diff options
author | Calvin Wan <calvinwan@google.com> | 2023-07-05 20:09:24 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2023-07-05 21:42:31 +0300 |
commit | 91c080dff511b7a81f91d1cc79589b49e16a2b7a (patch) | |
tree | 5730d26a094848ca2f652c507ce54519b981ef84 /alloc.h | |
parent | da9502ff4dc495471a1a080dc297cd6e4628c10c (diff) |
git-compat-util: move alloc macros to git-compat-util.h
alloc_nr, ALLOC_GROW, and ALLOC_GROW_BY are commonly used macros for
dynamic array allocation. Moving these macros to git-compat-util.h with
the other alloc macros focuses alloc.[ch] to allocation for Git objects
and additionally allows us to remove inclusions to alloc.h from files
that solely used the above macros.
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'alloc.h')
-rw-r--r-- | alloc.h | 75 |
1 files changed, 0 insertions, 75 deletions
@@ -17,79 +17,4 @@ void *alloc_object_node(struct repository *r); struct alloc_state *allocate_alloc_state(void); void clear_alloc_state(struct alloc_state *s); -#define alloc_nr(x) (((x)+16)*3/2) - -/** - * 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. - * - * DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'. - */ -#define ALLOC_GROW(x, nr, alloc) \ - do { \ - if ((nr) > alloc) { \ - if (alloc_nr(alloc) < (nr)) \ - alloc = (nr); \ - else \ - alloc = alloc_nr(alloc); \ - REALLOC_ARRAY(x, alloc); \ - } \ - } while (0) - -/* - * Similar to ALLOC_GROW but handles updating of the nr value and - * zeroing the bytes of the newly-grown array elements. - * - * DO NOT USE any expression with side-effect for any of the - * arguments. - */ -#define ALLOC_GROW_BY(x, nr, increase, alloc) \ - do { \ - if (increase) { \ - size_t new_nr = nr + (increase); \ - if (new_nr < nr) \ - BUG("negative growth in ALLOC_GROW_BY"); \ - ALLOC_GROW(x, new_nr, alloc); \ - memset((x) + nr, 0, sizeof(*(x)) * (increase)); \ - nr = new_nr; \ - } \ - } while (0) - #endif |