Add schema information to XML MI output

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/config/session-config.c b/src/common/config/session-config.c
index 11e0dcc4ea8e24120aadb74da453ab17b6faf70e..dec891349a5384a928abf153447452b51131498c 100644 (file)
--- a/src/common/config/session-config.c
+++ b/src/common/config/session-config.c
@@ -458,6 +458,39 @@ end:
        return ret >= 0 ? 0 : ret;
 }
 
+LTTNG_HIDDEN
+int config_writer_write_attribute(struct config_writer *writer,
+               const char *name, const char *value)
+{
+       int ret;
+       xmlChar *encoded_name = NULL;
+       xmlChar *encoded_value = NULL;
+
+       if (!writer || !writer->writer || !name || !name[0]) {
+               ret = -1;
+               goto end;
+       }
+
+       encoded_name = encode_string(name);
+       if (!encoded_name) {
+               ret = -1;
+               goto end;
+       }
+
+       encoded_value = encode_string(value);
+       if (!encoded_value) {
+               ret = -1;
+               goto end;
+       }
+
+       ret = xmlTextWriterWriteAttribute(writer->writer, encoded_name,
+                       encoded_value);
+end:
+       xmlFree(encoded_name);
+       xmlFree(encoded_value);
+       return ret >= 0 ? 0 : ret;
+}
+
 LTTNG_HIDDEN
 int config_writer_close_element(struct config_writer *writer)
 {

diff --git a/src/common/config/session-config.h b/src/common/config/session-config.h
index 2fed612a1cfbd5783891ec16e99808dc386e3645..a53a8f91c753339daa28e29afffebd6c507c58b3 100644 (file)
--- a/src/common/config/session-config.h
+++ b/src/common/config/session-config.h
@@ -108,13 +108,27 @@ int config_writer_destroy(struct config_writer *writer);
  *
  * element_name Element tag name.
  *
- * Returns zero if the XML document could be closed cleanly.
+ * Returns zero if the XML element could be opened.
  * Negative values indicate an error.
  */
 LTTNG_HIDDEN
 int config_writer_open_element(struct config_writer *writer,
                const char *element_name);
 
+/*
+ * Write an element tag attribute.
+ *
+ * writer An instance of a configuration writer.
+ *
+ * name Attribute name.
+ *
+ * Returns zero if the XML element's attribute could be written.
+ * Negative values indicate an error.
+ */
+LTTNG_HIDDEN
+int config_writer_write_attribute(struct config_writer *writer,
+               const char *name, const char *value);
+
 /*
  * Close the current element tag.
  *

diff --git a/src/common/mi-lttng.c b/src/common/mi-lttng.c
index 30bd60328f33bc305cc8937811bebf71b642c6a7..f77b6b648c30b541817c237cf0cfdb59f2f2afb0 100644 (file)
--- a/src/common/mi-lttng.c
+++ b/src/common/mi-lttng.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2014 - Jonathan Rajotte <jonathan.r.julien@gmail.com>
  *                    - Olivier Cotte <olivier.cotte@polymtl.ca>
+ * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License, version 2 only, as
@@ -23,6 +24,24 @@
 
 #include <assert.h>
 
+#define MI_SCHEMA_MAJOR_VERSION 3
+#define MI_SCHEMA_MINOR_VERSION 0
+
+/* Machine interface namespace URI */
+const char * const mi_lttng_xmlns = "xmlns";
+const char * const mi_lttng_ns_uri = "http://lttng.org/xml/ns/lttng-mi";
+const char * const mi_lttng_xmlns_xsi = "xmlns:xsi";
+const char * const mi_lttng_w3_schema_uri = "http://www.w3.org/2001/XMLSchema-instance";
+const char * const mi_lttng_schema_location = "xsi:schemaLocation";
+const char * const mi_lttng_schema_location_uri =
+       "http://lttng.org/xml/ns/lttng-mi" " "
+       "http://lttng.org/xml/schemas/lttng-mi/" XSTR(MI_SCHEMA_MAJOR_VERSION)
+       "/lttng-mi-" XSTR(MI_SCHEMA_MAJOR_VERSION) "."
+       XSTR(MI_SCHEMA_MINOR_VERSION) ".xsd";
+const char * const mi_lttng_schema_version = "schemaVersion";
+const char * const mi_lttng_schema_version_value = XSTR(MI_SCHEMA_MAJOR_VERSION)
+       "." XSTR(MI_SCHEMA_MINOR_VERSION);
+
 /* Strings related to command */
 const char * const mi_lttng_element_command = "command";
 const char * const mi_lttng_element_command_action = "snapshot_action";
@@ -487,10 +506,42 @@ int mi_lttng_writer_command_open(struct mi_writer *writer, const char *command)
 {
        int ret;
 
-       ret = mi_lttng_writer_open_element(writer, mi_lttng_element_command);
+       /*
+        * A command is always the MI's root node, it must declare the current
+        * namespace and schema URIs and the schema's version.
+        */
+       ret = config_writer_open_element(writer->writer,
+                       mi_lttng_element_command);
+       if (ret) {
+               goto end;
+       }
+
+       ret = config_writer_write_attribute(writer->writer,
+                       mi_lttng_xmlns, mi_lttng_ns_uri);
+       if (ret) {
+               goto end;
+       }
+
+       ret = config_writer_write_attribute(writer->writer,
+                       mi_lttng_xmlns_xsi, mi_lttng_w3_schema_uri);
+       if (ret) {
+               goto end;
+       }
+
+       ret = config_writer_write_attribute(writer->writer,
+                       mi_lttng_schema_location,
+                       mi_lttng_schema_location_uri);
        if (ret) {
                goto end;
        }
+
+       ret = config_writer_write_attribute(writer->writer,
+                       mi_lttng_schema_version,
+                       mi_lttng_schema_version_value);
+       if (ret) {
+               goto end;
+       }
+
        ret = mi_lttng_writer_write_element_string(writer,
                        mi_lttng_element_command_name, command);
 end: