str: preallocate " " string Since this is a relatively common string we can preallocate it and return it instead of going to the heap. One of the consumers of libjeffpc saw almost a 17% reduction in struct str allocations during startup: cache buf buf buf buf memory alloc alloc name size in use in ptc total in use succeed fail ------------------------- ------ ------- ------- ------- ------- --------- ----- str-cache (before) 24 5347 - 5577 132K 795715 0 str-cache (after) 24 5347 - 5577 132K 663036 0 Note: This consumer is a heavy user of strings. Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>

--- a/str.c	Sat Apr 15 19:31:05 2017 -0400
+++ b/str.c	Sat Apr 15 19:38:57 2017 -0400
@@ -29,7 +29,9 @@
 #include <jeffpc/jeffpc.h>
 
 static struct str empty_string = STR_STATIC_INITIALIZER("");
-static struct str one_char[128];
+static struct str one_char[128] = {
+	[' '] = STR_STATIC_INITIALIZER(" "),
+};
 
 static struct mem_cache *str_cache;