Optimize git status parsing slightly.

Instead of paying for multiple function calls and any string parsing at
all, use a fast integer that can fit at least two chars inside and
compare them directly.

We also move the struct and enum declarations into the only function
that uses them.

Also make the .s buffer for the resulting string smaller. It doesn't
need 64 chars.

git.c

@@ -1,4 +1,6 @@
+#include <limits.h>
 #include <string.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <pthread.h>
@@ -104,14 +106,6 @@ void *git_thread(void *arg)
  return git_info;
 }
 
-struct statuses {
- size_t c;
- char s[64];
- char format[3];
- char prefix;
-};
-enum status_index { added, deleted, modified_unstaged, modified_staged, modified_both, untracked, status_index_n };
-
 static void *get_git_status(void *arg)
 {
  struct git_info *git_info = arg;
@@ -120,13 +114,21 @@ static void *get_git_status(void *arg)
  if (!f)
  return NULL;
 
- struct statuses g[status_index_n] = {
- [added] = { .format = "A ", .prefix = '+' },
- [deleted] = { .format = "D ", .prefix = '-' },
- [modified_unstaged] = { .format = " M", .prefix = '~' },
- [modified_staged] = { .format = "M ", .prefix = '>' },
- [modified_both] = { .format = "MM", .prefix = '~' },
- [untracked] = { .format = "??", .prefix = '+' },
+ typedef uint_fast16_t t_format;
+ #define FORMAT(s) (((t_format)(unsigned char)s[0]) | (((t_format)(unsigned char)s[1]) << CHAR_BIT))
+ enum status_index { added, deleted, modified_unstaged, modified_staged, modified_both, untracked, status_index_n };
+ struct statuses {
+ size_t c;
+ char s[32];
+ t_format format;
+ char prefix;
+ } g[status_index_n] = {
+ [added] = { .format = FORMAT("A "), .prefix = '+' },
+ [deleted] = { .format = FORMAT("D "), .prefix = '-' },
+ [modified_unstaged] = { .format = FORMAT(" M"), .prefix = '~' },
+ [modified_staged] = { .format = FORMAT("M "), .prefix = '>' },
+ [modified_both] = { .format = FORMAT("MM"), .prefix = '~' },
+ [untracked] = { .format = FORMAT("??"), .prefix = '+' },
  };
 
  char *line = NULL;
@@ -135,11 +137,12 @@ static void *get_git_status(void *arg)
  while ((l = getdelim(&line, &n, 0, f)) != -1) {
  if (l > 4) {
  for (int i = 0; i < status_index_n; i++) {
- g[i].c += !strncmp(g[i].format, line, 2);
+ g[i].c += FORMAT(line) == g[i].format;
  }
  }
  }
  free(line);
+ #undef FORMAT
 
  /* cheat to display things closer to a "userful" measure */
  g[added].c += g[modified_staged].c + g[modified_both].c;