[RFC][PATCH] perf config: Introduce perf_config_set class

[Taeung Song]

In order to variously handle config key-value pairs,
prepare all default configs and collect
config key-value pairs from user and
system config files (i.e user wide ~/.perfconfig
and system wide $(sysconfdir)/perfconfig)

The various purposes are like
showing current configs,
in the near future, showing all configs with
default value, getting current configs or
setting configs that user type, etc.

There aren't additional functionalities by appearances
excluding handling the error by file status.
(e.g checking permission, whether it is empty or etc)
and when the two config files have each other's
values of same key i.e.

    # cat ~/.perfconfig
    [top]
        children = false

    when $(sysconfdir) is /usr/local/etc
    # cat /usr/local/etc/perfconfig
    [top]
        children = true

Before:
    # perf config --user --list
    top.children=false

    # perf config --system --list
    top.children=true

    # perf config --list
    top.children=true
    top.children=false

After:
    # perf config --user --list
    top.children=false

    # perf config --system --list
    top.children=true

    # perf config --list
    top.children=false

But this patch is designed with considering
not only current functionality but also upcoming features.

And send [TEST REPORT] email follwing this patch
to save time for review. (kinds of test: BASIC, EXCEP HANDLING)

Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
---
 tools/perf/builtin-config.c |  61 +++++++---
 tools/perf/util/cache.h     |   2 -
 tools/perf/util/config.c    | 268 +++++++++++++++++++++++++++++++++++++++++---
 tools/perf/util/config.h    | 138 +++++++++++++++++++++++
 4 files changed, 433 insertions(+), 36 deletions(-)
 create mode 100644 tools/perf/util/config.h

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index c42448e..d79f4d9 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -12,6 +12,7 @@
 #include <subcmd/parse-options.h>
 #include "util/util.h"
 #include "util/debug.h"
+#include "util/config.h"
 
 static bool use_system_config, use_user_config;
 
@@ -32,21 +33,40 @@ static struct option config_options[] = {
 	OPT_END()
 };
 
-static int show_config(const char *key, const char *value,
-		       void *cb __maybe_unused)
+static int show_config(struct perf_config_set *perf_configs)
 {
-	if (value)
-		printf("%s=%s\n", key, value);
-	else
-		printf("%s\n", key);
+	struct perf_config_item *config;
+	enum perf_config_kind pos = perf_configs->pos;
+	bool *file_usable = perf_configs->file_usable;
+	struct list_head *config_list = &perf_configs->config_list;
+
+	if (pos == BOTH) {
+		if (!file_usable[USER] && !file_usable[SYSTEM])
+			return -1;
+	} else if (!file_usable[pos])
+		return -1;
+
+	list_for_each_entry(config, config_list, list) {
+		char *value = config->value[pos];
+
+		if (value)
+			printf("%s.%s=%s\n", config->section,
+			       config->name, value);
+	}
 
 	return 0;
 }
 
 int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 {
+	/*
+	 * The perf_configs that contains not only default configs
+	 * but also key-value pairs from config files.
+	 * (i.e user wide ~/.perfconfig and system wide $(sysconfdir)/perfconfig)
+	 * This is designed to be used by several functions that handle config set.
+	 */
+	struct perf_config_set *perf_configs;
 	int ret = 0;
-	char *user_config = mkpath("%s/.perfconfig", getenv("HOME"));
 
 	argc = parse_options(argc, argv, config_options, config_usage,
 			     PARSE_OPT_STOP_AT_NON_OPTION);
@@ -58,10 +78,17 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 		return -1;
 	}
 
-	if (use_system_config)
-		config_exclusive_filename = perf_etc_perfconfig();
-	else if (use_user_config)
-		config_exclusive_filename = user_config;
+	perf_configs = perf_config_set__new();
+	if (!perf_configs)
+		return -1;
+
+	if (use_user_config)
+		perf_configs->pos = USER;
+	else if (use_system_config)
+		perf_configs->pos = SYSTEM;
+	else
+		perf_configs->pos = BOTH;
+
 
 	switch (actions) {
 	case ACTION_LIST:
@@ -69,19 +96,17 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 			pr_err("Error: takes no arguments\n");
 			parse_options_usage(config_usage, config_options, "l", 1);
 		} else {
-			ret = perf_config(show_config, NULL);
-			if (ret < 0) {
-				const char * config_filename = config_exclusive_filename;
-				if (!config_exclusive_filename)
-					config_filename = user_config;
+			ret = show_config(perf_configs);
+			if (ret < 0)
 				pr_err("Nothing configured, "
-				       "please check your %s \n", config_filename);
-			}
+				       "please check your %s \n",
+				       perf_configs->file_path[perf_configs->pos]);
 		}
 		break;
 	default:
 		usage_with_options(config_usage, config_options);
 	}
 
+	perf_config_set__delete(perf_configs);
 	return ret;
 }
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index 3ca453f..ba657ad 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -23,8 +23,6 @@
 #define PERF_TRACEFS_ENVIRONMENT "PERF_TRACEFS_DIR"
 #define PERF_PAGER_ENVIRONMENT "PERF_PAGER"
 
-extern const char *config_exclusive_filename;
-
 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 4e72763..f827932 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -13,6 +13,7 @@
 #include <subcmd/exec-cmd.h>
 #include "util/hist.h"  /* perf_hist_config */
 #include "util/llvm-utils.h"   /* perf_llvm_config */
+#include "config.h"
 
 #define MAXNAME (256)
 
@@ -26,7 +27,53 @@ static const char *config_file_name;
 static int config_linenr;
 static int config_file_eof;
 
-const char *config_exclusive_filename;
+static const char *config_exclusive_filename;
+
+struct perf_config_item default_configs[] = {
+	CONF_STR_VAR(COLORS_TOP, "colors", "top", "red, default"),
+	CONF_STR_VAR(COLORS_MEDIUM, "colors", "medium", "green, default"),
+	CONF_STR_VAR(COLORS_NORMAL, "colors", "normal", "lightgray, default"),
+	CONF_STR_VAR(COLORS_SELECTED, "colors", "selected", "white, lightgray"),
+	CONF_STR_VAR(COLORS_JUMP_ARROWS, "colors", "jump_arrows", "blue, default"),
+	CONF_STR_VAR(COLORS_ADDR, "colors", "addr", "magenta, default"),
+	CONF_STR_VAR(COLORS_ROOT, "colors", "root", "white, blue"),
+	CONF_BOOL_VAR(TUI_REPORT, "tui", "report", true),
+	CONF_BOOL_VAR(TUI_ANNOTATE, "tui", "annotate", true),
+	CONF_BOOL_VAR(TUI_TOP, "tui", "top", true),
+	CONF_STR_VAR(BUILDID_DIR, "buildid", "dir", "~/.debug"),
+	CONF_BOOL_VAR(ANNOTATE_HIDE_SRC_CODE, "annotate", "hide_src_code", false),
+	CONF_BOOL_VAR(ANNOTATE_USE_OFFSET, "annotate", "use_offset", true),
+	CONF_BOOL_VAR(ANNOTATE_JUMP_ARROWS, "annotate", "jump_arrows", true),
+	CONF_BOOL_VAR(ANNOTATE_SHOW_NR_JUMPS, "annotate", "show_nr_jumps", false),
+	CONF_BOOL_VAR(ANNOTATE_SHOW_LINENR, "annotate", "show_linenr", false),
+	CONF_BOOL_VAR(ANNOTATE_SHOW_TOTAL_PERIOD, "annotate", "show_total_period", false),
+	CONF_BOOL_VAR(GTK_ANNOTATE, "gtk", "annotate", false),
+	CONF_BOOL_VAR(GTK_REPORT, "gtk", "report", false),
+	CONF_BOOL_VAR(GTK_TOP, "gtk", "top", false),
+	CONF_BOOL_VAR(PAGER_CMD, "pager", "cmd", true),
+	CONF_BOOL_VAR(PAGER_REPORT, "pager", "report", true),
+	CONF_BOOL_VAR(PAGER_ANNOTATE, "pager", "annotate", true),
+	CONF_BOOL_VAR(PAGER_TOP, "pager", "top", true),
+	CONF_BOOL_VAR(PAGER_DIFF, "pager", "diff", true),
+	CONF_STR_VAR(HELP_FORMAT, "help", "format", "man"),
+	CONF_INT_VAR(HELP_AUTOCORRECT, "help", "autocorrect", 0),
+	CONF_STR_VAR(HIST_PERCENTAGE, "hist", "percentage", "absolute"),
+	CONF_BOOL_VAR(UI_SHOW_HEADERS, "ui", "show-headers", true),
+	CONF_STR_VAR(CALL_GRAPH_RECORD_MODE, "call-graph", "record-mode", "fp"),
+	CONF_LONG_VAR(CALL_GRAPH_DUMP_SIZE, "call-graph", "dump-size", 8192),
+	CONF_STR_VAR(CALL_GRAPH_PRINT_TYPE, "call-graph", "print-type", "graph"),
+	CONF_STR_VAR(CALL_GRAPH_ORDER, "call-graph", "order", "callee"),
+	CONF_STR_VAR(CALL_GRAPH_SORT_KEY, "call-graph", "sort-key", "function"),
+	CONF_DOUBLE_VAR(CALL_GRAPH_THRESHOLD, "call-graph", "threshold", 0.5),
+	CONF_LONG_VAR(CALL_GRAPH_PRINT_LIMIT, "call-graph", "print-limit", 0),
+	CONF_BOOL_VAR(REPORT_GROUP, "report", "group", true),
+	CONF_BOOL_VAR(REPORT_CHILDREN, "report", "children", true),
+	CONF_FLOAT_VAR(REPORT_PERCENT_LIMIT, "report", "percent-limit", 0),
+	CONF_U64_VAR(REPORT_QUEUE_SIZE, "report", "queue-size", 0),
+	CONF_BOOL_VAR(TOP_CHILDREN, "top", "children", true),
+	CONF_STR_VAR(MAN_VIEWER, "man", "viewer", "man"),
+	CONF_STR_VAR(KMEM_DEFAULT, "kmem", "default", "slab"),
+};
 
 static int get_next_char(void)
 {
@@ -458,21 +505,10 @@ static int perf_config_global(void)
 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 }
 
-int perf_config(config_fn_t fn, void *data)
+static char *perf_user_perfconfig(void)
 {
-	int ret = 0, found = 0;
-	const char *home = NULL;
+	const char *home = getenv("HOME");
 
-	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
-	if (config_exclusive_filename)
-		return perf_config_from_file(fn, config_exclusive_filename, data);
-	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
-		ret += perf_config_from_file(fn, perf_etc_perfconfig(),
-					    data);
-		found += 1;
-	}
-
-	home = getenv("HOME");
 	if (perf_config_global() && home) {
 		char *user_config = strdup(mkpath("%s/.perfconfig", home));
 		struct stat st;
@@ -495,17 +531,217 @@ int perf_config(config_fn_t fn, void *data)
 		if (!st.st_size)
 			goto out_free;
 
-		ret += perf_config_from_file(fn, user_config, data);
-		found += 1;
+		return user_config;
+
 out_free:
 		free(user_config);
 	}
 out:
+	return NULL;
+}
+
+int perf_config(config_fn_t fn, void *data)
+{
+	int ret = 0, found = 0;
+	char *user_config;
+
+	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
+	if (config_exclusive_filename)
+		return perf_config_from_file(fn, config_exclusive_filename, data);
+	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
+		ret += perf_config_from_file(fn, perf_etc_perfconfig(),
+					    data);
+		found += 1;
+	}
+
+	user_config = perf_user_perfconfig();
+	if (user_config) {
+		ret += perf_config_from_file(fn, user_config, data);
+		found += 1;
+		free(user_config);
+	}
+
 	if (found == 0)
 		return -1;
 	return ret;
 }
 
+static struct perf_config_item *find_config(struct list_head *config_list,
+				       const char *section,
+				       const char *name)
+{
+	struct perf_config_item *config;
+
+	list_for_each_entry(config, config_list, list) {
+		if (!strcmp(config->section, section) &&
+		    !strcmp(config->name, name))
+			return config;
+	}
+
+	return NULL;
+}
+
+static struct perf_config_item *add_config(struct list_head *config_list,
+					   const char *section,
+					   const char *name)
+{
+	struct perf_config_item *config = zalloc(sizeof(*config));
+
+	if (!config)
+		return NULL;
+
+	config->is_custom = true;
+	config->section = strdup(section);
+	if (!section)
+		goto out_err;
+
+	config->name = strdup(name);
+	if (!name) {
+		free((char *)config->section);
+		goto out_err;
+	}
+
+	list_add_tail(&config->list, config_list);
+	return config;
+
+out_err:
+	free(config);
+	pr_err("%s: strdup failed\n", __func__);
+	return NULL;
+}
+
+static int set_value(struct perf_config_item *config, enum perf_config_kind pos,
+		     const char *value)
+{
+	char *val = strdup(value);
+
+	if (!val)
+		return -1;
+
+	config->value[BOTH] = val;
+	config->value[pos] = val;
+	return 0;
+}
+
+static int collect_current_config(const char *var, const char *value,
+				  void *perf_config_set)
+{
+	int ret = 0;
+	char *ptr, *key;
+	char *section, *name;
+	struct perf_config_item *config;
+	struct perf_config_set *perf_configs = perf_config_set;
+	struct list_head *config_list = &perf_configs->config_list;
+
+	key = ptr = strdup(var);
+	if (!key) {
+		pr_err("%s: strdup failed\n", __func__);
+		return -1;
+	}
+
+	section = strsep(&ptr, ".");
+	name = ptr;
+	if (name == NULL || value == NULL) {
+		ret = -1;
+		goto out_err;
+	}
+
+	config = find_config(config_list, section, name);
+	if (!config) {
+		config = add_config(config_list, section, name);
+		if (!config) {
+			free((char *)config->section);
+			free((char *)config->name);
+			goto out_err;
+		}
+	}
+	ret = set_value(config, perf_configs->pos, value);
+
+out_err:
+	free(key);
+	return ret;
+}
+
+static struct perf_config_set *perf_config_set__init(struct perf_config_set *perf_configs)
+{
+	int i;
+	struct list_head *head = &perf_configs->config_list;
+
+	INIT_LIST_HEAD(&perf_configs->config_list);
+
+	for (i = 0; i != CONFIG_END; i++) {
+		struct perf_config_item *config = &default_configs[i];
+
+		list_add_tail(&config->list, head);
+	}
+	return perf_configs;
+}
+
+struct perf_config_set *perf_config_set__new(void)
+{
+	int ret;
+	struct perf_config_set *perf_configs = zalloc(sizeof(*perf_configs));
+	char *user_config = perf_user_perfconfig();
+	char *system_config = strdup(perf_etc_perfconfig());
+
+	if (!system_config)
+		goto out_err;
+
+	perf_config_set__init(perf_configs);
+
+	if (!access(system_config, R_OK)) {
+		perf_configs->pos = SYSTEM;
+		ret = perf_config_from_file(collect_current_config, system_config,
+					    perf_configs);
+		if (ret == 0)
+			perf_configs->file_usable[SYSTEM] = true;
+	}
+
+	if (user_config) {
+		perf_configs->pos = USER;
+		ret = perf_config_from_file(collect_current_config, user_config,
+				      perf_configs);
+		if (ret == 0)
+			perf_configs->file_usable[USER] = true;
+	} else {
+		user_config = strdup(mkpath("%s/.perfconfig", getenv("HOME")));
+		if (!user_config)
+			goto out_err;
+	}
+
+	/* user config file has order of priority */
+	perf_configs->file_path[BOTH] = user_config;
+	perf_configs->file_path[USER] = user_config;
+	perf_configs->file_path[SYSTEM] = system_config;
+
+	return perf_configs;
+
+out_err:
+	pr_err("%s: strdup failed\n", __func__);
+	free(perf_configs);
+	return NULL;
+}
+
+void perf_config_set__delete(struct perf_config_set *perf_configs)
+{
+	struct perf_config_item *pos, *item;
+
+	free(perf_configs->file_path[USER]);
+	free(perf_configs->file_path[SYSTEM]);
+
+	list_for_each_entry_safe(pos, item, &perf_configs->config_list, list) {
+		list_del(&pos->list);
+		if (pos->is_custom) {
+			free((char *)pos->section);
+			free((char *)pos->name);
+		}
+		free(pos->value[USER]);
+		free(pos->value[SYSTEM]);
+	}
+
+	free(perf_configs);
+}
+
 /*
  * Call this to report error for your variable that should not
  * get a boolean value (i.e. "[my] var" means "true").
diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
new file mode 100644
index 0000000..2523221
--- /dev/null
+++ b/tools/perf/util/config.h
@@ -0,0 +1,138 @@
+#ifndef __PERF_CONFIG_H
+#define __PERF_CONFIG_H
+
+#include <stdbool.h>
+#include <linux/list.h>
+
+/**
+ * enum perf_config_kind - three kinds of config information
+ *
+ * @USER: user wide ~/.perfconfig
+ * @SYSTEM: systeom wide $(sysconfdir)/perfconfig
+ * @BOTH: both the config files
+ * but user config file has order of priority.
+ */
+#define CONFIG_KIND 3
+enum perf_config_kind {
+	BOTH,
+	USER,
+	SYSTEM,
+};
+
+enum perf_config_type {
+	CONFIG_TYPE_BOOL,
+	CONFIG_TYPE_INT,
+	CONFIG_TYPE_LONG,
+	CONFIG_TYPE_U64,
+	CONFIG_TYPE_FLOAT,
+	CONFIG_TYPE_DOUBLE,
+	CONFIG_TYPE_STRING
+};
+
+/**
+ * struct perf_config_item - element of perf's configs
+ *
+ * @value: array that has values for each kind (USER/SYSTEM/BOTH)
+ * @is_custom: if the user or system config files contain this
+ */
+struct perf_config_item {
+	const char *section;
+	const char *name;
+	char *value[CONFIG_KIND];
+	union {
+		bool b;
+		int i;
+		u32 l;
+		u64 ll;
+		float f;
+		double d;
+		const char *s;
+	} default_value;
+	enum perf_config_type type;
+	bool is_custom;
+	struct list_head list;
+};
+
+/**
+ * struct perf_config_set - perf's config set from the config files
+ *
+ * @file_path: array that has paths of config files
+ * @pos: current major config file
+ * @config_list: perf_config_item list head
+ */
+struct perf_config_set {
+	enum perf_config_kind pos;
+	char *file_path[CONFIG_KIND];
+	bool file_usable[CONFIG_KIND];
+	struct list_head config_list;
+};
+
+enum perf_config_idx {
+	CONFIG_COLORS_TOP,
+	CONFIG_COLORS_MEDIUM,
+	CONFIG_COLORS_NORMAL,
+	CONFIG_COLORS_SELECTED,
+	CONFIG_COLORS_JUMP_ARROWS,
+	CONFIG_COLORS_ADDR,
+	CONFIG_COLORS_ROOT,
+	CONFIG_TUI_REPORT,
+	CONFIG_TUI_ANNOTATE,
+	CONFIG_TUI_TOP,
+	CONFIG_BUILDID_DIR,
+	CONFIG_ANNOTATE_HIDE_SRC_CODE,
+	CONFIG_ANNOTATE_USE_OFFSET,
+	CONFIG_ANNOTATE_JUMP_ARROWS,
+	CONFIG_ANNOTATE_SHOW_NR_JUMPS,
+	CONFIG_ANNOTATE_SHOW_LINENR,
+	CONFIG_ANNOTATE_SHOW_TOTAL_PERIOD,
+	CONFIG_GTK_ANNOTATE,
+	CONFIG_GTK_REPORT,
+	CONFIG_GTK_TOP,
+	CONFIG_PAGER_CMD,
+	CONFIG_PAGER_REPORT,
+	CONFIG_PAGER_ANNOTATE,
+	CONFIG_PAGER_TOP,
+	CONFIG_PAGER_DIFF,
+	CONFIG_HELP_FORMAT,
+	CONFIG_HELP_AUTOCORRECT,
+	CONFIG_HIST_PERCENTAGE,
+	CONFIG_UI_SHOW_HEADERS,
+	CONFIG_CALL_GRAPH_RECORD_MODE,
+	CONFIG_CALL_GRAPH_DUMP_SIZE,
+	CONFIG_CALL_GRAPH_PRINT_TYPE,
+	CONFIG_CALL_GRAPH_ORDER,
+	CONFIG_CALL_GRAPH_SORT_KEY,
+	CONFIG_CALL_GRAPH_THRESHOLD,
+	CONFIG_CALL_GRAPH_PRINT_LIMIT,
+	CONFIG_REPORT_GROUP,
+	CONFIG_REPORT_CHILDREN,
+	CONFIG_REPORT_PERCENT_LIMIT,
+	CONFIG_REPORT_QUEUE_SIZE,
+	CONFIG_TOP_CHILDREN,
+	CONFIG_MAN_VIEWER,
+	CONFIG_KMEM_DEFAULT,
+	CONFIG_END
+};
+
+#define CONF_VAR(_sec, _name, _field, _val, _type)			\
+	{ .section = _sec, .name = _name, .default_value._field = _val, .type = _type }
+
+#define CONF_BOOL_VAR(_idx, _sec, _name, _val)				\
+	[CONFIG_##_idx] = CONF_VAR(_sec, _name, b, _val, CONFIG_TYPE_BOOL)
+#define CONF_INT_VAR(_idx, _sec, _name, _val)				\
+	[CONFIG_##_idx] = CONF_VAR(_sec, _name, i, _val, CONFIG_TYPE_INT)
+#define CONF_LONG_VAR(_idx, _sec, _name, _val)				\
+	[CONFIG_##_idx] = CONF_VAR(_sec, _name, l, _val, CONFIG_TYPE_LONG)
+#define CONF_U64_VAR(_idx, _sec, _name, _val)				\
+	[CONFIG_##_idx] = CONF_VAR(_sec, _name, ll, _val, CONFIG_TYPE_U64)
+#define CONF_FLOAT_VAR(_idx, _sec, _name, _val)				\
+	[CONFIG_##_idx] = CONF_VAR(_sec, _name, f, _val, CONFIG_TYPE_FLOAT)
+#define CONF_DOUBLE_VAR(_idx, _sec, _name, _val)			\
+	[CONFIG_##_idx] = CONF_VAR(_sec, _name, d, _val, CONFIG_TYPE_DOUBLE)
+#define CONF_STR_VAR(_idx, _sec, _name, _val)				\
+	[CONFIG_##_idx] = CONF_VAR(_sec, _name, s, _val, CONFIG_TYPE_STRING)
+
+struct perf_config_set *perf_config_set__new(void);
+void perf_config_set__delete(struct perf_config_set *perf_configs);
+
+#endif /* __PERF_CONFIG_H */
-- 
2.5.0