Re: [PATCH v7 2/7] perf config: Add '--system' and '--user' options to select which config file is used

[Namhyung Kim <namhyung@kernel.org>]

On Sun, Oct 04, 2015 at 04:35:05PM +0900, Taeung Song wrote:
> Which config file is used is decided in only perf_config().
> And a perf-config command depend on perf_config() to list
> config variables with values. So add '--system' and '--user'
> options to select which config file to be used without perf_config().
> 
> The file-options '--system' means $(sysconfdir)/perfconfig and
> '--user' means $HOME/.perfconfig. If file-option isn't used,
> both system and user config file is read
> but user config have priority. The syntax examples are like below
> 
>     perf config [<file-option>] [options]
> 
>     a specific config file.
>     # perf config --user | --system
>     or
>     both user and system config file.
>     # perf config
> 
> In addition, use List data structure which has config info.
> Because perf_config() isn't used any more and directly collect
> config info by perf_config_from_file() with a specific config
> file path. Whichever config file or both are used, list is required
> to keep and handle config variables and values.
> 
> Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
> ---

Hmm.. Isn't it just a matter of setting of config_exclusive_filename
variable?  And then we can still use perf_config() no?

I think it'd be better to split the collecting configs part into a
separate patch.

Thanks,
Namhyung


>  tools/perf/Documentation/perf-config.txt |  14 ++-
>  tools/perf/builtin-config.c              | 163 +++++++++++++++++++++++++++++--
>  tools/perf/util/cache.h                  |  15 +++
>  tools/perf/util/config.c                 |   4 +-
>  4 files changed, 187 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
> index e8013b3..a42d409 100644
> --- a/tools/perf/Documentation/perf-config.txt
> +++ b/tools/perf/Documentation/perf-config.txt
> @@ -8,7 +8,7 @@ perf-config - Get and set variables in a configuration file.
>  SYNOPSIS
>  --------
>  [verse]
> -'perf config' -l | --list
> +'perf config' [<file-option>] -l | --list
>  
>  DESCRIPTION
>  -----------
> @@ -21,6 +21,14 @@ OPTIONS
>  --list::
>  	Show current config variables, name and value, for all sections.
>  
> +--user::
> +	For writing and reading options: write to user
> +	'$HOME/.perfconfig' file or read it.
> +
> +--system::
> +	For writing and reading options: write to system-wide
> +	'$(sysconfdir)/perfconfig' or read it.
> +
>  CONFIGURATION FILE
>  ------------------
>  
> @@ -33,6 +41,10 @@ store a system-wide default configuration.
>  The variables are divided into sections. In each section, the variables
>  that are composed of a name and value.
>  
> +When reading or writing, the values are read from the system and user
> +configuration files by default, and options '--system' and '--user'
> +can be used to tell the command to read from or write to only that location.
> +
>  Syntax
>  ~~~~~~
>  
> diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
> index 30b1500..92be3eb 100644
> --- a/tools/perf/builtin-config.c
> +++ b/tools/perf/builtin-config.c
> @@ -13,8 +13,10 @@
>  #include "util/util.h"
>  #include "util/debug.h"
>  
> +static bool use_system_config, use_user_config;
> +
>  static const char * const config_usage[] = {
> -	"perf config [options]",
> +	"perf config [<file-option>] [options]",
>  	NULL
>  };
>  
> @@ -23,19 +25,150 @@ enum actions {
>  } actions;
>  
>  static struct option config_options[] = {
> +	OPT_GROUP("Config file location"),
> +	OPT_BOOLEAN(0, "system", &use_system_config, "use system config file"),
> +	OPT_BOOLEAN(0, "user", &use_user_config, "use user config file"),
>  	OPT_GROUP("Action"),
>  	OPT_SET_UINT('l', "list", &actions,
>  		     "show current config variables", ACTION_LIST),
>  	OPT_END()
>  };
> +static int show_config(struct list_head *sections)
> +{
> +	struct config_section *section;
> +	struct config_element *element;
> +
> +	list_for_each_entry(section, sections, list) {
> +		list_for_each_entry(element, &section->element_head, list) {
> +			printf("%s.%s=%s\n", section->name,
> +				       element->name, element->value);
> +		}
> +	}
> +
> +	return 0;
> +}
>  
> -static int show_config(const char *key, const char *value,
> -		       void *cb __maybe_unused)
> +static struct config_section *find_section(struct list_head *sections,
> +					   const char *section_name)
>  {
> +	struct config_section *section;
> +
> +	list_for_each_entry(section, sections, list)
> +		if (!strcmp(section->name, section_name))
> +			return section;
> +
> +	return NULL;
> +}
> +
> +static struct config_element *find_element(const char *name,
> +					   struct config_section *section)
> +{
> +	struct config_element *element;
> +
> +	list_for_each_entry(element, &section->element_head, list)
> +		if (!strcmp(element->name, name))
> +			return element;
> +
> +	return NULL;
> +}
> +
> +static void find_config(struct list_head *sections,
> +			struct config_section **section,
> +			struct config_element **element,
> +			const char *section_name, const char *name)
> +{
> +	*section = find_section(sections, section_name);
> +
> +	if (*section != NULL)
> +		*element = find_element(name, *section);
> +	else
> +		*element = NULL;
> +}
> +
> +static struct config_section *init_section(const char *section_name)
> +{
> +	struct config_section *section;
> +
> +	section = zalloc(sizeof(*section));
> +	if (!section)
> +		return NULL;
> +
> +	INIT_LIST_HEAD(&section->element_head);
> +	section->name = strdup(section_name);
> +	if (!section->name) {
> +		pr_err("%s: strdup failed\n", __func__);
> +		free(section);
> +		return NULL;
> +	}
> +
> +	return section;
> +}
> +
> +static int add_element(struct list_head *head,
> +			      const char *name, const char *value)
> +{
> +	struct config_element *element;
> +
> +	element = zalloc(sizeof(*element));
> +	if (!element)
> +		return -1;
> +
> +	element->name = strdup(name);
> +	if (!element->name) {
> +		pr_err("%s: strdup failed\n", __func__);
> +		free(element);
> +		return -1;
> +	}
>  	if (value)
> -		printf("%s=%s\n", key, value);
> +		element->value = (char *)value;
>  	else
> -		printf("%s\n", key);
> +		element->value = NULL;
> +
> +	list_add_tail(&element->list, head);
> +	return 0;
> +}
> +
> +static int collect_current_config(const char *var, const char *value,
> +				  void *spec_sections __maybe_unused)
> +{
> +	struct config_section *section = NULL;
> +	struct config_element *element = NULL;
> +	struct list_head *sections = (struct list_head *)spec_sections;
> +	char *key = strdup(var);
> +	char *section_name, *name;
> +
> +	if (!key) {
> +		pr_err("%s: strdup failed\n", __func__);
> +		return -1;
> +	}
> +
> +	section_name = strsep(&key, ".");
> +	name = strsep(&key, ".");
> +	free(key);
> +	if (name == NULL)
> +		return -1;
> +
> +	find_config(sections, &section, &element, section_name, name);
> +
> +	if (!section) {
> +		section = init_section(section_name);
> +		if (!section)
> +			return -1;
> +		list_add_tail(&section->list, sections);
> +	}
> +
> +	value = strdup(value);
> +	if (!value) {
> +		pr_err("%s: strdup failed\n", __func__);
> +		return -1;
> +	}
> +
> +	if (!element)
> +		return add_element(&section->element_head, name, value);
> +	else {
> +		free(element->value);
> +		element->value = (char *)value;
> +	}
>  
>  	return 0;
>  }
> @@ -43,10 +176,28 @@ static int show_config(const char *key, const char *value,
>  int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
>  {
>  	int ret = 0;
> +	struct list_head sections;
> +	const char *system_config = perf_etc_perfconfig();
> +	char *user_config = mkpath("%s/.perfconfig", getenv("HOME"));
>  
>  	argc = parse_options(argc, argv, config_options, config_usage,
>  			     PARSE_OPT_STOP_AT_NON_OPTION);
>  
> +	if (use_system_config && use_user_config) {
> +		pr_err("Error: only one config file at a time\n");
> +		parse_options_usage(config_usage, config_options, "user", 0);
> +		parse_options_usage(NULL, config_options, "system", 0);
> +		return -1;
> +	}
> +
> +	INIT_LIST_HEAD(&sections);
> +
> +	if (use_system_config || (!use_system_config && !use_user_config))
> +		perf_config_from_file(collect_current_config, system_config, &sections);
> +
> +	if (use_user_config || (!use_system_config && !use_user_config))
> +		perf_config_from_file(collect_current_config, user_config, &sections);
> +
>  	switch (actions) {
>  	case ACTION_LIST:
>  	default:
> @@ -55,7 +206,7 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
>  			parse_options_usage(config_usage, config_options, "l", 1);
>  			return -1;
>  		} else
> -			ret = perf_config(show_config, NULL);
> +			ret = show_config(&sections);
>  	}
>  
>  	return ret;
> diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
> index c861373..712e82b 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"
> @@ -19,14 +20,28 @@
>  #define PERF_DEBUGFS_ENVIRONMENT "PERF_DEBUGFS_DIR"
>  #define PERF_TRACEFS_ENVIRONMENT "PERF_TRACEFS_DIR"
>  
> +struct config_element {
> +	char *name;
> +	char *value;
> +	struct list_head list;
> +};
> +
> +struct config_section {
> +	char *name;
> +	struct list_head element_head;
> +	struct list_head list;
> +};
> +
>  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 *);
> +extern int perf_config_from_file(config_fn_t fn, const char *filename, void *data);
>  extern int perf_config_int(const char *, const char *);
>  extern u64 perf_config_u64(const char *, const char *);
>  extern int perf_config_bool(const char *, const char *);
>  extern int config_error_nonbool(const char *);
>  extern const char *perf_config_dirname(const char *, const char *);
> +extern const char *perf_etc_perfconfig(void);
>  
>  /* pager.c */
>  extern void setup_pager(void);
> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
> index 2e452ac..23fa8c5 100644
> --- a/tools/perf/util/config.c
> +++ b/tools/perf/util/config.c
> @@ -416,7 +416,7 @@ int perf_default_config(const char *var, const char *value,
>  	return 0;
>  }
>  
> -static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
> +int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
>  {
>  	int ret;
>  	FILE *f = fopen(filename, "r");
> @@ -434,7 +434,7 @@ static int perf_config_from_file(config_fn_t fn, const char *filename, void *dat
>  	return ret;
>  }
>  
> -static const char *perf_etc_perfconfig(void)
> +const char *perf_etc_perfconfig(void)
>  {
>  	static const char *system_wide;
>  	if (!system_wide)
> -- 
> 1.9.1
>