From 3ac22f82edec108986b2627fcd6f2a8039617a23 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ren=C3=A9=20Scharfe?= Date: Tue, 16 Sep 2014 20:56:48 +0200 Subject: [PATCH] add macro REALLOC_ARRAY The macro ALLOC_GROW manages several aspects of dynamic memory allocations for arrays: It performs overprovisioning in order to avoid reallocations in future calls, updates the allocation size variable, multiplies the item size and thus allows users to simply specify the item count, performs the reallocation and updates the array pointer. Sometimes this is too much. Add the macro REALLOC_ARRAY, which only takes care of the latter three points and allows users to specfiy the number of items the array can store. It can increase and also decrease the size. Using the macro avoid duplicating the variable name and takes care of the item sizes automatically. Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano --- Documentation/technical/api-allocation-growing.txt | 3 +++ git-compat-util.h | 2 ++ 2 files changed, 5 insertions(+) diff --git a/Documentation/technical/api-allocation-growing.txt b/Documentation/technical/api-allocation-growing.txt index 542946b1ba..5a59b54844 100644 --- a/Documentation/technical/api-allocation-growing.txt +++ b/Documentation/technical/api-allocation-growing.txt @@ -34,3 +34,6 @@ 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/git-compat-util.h b/git-compat-util.h index 4e7e3f8726..5a15b53d67 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -626,6 +626,8 @@ extern int odb_mkstemp(char *template, size_t limit, const char *pattern); extern int odb_pack_keep(char *name, size_t namesz, const unsigned char *sha1); extern char *xgetcwd(void); +#define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), (alloc) * sizeof(*(x))) + static inline size_t xsize_t(off_t len) { if (len > (size_t) len) -- 2.11.4.GIT