comparison: docs/Writerside/topics/hash_map.h.md
docs/Writerside/topics/hash_map.h.md
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| 1227:0bf1c1fdf1e3 | 1228:c231f6a259b5 |
|---|---|
| 1 # Hash Map | 1 # Hash Map |
| 2 | |
| 3 <warning> | |
| 4 Outdated Section - will be updated soon! | |
| 5 </warning> | |
| 6 | 2 |
| 7 UCX provides a basic hash map implementation with a configurable amount of buckets. | 3 UCX provides a basic hash map implementation with a configurable amount of buckets. |
| 8 If you do not specify the number of buckets, a default of 16 buckets will be used. | 4 If you do not specify the number of buckets, a default of 16 buckets will be used. |
| 9 You can always rehash the map with `cxMapRehash()` to change the number of buckets to something more efficient, | 5 You can always rehash the map with `cxMapRehash()` to change the number of buckets to something more efficient, |
| 10 but you need to be careful, because when you use this function you are effectively locking into using this | 6 but you need to be careful, because when you use this function you are effectively locking into using this |
| 11 specific hash map implementation, and you would need to remove all calls to this function when you want to | 7 specific hash map implementation, and you would need to remove all calls to this function when you want to |
| 12 exchange the concrete map implementation with something different. | 8 exchange the concrete map implementation with something different. |
| 13 | 9 |
| 14 <!-- | 10 ```C |
| 15 ## Undocumented Symbols (TODO) | 11 #include <cx/hash_map.h> |
| 16 ### cxHashMapCreate | 12 |
| 17 ### cxMapRehash | 13 CxMap *cxHashMapCreate(const CxAllocator *allocator, |
| 18 --> | 14 size_t itemsize, size_t buckets); |
| 15 | |
| 16 CxMap *cxHashMapCreateSimple(size_t itemsize); | |
| 17 | |
| 18 int cxMapRehash(CxMap *map); | |
| 19 ``` | |
| 20 | |
| 21 The function `cxHashMapCreate()` creates a new [map](map.h.md) where both the map structure | |
| 22 and the contained buckets are allocated by the specified `allocator`. | |
| 23 The default stdlib allocator is used in `cxHashMapCreateSimple()`. | |
| 24 | |
| 25 The map will store items of size `itemsize`. | |
| 26 You can use the `CX_STORE_POINTERS` macro for `itemsize` to indicate that the map shall store | |
| 27 pointers instead of actual items. | |
| 28 | |
| 29 If you pass zero for the number of `buckets`, or use `cxHashMapSimple()`, | |
| 30 the map is initialized with a default of 16 buckets, otherwise the specified number of buckets is allocated. | |
| 31 | |
| 32 The function `cxMapRehash()` allocates a new array of buckets and re-distributes all elements, | |
| 33 if the number of elements exceeds ¾ of the number of buckets. | |
| 34 Otherwise, no action is performed and this function simply returns 0. | |
| 35 After rehashing, the number of buckets is at least 2½ times the number of elements. | |
| 36 | |
| 37 > Advice if you want to create your own hash map structures: | |
| 38 > Calling `cxMapRehash()` on a map is only defined, when the map is based on the | |
| 39 > `struct cx_hash_map_s` structure. | |
| 19 | 40 |
| 20 <seealso> | 41 <seealso> |
| 21 <category ref="apidoc"> | 42 <category ref="apidoc"> |
| 22 <a href="https://ucx.sourceforge.io/api/hash__map_8h.html">hash_map.h</a> | 43 <a href="https://ucx.sourceforge.io/api/hash__map_8h.html">hash_map.h</a> |
| 23 </category> | 44 </category> |
