Edit File: json.stpm
// JSON tapset macros. // Copyright (C) 2015 Red Hat Inc. // // This file is part of systemtap, and is free software. You can // redistribute it and/or modify it under the terms of the GNU General // Public License (GPL); either version 2, or (at your option) any // later version. // // NB: tapsetdescription is in tapset/linux/json.stp @define __json_output_metric_metadata(indent_str, name, pointer, type, description, units) %( $value .= sprintf("%s{\n", @indent_str) $value .= sprintf("%s \"name\": \"%s\",\n", @indent_str, @name) $value .= sprintf("%s \"pointer\": \"%s\",\n", @indent_str, @pointer) $value .= sprintf("%s \"type\": \"%s\"", @indent_str, @type) if (strlen(@description) > 0) { $value .= sprintf(",\n%s \"description\": \"%s\"", @indent_str, @description) } if (strlen(@units) > 0) { $value .= sprintf(",\n%s \"units\": \"%s\"", @indent_str, @units) } $value .= sprintf("\n%s}", @indent_str) %) /** * smacro json_output_data_start - Start the json output. * * Description: The json_output_data_start macro is designed to be * called from the 'json_data' probe from the user's script. It marks * the start of the JSON output. */ @define json_output_data_start %( __comma_needed = 0 $value = "{\n" %) # Make sure we don't try to output the same metric twice in the same # data fetch. @define __json_output_check(name) %( if (@name in __json_metric_output) error(sprintf("Metric '%s' already output", @name)) __json_metric_output[@name] = 1 %) # Make sure we don't try to output the same array index twice in the same # data fetch. @define __json_output_array_check(array_index) %( if (@array_index in __json_array_output) error(sprintf("Array index '%s' already output for array metric %s", @array_index, __json_array_started)) __json_array_output[@array_index] = 1 %) /** * smacro json_output_string_value - Output a string value. * * @name: The name of the string metric. * @value: The string value to output. * * Description: The json_output_string_value macro is designed to be * called from the 'json_data' probe in the user's script to output a * metric's string value. This metric should have been added with * json_add_string_metric(). */ @define json_output_string_value(name, value) %( @__json_output_check(@name) @__json_output_array_end if (__comma_needed) $value .= ",\n" __comma_needed = 1 $value .= sprintf(" \"%s\": \"%s\"", @name, @value) %) /** * smacro json_output_numeric_value - Output a numeric value. * * @name: The name of the numeric metric. * @value: The numeric value to output. * * Description: The json_output_numeric_value macro is designed to be * called from the 'json_data' probe in the user's script to output a * metric's numeric value. This metric should have been added with * json_add_numeric_metric(). */ @define json_output_numeric_value(name, value) %( @__json_output_check(@name) @__json_output_array_end if (__comma_needed) $value .= ",\n" __comma_needed = 1 $value .= sprintf(" \"%s\": %d", @name, @value) %) /** * smacro json_output_array_string_value - Output a string value for metric in an array. * * @array_name: The name of the array. * @array_index: The array index (as a string) indicating where to store the string value. * @metric_name: The name of the string metric. * @value: The string value to output. * * Description: The json_output_array_string_value macro is designed * to be called from the 'json_data' probe in the user's script to * output a metric's string value that is in an array. This metric * should have been added with json_add_array_string_metric(). */ @define json_output_array_string_value(array_name, array_index, metric_name, value) %( @__json_output_array_start(@array_name, @array_index) if (__comma_needed) $value .= ",\n" __comma_needed = 1 $value .= sprintf(" \"%s\": \"%s\"", @metric_name, @value) %) /** * smacro json_output_array_numeric_value - Output a numeric value for metric in an array. * * @array_name: The name of the array. * @array_index: The array index (as a string) indicating where to store the numeric value. * @metric_name: The name of the numeric metric. * @value: The numeric value to output. * * Description: The json_output_array_numeric_value macro is designed * to be called from the 'json_data' probe in the user's script to * output a metric's numeric value that is in an array. This metric * should have been added with json_add_array_numeric_metric(). */ @define json_output_array_numeric_value(array_name, array_index, metric_name, value) %( @__json_output_array_start(@array_name, @array_index) if (__comma_needed) $value .= ",\n" __comma_needed = 1 $value .= sprintf(" \"%s\": %d", @metric_name, @value) %) # Handle the details of starting the output of an array. @define __json_output_array_start(array_name, array_index) %( if (__json_array_started != @array_name) { @__json_output_check(@array_name) @__json_output_array_end if (__comma_needed) $value .= ",\n" __comma_needed = 1 $value .= sprintf(" \"%s\": [\n", @array_name) $value .= " {\n" __json_array_started = @array_name } if (__json_array_index_started != @array_index) { @__json_output_array_check(@array_index) if (__json_array_index_started != "") { $value .= "\n" " },\n" " {\n" } __json_array_index_started = @array_index $value .= sprintf(" \"__id\": \"%s\"", @array_index) } %) # Handle the details of finishing the output of an array. @define __json_output_array_end %( if (__json_array_started != "") { $value .= "\n" " }\n" " ]" __json_array_started = "" __json_array_index_started = "" delete __json_array_output } %) /** * smacro json_output_data_end - End the json output. * * Description: The json_output_data_end macro is designed to be * called from the 'json_data' probe from the user's script. It marks * the end of the JSON output. */ @define json_output_data_end %( @__json_output_array_end $value .= "\n" "}\n" __comma_needed = 0 delete __json_metric_output %)