libmount: add list routines and generic iterator

Signed-off-by: Karel Zak <kzak@redhat.com>

5 files changed, 281 insertions, 1 deletions

diff --git a/shlibs/mount/src/Makefile.am b/shlibs/mount/src/Makefile.am
index e9c7cc923..6f2b95023 100644
--- a/shlibs/mount/src/Makefile.am
+++ b/shlibs/mount/src/Makefile.am
@@ -12,7 +12,7 @@ usrlib_exec_LTLIBRARIES = libmount.la
 libmount_la_SOURCES = $(mountinc_HEADERS)
 
 nodist_libmount_la_SOURCES = mount.h version.c utils.c test.c init.c cache.c \
-			optstr.c \
+			optstr.c iter.c list.h \
 			$(top_srcdir)/lib/canonicalize.c
 
 libmount_la_LIBADD = $(ul_libblkid_la)
diff --git a/shlibs/mount/src/iter.c b/shlibs/mount/src/iter.c
new file mode 100644
index 000000000..d64f2d40d
--- /dev/null
+++ b/shlibs/mount/src/iter.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "mountP.h"
+
+/**
+ * mnt_new_iter:
+ * @direction: MNT_INTER_{FOR,BACK}WARD direction
+ *
+ * Returns newly allocated generic libmount iterator.
+ */
+mnt_iter *mnt_new_iter(int direction)
+{
+	mnt_iter *itr = calloc(1, sizeof(struct _mnt_iter));
+	if (!itr)
+		return NULL;
+	itr->direction = direction;
+	return itr;
+}
+
+/**
+ * mnt_free_iter:
+ * @itr: iterator pointer
+ *
+ * Deallocates iterator.
+ */
+void mnt_free_iter(mnt_iter *itr)
+{
+	free(itr);
+}
+
+/**
+ * mnt_reset_iter:
+ * @itr: iterator pointer
+ * @direction: MNT_INTER_{FOR,BACK}WARD iterator direction
+ *
+ * Resets iterator.
+ */
+void mnt_reset_iter(mnt_iter *itr, int direction)
+{
+	assert(itr);
+
+	if (itr) {
+		memset(itr, 0, sizeof(struct _mnt_iter));
+		itr->direction = direction;
+	}
+}
diff --git a/shlibs/mount/src/list.h b/shlibs/mount/src/list.h
new file mode 100644
index 000000000..9f8b88a23
--- /dev/null
+++ b/shlibs/mount/src/list.h
@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
+ * Copyright (C) 1999-2008 by Theodore Ts'o
+ *
+ * (based on list.h from e2fsprogs)
+ */
+
+#if !defined(_LIBMOUNT_LIST_H) && !defined(LIST_HEAD)
+#define _LIBMOUNT_LIST_H
+
+/* TODO: use AC_C_INLINE */
+#ifdef __GNUC__
+#define _INLINE_ static __inline__
+#else                         /* For Watcom C */
+#define _INLINE_ static inline
+#endif
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+struct list_head {
+	struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+	struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+	(ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+_INLINE_ void __list_add(struct list_head * add,
+	struct list_head * prev,
+	struct list_head * next)
+{
+	next->prev = add;
+	add->next = next;
+	add->prev = prev;
+	prev->next = add;
+}
+
+/**
+ * list_add - add a new entry
+ * @add:	new entry to be added
+ * @head:	list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+_INLINE_ void list_add(struct list_head *add, struct list_head *head)
+{
+	__list_add(add, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @add:	new entry to be added
+ * @head:	list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+_INLINE_ void list_add_tail(struct list_head *add, struct list_head *head)
+{
+	__list_add(add, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+_INLINE_ void __list_del(struct list_head * prev,
+				  struct list_head * next)
+{
+	next->prev = prev;
+	prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry:	the element to delete from the list.
+ *
+ * list_empty() on @entry does not return true after this, @entry is
+ * in an undefined state.
+ */
+_INLINE_ void list_del(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry:	the element to delete from the list.
+ */
+_INLINE_ void list_del_init(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head:	the list to test.
+ */
+_INLINE_ int list_empty(struct list_head *head)
+{
+	return head->next == head;
+}
+
+/**
+ * list_splice - join two lists
+ * @list:	the new list to add.
+ * @head:	the place to add it in the first list.
+ */
+_INLINE_ void list_splice(struct list_head *list, struct list_head *head)
+{
+	struct list_head *first = list->next;
+
+	if (first != list) {
+		struct list_head *last = list->prev;
+		struct list_head *at = head->next;
+
+		first->prev = head;
+		head->next = first;
+
+		last->next = at;
+		at->prev = last;
+	}
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr:	the &struct list_head pointer.
+ * @type:	the type of the struct this is embedded in.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+/**
+ * list_for_each - iterate over elements in a list
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ */
+#define list_for_each(pos, head) \
+	for (pos = (head)->next; pos != (head); pos = pos->next)
+
+/**
+ * list_for_each_safe - iterate over elements in a list, but don't dereference
+ *                      pos after the body is done (in case it is freed)
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @pnext:	the &struct list_head to use as a pointer to the next item.
+ * @head:	the head for your list (not included in iteration).
+ */
+#define list_for_each_safe(pos, pnext, head) \
+	for (pos = (head)->next, pnext = pos->next; pos != (head); \
+	     pos = pnext, pnext = pos->next)
+
+#undef _INLINE_
+
+#endif /* __LIBFSPROBE_LIST_H__ */
diff --git a/shlibs/mount/src/mount.h.in b/shlibs/mount/src/mount.h.in
index 3426729bf..696c29409 100644
--- a/shlibs/mount/src/mount.h.in
+++ b/shlibs/mount/src/mount.h.in
@@ -34,6 +34,13 @@ extern "C" {
  */
 typedef struct _mnt_cache mnt_cache;
 
+/**
+ * mnt_iter
+ *
+ * Generic iterator (stores state about lists)
+ */
+typedef struct _mnt_iter mnt_iter;
+
 /* version.c */
 extern int mnt_parse_version_string(const char *ver_string);
 extern int mnt_get_library_version(const char **ver_string);
@@ -67,6 +74,17 @@ extern int mnt_optstr_set_option(char **optstr, const char *name,
 				const char *value);
 extern int mnt_optstr_remove_option(char **optstr, const char *name);
 
+
+/* iter.c */
+enum {
+
+	MNT_ITER_FORWARD = 0,
+	MNT_ITER_BACKWARD
+};
+extern mnt_iter *mnt_new_iter(int direction);
+extern void mnt_free_iter(mnt_iter *mi);
+extern void mnt_reset_iter(mnt_iter *mi, int direction);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/shlibs/mount/src/mountP.h b/shlibs/mount/src/mountP.h
index 74db25568..ef3c1a661 100644
--- a/shlibs/mount/src/mountP.h
+++ b/shlibs/mount/src/mountP.h
@@ -11,7 +11,9 @@
 #define _LIBMOUNT_PRIVATE_H
 
 #include <sys/types.h>
+
 #include "mount.h"
+#include "list.h"
 
 /* features */
 #define CONFIG_CDROM_NOMEDIUM_RETRIES    5
@@ -69,4 +71,31 @@ extern char *strnchr(const char *s, size_t maxlen, int c);
 extern char *mnt_get_username(const uid_t uid);
 extern char *mnt_strconcat3(char *s, const char *t, const char *u);
 
+
+/*
+ * Generic iterator
+ */
+struct _mnt_iter {
+        struct list_head        *p;		/* current position */
+        struct list_head        *head;		/* start position */
+	int			direction;	/* MNT_ITER_{FOR,BACK}WARD */
+};
+
+#define IS_ITER_FORWARD(_i)	((_i)->direction == MNT_ITER_FORWARD)
+#define IS_ITER_BACKWARD(_i)	((_i)->direction == MNT_ITER_BACKWARD)
+
+#define MNT_ITER_INIT(itr, list) \
+	do { \
+		(itr)->p = IS_ITER_FORWARD(itr) ? \
+				(list)->next : (list)->prev; \
+		(itr)->head = (list); \
+	} while(0)
+
+#define MNT_ITER_ITERATE(itr, res, restype, member) \
+	do { \
+		res = list_entry((itr)->p, restype, member); \
+		(itr)->p = IS_ITER_FORWARD(itr) ? \
+				(itr)->p->next : (itr)->p->prev; \
+	} while(0)
+
 #endif