[PATCH 2/2] perf tools: Add a option 'remove' to perf-config and features which get or set a config variable.

From: Taeung Song
Date: Thu Apr 09 2015 - 10:26:53 EST

This patch consists of adding functions
which get, set or remove a specific config variable.
For the syntax examples,

perf config [options] [section.subkey[=value]]

display all perf config with default values
# perf config
or
# perf config -a | --all

display a specific key(section.subkey) and value
# perf config report.queue

set a specific key and value
# perf config report.queue=100M

remove a specific key
# perf config -r | --remove report.queue

Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
---
tools/perf/Documentation/perf-config.txt | 8 ++
tools/perf/builtin-config.c | 223 ++++++++++++++++++++++++++++++-
tools/perf/util/cache.h | 17 +++
tools/perf/util/config.c | 35 ++++-
4 files changed, 277 insertions(+), 6 deletions(-)

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index b251702..7354b18 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -8,7 +8,11 @@ perf-config - Get and set variables in configuration file.
SYNOPSIS
--------
[verse]
+'perf config' section.subkey[=value]
+or
'perf config' -a | --all
+or
+'perf config' -r | --remove section.subkey

DESCRIPTION
-----------
@@ -21,6 +25,10 @@ OPTIONS
--all::
Show all variables with key and value into each sections.

+-r::
+--remove::
+ Remove a specific variable.
+
CONFIGURATION FILE
------------------

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 32f8ae6..20ae4a2 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -15,15 +15,24 @@

static struct {
bool all_action;
+ bool get_action;
+ bool set_action;
+ bool remove_action;
} params;

+LIST_HEAD(sections);
+static char *given_section_name;
+static char *given_subkey;
+static char *given_value;
+
static const char * const config_usage[] = {
- "perf config [options]",
+ "perf config [options] [section.subkey[=value]]",
NULL
};
static const struct option config_options[] = {
OPT_GROUP("Action"),
OPT_BOOLEAN('a', "all", &params.all_action, "print all configurations"),
+ OPT_BOOLEAN('r', "remove", &params.remove_action, "remove a variable: section.subkey"),
OPT_END()
};

@@ -35,6 +44,72 @@ static void check_argc(int argc, int limit)
usage_with_options(config_usage, config_options);
}

+static struct config_section *find_config_section(const char *section_name)
+{
+ struct config_section *section_node;
+ list_for_each_entry(section_node, &sections, list)
+ if (!strcmp(section_node->name, section_name))
+ return section_node;
+
+ return NULL;
+}
+
+static struct config_element *find_config_element(const char *subkey
+ , struct config_section *section_node)
+{
+ struct config_element *element_node;
+
+ list_for_each_entry(element_node, &section_node->element_head, list)
+ if (!strcmp(element_node->subkey, subkey))
+ return element_node;
+
+ return NULL;
+}
+
+static struct config_section *init_config_section(const char *section_name)
+{
+ struct config_section *section_node;
+ LIST_HEAD(element_head);
+
+ section_node = zalloc(sizeof(*section_node));
+ if (!section_node)
+ return NULL;
+
+ INIT_LIST_HEAD(&section_node->element_head);
+ list_splice(&element_head, &section_node->element_head);
+ section_node->name = strdup(section_name);
+ if (!section_node->name) {
+ pr_err("%s: strdup failed\n", __func__);
+ return NULL;
+ }
+
+ return section_node;
+}
+
+static int add_config_element(struct list_head *head
+ , const char *subkey, const char *value)
+{
+ struct config_element *element_node;
+ element_node = zalloc(sizeof(*element_node));
+ element_node->subkey = strdup(subkey);
+ if (!element_node->subkey) {
+ pr_err("%s: strdup failed\n", __func__);
+ return -1;
+ }
+ if (value) {
+ element_node->value = strdup(value);
+ if (!element_node->value) {
+ pr_err("%s: strdup failed\n", __func__);
+ return -1;
+ }
+ } else
+ element_node->value = NULL;
+
+ list_add_tail(&element_node->list, head);
+
+ return 0;
+}
+
static int show_config(const char *key, const char *value,
void *cb __maybe_unused)
{
@@ -46,22 +121,164 @@ static int show_config(const char *key, const char *value,
return 0;
}

+static int show_spec_config(struct config_section *section_node
+ , struct config_element *element_node)
+{
+ char key[BUFSIZ];
+
+ if (section_node && element_node) {
+ sprintf(key, "%s.%s", section_node->name, element_node->subkey);
+ show_config(key, element_node->value, NULL);
+ }
+
+ return 0;
+}
+
+static int set_config(struct config_section *section_node, struct config_element *element_node)
+{
+ if (!given_value) {
+ /* value == NULL means remove the variable */
+ if (section_node && element_node)
+ element_node->value = NULL;
+ else /* do nothing */
+ return 0;
+ } else {
+ /* if there isn't existent section, add a new section */
+ if (!section_node) {
+ section_node = init_config_section(given_section_name);
+ if (!section_node)
+ return -1;
+ list_add_tail(&section_node->list, &sections);
+ }
+ /* if nothing to replace, add a new element which contains key-value pair. */
+ if (!element_node)
+ add_config_element(&section_node->element_head, given_subkey, given_value);
+ else
+ element_node->value = given_value;
+ }
+
+ perf_configset_write_in_full();
+
+ return 0;
+}
+
+static int collect_config(const char *var, const char *value
+ , void *cb __maybe_unused)
+{
+ struct config_section *section_node;
+ char *section_name, *subkey;
+ char *key = strdup(var);
+
+ if (!key) {
+ pr_err("%s: strdup failed\n", __func__);
+ return -1;
+ }
+ section_name = strsep(&key, ".");
+ subkey = strsep(&key, ".");
+ section_node = find_config_section(section_name);
+ if (!section_node) {
+ /* Add a new section */
+ section_node = init_config_section(section_name);
+ if (!section_node)
+ return -1;
+ list_add_tail(&section_node->list, &sections);
+ }
+
+ add_config_element(&section_node->element_head, subkey, value);
+
+ return 0;
+}
+
+static int perf_configset_with_option(configset_fn_t fn, const char *var)
+{
+ struct config_section *section_node = NULL;
+ struct config_element *element_node = NULL;
+ char *key = strdup(var);
+ const char *last_dot = strrchr(key, '.');
+ /*
+ * Since "key" actually contains the section name and the real
+ * key name separated by a dot, we have to know where the dot is.
+ */
+ if (last_dot == NULL || last_dot == key) {
+ pr_err("The config variable does not contain a section: %s", key);
+ return -1;
+ }
+ if (!last_dot[1]) {
+ pr_err("The config varible does not contain variable name: %s", key);
+ return -1;
+ }
+
+ given_value = strrchr(key, '=');
+ if (given_value == NULL || given_value == key)
+ given_value = NULL;
+ else {
+ if (!given_value[1]) {
+ pr_err("The config variable does not contain a value: %s", key);
+ return -1;
+ } else
+ given_value++;
+ }
+ given_section_name = strsep(&key, ".");
+ given_subkey = strsep(&key, ".");
+ if (strsep(&key, ".") != NULL)
+ return -1;
+ if (given_value)
+ given_subkey = strsep(&given_subkey, "=");
+
+ perf_config(collect_config, NULL);
+
+ section_node = find_config_section(given_section_name);
+
+ if (section_node != NULL)
+ element_node = find_config_element(given_subkey, section_node);
+
+ fn(section_node, element_node);
+
+ return 0;
+}
+
int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
{
int ret = 0;
+ int origin_argc = argc - 1;
+ char *value;
+ bool is_option;

argc = parse_options(argc, argv, config_options, config_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
- if (argc > 0) {
+ if (origin_argc > argc)
+ is_option = true;
+ else
+ is_option = false;
+
+ if (!is_option && argc > 0) {
if (strcmp(argv[0], "-") == 0) {
pr_warning(" Error: '-' is not supported.\n");
usage_with_options(config_usage, config_options);
}
+
+ switch (argc) {
+ case 1:
+ value = strrchr(argv[0], '=');
+ if (value == NULL || value == argv[0])
+ params.get_action = true;
+ else
+ params.set_action = true;
+ break;
+ default:
+ usage_with_options(config_usage, config_options);
+ }
}

- if (argc == 0 || params.all_action) {
+ if ((!is_option && argc == 0) || params.all_action) {
check_argc(argc, 0);
ret = perf_config(show_config, NULL);
+ } else if (params.get_action) {
+ check_argc(argc, 1);
+ ret = perf_configset_with_option(show_spec_config, argv[0]);
+ } else if (params.set_action || params.remove_action) {
+ check_argc(argc, 1);
+ ret = perf_configset_with_option(set_config, argv[0]);
}

return ret;
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index fbcca21..17b271f 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -1,6 +1,7 @@
#ifndef __PERF_CACHE_H
#define __PERF_CACHE_H

+#include <linux/list.h>
#include <stdbool.h>
#include "util.h"
#include "strbuf.h"
@@ -19,6 +20,22 @@
#define PERF_DEBUGFS_ENVIRONMENT "PERF_DEBUGFS_DIR"
#define PERF_TRACEFS_ENVIRONMENT "PERF_TRACEFS_DIR"

+struct config_element {
+ char *subkey;
+ char *value;
+ struct list_head list;
+};
+
+struct config_section {
+ char *name;
+ struct list_head element_head;
+ struct list_head list;
+};
+
+extern struct list_head sections;
+
+typedef int (*configset_fn_t)(struct config_section *, struct config_element *);
+extern int perf_configset_write_in_full(void);
typedef int (*config_fn_t)(const char *, const char *, void *);
extern int perf_default_config(const char *, const char *, void *);
extern int perf_config(config_fn_t fn, void *);
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index e18f653..ffcbe96 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -21,7 +21,7 @@
char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */

static FILE *config_file;
-static const char *config_file_name;
+static char *config_file_name;
static int config_linenr;
static int config_file_eof;

@@ -420,12 +420,11 @@ static int perf_config_from_file(config_fn_t fn, const char *filename, void *dat
ret = -1;
if (f) {
config_file = f;
- config_file_name = filename;
+ config_file_name = strdup(filename);
config_linenr = 1;
config_file_eof = 0;
ret = perf_parse_file(fn, data);
fclose(f);
- config_file_name = NULL;
}
return ret;
}
@@ -502,6 +501,36 @@ out:
return ret;
}

+int perf_configset_write_in_full(void)
+{
+ struct config_section *section_node;
+ struct config_element *element_node;
+ char section[BUFSIZ];
+ char key_value_pair[BUFSIZ];
+ const char *first_line = "# this file is auto-generated.\n";
+ FILE *f = fopen(config_file_name, "w");
+
+ if (!f)
+ return -1;
+
+ fwrite(first_line, strlen(first_line), 1, f);
+ /* overwrite configvariables */
+ list_for_each_entry(section_node, &sections, list) {
+ sprintf(section, "[%s]\n", section_node->name);
+ fwrite(section, strlen(section), 1, f);
+ list_for_each_entry(element_node, &section_node->element_head, list) {
+ if (element_node->value) {
+ sprintf(key_value_pair, "\t%s = %s\n"
+ , element_node->subkey, element_node->value);
+ fwrite(key_value_pair, strlen(key_value_pair), 1, f);
+ }
+ }
+ }
+ fclose(f);
+
+ return 0;
+}
+
/*
* Call this to report error for your variable that should not
* get a boolean value (i.e. "[my] var" means "true").
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/