[PATCH 2/4] perf tools: Add functions which can get or set perf config variables.

Taeung Song
2015-04-27T06:34:59Z

This patch consists of functions
which can get, set specific config variables.
For the syntax examples,

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

display key-value pairs of specific config variables
# perf config report.queue-size report.children

set specific config variables
# perf config report.queue-size=100M report.children=true

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
tools/perf/Documentation/perf-config.txt | 2 +
tools/perf/builtin-config.c | 276 ++++++++++++++++++++++++++++++-
tools/perf/util/cache.h | 17 ++
tools/perf/util/config.c | 30 +++-
4 files changed, 320 insertions(+), 5 deletions(-)

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index 489c2c6..b2b3321 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -8,6 +8,8 @@ perf-config - Get and set variables in configuration file.
SYNOPSIS
--------
[verse]
+'perf config' [section.subkey[=value] ...]
+or
'perf config' -l | --list

DESCRIPTION
diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 9e4ba72..99292f6 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -15,10 +15,14 @@

static struct {
bool list_action;
+ bool get_action;
+ bool set_action;
} params;

+struct list_head *sections;
+
static const char * const config_usage[] = {
- "perf config [options]",
+ "perf config [options] [section.subkey[=value] ...]",
NULL
};
static const struct option config_options[] = {
@@ -27,6 +31,74 @@ static const struct option config_options[] = {
OPT_END()
};

+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;
+
+ section_node = zalloc(sizeof(*section_node));
+ if (!section_node)
+ return NULL;
+
+ INIT_LIST_HEAD(&section_node->element_head);
+ section_node->name = strdup(section_name);
+ if (!section_node->name) {
+ pr_err("%s: strdup failed\n", __func__);
+ free(section_node);
+ 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__);
+ goto out_free;
+ }
+ if (value) {
+ element_node->value = strdup(value);
+ if (!element_node->value) {
+ pr_err("%s: strdup failed\n", __func__);
+ goto out_free;
+ }
+ } else
+ element_node->value = NULL;
+
+ list_add_tail(&element_node->list, head);
+ return 0;
+
+out_free:
+ free(element_node);
+ return -1;
+}
+
static int show_config(const char *key, const char *value,
void *cb __maybe_unused)
{
@@ -38,12 +110,211 @@ static int show_config(const char *key, const char *value,
return 0;
}

-int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
+static void find_config(struct config_section **section_node, struct config_element **element_node,
+ const char *given_section_name, const char *given_subkey)
+{
+ *section_node = find_config_section(given_section_name);
+
+ if (*section_node != NULL)
+ *element_node = find_config_element(given_subkey, *section_node);
+ else
+ *element_node = NULL;
+}
+
+static int show_spec_config(const char *section_name, const char *subkey,
+ const char *value __maybe_unused)
+{
+ struct config_section *section_node = NULL;
+ struct config_element *element_node = NULL;
+ char key[BUFSIZ];
+
+ find_config(&section_node, &element_node, section_name, subkey);
+
+ if (section_node && element_node) {
+ scnprintf(key, sizeof(key), "%s.%s", section_node->name, element_node->subkey);
+ show_config(key, element_node->value, NULL);
+ } else
+ pr_err("Error: Failed to find the variable.\n");
+
+ return 0;
+}
+
+static int set_config(const char *section_name, const char *subkey,
+ const char *value)
+{
+ struct config_section *section_node = NULL;
+ struct config_element *element_node = NULL;
+
+ find_config(&section_node, &element_node, section_name, subkey);
+
+ /* if there isn't existent section, add a new section */
+ if (!section_node) {
+ section_node = init_config_section(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)
+ return add_config_element(&section_node->element_head, subkey, value);
+ else
+ element_node->value = (char *)value;
+
+ return 0;
+}
+
+static int set_spec_config(const char *section_name, const char *subkey,
+ const char *value)
{
int ret = 0;
+ ret += set_config(section_name, subkey, value);
+ ret += perf_configset_write_in_full();
+
+ return ret;
+}
+
+static void parse_key(const char *var, const char **section_name, const char **subkey)
+{
+ char *key = strdup(var);
+
+ if (!key)
+ die("%s: strdup failed\n", __func__);
+
+ *section_name = strsep(&key, ".");
+ *subkey = strsep(&key, ".");
+}
+
+static int collect_config(const char *var, const char *value,
+ void *cb __maybe_unused)
+{
+ struct config_section *section_node;
+ const char *section_name, *subkey;
+
+ parse_key(var, &section_name, &subkey);
+
+ 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);
+ }
+
+ return add_config_element(&section_node->element_head, subkey, value);
+}
+
+static int perf_configset_with_option(configset_fn_t fn, const char *var)
+{
+ int i, num_dot = 0, num_equals = 0;
+ static char *given_section_name;
+ static char *given_subkey;
+ static char *given_value;
+ const char *last_dot;
+ char *key = strdup(var);
+
+ if (!key) {
+ pr_err("%s: strdup failed\n", __func__);
+ return -1;
+ }
+ 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\n", key);
+ return -1;
+ }
+ if (!last_dot[1]) {
+ pr_err("The config varible does not contain variable name: %s\n", key);
+ return -1;
+ }
+ for (i = 0; key[i]; i++) {
+ if (i == 0 && !isalpha(key[i++]))
+ goto out_err;
+
+ switch (key[i]) {
+ case '.':
+ num_dot += 1;
+ if (!isalpha(key[++i]))
+ goto out_err;
+ break;
+ case '=':
+ num_equals += 1;
+ break;
+ default:
+ if (!isalpha(key[i]) && !isalnum(key[i]))
+ goto out_err;
+ }
+ }
+
+ if (num_equals > 1 || num_dot > 1)
+ goto out_err;
+
+ given_value = strchr(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\n", key);
+ return -1;
+ } else
+ given_value++;
+ }
+ given_section_name = strsep(&key, ".");
+ given_subkey = strsep(&key, ".");
+
+ if (given_value)
+ given_subkey = strsep(&given_subkey, "=");
+
+ if (!sections) {
+ sections = zalloc(sizeof(*sections));
+ if (!sections)
+ return -1;
+
+ INIT_LIST_HEAD(sections);
+ perf_config(collect_config, NULL);
+ }
+
+ return fn(given_section_name, given_subkey, given_value);
+
+out_err:
+ pr_err("invalid key: %s", var);
+ return -1;
+}
+
+int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
+{
+ int i, 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 (origin_argc > argc)
+ is_option = true;
+ else
+ is_option = false;
+
+ if (!is_option && argc >= 0) {
+ switch (argc) {
+ case 0:
+ break;
+ default:
+ for (i = 0; argv[i]; i++) {
+ value = strrchr(argv[i], '=');
+ if (value == NULL || value == argv[i])
+ ret = perf_configset_with_option(show_spec_config, argv[i]);
+ else
+ ret = perf_configset_with_option(set_spec_config, argv[i]);
+ if (ret < 0)
+ break;
+ }
+ goto out;
+ }
+ }

if (params.list_action && argc == 0)
ret = perf_config(show_config, NULL);
@@ -52,5 +323,6 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
usage_with_options(config_usage, config_options);
}

+out:
return ret;
}
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index fbcca21..d333753 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)(const char *, const char *, const char*);
+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..71294ef 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 +501,31 @@ out:
return ret;
}

+int perf_configset_write_in_full(void)
+{
+ struct config_section *section_node;
+ struct config_element *element_node;
+ const char *first_line = "# this file is auto-generated.";
+ FILE *fp = fopen(config_file_name, "w");
+
+ if (!fp)
+ return -1;
+
+ fprintf(fp, "%s\n", first_line);
+ /* overwrite configvariables */
+ list_for_each_entry(section_node, sections, list) {
+ fprintf(fp, "[%s]\n", section_node->name);
+ list_for_each_entry(element_node, &section_node->element_head, list) {
+ if (element_node->value)
+ fprintf(fp, "\t%s = %s\n",
+ element_node->subkey, element_node->value);
+ }
+ }
+ fclose(fp);
+
+ 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