vector.h

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * David M. Lee, II <[email protected]>
 *
 * 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

#include "asterisk/lock.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 <[email protected]>
 * \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 Integer vector definition */
AST_VECTOR(ast_vector_int, int);

/*! \brief String vector definitions */
AST_VECTOR(ast_vector_string, char *);
AST_VECTOR(ast_vector_const_string, const char *);

/*! Options to override default processing of ast_vector_string_split. */
enum ast_vector_string_split_flags {
   /*! Do not trim whitespace from values. */
   AST_VECTOR_STRING_SPLIT_NO_TRIM = 0x01,
   /*! Append empty strings to the vector. */
   AST_VECTOR_STRING_SPLIT_ALLOW_EMPTY = 0x02,
};

/*!
 * \brief Append a string vector by splitting a string.
 *
 * \param dest Pointer to an initialized vector.
 * \param input String buffer to split.
 * \param delim String delimeter passed to strsep.
 * \param flags Processing options defined by \ref enum ast_vector_string_split_flags.
 * \param excludes_cmp NULL or a function like strcmp to exclude duplicate strings.
 *
 * \retval 0 Success
 * \retval -1 Failure
 *
 * \note All elements added to the vector are allocated.  The caller is always
 *       responsible for calling ast_free on each element in the vector even
 *       after failure.  It's possible for this function to successfully add
 *       some elements before failing.
 */
int ast_vector_string_split(struct ast_vector_string *dest,
   const char *input, const char *delim, int flags,
   int (*excludes_cmp)(const char *s1, const char *s2));

/*!
 * \brief Define a vector structure with a read/write lock
 *
 * \param name Optional vector struct name.
 * \param type Vector element type.
 */
#define AST_VECTOR_RW(name, type) \
   struct name {            \
      type *elems;         \
      size_t max;          \
      size_t current;      \
      ast_rwlock_t lock;   \
   }

/*!
 * \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 Steal the elements from a vector and reinitialize.
 *
 * \param vec Vector to operate on.
 *
 * This allows you to use vector.h to construct a list and use the
 * data as a bare array.
 *
 * \note The stolen array must eventually be released using ast_free.
 *
 * \warning AST_VECTOR_SIZE and AST_VECTOR_MAX_SIZE are both reset
 *          to 0.  If either are needed they must be saved to a local
 *          variable before stealing the elements.
 */
#define AST_VECTOR_STEAL_ELEMENTS(vec) ({ \
   typeof((vec)->elems) __elems = (vec)->elems; \
   AST_VECTOR_INIT((vec), 0); \
   (__elems); \
})

/*!
 * \brief Initialize a vector with a read/write lock
 *
 * 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_RW_INIT(vec, size) ({ \
   int res = -1; \
   if (AST_VECTOR_INIT(vec, size) == 0) { \
      res = ast_rwlock_init(&(vec)->lock); \
   } \
   res; \
})

/*!
 * \brief Deallocates this vector.
 *
 * If any code to free the elements of this vector needs 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 Deallocates this vector pointer.
 *
 * If any code to free the elements of this vector need to be run, that should
 * be done prior to this call.
 *
 * \param vec Pointer to a malloc'd vector structure.
 */
#define AST_VECTOR_PTR_FREE(vec) do { \
   AST_VECTOR_FREE(vec); \
   ast_free(vec); \
} while (0)

/*!
 * \brief Deallocates this locked 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_RW_FREE(vec) do { \
   AST_VECTOR_FREE(vec); \
   ast_rwlock_destroy(&(vec)->lock); \
} while(0)

/*!
 * \brief Deallocates this locked vector pointer.
 *
 * If any code to free the elements of this vector need to be run, that should
 * be done prior to this call.
 *
 * \param vec Pointer to a malloc'd vector structure.
 */
#define AST_VECTOR_RW_PTR_FREE(vec) do { \
   AST_VECTOR_RW_FREE(vec); \
   ast_free(vec); \
} while(0)

/*!
 * \internal
 */
#define __make_room(idx, vec) ({ \
   int res = 0;                        \
   do {                                         \
      if ((idx) >= (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) {                          \
            if ((vec)->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;                                 \
         }                                      \
      }                                         \
   } while(0);                                     \
   res;                                         \
})

/*!
 * \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 (__make_room((vec)->current, vec) != 0) {       \
         res = -1;                              \
         break;                                 \
      }                                      \
      (vec)->elems[(vec)->current++] = (elem);        \
   } while (0);                                 \
   res;                                      \
})

/*!
 * \brief Replace an element at a specific position in a vector, growing the vector if needed.
 *
 * \param vec Vector to replace into.
 * \param idx Position to replace.
 * \param elem Element to replace.
 *
 * \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_REPLACE(vec, idx, elem) ({      \
   int res = 0;                           \
   do {                                \
      if (__make_room((idx), vec) != 0) {       \
         res = -1;                        \
         break;                           \
      }                                \
      (vec)->elems[(idx)] = (elem);          \
      if (((idx) + 1) > (vec)->current) {       \
         (vec)->current = (idx) + 1;            \
      }                                \
   } while(0);                            \
   res;                                \
})

/*!
 * \brief Default a vector up to size with the given value.
 *
 * \note If a size of 0 is given then all elements in the given vector are set.
 * \note The vector will grow to the given size if needed.
 *
 * \param vec Vector to default.
 * \param size The number of elements to default
 * \param value The default value to set each element to
 */
#define AST_VECTOR_DEFAULT(vec, size, value) ({ \
   int res = 0;                     \
   typeof((size)) __size = (size) ? (size) : AST_VECTOR_SIZE(vec);   \
   size_t idx;                   \
   for (idx = 0; idx < __size; ++idx) {            \
      res = AST_VECTOR_REPLACE(vec, idx, value);      \
      if (res == -1) {              \
         break;                  \
      }                    \
   }                       \
   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 shift existing elements right to make room for the new element.
 *
 * \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_AT(vec, idx, elem) ({ \
   int res = 0; \
   size_t __move; \
   do { \
      if (__make_room(((idx) > (vec)->current ? (idx) : (vec)->current), vec) != 0) {                    \
         res = -1;                              \
         break;                                 \
      }                                         \
      if ((vec)->current > 0 && (idx) < (vec)->current) { \
         __move = ((vec)->current - (idx)) * sizeof(typeof((vec)->elems[0])); \
         memmove(&(vec)->elems[(idx) + 1], &(vec)->elems[(idx)], __move); \
      } \
      (vec)->elems[(idx)] = (elem); \
      (vec)->current = ((idx) > (vec)->current ? (idx) : (vec)->current) + 1; \
   } while (0); \
   res; \
})

/*!
 * \brief Add an element into a sorted vector
 *
 * \param vec Sorted vector to add to.
 * \param elem Element to insert. Must not be an array type.
 * \param cmp A strcmp compatible compare function.
 *
 * \return 0 on success.
 * \return Non-zero on failure.
 *
 * \warning Use of this macro on an unsorted vector will produce unpredictable results
 * \warning 'elem' must not be an array type so passing 'x' where 'x' is defined as
 *          'char x[4]' will fail to compile. However casting 'x' as 'char *' does
 *          result in a value that CAN be used.
 */
#define AST_VECTOR_ADD_SORTED(vec, elem, cmp) ({ \
   int res = 0; \
   size_t __idx = (vec)->current; \
   typeof(elem) __elem = (elem); \
   do { \
      if (__make_room((vec)->current, vec) != 0) { \
         res = -1; \
         break; \
      } \
      while (__idx > 0 && (cmp((vec)->elems[__idx - 1], __elem) > 0)) { \
         (vec)->elems[__idx] = (vec)->elems[__idx - 1]; \
         __idx--; \
      } \
      (vec)->elems[__idx] = __elem; \
      (vec)->current++; \
   } while (0); \
   res; \
})

/*!
 * \brief Sort a vector in-place
 *
 * \param vec Vector to sort
 * \param cmp A memcmp compatible compare function
 */
#define AST_VECTOR_SORT(vec, cmp) ({ \
   qsort((vec)->elems, (vec)->current, sizeof(typeof((vec)->elems[0])), cmp); \
})

/*!
 * \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.
 * \param preserve_order Preserve the vector order.
 *
 * \return The element that was removed.
 */
#define AST_VECTOR_REMOVE(vec, idx, preserve_ordered) ({ \
   typeof((vec)->elems[0]) res; \
   size_t __idx = (idx); \
   ast_assert(__idx < (vec)->current); \
   res = (vec)->elems[__idx]; \
   if ((preserve_ordered)) { \
      size_t __move; \
      __move = ((vec)->current - (__idx) - 1) * sizeof(typeof((vec)->elems[0])); \
      memmove(&(vec)->elems[__idx], &(vec)->elems[__idx + 1], __move); \
      (vec)->current--; \
   } else { \
      (vec)->elems[__idx] = (vec)->elems[--(vec)->current]; \
   }; \
   res;                    \
})

/*!
 * \brief Remove an element from an unordered 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) \
   AST_VECTOR_REMOVE(vec, idx, 0)

/*!
 * \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) \
   AST_VECTOR_REMOVE(vec, idx, 1)

/*!
 * \brief Remove all elements 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 the number of deleted elements.
 */
#define AST_VECTOR_REMOVE_ALL_CMP_UNORDERED(vec, value, cmp, cleanup) ({   \
   int count = 0;                   \
   size_t idx;                   \
   typeof(value) __value = (value);          \
   for (idx = 0; idx < (vec)->current; ) {            \
      if (cmp((vec)->elems[idx], __value)) {       \
         cleanup((vec)->elems[idx]);         \
         AST_VECTOR_REMOVE_UNORDERED((vec), idx);  \
         ++count;             \
      } else {                \
         ++idx;                  \
      }                    \
   }                       \
   count;                        \
})

/*!
 * \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 all elements 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 the number of deleted elements.
 */
#define AST_VECTOR_REMOVE_ALL_CMP_ORDERED(vec, value, cmp, cleanup) ({  \
   int count = 0;                   \
   size_t idx;                   \
   typeof(value) __value = (value);          \
   for (idx = 0; idx < (vec)->current; ) {            \
      if (cmp((vec)->elems[idx], __value)) {       \
         cleanup((vec)->elems[idx]);         \
         AST_VECTOR_REMOVE_ORDERED((vec), idx);    \
         ++count;             \
      } else {                \
         ++idx;                  \
      }                    \
   }                       \
   count;                        \
})

/*!
 * \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 the maximum number of elements the vector can currently hold.
 *
 * \param vec Vector to query.
 * \return Maximum number of elements the vector can currently hold.
 */
#define AST_VECTOR_MAX_SIZE(vec) (vec)->max

/*!
 * \brief Reset vector.
 *
 * \param vec Vector to reset.
 * \param callback A cleanup callback or AST_VECTOR_ELEM_CLEANUP_NOOP.
 */
#define AST_VECTOR_RESET(vec, cleanup) ({ \
   AST_VECTOR_CALLBACK_VOID(vec, cleanup); \
   (vec)->current = 0; \
})

/*!
 * \brief Resize a vector so that its capacity is the same as its size.
 *
 * \param vec Vector to compact.
 *
 * \return 0 on success.
 * \return Non-zero on failure.
 */
#define AST_VECTOR_COMPACT(vec) ({              \
   int res = 0;                     \
   do {                       \
      size_t new_max = (vec)->current;       \
      if (new_max == 0) {              \
         ast_free((vec)->elems);          \
         (vec)->elems = NULL;          \
         (vec)->max = 0;               \
      } else if ((vec)->max > new_max) {        \
         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;               \
         }                 \
      }                    \
   } while(0);                   \
   res;                       \
})

/*!
 * \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];       \
})

/*!
 * \brief Get the nth index from a vector that matches the given comparison
 *
 * \param vec Vector to get from.
 * \param nth The nth index to find
 * \param value Value to pass into comparator.
 * \param cmp Comparator function/macros (called as \c cmp(elem, value))
 *
 * \return a pointer to the element that was found or NULL
 */
#define AST_VECTOR_GET_INDEX_NTH(vec, nth, value, cmp) ({ \
   int res = -1; \
   size_t idx; \
   typeof(nth) __nth = (nth); \
   typeof(value) __value = (value); \
   for (idx = 0; idx < (vec)->current; ++idx) { \
      if (cmp((vec)->elems[idx], __value) && !(--__nth)) {  \
         res = (int)idx;               \
         break; \
      } \
   } \
   res; \
})

/*!
 * \brief Get the 1st index from a vector that matches the given comparison
 *
 * \param vec Vector to get from.
 * \param value Value to pass into comparator.
 * \param cmp Comparator function/macros (called as \c cmp(elem, value))
 *
 * \return a pointer to the element that was found or NULL
 */
#define AST_VECTOR_GET_INDEX(vec, value, cmp) \
   AST_VECTOR_GET_INDEX_NTH(vec, 1, value, cmp)

/*!
 * \brief Get an element from a vector that matches the given comparison
 *
 * \param vec Vector to get from.
 * \param value Value to pass into comparator.
 * \param cmp Comparator function/macros (called as \c cmp(elem, value))
 *
 * \return a pointer to the element that was found or NULL
 */
#define AST_VECTOR_GET_CMP(vec, value, cmp) ({ \
   void *res = NULL; \
   size_t idx; \
   typeof(value) __value = (value); \
   for (idx = 0; idx < (vec)->current; ++idx) { \
      if (cmp((vec)->elems[idx], __value)) { \
         res = &(vec)->elems[idx]; \
         break; \
      } \
   } \
   res; \
})

/*!
 * \brief Default callback for AST_VECTOR_CALLBACK()
 *
 * \param elem Element to compare against
 * \param value Value to compare with the vector element.
 *
 * \return CMP_MATCH always.
 */
#define AST_VECTOR_MATCH_ALL(element) (CMP_MATCH)


/*!
 * \brief Execute a callback on every element in a vector returning the first matched
 *
 * \param vec Vector to operate on.
 * \param callback A callback that takes at least 1 argument (the element)
 * plus number of optional arguments
 * \param default_value A default value to return if no elements matched
 *
 * \return the first element matched before CMP_STOP was returned
 * or the end of the vector was reached. Otherwise, default_value
 */
#define AST_VECTOR_CALLBACK(vec, callback, default_value, ...) ({ \
   size_t idx; \
   typeof((vec)->elems[0]) res = default_value;          \
   for (idx = 0; idx < (vec)->current; idx++) { \
      int rc = callback((vec)->elems[idx], ##__VA_ARGS__);  \
      if (rc & CMP_MATCH) { \
         res = (vec)->elems[idx]; \
         break; \
      }\
      if (rc & CMP_STOP) { \
         break; \
      }\
   } \
   res; \
})

/*!
 * \brief Execute a callback on every element in a vector returning the matching
 * elements in a new vector
 *
 * This macro basically provides a filtered clone.
 *
 * \param vec Vector to operate on.
 * \param callback A callback that takes at least 1 argument (the element)
 * plus number of optional arguments
 *
 * \return a vector containing the elements matched before CMP_STOP was returned
 * or the end of the vector was reached. The vector may be empty and could be NULL
 * if there was not enough memory to allocate it's control structure.
 *
 * \warning The returned vector must have AST_VECTOR_PTR_FREE()
 * called on it after you've finished with it.
 *
 * \note The type of the returned vector must be traceable to the original vector.
 *
 * The following will resut in "error: assignment from incompatible pointer type"
 * because these declare 2 different structures.
 *
 * \code
 * AST_VECTOR(, char *) vector_1;
 * AST_VECTOR(, char *) *vector_2;
 *
 * vector_2 = AST_VECTOR_CALLBACK_MULTIPLE(&vector_1, callback);
 * \endcode
 *
 * This will work because you're using the type of the first
 * to declare the second:
 *
 * \code
 * AST_VECTOR(mytype, char *) vector_1;
 * struct mytype *vector_2 = NULL;
 *
 * vector_2 = AST_VECTOR_CALLBACK_MULTIPLE(&vector_1, callback);
 * \endcode
 *
 * This will also work because you're declaring both vector_1 and
 * vector_2 from the same definition.
 *
 * \code
 * AST_VECTOR(, char *) vector_1, *vector_2 = NULL;
 *
 * vector_2 = AST_VECTOR_CALLBACK_MULTIPLE(&vector_1, callback);
 * \endcode
 */
#define AST_VECTOR_CALLBACK_MULTIPLE(vec, callback, ...) ({ \
   size_t idx; \
   typeof((vec)) new_vec; \
   do { \
      new_vec = ast_malloc(sizeof(*new_vec)); \
      if (!new_vec) { \
         break; \
      } \
      if (AST_VECTOR_INIT(new_vec, AST_VECTOR_SIZE((vec))) != 0) { \
         ast_free(new_vec); \
         new_vec = NULL; \
         break; \
      } \
      for (idx = 0; idx < (vec)->current; idx++) { \
         int rc = callback((vec)->elems[idx], ##__VA_ARGS__);  \
         if (rc & CMP_MATCH) { \
            AST_VECTOR_APPEND(new_vec, (vec)->elems[idx]); \
         } \
         if (rc & CMP_STOP) { \
            break; \
         }\
      } \
   } while(0); \
   new_vec; \
})

/*!
 * \brief Execute a callback on every element in a vector disregarding callback return
 *
 * \param vec Vector to operate on.
 * \param callback A callback that takes at least 1 argument (the element)
 * plus number of optional arguments
 */
#define AST_VECTOR_CALLBACK_VOID(vec, callback, ...) ({ \
   size_t idx; \
   for (idx = 0; idx < (vec)->current; idx++) { \
      callback((vec)->elems[idx], ##__VA_ARGS__);  \
   } \
})

/*!
 * \brief Obtain read lock on vector
 *
 * \param vec Vector to operate on.
 *
 * \return 0 if success
 * \return Non-zero if error
 */
#define AST_VECTOR_RW_RDLOCK(vec) ast_rwlock_rdlock(&(vec)->lock)

/*!
 * \brief Obtain write lock on vector
 *
 * \param vec Vector to operate on.
 *
 * \return 0 if success
 * \return Non-zero if error
 */
#define AST_VECTOR_RW_WRLOCK(vec) ast_rwlock_wrlock(&(vec)->lock)

/*!
 * \brief Unlock vector
 *
 * \param vec Vector to operate on.
 *
 * \return 0 if success
 * \return Non-zero if error
 */
#define AST_VECTOR_RW_UNLOCK(vec) ast_rwlock_unlock(&(vec)->lock)

/*!
 * \brief Try to obtain read lock on vector failing immediately if unable
 *
 * \param vec Vector to operate on.
 *
 * \return 0 if success
 * \return Non-zero if error
 */
#define AST_VECTOR_RW_RDLOCK_TRY(vec) ast_rwlock_tryrdlock(&(vec)->lock)

/*!
 * \brief Try to obtain write lock on vector failing immediately if unable
 *
 * \param vec Vector to operate on.
 *
 * \return 0 if success
 * \return Non-zero if error
 */
#define AST_VECTOR_RW_WRLOCK_TRY(vec) ast_rwlock_trywrlock(&(vec)->lock)

/*!
 * \brief Try to obtain read lock on vector failing after timeout if unable
 *
 * \param vec Vector to operate on.
 *
 * \return 0 if success
 * \return Non-zero if error
 */
#define AST_VECTOR_RW_RDLOCK_TIMED(vec, timespec) ast_rwlock_timedrdlock(&(vec)->lock, timespec)

/*!
 * \brief Try to obtain write lock on vector failing after timeout if unable
 *
 * \param vec Vector to operate on.
 *
 * \return 0 if success
 * \return Non-zero if error
 */
#define AST_VECTOR_RW_WRLOCK_TIMED(vec, timespec) ast_rwlock_timedwrlock(&(vec)->lock, timespec)

#endif /* _ASTERISK_VECTOR_H */