[PATCH] Documentation: describe short-hand used in fetch/pull.
[gitweb.git] / rev-parse.c
index 7419d18b3bff8b3fc1160095c69f6b273ae27148..43af88b5a8f4414056a1a775c9d7e1de452f06c7 100644 (file)
@@ -4,6 +4,23 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "cache.h"
+#include "commit.h"
+#include "refs.h"
+
+static char *def = NULL;
+static int no_revs = 0;
+static int single_rev = 0;
+static int revs_only = 0;
+static int do_rev_argument = 1;
+static int output_revs = 0;
+static int flags_only = 0;
+static int no_flags = 0;
+
+#define NORMAL 0
+#define REVERSED 1
+static int show_type = NORMAL;
+
+static int get_extended_sha1(char *name, unsigned char *sha1);
 
 /*
  * Some arguments are relevant "revision" arguments,
@@ -32,10 +49,241 @@ static int is_rev_argument(const char *arg)
        }
 }
 
+static void show_rev(int type, const unsigned char *sha1)
+{
+       if (no_revs)
+               return;
+       output_revs++;
+       printf("%s%s\n", type == show_type ? "" : "^", sha1_to_hex(sha1));
+}
+
+static void show_rev_arg(char *rev)
+{
+       if (no_revs)
+               return;
+       puts(rev);
+}
+
+static void show_norev(char *norev)
+{
+       if (flags_only)
+               return;
+       if (revs_only)
+               return;
+       puts(norev);
+}
+
+static void show_arg(char *arg)
+{
+       if (no_flags)
+               return;
+       if (do_rev_argument && is_rev_argument(arg))
+               show_rev_arg(arg);
+       else
+               show_norev(arg);
+}
+
+static int get_parent(char *name, unsigned char *result, int idx)
+{
+       unsigned char sha1[20];
+       int ret = get_extended_sha1(name, sha1);
+       struct commit *commit;
+       struct commit_list *p;
+
+       if (ret)
+               return ret;
+       commit = lookup_commit_reference(sha1);
+       if (!commit)
+               return -1;
+       if (parse_commit(commit))
+               return -1;
+       if (!idx) {
+               memcpy(result, commit->object.sha1, 20);
+               return 0;
+       }
+       p = commit->parents;
+       while (p) {
+               if (!--idx) {
+                       memcpy(result, p->item->object.sha1, 20);
+                       return 0;
+               }
+               p = p->next;
+       }
+       return -1;
+}
+
+static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
+{
+       static char dirname[PATH_MAX];
+       char hex[40];
+       DIR *dir;
+       int found;
+
+       snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
+       dir = opendir(dirname);
+       sprintf(hex, "%.2s", name);
+       found = 0;
+       if (dir) {
+               struct dirent *de;
+               while ((de = readdir(dir)) != NULL) {
+                       if (strlen(de->d_name) != 38)
+                               continue;
+                       if (memcmp(de->d_name, name + 2, len-2))
+                               continue;
+                       memcpy(hex + 2, de->d_name, 38);
+                       if (++found > 1)
+                               break;
+               }
+               closedir(dir);
+       }
+       if (found == 1)
+               return get_sha1_hex(hex, sha1) == 0;
+       return 0;
+}
+
+static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
+{
+       do {
+               if (*a != *b)
+                       return 0;
+               a++;
+               b++;
+               len -= 2;
+       } while (len > 1);
+       if (len)
+               if ((*a ^ *b) & 0xf0)
+                       return 0;
+       return 1;
+}
+
+static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
+{
+       struct packed_git *p;
+
+       prepare_packed_git();
+       for (p = packed_git; p; p = p->next) {
+               unsigned num = num_packed_objects(p);
+               unsigned first = 0, last = num;
+               while (first < last) {
+                       unsigned mid = (first + last) / 2;
+                       unsigned char now[20];
+                       int cmp;
+
+                       nth_packed_object_sha1(p, mid, now);
+                       cmp = memcmp(match, now, 20);
+                       if (!cmp) {
+                               first = mid;
+                               break;
+                       }
+                       if (cmp > 0) {
+                               first = mid+1;
+                               continue;
+                       }
+                       last = mid;
+               }
+               if (first < num) {
+                       unsigned char now[20], next[20];
+                       nth_packed_object_sha1(p, first, now);
+                       if (match_sha(len, match, now)) {
+                               if (nth_packed_object_sha1(p, first+1, next) || !match_sha(len, match, next)) {
+                                       memcpy(sha1, now, 20);
+                                       return 1;
+                               }
+                       }
+               }       
+       }
+       return 0;
+}
+
+static int get_short_sha1(char *name, unsigned char *sha1)
+{
+       int i;
+       char canonical[40];
+       unsigned char res[20];
+
+       memset(res, 0, 20);
+       memset(canonical, 'x', 40);
+       for (i = 0;;i++) {
+               unsigned char c = name[i];
+               unsigned char val;
+               if (!c || i > 40)
+                       break;
+               if (c >= '0' && c <= '9')
+                       val = c - '0';
+               else if (c >= 'a' && c <= 'f')
+                       val = c - 'a' + 10;
+               else if (c >= 'A' && c <='F') {
+                       val = c - 'A' + 10;
+                       c -= 'A' - 'a';
+               }
+               else
+                       return -1;
+               canonical[i] = c;
+               if (!(i & 1))
+                       val <<= 4;
+               res[i >> 1] |= val;
+       }
+       if (i < 4)
+               return -1;
+       if (find_short_object_filename(i, canonical, sha1))
+               return 0;
+       if (find_short_packed_object(i, res, sha1))
+               return 0;
+       return -1;
+}
+
+/*
+ * This is like "get_sha1()", except it allows "sha1 expressions",
+ * notably "xyz^" for "parent of xyz"
+ */
+static int get_extended_sha1(char *name, unsigned char *sha1)
+{
+       int parent, ret;
+       int len = strlen(name);
+
+       parent = 1;
+       if (len > 2 && name[len-1] >= '0' && name[len-1] <= '9') {
+               parent = name[len-1] - '0';
+               len--;
+       }
+       if (len > 1 && name[len-1] == '^') {
+               name[len-1] = 0;
+               ret = get_parent(name, sha1, parent);
+               name[len-1] = '^';
+               if (!ret)
+                       return 0;
+       }
+       ret = get_sha1(name, sha1);
+       if (!ret)
+               return 0;
+       return get_short_sha1(name, sha1);
+}
+
+static void show_default(void)
+{
+       char *s = def;
+
+       if (s) {
+               unsigned char sha1[20];
+
+               def = NULL;
+               if (!get_extended_sha1(s, sha1)) {
+                       show_rev(NORMAL, sha1);
+                       return;
+               }
+               show_arg(s);
+       }
+}
+
+static int show_reference(const char *refname, const unsigned char *sha1)
+{
+       show_rev(NORMAL, sha1);
+       return 0;
+}
+
 int main(int argc, char **argv)
 {
-       int i, as_is = 0, revs_only = 0, no_revs = 0;
-       char *def = NULL;
+       int i, as_is = 0;
        unsigned char sha1[20];
 
        for (i = 1; i < argc; i++) {
@@ -43,22 +291,17 @@ int main(int argc, char **argv)
                char *dotdot;
        
                if (as_is) {
-                       printf("%s\n", arg);
+                       show_norev(arg);
                        continue;
                }
                if (*arg == '-') {
                        if (!strcmp(arg, "--")) {
-                               if (def) {
-                                       printf("%s\n", def);
-                                       def = NULL;
-                               }
+                               show_default();
                                if (revs_only)
                                        break;
                                as_is = 1;
                        }
                        if (!strcmp(arg, "--default")) {
-                               if (def)
-                                       printf("%s\n", def);
                                def = argv[i+1];
                                i++;
                                continue;
@@ -71,11 +314,29 @@ int main(int argc, char **argv)
                                no_revs = 1;
                                continue;
                        }
-                       if (revs_only | no_revs) {
-                               if (is_rev_argument(arg) != revs_only)
-                                       continue;
+                       if (!strcmp(arg, "--flags")) {
+                               flags_only = 1;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--no-flags")) {
+                               no_flags = 1;
+                               continue;
                        }
-                       printf("%s\n", arg);
+                       if (!strcmp(arg, "--verify")) {
+                               revs_only = 1;
+                               do_rev_argument = 0;
+                               single_rev = 1;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--not")) {
+                               show_type ^= REVERSED;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--all")) {
+                               for_each_ref(show_reference);
+                               continue;
+                       }
+                       show_arg(arg);
                        continue;
                }
                dotdot = strstr(arg, "..");
@@ -83,43 +344,41 @@ int main(int argc, char **argv)
                        unsigned char end[20];
                        char *n = dotdot+2;
                        *dotdot = 0;
-                       if (!get_sha1(arg, sha1)) {
+                       if (!get_extended_sha1(arg, sha1)) {
                                if (!*n)
                                        n = "HEAD";
-                               if (!get_sha1(n, end)) {
+                               if (!get_extended_sha1(n, end)) {
                                        if (no_revs)
                                                continue;
                                        def = NULL;
-                                       printf("%s\n", sha1_to_hex(end));
-                                       printf("^%s\n", sha1_to_hex(sha1));
+                                       show_rev(NORMAL, end);
+                                       show_rev(REVERSED, sha1);
                                        continue;
                                }
                        }
                        *dotdot = '.';
                }
-               if (!get_sha1(arg, sha1)) {
+               if (!get_extended_sha1(arg, sha1)) {
                        if (no_revs)
                                continue;
                        def = NULL;
-                       printf("%s\n", sha1_to_hex(sha1));
+                       show_rev(NORMAL, sha1);
                        continue;
                }
-               if (*arg == '^' && !get_sha1(arg+1, sha1)) {
+               if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
                        if (no_revs)
                                continue;
                        def = NULL;
-                       printf("^%s\n", sha1_to_hex(sha1));
+                       show_rev(REVERSED, sha1);
                        continue;
                }
-               if (def) {
-                       printf("%s\n", def);
-                       def = NULL;
-               }
-               if (revs_only)
-                       continue;
-               printf("%s\n", arg);
+               show_default();
+               show_norev(arg);
+       }
+       show_default();
+       if (single_rev && output_revs != 1) {
+               fprintf(stderr, "Needed a single revision\n");
+               exit(1);
        }
-       if (def)
-               printf("%s\n", def);
        return 0;
 }