[PATCH 2/5] qapi/qmp: QmpCommand: add .tracing field and API

[Vladimir Sementsov-Ogievskiy]

We are going to add a possibility to trace some qmp commands by user
selection. For now add a new field to QmpCommand structure and two
functions to manipulate with it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 include/qapi/qmp/dispatch.h | 14 ++++++++++++++
 qapi/qmp-registry.c         | 27 +++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/include/qapi/qmp/dispatch.h b/include/qapi/qmp/dispatch.h
index 075203dc67..5d0df2f984 100644
--- a/include/qapi/qmp/dispatch.h
+++ b/include/qapi/qmp/dispatch.h
@@ -38,6 +38,7 @@ typedef struct QmpCommand
     QTAILQ_ENTRY(QmpCommand) node;
     bool enabled;
     const char *disable_reason;
+    bool tracing;
 } QmpCommand;
 
 typedef QTAILQ_HEAD(QmpCommandList, QmpCommand) QmpCommandList;
@@ -64,4 +65,17 @@ typedef void (*qmp_cmd_callback_fn)(const QmpCommand *cmd, 
void *opaque);
 void qmp_for_each_command(const QmpCommandList *cmds, qmp_cmd_callback_fn fn,
                           void *opaque);
 
+/*
+ * Enable or disable tracing for commands matching the pattern.
+ * Pattern matching is handled by g_pattern_match_simple().
+ */
+void qmp_commands_set_tracing(QmpCommandList *cmds, const char *pattern,
+                              bool enable);
+
+/*
+ * Return true if tracing is enabled for any command matching the pattern.
+ * If pattern is NULL, return true if tracing is enabled for any command.
+ */
+bool qmp_commands_is_tracing_enabled(QmpCommandList *cmds, const char 
*pattern);
+
 #endif
diff --git a/qapi/qmp-registry.c b/qapi/qmp-registry.c
index f78c064aae..56e761857b 100644
--- a/qapi/qmp-registry.c
+++ b/qapi/qmp-registry.c
@@ -67,6 +67,33 @@ void qmp_enable_command(QmpCommandList *cmds, const char 
*name)
     qmp_toggle_command(cmds, name, true, NULL);
 }
 
+void qmp_commands_set_tracing(QmpCommandList *cmds, const char *pattern,
+                              bool enable)
+{
+    QmpCommand *cmd;
+
+    QTAILQ_FOREACH(cmd, cmds, node) {
+        if (g_pattern_match_simple(pattern, cmd->name)) {
+            cmd->tracing = true;
+        }
+    }
+}
+
+bool qmp_commands_is_tracing_enabled(QmpCommandList *cmds, const char *pattern)
+{
+    QmpCommand *cmd;
+
+    QTAILQ_FOREACH(cmd, cmds, node) {
+        if (cmd->tracing &&
+            (!pattern || g_pattern_match_simple(pattern, cmd->name)))
+        {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 bool qmp_command_is_enabled(const QmpCommand *cmd)
 {
     return cmd->enabled;
-- 
2.29.2