[PATCH] Add git-var a tool for reading interesting git variables.
[git.git] / rev-parse.c
index c134ffd..43af88b 100644 (file)
@@ -5,6 +5,7 @@
  */
 #include "cache.h"
 #include "commit.h"
+#include "refs.h"
 
 static char *def = NULL;
 static int no_revs = 0;
@@ -12,6 +13,8 @@ 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
@@ -46,7 +49,7 @@ static int is_rev_argument(const char *arg)
        }
 }
 
-static void show_rev(int type, unsigned char *sha1)
+static void show_rev(int type, const unsigned char *sha1)
 {
        if (no_revs)
                return;
@@ -63,6 +66,8 @@ static void show_rev_arg(char *rev)
 
 static void show_norev(char *norev)
 {
+       if (flags_only)
+               return;
        if (revs_only)
                return;
        puts(norev);
@@ -70,6 +75,8 @@ static void show_norev(char *norev)
 
 static void show_arg(char *arg)
 {
+       if (no_flags)
+               return;
        if (do_rev_argument && is_rev_argument(arg))
                show_rev_arg(arg);
        else
@@ -90,6 +97,10 @@ static int get_parent(char *name, unsigned char *result, int idx)
                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) {
@@ -101,29 +112,151 @@ static int get_parent(char *name, unsigned char *result, int idx)
        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;
+       int parent, ret;
        int len = strlen(name);
 
        parent = 1;
-       if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
+       if (len > 2 && name[len-1] >= '0' && name[len-1] <= '9') {
                parent = name[len-1] - '0';
                len--;
        }
        if (len > 1 && name[len-1] == '^') {
-               int ret;
                name[len-1] = 0;
                ret = get_parent(name, sha1, parent);
                name[len-1] = '^';
                if (!ret)
                        return 0;
        }
-       return get_sha1(name, sha1);
+       ret = get_sha1(name, sha1);
+       if (!ret)
+               return 0;
+       return get_short_sha1(name, sha1);
 }
 
 static void show_default(void)
@@ -142,6 +275,12 @@ static void show_default(void)
        }
 }
 
+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;
@@ -175,6 +314,14 @@ int main(int argc, char **argv)
                                no_revs = 1;
                                continue;
                        }
+                       if (!strcmp(arg, "--flags")) {
+                               flags_only = 1;
+                               continue;
+                       }
+                       if (!strcmp(arg, "--no-flags")) {
+                               no_flags = 1;
+                               continue;
+                       }
                        if (!strcmp(arg, "--verify")) {
                                revs_only = 1;
                                do_rev_argument = 0;
@@ -185,6 +332,10 @@ int main(int argc, char **argv)
                                show_type ^= REVERSED;
                                continue;
                        }
+                       if (!strcmp(arg, "--all")) {
+                               for_each_ref(show_reference);
+                               continue;
+                       }
                        show_arg(arg);
                        continue;
                }