[lvm-devel] master - config: add structs to represent config definition and register config_settings.h content
Peter Rajnoha
prajnoha at fedoraproject.org
Wed Mar 6 11:15:05 UTC 2013
Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=a3d891a29042e51a0f43ed02273a6dce194d6569
Commit: a3d891a29042e51a0f43ed02273a6dce194d6569
Parent: e947c362dd0ae1da2d76925fe6b38244c5f46d25
Author: Peter Rajnoha <prajnoha at redhat.com>
AuthorDate: Tue Mar 5 16:49:42 2013 +0100
Committer: Peter Rajnoha <prajnoha at redhat.com>
CommitterDate: Wed Mar 6 10:14:33 2013 +0100
config: add structs to represent config definition and register config_settings.h content
This patch adds basic structures that encapsulate the config_settings.h
content - it takes each item and puts it in structures:
- cfg_def_type_t to define config item type
- cfg_def_value_t to define config item (default) value
- flags used to define the nature and use of the config item:
- CFG_NAME_VARIABLE for items with variable names (e.g. tags)
- CFG_ALLOW_EMPTY for items where empty value is allowed
- CFG_ADVANCED for items which are considered as "advanced settings"
- CFG_UNSUPPORTED for items which are not officially supported
(config options mostly for internal use and testing/debugging)
- cfg_def_item_t to encapsulate the whole definition of the config
definition itself
Each config item is referenced by named ID, e.g. "devices_dir_CFG"
instead of directly typing the path "devices/dir" as it was before.
This patch also adds cfg_def_get_path helper function to get the
config setting path up to the root for given config ID
(it returns the path in form of "abc/def/.../xyz" where the "abc"
is the topmost element).
---
lib/config/config.c | 45 +++++++++++++++++++++++++++++++++++++
lib/config/config.h | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 107 insertions(+), 0 deletions(-)
diff --git a/lib/config/config.c b/lib/config/config.c
index 0820594..f2ee9e7 100644
--- a/lib/config/config.c
+++ b/lib/config/config.c
@@ -38,6 +38,21 @@ struct config_file {
struct device *dev;
};
+static char _cfg_path[CFG_PATH_MAX_LEN];
+
+/*
+ * Map each ID to respective definition of the configuration item.
+ */
+static struct cfg_def_item _cfg_def_items[CFG_COUNT + 1] = {
+#define cfg_section(id, name, parent, flags, since_version, comment) {id, parent, name, CFG_TYPE_SECTION, {0}, flags, since_version, comment},
+#define cfg(id, name, parent, flags, type, default_value, since_version, comment) {id, parent, name, type, {.v_##type = default_value}, flags, since_version, comment},
+#define cfg_array(id, name, parent, flags, types, default_value, since_version, comment) {id, parent, name, CFG_TYPE_ARRAY | types, {.v_CFG_TYPE_STRING = default_value}, flags, since_version, comment},
+#include "config_settings.h"
+#undef cfg_section
+#undef cfg
+#undef cfg_array
+};
+
/*
* public interface
*/
@@ -289,6 +304,36 @@ time_t config_file_timestamp(struct dm_config_tree *cft)
return cf->timestamp;
}
+#define cfg_def_get_item_p(id) (&_cfg_def_items[id])
+#define cfg_def_get_default_value(item,type) item->default_value.v_##type
+#define cfg_def_get_path(item) (_cfg_def_make_path(_cfg_path,CFG_PATH_MAX_LEN,item->id,item),_cfg_path)
+
+static int _cfg_def_make_path(char *buf, size_t buf_size, int id, cfg_def_item_t *item)
+{
+ int parent_id = item->parent;
+ int count, n;
+
+ if (id == parent_id)
+ return 0;
+
+ count = _cfg_def_make_path(buf, buf_size, parent_id, cfg_def_get_item_p(parent_id));
+ if ((n = dm_snprintf(buf + count, buf_size - count, "%s%s",
+ count ? "/" : "",
+ item->flags & CFG_NAME_VARIABLE ? "#" : item->name)) < 0) {
+ log_error(INTERNAL_ERROR "_cfg_def_make_path: supplied buffer too small for %s/%s",
+ cfg_def_get_item_p(parent_id)->name, item->name);
+ buf[0] = '\0';
+ return 0;
+ }
+
+ return count + n;
+}
+
+int config_def_get_path(char *buf, size_t buf_size, int id)
+{
+ return _cfg_def_make_path(buf, buf_size, id, cfg_def_get_item_p(id));
+}
+
const struct dm_config_node *find_config_tree_node(struct cmd_context *cmd,
const char *path)
{
diff --git a/lib/config/config.h b/lib/config/config.h
index 079e9d1..2317348 100644
--- a/lib/config/config.h
+++ b/lib/config/config.h
@@ -17,6 +17,7 @@
#define _LVM_CONFIG_H
#include "lvm-types.h"
+#include "defaults.h"
/* 16 bits: 3 bits for major, 4 bits for minor, 9 bits for patchlevel */
/* Max LVM version supported: 7.15.511. Just extend bits if ever needed. */
@@ -25,6 +26,67 @@
struct device;
struct cmd_context;
+#define CFG_PATH_MAX_LEN 64
+
+/*
+ * Structures used for definition of a configuration tree.
+ */
+
+/* configuration definition item type (for item's accepted types) */
+typedef enum {
+ CFG_TYPE_SECTION = 0, /* section */
+ CFG_TYPE_ARRAY = 1, /* setting */
+ CFG_TYPE_BOOL = 2, /* setting */
+ CFG_TYPE_INT = 4, /* setting */
+ CFG_TYPE_FLOAT = 8, /* setting */
+ CFG_TYPE_STRING = 16 /* setting */
+} cfg_def_type_t;
+
+/* configuration definition item value (for item's default value) */
+typedef union {
+ const int v_CFG_TYPE_BOOL, v_CFG_TYPE_INT;
+ const float v_CFG_TYPE_FLOAT;
+ const char *v_CFG_TYPE_STRING, *v_CFG_TYPE_ARRAY;
+} cfg_def_value_t;
+
+/* configuration definition item flags: */
+
+/* whether the configuration item name is variable */
+#define CFG_NAME_VARIABLE 0x01
+/* whether empty value is allowed */
+#define CFG_ALLOW_EMPTY 0x02
+/* whether the configuration item is for advanced use only */
+#define CFG_ADVANCED 0x04
+/* whether the configuraton item is not officially supported */
+#define CFG_UNSUPPORTED 0x08
+
+/* configuration definition item structure */
+typedef struct cfg_def_item {
+ int id; /* ID of this item */
+ int parent; /* ID of parent item */
+ const char *name; /* name of the item in configuration tree */
+ cfg_def_type_t type; /* configuration item type */
+ cfg_def_value_t default_value; /* default value (only for settings) */
+ uint16_t flags; /* configuration item definition flags */
+ uint16_t since_version; /* version this item appeared in */
+ const char *comment; /* brief comment */
+} cfg_def_item_t;
+
+/*
+ * Register ID for each possible item in the configuration tree.
+ */
+enum {
+#define cfg_section(id, name, parent, flags, since_version, comment) id,
+#define cfg(id, name, parent, flags, type, default_value, since_version, comment) id,
+#define cfg_array(id, name, parent, flags, types, default_value, since_version, comment) id,
+#include "config_settings.h"
+#undef cfg_section
+#undef cfg
+#undef cfg_array
+};
+
+int config_def_get_path(char *buf, size_t buf_size, int id);
+
int override_config_tree_from_string(struct cmd_context *cmd,
const char *config_settings);
struct dm_config_tree *remove_overridden_config_tree(struct cmd_context *cmd);
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