From 5576a5044f596fa7508f1cd0d20a7135772ac3e1 Mon Sep 17 00:00:00 2001 From: Sean Barrett Date: Sat, 31 May 2014 12:12:34 -0700 Subject: [PATCH] initial check-in --- stretchy_buffer.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 stretchy_buffer.h diff --git a/stretchy_buffer.h b/stretchy_buffer.h new file mode 100644 index 0000000..fd76e59 --- /dev/null +++ b/stretchy_buffer.h @@ -0,0 +1,28 @@ +// stretchy buffer // init: NULL // free: sbfree() // push_back: sbpush() // size: sbcount() // +#define stbcg_sbfree(a) ((a) ? free(stb__sbraw(a)),0 : 0) +#define stbcg_sbpush(a,v) (stb__sbmaybegrow(a,1), (a)[stb__sbn(a)++] = (v)) +#define stbcg_sbcount(a) ((a) ? stb__sbn(a) : 0) +#define stbcg_sbadd(a,n) (stb__sbmaybegrow(a,n), stb__sbn(a)+=(n), &(a)[stb__sbn(a)-(n)]) +#define stbcg_sblast(a) ((a)[stb__sbn(a)-1]) + +#include +#define stb__sbraw(a) ((int *) (a) - 2) +#define stb__sbm(a) stb__sbraw(a)[0] +#define stb__sbn(a) stb__sbraw(a)[1] + +#define stb__sbneedgrow(a,n) ((a)==0 || stb__sbn(a)+n >= stb__sbm(a)) +#define stb__sbmaybegrow(a,n) (stb__sbneedgrow(a,(n)) ? stb__sbgrow(a,n) : 0) +#define stb__sbgrow(a,n) stb__sbgrowf((void **) &(a), (n), sizeof(*(a))) + +static void stb__sbgrowf(void **arr, int increment, int itemsize) +{ + int d = *arr ? 2*stb__sbm(*arr) : 0, n2 = stbcg_sbcount(*arr) + increment; + int m = d > n2 ? d : n2; + void *p = realloc(*arr ? stb__sbraw(*arr) : 0, itemsize * m + sizeof(int)*2); + assert(p); + if (p) { + if (!*arr) ((int *) p)[1] = 0; + *arr = (void *) ((int *) p + 2); + stb__sbm(*arr) = m; + } +}