libsysprof-analyze: add sysprof_document_find_counter()

This allows finding a specific counter without having to traverse them
all from consumer code.

src/libsysprof-analyze/sysprof-document.c

@@ -1738,3 +1738,40 @@ sysprof_document_get_time_span (SysprofDocument *self)
 
   return &self->time_span;
 }
+
+/**
+ * sysprof_document_find_counter:
+ * @self: a #SysprofDocument
+ * @category: the category of the counter
+ * @name: the name of the counter
+ *
+ * Finds the first counter matching @category and @name.
+ *
+ * Returns: (transfer full) (nullable): a #SysprofDocumentCounter or %NULL
+ */
+SysprofDocumentCounter *
+sysprof_document_find_counter (SysprofDocument *self,
+                               const char      *category,
+                               const char      *name)
+{
+  g_autoptr(GListModel) counters = NULL;
+  guint n_items;
+
+  g_return_val_if_fail (SYSPROF_IS_DOCUMENT (self), NULL);
+  g_return_val_if_fail (category != NULL, NULL);
+  g_return_val_if_fail (name != NULL, NULL);
+
+  counters = sysprof_document_list_counters (self);
+  n_items = g_list_model_get_n_items (counters);
+
+  for (guint i = 0; i < n_items; i++)
+    {
+      g_autoptr(SysprofDocumentCounter) counter = g_list_model_get_item (counters, i);
+
+      if (g_strcmp0 (category, sysprof_document_counter_get_category (counter)) == 0 &&
+          g_strcmp0 (name, sysprof_document_counter_get_name (counter)) == 0)
+        return g_steal_pointer (&counter);
+    }
+
+  return NULL;
+}

src/libsysprof-analyze/sysprof-document.h

@@ -25,6 +25,7 @@
 #include <sysprof-capture.h>
 
 #include "sysprof-callgraph.h"
+#include "sysprof-document-counter.h"
 #include "sysprof-document-file.h"
 #include "sysprof-document-traceable.h"
 #include "sysprof-mark-catalog.h"
@@ -62,6 +63,11 @@ GListModel            *sysprof_document_list_marks                (SysprofDocume
 SYSPROF_AVAILABLE_IN_ALL
 GListModel            *sysprof_document_catalog_marks             (SysprofDocument           *self);
 SYSPROF_AVAILABLE_IN_ALL
+SysprofDocumentCounter
+                      *sysprof_document_find_counter              (SysprofDocument           *self,
+                                                                   const char                *category,
+                                                                   const char                *name);
+SYSPROF_AVAILABLE_IN_ALL
 GListModel            *sysprof_document_list_symbols_in_traceable (SysprofDocument           *self,
                                                                    SysprofDocumentTraceable  *traceable);
 SYSPROF_AVAILABLE_IN_ALL