[PATCH v5 4/6] perf config: Add 'get' functionality

From: Taeung Song
Date: Mon Aug 17 2015 - 13:29:41 EST


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

perf config [options] [section.name ...]

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

Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
---
tools/perf/Documentation/perf-config.txt | 2 +
tools/perf/builtin-config.c | 79 ++++++++++++++++++++++++++++++--
tools/perf/util/cache.h | 1 +
3 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index d95baad..691d52b 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 a configuration file.
SYNOPSIS
--------
[verse]
+'perf config' [<file-option>] [section.name ...]
+or
'perf config' [<file-option>] -l | --list
or
'perf config' [<file-option>] -a | --list-all
diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index ac13aaf..0f2193a 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -17,7 +17,7 @@ static bool use_system_config, use_user_config;
static const char *config_file_name;

static const char * const config_usage[] = {
- "perf config [options]",
+ "perf config [options] [section.name ...]",
NULL
};

@@ -412,6 +412,37 @@ static void find_config(struct config_section **section_node,
*element_node = NULL;
}

+static int show_spec_config(const char *section_name, const char *name)
+{
+ int i;
+ struct config_section *section_node = NULL;
+ struct config_element *element_node = NULL;
+ char key[BUFSIZ];
+
+ find_config(&section_node, &element_node, section_name, name);
+
+ if (section_node && element_node) {
+ scnprintf(key, sizeof(key), "%s.%s",
+ section_node->name, element_node->name);
+ return show_config(key, element_node->value, NULL);
+ }
+
+ for (i = 0; default_configsets[i].section_name != NULL; i++) {
+ struct default_configset *config = &default_configsets[i];
+
+ if (!strcmp(config->section_name, section_name) &&
+ !strcmp(config->name, name)) {
+ printf("%s.%s=%s (default)\n", config->section_name,
+ config->name, config->value);
+ return 0;
+ }
+ }
+
+ pr_err("Error: %s.%s: failed to find the variable.\n", section_name, name);
+
+ return 0;
+}
+
static char *normalize_value(const char *section_name, const char *name, const char *value)
{
int i, ret = 0;
@@ -526,9 +557,44 @@ static int show_all_config(void)
return 0;
}

+static int perf_configset_with_option(configset_fn_t fn, const char *var)
+{
+ char *section_name;
+ char *name;
+ const char *last_dot;
+ char *key = strdup(var);
+
+ if (!key) {
+ pr_err("%s: strdup failed\n", __func__);
+ return -1;
+ }
+ last_dot = strchr(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;
+ }
+
+ section_name = strsep(&key, ".");
+ name = strsep(&key, ".");
+ free(key);
+
+ return fn(section_name, name);
+
+ pr_err("invalid key: %s\n", var);
+ return -1;
+}
+
int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
{
- int ret = 0;
+ int i, ret = 0;

argc = parse_options(argc, argv, config_options, config_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
@@ -552,10 +618,17 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
break;
}
case ACTION_LIST:
- default:
if (argc) {
pr_err("Error: unknown argument\n");
goto out_err;
+ }
+ default:
+ if (argc) {
+ for (i = 0; argv[i]; i++) {
+ ret = perf_configset_with_option(show_spec_config, argv[i]);
+ if (ret < 0)
+ break;
+ }
} else
ret = perf_config_from_file(show_config, config_file_name, NULL);
}
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index f49a5e2..6fe734c 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -34,6 +34,7 @@ struct config_section {

struct list_head sections;

+typedef int (*configset_fn_t)(const char *, const char *);
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 *);
--
1.9.1

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