patch-id.c

   1 #include "cache.h"
   2
   3 static void flush_current_id(int patchlen, unsigned char *id, SHA_CTX *c)
   4 {
   5         unsigned char result[20];
   6         char name[50];
   7
   8         if (!patchlen)
   9                 return;
  10
  11         SHA1_Final(result, c);
  12         memcpy(name, sha1_to_hex(id), 41);
  13         printf("%s %s\n", sha1_to_hex(result), name);
  14         SHA1_Init(c);
  15 }
  16
  17 static int remove_space(char *line)
  18 {
  19         char *src = line;
  20         char *dst = line;
  21         unsigned char c;
  22
  23         while ((c = *src++) != '\0') {
  24                 if (!isspace(c))
  25                         *dst++ = c;
  26         }
  27         return dst - line;
  28 }
  29
  30 static void generate_id_list(void)
  31 {
  32         static unsigned char sha1[20];
  33         static char line[1000];
  34         SHA_CTX ctx;
  35         int patchlen = 0;
  36
  37         SHA1_Init(&ctx);
  38         while (fgets(line, sizeof(line), stdin) != NULL) {
  39                 unsigned char n[20];
  40                 char *p = line;
  41                 int len;
  42
  43                 if (!memcmp(line, "diff-tree ", 10))
  44                         p += 10;
  45                 else if (!memcmp(line, "commit ", 7))
  46                         p += 7;
  47
  48                 if (!get_sha1_hex(p, n)) {
  49                         flush_current_id(patchlen, sha1, &ctx);
  50                         hashcpy(sha1, n);
  51                         patchlen = 0;
  52                         continue;
  53                 }
  54
  55                 /* Ignore commit comments */
  56                 if (!patchlen && memcmp(line, "diff ", 5))
  57                         continue;
  58
  59                 /* Ignore git-diff index header */
  60                 if (!memcmp(line, "index ", 6))
  61                         continue;
  62
  63                 /* Ignore line numbers when computing the SHA1 of the patch */
  64                 if (!memcmp(line, "@@ -", 4))
  65                         continue;
  66
  67                 /* Compute the sha without whitespace */
  68                 len = remove_space(line);
  69                 patchlen += len;
  70                 SHA1_Update(&ctx, line, len);
  71         }
  72         flush_current_id(patchlen, sha1, &ctx);
  73 }
  74
  75 static const char patch_id_usage[] = "git-patch-id < patch";
  76
  77 int main(int argc, char **argv)
  78 {
  79         if (argc != 1)
  80                 usage(patch_id_usage);
  81
  82         generate_id_list();
  83         return 0;
  84 }