diff --git a/include/asterisk/vector.h b/include/asterisk/vector.h new file mode 100644 index 0000000000000000000000000000000000000000..0053d8a32523b851c688755ae52567477917ac07 --- /dev/null +++ b/include/asterisk/vector.h @@ -0,0 +1,333 @@ +/* + * 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 */