Merge "include/asterisk/vector.h: Backport vector.h to Asterisk 11" into 11

include/asterisk/vector.h

+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * David M. Lee, II <dlee@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+#ifndef _ASTERISK_VECTOR_H
+#define _ASTERISK_VECTOR_H
+
+/*! \file
+ *
+ * \brief Vector container support.
+ *
+ * A vector is a variable length array, with properties that can be useful when
+ * order doesn't matter.
+ *  - Appends are asymptotically constant time.
+ *  - Unordered removes are constant time.
+ *  - Search is linear time
+ *
+ * \author David M. Lee, II <dlee@digium.com>
+ * \since 12
+ */
+
+/*!
+ * \brief Define a vector structure
+ *
+ * \param name Optional vector struct name.
+ * \param type Vector element type.
+ */
+#define AST_VECTOR(name, type)			\
+	struct name {				\
+		type *elems;			\
+		size_t max;			\
+		size_t current;			\
+	}
+
+/*!
+ * \brief Initialize a vector
+ *
+ * If \a size is 0, then no space will be allocated until the vector is
+ * appended to.
+ *
+ * \param vec Vector to initialize.
+ * \param size Initial size of the vector.
+ *
+ * \return 0 on success.
+ * \return Non-zero on failure.
+ */
+#define AST_VECTOR_INIT(vec, size) ({					\
+	size_t __size = (size);						\
+	size_t alloc_size = __size * sizeof(*((vec)->elems));		\
+	(vec)->elems = alloc_size ? ast_calloc(1, alloc_size) : NULL;	\
+	(vec)->current = 0;						\
+	if ((vec)->elems) {						\
+		(vec)->max = __size;					\
+	} else {							\
+		(vec)->max = 0;						\
+	}								\
+	(alloc_size == 0 || (vec)->elems != NULL) ? 0 : -1;		\
+})
+
+/*!
+ * \brief Deallocates this vector.
+ *
+ * If any code to free the elements of this vector need to be run, that should
+ * be done prior to this call.
+ *
+ * \param vec Vector to deallocate.
+ */
+#define AST_VECTOR_FREE(vec) do {		\
+	ast_free((vec)->elems);			\
+	(vec)->elems = NULL;			\
+	(vec)->max = 0;				\
+	(vec)->current = 0;			\
+} while (0)
+
+/*!
+ * \brief Append an element to a vector, growing the vector if needed.
+ *
+ * \param vec Vector to append to.
+ * \param elem Element to append.
+ *
+ * \return 0 on success.
+ * \return Non-zero on failure.
+ */
+#define AST_VECTOR_APPEND(vec, elem) ({						\
+	int res = 0;								\
+	do {									\
+		if ((vec)->current + 1 > (vec)->max) {				\
+			size_t new_max = (vec)->max ? 2 * (vec)->max : 1;	\
+			typeof((vec)->elems) new_elems = ast_realloc(		\
+				(vec)->elems, new_max * sizeof(*new_elems));	\
+			if (new_elems) {					\
+				(vec)->elems = new_elems;			\
+				(vec)->max = new_max;				\
+			} else {						\
+				res = -1;					\
+				break;						\
+			}							\
+		}								\
+		(vec)->elems[(vec)->current++] = (elem);			\
+	} while (0);								\
+	res;									\
+})
+
+/*!
+ * \brief Insert an element at a specific position in a vector, growing the vector if needed.
+ *
+ * \param vec Vector to insert into.
+ * \param idx Position to insert at.
+ * \param elem Element to insert.
+ *
+ * \return 0 on success.
+ * \return Non-zero on failure.
+ *
+ * \warning This macro will overwrite anything already present at the position provided.
+ *
+ * \warning Use of this macro with the expectation that the element will remain at the provided
+ * index means you can not use the UNORDERED assortment of macros. These macros alter the ordering
+ * of the vector itself.
+ */
+#define AST_VECTOR_INSERT(vec, idx, elem) ({					\
+ 	int res = 0;												\
+ 	do {														\
+ 		if (((idx) + 1) > (vec)->max) {							\
+ 			size_t new_max = ((idx) + 1) * 2;					\
+			typeof((vec)->elems) new_elems = ast_calloc(1,		\
+				new_max * sizeof(*new_elems));					\
+			if (new_elems) {									\
+				memcpy(new_elems, (vec)->elems,					\
+					(vec)->current * sizeof(*new_elems)); 		\
+				ast_free((vec)->elems);							\
+				(vec)->elems = new_elems;						\
+				(vec)->max = new_max;							\
+			} else {											\
+				res = -1;										\
+				break;											\
+			}													\
+ 		}														\
+ 		(vec)->elems[(idx)] = (elem);							\
+ 		if (((idx) + 1) > (vec)->current) {						\
+ 			(vec)->current = (idx) + 1;							\
+ 		}														\
+ 	} while(0);													\
+ 	res;														\
+})
+
+/*!
+ * \brief Remove an element from a vector by index.
+ *
+ * Note that elements in the vector may be reordered, so that the remove can
+ * happen in constant time.
+ *
+ * \param vec Vector to remove from.
+ * \param idx Index of the element to remove.
+ * \return The element that was removed.
+ */
+#define AST_VECTOR_REMOVE_UNORDERED(vec, idx) ({		\
+	typeof((vec)->elems[0]) res;				\
+	size_t __idx = (idx);					\
+	ast_assert(__idx < (vec)->current);			\
+	res = (vec)->elems[__idx];				\
+	(vec)->elems[__idx] = (vec)->elems[--(vec)->current];	\
+	res;							\
+})
+
+/*!
+ * \brief Remove an element from a vector by index while maintaining order.
+ *
+ * \param vec Vector to remove from.
+ * \param idx Index of the element to remove.
+ * \return The element that was removed.
+ */
+#define AST_VECTOR_REMOVE_ORDERED(vec, idx) ({				\
+      	typeof((vec)->elems[0]) res;					\
+	size_t __idx = (idx);						\
+	size_t __move;							\
+	ast_assert(__idx < (vec)->current);				\
+	res = (vec)->elems[__idx];					\
+	__move = ((vec)->current - (__idx) - 1) * sizeof(typeof((vec)->elems[0])); \
+	memmove(&(vec)->elems[__idx], &(vec)->elems[__idx + 1], __move); \
+	(vec)->current--;						\
+	res;								\
+})
+
+
+/*!
+ * \brief Remove an element from a vector that matches the given comparison
+ *
+ * \param vec Vector to remove from.
+ * \param value Value to pass into comparator.
+ * \param cmp Comparator function/macros (called as \c cmp(elem, value))
+ * \param cleanup How to cleanup a removed element macro/function.
+ *
+ * \return 0 if element was removed.
+ * \return Non-zero if element was not in the vector.
+ */
+#define AST_VECTOR_REMOVE_CMP_UNORDERED(vec, value, cmp, cleanup) ({	\
+	int res = -1;							\
+	size_t idx;							\
+	typeof(value) __value = (value);				\
+	for (idx = 0; idx < (vec)->current; ++idx) {			\
+		if (cmp((vec)->elems[idx], __value)) {			\
+			cleanup((vec)->elems[idx]);			\
+			AST_VECTOR_REMOVE_UNORDERED((vec), idx);	\
+			res = 0;					\
+			break;						\
+		}							\
+	}								\
+	res;								\
+})
+
+/*!
+ * \brief Remove an element from a vector that matches the given comparison while maintaining order
+ *
+ * \param vec Vector to remove from.
+ * \param value Value to pass into comparator.
+ * \param cmp Comparator function/macros (called as \c cmp(elem, value))
+ * \param cleanup How to cleanup a removed element macro/function.
+ *
+ * \return 0 if element was removed.
+ * \return Non-zero if element was not in the vector.
+ */
+#define AST_VECTOR_REMOVE_CMP_ORDERED(vec, value, cmp, cleanup) ({	\
+	int res = -1;							\
+	size_t idx;							\
+	typeof(value) __value = (value);				\
+	for (idx = 0; idx < (vec)->current; ++idx) {			\
+		if (cmp((vec)->elems[idx], __value)) {			\
+			cleanup((vec)->elems[idx]);			\
+			AST_VECTOR_REMOVE_ORDERED((vec), idx);	\
+			res = 0;					\
+			break;						\
+		}							\
+	}								\
+	res;								\
+})
+
+/*!
+ * \brief Default comparator for AST_VECTOR_REMOVE_ELEM_UNORDERED()
+ *
+ * \param elem Element to compare against
+ * \param value Value to compare with the vector element.
+ *
+ * \return 0 if element does not match.
+ * \return Non-zero if element matches.
+ */
+#define AST_VECTOR_ELEM_DEFAULT_CMP(elem, value) ((elem) == (value))
+
+/*!
+ * \brief Vector element cleanup that does nothing.
+ *
+ * \param elem Element to cleanup
+ *
+ * \return Nothing
+ */
+#define AST_VECTOR_ELEM_CLEANUP_NOOP(elem)
+
+/*!
+ * \brief Remove an element from a vector.
+ *
+ * \param vec Vector to remove from.
+ * \param elem Element to remove
+ * \param cleanup How to cleanup a removed element macro/function.
+ *
+ * \return 0 if element was removed.
+ * \return Non-zero if element was not in the vector.
+ */
+#define AST_VECTOR_REMOVE_ELEM_UNORDERED(vec, elem, cleanup) ({	\
+	AST_VECTOR_REMOVE_CMP_UNORDERED((vec), (elem),		\
+		AST_VECTOR_ELEM_DEFAULT_CMP, cleanup);		\
+})
+
+/*!
+ * \brief Remove an element from a vector while maintaining order.
+ *
+ * \param vec Vector to remove from.
+ * \param elem Element to remove
+ * \param cleanup How to cleanup a removed element macro/function.
+ *
+ * \return 0 if element was removed.
+ * \return Non-zero if element was not in the vector.
+ */
+#define AST_VECTOR_REMOVE_ELEM_ORDERED(vec, elem, cleanup) ({	\
+	AST_VECTOR_REMOVE_CMP_ORDERED((vec), (elem),		\
+		AST_VECTOR_ELEM_DEFAULT_CMP, cleanup);		\
+})
+
+/*!
+ * \brief Get the number of elements in a vector.
+ *
+ * \param vec Vector to query.
+ * \return Number of elements in the vector.
+ */
+#define AST_VECTOR_SIZE(vec) (vec)->current
+
+/*!
+ * \brief Get an address of element in a vector.
+ *
+ * \param vec Vector to query.
+ * \param idx Index of the element to get address of.
+ */
+#define AST_VECTOR_GET_ADDR(vec, idx) ({	\
+	size_t __idx = (idx);			\
+	ast_assert(__idx < (vec)->current);	\
+	&(vec)->elems[__idx];			\
+})
+
+/*!
+ * \brief Get an element from a vector.
+ *
+ * \param vec Vector to query.
+ * \param idx Index of the element to get.
+ */
+#define AST_VECTOR_GET(vec, idx) ({		\
+	size_t __idx = (idx);			\
+	ast_assert(__idx < (vec)->current);	\
+	(vec)->elems[__idx];			\
+})
+
+#endif /* _ASTERISK_VECTOR_H */