Data Structures | |
| struct | cuflowP_cachebin |
| struct | cuflow_cache |
| struct | cuflowP_cacheobjhdr |
| struct | cuflow_cacheobj |
Defines | |
| #define | CUFLOWP_CACHE_LOG2_BIN_COUNT 5 |
| #define | CUFLOWP_CACHE_BIN_COUNT (1 << CUFLOWP_CACHE_LOG2_BIN_COUNT) |
| #define | CUFLOW_FNCODE(index, key_wsize) (((index) << 16) + (key_wsize)) |
| #define | CUFLOW_FNCODE_KEY_SIZEW(code) ((code) & 0xffff) |
| #define | CUFLOW_FNCODE_SLOT(code) ((code) >> 16) |
| #define | CUFLOWP_CACHEOBJ_HDR(obj) ((cuflowP_cacheobjhdr_t)(obj) - 1) |
| #define | cuflow_cached_edcl(NAME, key_struct, value_struct) |
| #define | cuflow_cached_fncode(NAME) CUFLOW_FNCODE(NAME##_index, sizeof(NAME##_key_t)/sizeof(cu_word_t)); |
| #define | cuflow_cached_edef(NAME) NAME##_obj_t *NAME##_fn(NAME##_key_t *key) |
| #define | cuflow_cached_new(NAME, extra_size) |
Typedefs | |
| typedef struct cuflowP_cachebin * | cuflowP_cachebin_t |
| typedef struct cuflow_cache * | cuflow_cache_t |
|
typedef struct cuflowP_cacheobjhdr * | cuflowP_cacheobjhdr_t |
| typedef struct cuflow_cacheobj * | cuflow_cacheobj_t |
Functions | |
| void | cuflow_cache_init (cuflow_cache_t cache, cuflow_cacheconf_t conf, cuflow_cacheobj_t(**fn_arr)(cuflow_cacheobj_t key)) |
| void | cuflow_cache_deinit (cuflow_cache_t cache) |
| cuflow_cacheobj_t | cuflow_cacheobj_alloc (size_t full_size, cuflow_cacheobj_t key) |
| void | cuflow_cacheobj_set_gain (cuflow_cacheobj_t obj, float gain) |
| cuflow_cacheobj_t | cuflow_cache_call (cuflow_cache_t cache, cu_word_t fncode, cuflow_cacheobj_t key) |
| #define cuflow_cached_edcl | ( | NAME, | |||
| key_struct, | |||||
| value_struct | ) |
struct NAME##_key \ { \ cu_inherit (cuflow_cacheobj); \ cuPP_splice key_struct \ }; \ struct NAME##_obj \ { \ struct NAME##_key key; \ cuPP_splice value_struct \ }; \ typedef struct NAME##_key NAME##_key_t; \ typedef struct NAME##_obj NAME##_obj_t
Template macro for creating the type definitions of a cached function, suited for use with the cuflow_cachetab command. NAME is the function name to be passed as the first argument of the CACHENAME_call macro that is generated by cuflow_cachetab -p CACHENAME ....
| #define cuflow_cached_edef | ( | NAME | ) | NAME##_obj_t *NAME##_fn(NAME##_key_t *key) |
This is the template for the prototype of the definition of the NAME cached function. This should be followed by a function body surrounded by { }, which receives a parameter key. The function body shall return an object allocated with cuflow_cached_new and tagged with cuflow_cacheobj_set_gain. A previous cuflow_cached_edcl must be issued.
| #define cuflow_cached_fncode | ( | NAME | ) | CUFLOW_FNCODE(NAME##_index, sizeof(NAME##_key_t)/sizeof(cu_word_t)); |
When cache header generated by cuflow_cachetab is included, this gives the function index of NAME.
| #define cuflow_cached_new | ( | NAME, | |||
| extra_size | ) |
((NAME##_obj_t *) \
cuflow_cacheobj_alloc(sizeof(struct NAME##_obj) + (extra_size), \
(cuflow_cacheobj_t)(key)))
Allocate an object suitable for returning from the cache function with name NAME. The returned value is a struct containing the members declared in the value_struct parameter of the corresponding cuflow_cached_edcl. If extra_size is not 0, this number of extra bytes will be allocated after the value_struct fields.
| #define CUFLOW_FNCODE | ( | index, | |||
| key_wsize | ) | (((index) << 16) + (key_wsize)) |
Returns a function code identifying slot number index in a cache which takes a key of key_wsize words size.
| #define CUFLOW_FNCODE_KEY_SIZEW | ( | code | ) | ((code) & 0xffff) |
The key size in words of code.
| cuflow_cacheobj_t cuflow_cache_call | ( | cuflow_cache_t | cache, | |
| cu_word_t | fncode, | |||
| cuflow_cacheobj_t | key | |||
| ) |
Return the computed object with key-part equal to key. key may be a stack object or static storage. The callback and key size is determined from fncode. The callback is only called if cache does not already contain the requested object.
| void cuflow_cache_deinit | ( | cuflow_cache_t | cache | ) |
Unlink cache from it's configuration.
| void cuflow_cache_init | ( | cuflow_cache_t | cache, | |
| cuflow_cacheconf_t | conf, | |||
| cuflow_cacheobj_t(**)(cuflow_cacheobj_t key) | fn_arr | |||
| ) |
Creates a cache with a unique set of callbacks stored in fn_arr. Normally a cache is called at program initialisation and kept for the lifetime of the program, but if you want to despose of a cache, call cuflow_cache_deinit, since cache will be linked into conf.
| cuflow_cacheobj_t cuflow_cacheobj_alloc | ( | size_t | full_size, | |
| cuflow_cacheobj_t | key | |||
| ) |
Return a pointer into the data area of a newly allocated cache object. The cache callbacks must use this to allocate objects and must call cuflow_cacheobj_set_gain before returning them.
| void cuflow_cacheobj_set_gain | ( | cuflow_cacheobj_t | obj, | |
| float | gain | |||
| ) |
Set the gain of obj to gain. The gain is an estimate of C/S where C is the cost of computing the retured object in CPU cycles, and S is the size of the returned object in bytes including a fixed overhead of about 5 words. The C may include cost of using other resources multiplied with suitable constants to make them cycle-equivanent according to the desired resource utilization.
These quastities are hard to determine precisely. Available CPU clocks are typically not precise enough to measure C, and computing S may be expensive for tree-structures or even ambiguous when sharing is involved. Therefore, rule of thumb estimates will have to do. Some suggestions: