Split header file III

Changelog:
 - since there are no global macros, base.h is gone
 - since there is no base.h, all headers need to include <features.h> to get
   __BEGIN_DECLS
 - new init.h with cgroup_init() and cgroup_get_subsys_mount_point()
 - new error.h with error handling enum and related stuff
 - use #ifndef _LIBCGROUP_*_H instead _LIBCG_*_H in header guards
 - fix few checkpatch complaints (long lines, whitespaces, ...)

The patch includes Makefile and .spec changes. I tested it compiles,
make dist produces tarball with all headers, so does also the rpm.
'make' should automatically catch all changes in new headers and
recompile dependent (=all) sources when any header changes.

libcgroup.h
  - does not declare anything, it just includes all the other files. In
    future, it might contain base of doxygen documentation (some
    introduction etc.)

libcgroup/error.h
  - the big enum with errors + error related functions

libcgroup/init.h
  - libcgroup_init() and cgroup_get_subsys_mount_point()

libcgroup/config.h
  - configuration reading/unloading

libcgroup/groups.h
  - group manipulation stuff (create/modify/delete/free, incl. controllers and
    get/set values) + definition of struct cgroup (=must be included by
    libcgroup/tasks.h, which needs it)

libcgroup/iterators.h
  - various walks, *_begin/next/end

libcgroup/tasks.h
  - task classification, incl. rules cache manipulation

In addition, I probably removed some #includes, which are not needed now when
looking for the minimal #include set to build the project. I also hope I did not
miss any function declaration or macro...

Signed-off-by: Jan Safranek <jsafrane@redhat.com>
Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com>

1 files changed, 170 insertions, 0 deletions

diff --git a/include/libcgroup/iterators.h b/include/libcgroup/iterators.h
new file mode 100644
index 0000000..c724abf
--- /dev/null
+++ b/include/libcgroup/iterators.h
@@ -0,0 +1,170 @@
+#ifndef _LIBCGROUP_ITERATORS_H
+#define _LIBCGROUP_ITERATORS_H
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <features.h>
+
+__BEGIN_DECLS
+
+/*
+ * Don't use CGROUP_WALK_TYPE_FILE right now. It is added here for
+ * later refactoring and better implementation. Most users *should*
+ * use CGROUP_WALK_TYPE_PRE_DIR.
+ */
+enum cgroup_walk_type {
+	CGROUP_WALK_TYPE_PRE_DIR = 0x1,	/* Pre Order Directory */
+	CGROUP_WALK_TYPE_POST_DIR = 0x2,	/* Post Order Directory */
+};
+
+enum cgroup_file_type {
+	CGROUP_FILE_TYPE_FILE,		/* File */
+	CGROUP_FILE_TYPE_DIR,		/* Directory */
+	CGROUP_FILE_TYPE_OTHER,		/* Directory */
+};
+struct cgroup_file_info {
+	enum cgroup_file_type type;
+	const char *path;
+	const char *parent;
+	const char *full_path;
+	short depth;
+};
+
+#define CG_VALUE_MAX 100
+struct cgroup_stat {
+	char name[FILENAME_MAX];
+	char value[CG_VALUE_MAX];
+};
+
+struct cgroup_mount_point {
+	char name[FILENAME_MAX];
+	char path[FILENAME_MAX];
+};
+
+/*
+ * Detailed information about available controller.
+ */
+
+struct controller_data {
+/** Controller name. */
+	char name[FILENAME_MAX];
+/**
+ * Hierarchy ID. Controllers with the same hierarchy ID
+ * are mounted together as one hierarchy. Controllers with
+ * ID 0 are not currently used.
+ */
+	int hierarchy;
+/** Number of groups. */
+	int num_cgroups;
+/** Enabled flag */
+	int enabled;
+};
+
+/**
+ * Walk through the directory tree for the specified controller.
+ * @controller: Name of the controller, for which we want to walk
+ * the directory tree
+ * @base_path: Begin walking from this path
+ * @depth: The maximum depth to which the function should walk, 0
+ * implies all the way down
+ * @handle: Handle to be used during iteration
+ * @info: info filled and returned about directory information
+ */
+int cgroup_walk_tree_begin(char *controller, char *base_path, const int depth,
+				void **handle, struct cgroup_file_info *info,
+				int *base_level);
+/**
+ * Get the next element during the walk
+ * @depth: The maximum depth to which the function should walk, 0
+ * implies all the way down
+ * @handle: Handle to be used during iteration
+ * @info: info filled and returned about directory information
+ *
+ * Returns ECGEOF when we are done walking through the nodes.
+ */
+int cgroup_walk_tree_next(const int depth, void **handle,
+				struct cgroup_file_info *info, int base_level);
+int cgroup_walk_tree_end(void **handle);
+
+/**
+ * This API is used to set the flags for walk_tree API. Currently availble
+ *  flags are
+ *
+ *  CGROUP_WALK_TYPE_PRE_DIR
+ *  CGROUP_WALK_TYPE_POST_DIR
+ *
+ */
+int cgroup_walk_tree_set_flags(void **handle, int flags);
+
+/**
+ * Read the statistics values for the specified controller
+ * @controller: Name of the controller for which stats are requested.
+ * @path: cgroup path.
+ * @handle: Handle to be used during iteration.
+ * @stat: Stats values will be filled and returned here.
+ */
+int cgroup_read_stats_begin(char *controller, char *path, void **handle,
+				struct cgroup_stat *stat);
+
+/**
+ * Read the next stat value.
+ * @handle: Handle to be used during iteration.
+ * @stat: Stats values will be filled and returned here.
+ */
+int cgroup_read_stats_next(void **handle, struct cgroup_stat *stat);
+
+int cgroup_read_stats_end(void **handle);
+
+/**
+ * Read the tasks file to get the list of tasks in a cgroup
+ * @cgroup: Name of the cgroup
+ * @controller: Name of the cgroup subsystem
+ * @handle: Handle to be used in the iteration
+ * @pid: The pid read from the tasks file. Will be filled in by the API
+ */
+int cgroup_get_task_begin(char *cgroup, char *controller, void **handle,
+								pid_t *pid);
+
+/**
+ * Read the next task value
+ * @handle: The handle used for iterating
+ * @pid: The variable where the value will be stored
+ *
+ * return ECGEOF when the iterator finishes getting the list of tasks.
+ */
+int cgroup_get_task_next(void **handle, pid_t *pid);
+int cgroup_get_task_end(void **handle);
+
+/**
+ * Read the mount table to give a list where each controller is
+ * mounted
+ * @handle: Handle to be used for iteration.
+ * @name: The variable where the name is stored. Should be freed by caller.
+ * @path: Te variable where the path to the controller is stored. Should be
+ * freed by the caller.
+ */
+int cgroup_get_controller_begin(void **handle, struct cgroup_mount_point *info);
+/*
+ * While walking through the mount table, the controllers will be
+ * returned in order of their mount points.
+ */
+int cgroup_get_controller_next(void **handle, struct cgroup_mount_point *info);
+int cgroup_get_controller_end(void **handle);
+
+/**
+ * Read the list of controllers from /proc/cgroups (not mounted included)
+ * @param handle: Handle to be used for iteration.
+ * @param info: The structure which contains all controller data
+ */
+int cgroup_get_all_controller_begin(void **handle,
+	struct controller_data *info);
+/*
+ * While walking through the mount table, the controllers will be
+ * returned in the same order as is in /proc/cgroups file
+ */
+int cgroup_get_all_controller_next(void **handle, struct controller_data *info);
+int cgroup_get_all_controller_end(void **handle);
+
+__END_DECLS
+
+#endif /* _LIBCGROUP_ITERATORS_H */