon_handle h,
  done:
     if (nsc)
         cvec_free(nsc);
-    if (xtop)
-        xml_free(xtop);
     return retval;
 }
 

src/controller_device_state.c

@@ -713,7 +713,7 @@ device_config_write(clixon_handle h,
     return retval;
 }
 
-/*! Get local (cached) device datastore
+/*! Get local copy device datastore
  *
  * @param[in]  h           Clixon handle
  * @param[in]  name        Device name
@@ -774,6 +774,63 @@ device_config_read(clixon_handle h,
     goto done;
 }
 
+/*! Get local cache device datastore
+ *
+ * @param[in]  h           Clixon handle
+ * @param[in]  name        Device name
+ * @param[in]  config_type Device config tyoe
+ * @param[out] xdatap      Device config XML (if retval=1)
+ * @param[out] cberr       Error message (if retval=0)
+ * @retval     1           OK
+ * @retval     0           Failed (No such device tree)
+ * @retval    -1           Error
+ */
+int
+device_config_read_cache(clixon_handle h,
+                         char         *devname,
+                         char         *config_type,
+                         cxobj       **xdatap,
+                         cbuf        **cberr)
+{
+    int    retval = -1;
+    cbuf  *cb = NULL;
+    char  *db;
+    cxobj *xt = NULL;
+    cxobj *xroot;
+
+    if (devname == NULL || config_type == NULL){
+        clixon_err(OE_UNIX, EINVAL, "devname or config_type is NULL");
+        goto done;
+    }
+    if ((cb = cbuf_new()) == NULL){
+        clixon_err(OE_UNIX, errno, "cbuf_new");
+        goto done;
+    }
+    cprintf(cb, "device-%s-%s", devname, config_type);
+    db = cbuf_get(cb);
+    if (xmldb_get_cache(h, db, YB_MODULE, &xt, NULL, NULL) < 0)
+        goto done;
+    if ((xroot = xpath_first(xt, NULL, "devices/device/config")) == NULL){
+        if ((*cberr = cbuf_new()) == NULL){
+            clixon_err(OE_UNIX, errno, "cbuf_new");
+            goto done;
+        }
+        cprintf(*cberr, "No such device tree");
+        goto failed;
+    }
+    if (xdatap){
+        *xdatap = xroot;
+    }
+    retval = 1;
+ done:
+    if (cb)
+        cbuf_free(cb);
+    return retval;
+ failed:
+    retval = 0;
+    goto done;
+}
+
 /*! Get local (cached) device datastore
  *
  * @param[in]  h        Clixon handle
@@ -843,9 +900,9 @@ device_config_compare(clixon_handle           h,
     int     eq;
     int     ret;
 
-    if ((ret = device_config_read(h, name, "SYNCED", &x0, &cberr)) < 0)
+    if ((ret = device_config_read_cache(h, name, "SYNCED", &x0, &cberr)) < 0)
         goto done;
-    if (ret && (ret = device_config_read(h, name, "TRANSIENT", &x1, &cberr)) < 0)
+    if (ret && (ret = device_config_read_cache(h, name, "TRANSIENT", &x1, &cberr)) < 0)
         goto done;
     if (ret == 0){
         if (device_close_connection(dh, "%s", cbuf_get(cberr)) < 0)
@@ -867,10 +924,6 @@ device_config_compare(clixon_handle           h,
  done:
     if (cberr)
         cbuf_free(cberr);
-    if (x0)
-        xml_free(x0);
-    if (x1)
-        xml_free(x1);
     return retval;
  closed:
     retval = 0;
@@ -1680,6 +1733,7 @@ device_state_handler(clixon_handle h,
                 goto done;
             }
             cprintf(cb, "devices/device[name='%s']/config", name);
+            /* xt is used to put which requires a copy */
             if (ct->ct_actions_type == AT_NONE){
                 if (xmldb_get0(h, ct->ct_sourcedb, YB_MODULE, NULL, cbuf_get(cb), 1, WITHDEFAULTS_EXPLICIT, &xt, NULL, NULL) < 0)
                     goto done;

src/controller_device_state.h

@@ -129,6 +129,7 @@ int          device_state_timeout_register(device_handle ch);
 int          device_state_timeout_unregister(device_handle ch);
 int          device_state_set(device_handle dh, conn_state state);
 int          device_config_read(clixon_handle h, char *devname, char *config_type, cxobj **xrootp, cbuf **cberr);
+int          device_config_read_cache(clixon_handle h, char *devname, char *config_type, cxobj **xrootp, cbuf **cberr);
 int          device_config_write(clixon_handle h, char *name, char *config_type, cxobj *xdata, cbuf *cbret);
 int          device_state_handler(clixon_handle h, device_handle ch, int s, cxobj *xmsg);
 int          devices_statedata(clixon_handle h, cvec *nsc, char *xpath, cxobj *xstate);