patch-id.c

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