@matheusbsbs / matheus-bagliano / commits / b70c82e6ed

strmap: add more utility functions

This adds a number of additional convienence functions I want/need: * strmap_get_size() * strmap_empty() * strmap_remove() * strmap_for_each_entry() * strmap_get_entry() I suspect the first four are self-explanatory. strmap_get_entry() is similar to strmap_get() except that instead of just returning the void* value that the string maps to, it returns the strmap_entry that contains both the string and the void* value (or NULL if the string isn't in the map). This is helpful because it avoids multiple lookups, e.g. in some cases a caller would need to call: * strmap_contains() to check that the map has an entry for the string * strmap_get() to get the void* value * <do some work to update the value> * strmap_put() to update/overwrite the value If the void* pointer returned really is a pointer, then the last step is unnecessary, but if the void* pointer is just cast to an integer then strmap_put() will be needed. In contrast, one can call strmap_get_entry() and then: * check if the string was in the map by whether the pointer is NULL * access the value via entry->value * directly update entry->value meaning that we can replace two or three hash table lookups with one. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Elijah Newren committed Nov 5, 2020 at 00:22 UTC b70c82e6edd33aa03afecd52b0265cf1d9762e1b
2 files changed +54
strmap.c
+20
@@ -87,6 +87,11 @@ void *strmap_put(struct strmap *map, const char *str, void *data)
87 return old;
88 }
89
90 +struct strmap_entry *strmap_get_entry(struct strmap *map, const char *str)
91 +{
92 + return find_strmap_entry(map, str);
93 +}
94 +
95 void *strmap_get(struct strmap *map, const char *str)
96 {
97 struct strmap_entry *entry = find_strmap_entry(map, str);
@@ -97,3 +102,18 @@ int strmap_contains(struct strmap *map, const char *str)
102 {
103 return find_strmap_entry(map, str) != NULL;
104 }
105 +
106 +void strmap_remove(struct strmap *map, const char *str, int free_value)
107 +{
108 + struct strmap_entry entry, *ret;
109 + hashmap_entry_init(&entry.ent, strhash(str));
110 + entry.key = str;
111 + ret = hashmap_remove_entry(&map->map, &entry, ent, NULL);
112 + if (!ret)
113 + return;
114 + if (free_value)
115 + free(ret->value);
116 + if (map->strdup_strings)
117 + free((char*)ret->key);
118 + free(ret);
119 +}
strmap.h
+34
@@ -50,6 +50,12 @@ void strmap_clear(struct strmap *map, int free_values);
50 */
51 void *strmap_put(struct strmap *map, const char *str, void *data);
52
53 +/*
54 + * Return the strmap_entry mapped by "str", or NULL if there is not such
55 + * an item in map.
56 + */
57 +struct strmap_entry *strmap_get_entry(struct strmap *map, const char *str);
58 +
59 /*
60 * Return the data pointer mapped by "str", or NULL if the entry does not
61 * exist.
@@ -62,4 +68,32 @@ void *strmap_get(struct strmap *map, const char *str);
68 */
69 int strmap_contains(struct strmap *map, const char *str);
70
71 +/*
72 + * Remove the given entry from the strmap. If the string isn't in the
73 + * strmap, the map is not altered.
74 + */
75 +void strmap_remove(struct strmap *map, const char *str, int free_value);
76 +
77 +/*
78 + * Return how many entries the strmap has.
79 + */
80 +static inline unsigned int strmap_get_size(struct strmap *map)
81 +{
82 + return hashmap_get_size(&map->map);
83 +}
84 +
85 +/*
86 + * Return whether the strmap is empty.
87 + */
88 +static inline int strmap_empty(struct strmap *map)
89 +{
90 + return strmap_get_size(map) == 0;
91 +}
92 +
93 +/*
94 + * iterate through @map using @iter, @var is a pointer to a type strmap_entry
95 + */
96 +#define strmap_for_each_entry(mystrmap, iter, var) \
97 + hashmap_for_each_entry(&(mystrmap)->map, iter, var, ent)
98 +
99 #endif /* STRMAP_H */