Hash tables templates, take 2.
Note: this version can handle structures as entries, and it can be used without <sofia-sip/su_alloc.h>.
This file contain a hash table template for C. The hash tables are resizeable, and they usually contain pointers to entries. The declaration for template datatypes is instantiated with macro HTABLE2_DECLARE(). The prototypes for hashing functions are instantiated with macro HTABLE2_PROTOS(). The implementation is instantiated with macro HTABLE2_BODIES().
The hash table template is most efficient when the hash value is precalculated and stored in each entry. The hash "function" given to the HTABLE2_BODIES() would then be something like macro
#define HTABLE2_ENTRY_HASH(e) ((e).e_hash_value)
When a entry with new identical hash key is added to the table, it can be either inserted (before any other entry with same key value) or appended.
Example code can be found from <htable_test.c>.
Go to the source code of this file.
Defines | |
#define | HTABLE2_MIN_SIZE |
Minimum size of hash table. | |
#define | HTABLE2_DECLARE(sname, prefix, pr, entrytype) |
Declare hash table structure type. | |
#define | HTABLE2_SCOPE |
Default scope for hash table functions. | |
#define | HTABLE2_PROTOS(type, prefix, pr, entrytype) |
Prototypes for hash table. | |
#define | HTABLE2_BODIES(type, prefix, pr, entrytype,hfun, is_used, reclaim, is_equal, halloc) |
Hash table implementation. |
#define HTABLE2_BODIES | ( | type, | |||
prefix, | |||||
pr, | |||||
entrytype, | |||||
hfun, | |||||
is_used, | |||||
reclaim, | |||||
is_equal, | |||||
halloc | ) |
Hash table implementation.
The macro HTABLE2_BODIES() expands the hash table functions. The function and type names start with prefix, the field names start with pr. The entry type is entrytype. The function (or macro) name returning hash value of each entry is given as hfun.
type | hash table type | |
prefix | function prefix for hash table | |
pr | field prefix for hash table | |
entrytype | type of entry element | |
hfun | function or macro returning hash value of entry | |
is_used | function or macro returning true if entry is occupied | |
reclaim | function or macro zeroing entry | |
is_equal | equality test | |
halloc | function allocating or freeing memory |
#define HTABLE2_DECLARE | ( | sname, | |||
prefix, | |||||
pr, | |||||
entrytype | ) |
Declare hash table structure type.
The macro HTABLE2_DECLARE() expands to a declaration for hash table structure. The its typedef will be prefix_t
, the field names start with pr. The entry type is entrytype.
sname | name of struct | |
prefix | hash table type and function prefix | |
pr | hash table field prefix | |
entrytype | entry type |
#define HTABLE2_PROTOS | ( | type, | |||
prefix, | |||||
pr, | |||||
entrytype | ) |
Prototypes for hash table.
The macro HTABLE2_PROTOS() expands to the prototypes of hash table functions. The function and type names start with prefix, the field names start with pr. The entry type is entrytype.
type | hash table typedef | |
prefix | function prefix | |
pr | hash table field prefix | |
entrytype | entry type |
#define HTABLE2_SCOPE |
Default scope for hash table functions.