From 13aa9c8b708dd65f32ac12f8b2faa48f5a89f07d Mon Sep 17 00:00:00 2001 From: Heba Waly Date: Sun, 17 Nov 2019 21:04:51 +0000 Subject: cache: move doc to cache.h Move the documentation from Documentation/technical/api-allocation-growing.txt to cache.h as it's easier for the developers to find the usage information beside the code instead of looking for it in another doc file. Also documentation/technical/api-allocation-growing.txt is removed because the information it has is now redundant and it'll be hard to keep it up to date and synchronized with the documentation in the header file. Signed-off-by: Heba Waly Signed-off-by: Junio C Hamano diff --git a/Documentation/MyFirstObjectWalk.txt b/Documentation/MyFirstObjectWalk.txt index 321c0ba..aa828df 100644 --- a/Documentation/MyFirstObjectWalk.txt +++ b/Documentation/MyFirstObjectWalk.txt @@ -119,9 +119,8 @@ parameters provided by the user over the CLI. `nr` represents the number of `rev_cmdline_entry` present in the array. -`alloc` is used by the `ALLOC_GROW` macro. Check -`Documentation/technical/api-allocation-growing.txt` - this variable is used to -track the allocated size of the list. +`alloc` is used by the `ALLOC_GROW` macro. Check `cache.h` - this variable is +used to track the allocated size of the list. Per entry, we find: diff --git a/Documentation/technical/api-allocation-growing.txt b/Documentation/technical/api-allocation-growing.txt deleted file mode 100644 index 5a59b54..0000000 --- a/Documentation/technical/api-allocation-growing.txt +++ /dev/null @@ -1,39 +0,0 @@ -allocation growing API -====================== - -Dynamically growing an array using realloc() is error prone and boring. - -Define your array with: - -* a pointer (`item`) that points at the array, initialized to `NULL` - (although please name the variable based on its contents, not on its - type); - -* an integer variable (`alloc`) that keeps track of how big the current - allocation is, initialized to `0`; - -* another integer variable (`nr`) to keep track of how many elements the - array currently has, initialized to `0`. - -Then before adding `n`th element to the item, call `ALLOC_GROW(item, n, -alloc)`. This ensures that the array can hold at least `n` elements by -calling `realloc(3)` and adjusting `alloc` variable. - ------------- -sometype *item; -size_t nr; -size_t alloc - -for (i = 0; i < nr; i++) - if (we like item[i] already) - return; - -/* we did not like any existing one, so add one */ -ALLOC_GROW(item, nr + 1, alloc); -item[nr++] = value you like; ------------- - -You are responsible for updating the `nr` variable. - -If you need to specify the number of elements to allocate explicitly -then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`. diff --git a/cache.h b/cache.h index 04cabaa..8fbbdf9 100644 --- a/cache.h +++ b/cache.h @@ -632,10 +632,43 @@ int daemonize(void); #define alloc_nr(x) (((x)+16)*3/2) -/* - * Realloc the buffer pointed at by variable 'x' so that it can hold - * at least 'nr' entries; the number of entries currently allocated - * is 'alloc', using the standard growing factor alloc_nr() macro. +/** + * Dynamically growing an array using realloc() is error prone and boring. + * + * Define your array with: + * + * - a pointer (`item`) that points at the array, initialized to `NULL` + * (although please name the variable based on its contents, not on its + * type); + * + * - an integer variable (`alloc`) that keeps track of how big the current + * allocation is, initialized to `0`; + * + * - another integer variable (`nr`) to keep track of how many elements the + * array currently has, initialized to `0`. + * + * Then before adding `n`th element to the item, call `ALLOC_GROW(item, n, + * alloc)`. This ensures that the array can hold at least `n` elements by + * calling `realloc(3)` and adjusting `alloc` variable. + * + * ------------ + * sometype *item; + * size_t nr; + * size_t alloc + * + * for (i = 0; i < nr; i++) + * if (we like item[i] already) + * return; + * + * // we did not like any existing one, so add one + * ALLOC_GROW(item, nr + 1, alloc); + * item[nr++] = value you like; + * ------------ + * + * You are responsible for updating the `nr` variable. + * + * If you need to specify the number of elements to allocate explicitly + * then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`. * * Consider using ALLOC_GROW_BY instead of ALLOC_GROW as it has some * added niceties. -- cgit v0.10.2-6-g49f6