src/offmap.h

   1 /*
   2  * Copyright (C) 2012 the libgit2 contributors
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7 #ifndef INCLUDE_offmap_h__
   8 #define INCLUDE_offmap_h__
   9
  10 #include "common.h"
  11
  12 #include "git2/types.h"
  13
  14 /** A map with `off64_t`s as key. */
  15 typedef struct kh_off_s git_offmap;
  16
  17 /**
  18  * Allocate a new `off64_t` map.
  19  *
  20  * @param out Pointer to the map that shall be allocated.
  21  * @return 0 on success, an error code if allocation has failed.
  22  */
  23 int git_offmap_new(git_offmap **out);
  24
  25 /**
  26  * Free memory associated with the map.
  27  *
  28  * Note that this function will _not_ free values added to this
  29  * map.
  30  *
  31  * @param map Pointer to the map that is to be free'd. May be
  32  *            `NULL`.
  33  */
  34 void git_offmap_free(git_offmap *map);
  35
  36 /**
  37  * Clear all entries from the map.
  38  *
  39  * This function will remove all entries from the associated map.
  40  * Memory associated with it will not be released, though.
  41  *
  42  * @param map Pointer to the map that shall be cleared. May be
  43  *            `NULL`.
  44  */
  45 void git_offmap_clear(git_offmap *map);
  46
  47 /**
  48  * Return the number of elements in the map.
  49  *
  50  * @parameter map map containing the elements
  51  * @return number of elements in the map
  52  */
  53 size_t git_offmap_size(git_offmap *map);
  54
  55 /**
  56  * Return value associated with the given key.
  57  *
  58  * @param map map to search key in
  59  * @param key key to search for
  60  * @return value associated with the given key or NULL if the key was not found
  61  */
  62 void *git_offmap_get(git_offmap *map, const off64_t key);
  63
  64 /**
  65  * Set the entry for key to value.
  66  *
  67  * If the map has no corresponding entry for the given key, a new
  68  * entry will be created with the given value. If an entry exists
  69  * already, its value will be updated to match the given value.
  70  *
  71  * @param map map to create new entry in
  72  * @param key key to set
  73  * @param value value to associate the key with; may be NULL
  74  * @return zero if the key was successfully set, a negative error
  75  *         code otherwise
  76  */
  77 int git_offmap_set(git_offmap *map, const off64_t key, void *value);
  78
  79 /**
  80  * Delete an entry from the map.
  81  *
  82  * Delete the given key and its value from the map. If no such
  83  * key exists, this will do nothing.
  84  *
  85  * @param map map to delete key in
  86  * @param key key to delete
  87  * @return `0` if the key has been deleted, GIT_ENOTFOUND if no
  88  *         such key was found, a negative code in case of an
  89  *         error
  90  */
  91 int git_offmap_delete(git_offmap *map, const off64_t key);
  92
  93 /**
  94  * Check whether a key exists in the given map.
  95  *
  96  * @param map map to query for the key
  97  * @param key key to search for
  98  * @return 0 if the key has not been found, 1 otherwise
  99  */
 100 int git_offmap_exists(git_offmap *map, const off64_t key);
 101
 102 /**
 103  * Iterate over entries of the map.
 104  *
 105  * This functions allows to iterate over all key-value entries of
 106  * the map. The current position is stored in the `iter` variable
 107  * and should be initialized to `0` before the first call to this
 108  * function.
 109  *
 110  * @param map map to iterate over
 111  * @param value pointer to the variable where to store the current
 112  *            value. May be NULL.
 113  * @param iter iterator storing the current position. Initialize
 114  *             with zero previous to the first call.
 115  * @param key pointer to the variable where to store the current
 116  *            key. May be NULL.
 117  * @return `0` if the next entry was correctly retrieved.
 118  *        GIT_ITEROVER if no entries are left. A negative error
 119  *        code otherwise.
 120  */
 121 int git_offmap_iterate(void **value, git_offmap *map, size_t *iter, off64_t *key);
 122
 123 #define git_offmap_foreach(h, kvar, vvar, code) { size_t __i = 0;               \
 124         while (git_offmap_iterate((void **) &(vvar), h, &__i, &(kvar)) == 0) {  \
 125                 code;                                                           \
 126         } }
 127
 128 #define git_offmap_foreach_value(h, vvar, code) { size_t __i = 0;               \
 129         while (git_offmap_iterate((void **) &(vvar), h, &__i, NULL) == 0) {     \
 130                 code;                                                           \
 131         } }
 132
 133 #endif