Allow cloning an empty repository
[gitweb.git] / builtin-rerere.c
index 85222d9bc591e0b603bf6f33c32d6bb1bad479ee..bd8fc77a7a65a21a401f917b75d36883cda634ed 100644 (file)
 #include "builtin.h"
 #include "cache.h"
-#include "path-list.h"
+#include "dir.h"
+#include "string-list.h"
+#include "rerere.h"
 #include "xdiff/xdiff.h"
 #include "xdiff-interface.h"
 
-#include <time.h>
-
 static const char git_rerere_usage[] =
-"git-rerere [clear | status | diff | gc]";
+"git rerere [clear | status | diff | gc]";
 
 /* these values are days */
 static int cutoff_noresolve = 15;
 static int cutoff_resolve = 60;
 
-/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
-static int rerere_enabled = -1;
-
-static char *merge_rr_path;
-
 static const char *rr_path(const char *name, const char *file)
 {
        return git_path("rr-cache/%s/%s", name, file);
 }
 
-static void read_rr(struct path_list *rr)
-{
-       unsigned char sha1[20];
-       char buf[PATH_MAX];
-       FILE *in = fopen(merge_rr_path, "r");
-       if (!in)
-               return;
-       while (fread(buf, 40, 1, in) == 1) {
-               int i;
-               char *name;
-               if (get_sha1_hex(buf, sha1))
-                       die("corrupt MERGE_RR");
-               buf[40] = '\0';
-               name = xstrdup(buf);
-               if (fgetc(in) != '\t')
-                       die("corrupt MERGE_RR");
-               for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
-                       ; /* do nothing */
-               if (i == sizeof(buf))
-                       die("filename too long");
-               path_list_insert(buf, rr)->util = name;
-       }
-       fclose(in);
-}
-
-static struct lock_file write_lock;
-
-static int write_rr(struct path_list *rr, int out_fd)
-{
-       int i;
-       for (i = 0; i < rr->nr; i++) {
-               const char *path = rr->items[i].path;
-               int length = strlen(path) + 1;
-               if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
-                   write_in_full(out_fd, "\t", 1) != 1 ||
-                   write_in_full(out_fd, path, length) != length)
-                       die("unable to write rerere record");
-       }
-       if (commit_lock_file(&write_lock) != 0)
-               die("unable to write rerere record");
-       return 0;
-}
-
-static int handle_file(const char *path,
-        unsigned char *sha1, const char *output)
-{
-       SHA_CTX ctx;
-       char buf[1024];
-       int hunk = 0, hunk_no = 0;
-       struct strbuf one, two;
-       FILE *f = fopen(path, "r");
-       FILE *out = NULL;
-
-       if (!f)
-               return error("Could not open %s", path);
-
-       if (output) {
-               out = fopen(output, "w");
-               if (!out) {
-                       fclose(f);
-                       return error("Could not write %s", output);
-               }
-       }
-
-       if (sha1)
-               SHA1_Init(&ctx);
-
-       strbuf_init(&one, 0);
-       strbuf_init(&two,  0);
-       while (fgets(buf, sizeof(buf), f)) {
-               if (!prefixcmp(buf, "<<<<<<< "))
-                       hunk = 1;
-               else if (!prefixcmp(buf, "======="))
-                       hunk = 2;
-               else if (!prefixcmp(buf, ">>>>>>> ")) {
-                       int cmp = strbuf_cmp(&one, &two);
-
-                       hunk_no++;
-                       hunk = 0;
-                       if (cmp > 0) {
-                               strbuf_swap(&one, &two);
-                       }
-                       if (out) {
-                               fputs("<<<<<<<\n", out);
-                               fwrite(one.buf, one.len, 1, out);
-                               fputs("=======\n", out);
-                               fwrite(two.buf, two.len, 1, out);
-                               fputs(">>>>>>>\n", out);
-                       }
-                       if (sha1) {
-                               SHA1_Update(&ctx, one.buf ? one.buf : "",
-                                           one.len + 1);
-                               SHA1_Update(&ctx, two.buf ? two.buf : "",
-                                           two.len + 1);
-                       }
-                       strbuf_reset(&one);
-                       strbuf_reset(&two);
-               } else if (hunk == 1)
-                       strbuf_addstr(&one, buf);
-               else if (hunk == 2)
-                       strbuf_addstr(&two, buf);
-               else if (out)
-                       fputs(buf, out);
-       }
-       strbuf_release(&one);
-       strbuf_release(&two);
-
-       fclose(f);
-       if (out)
-               fclose(out);
-       if (sha1)
-               SHA1_Final(sha1, &ctx);
-       return hunk_no;
-}
-
-static int find_conflict(struct path_list *conflict)
+static time_t rerere_created_at(const char *name)
 {
-       int i;
-       if (read_cache() < 0)
-               return error("Could not read index");
-       for (i = 0; i+1 < active_nr; i++) {
-               struct cache_entry *e2 = active_cache[i];
-               struct cache_entry *e3 = active_cache[i+1];
-               if (ce_stage(e2) == 2 &&
-                   ce_stage(e3) == 3 &&
-                   ce_same_name(e2, e3) &&
-                   S_ISREG(e2->ce_mode) &&
-                   S_ISREG(e3->ce_mode)) {
-                       path_list_insert((const char *)e2->name, conflict);
-                       i++; /* skip over both #2 and #3 */
-               }
-       }
-       return 0;
+       struct stat st;
+       return stat(rr_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
 }
 
-static int merge(const char *name, const char *path)
+static int has_resolution(const char *name)
 {
-       int ret;
-       mmfile_t cur, base, other;
-       mmbuffer_t result = {NULL, 0};
-       xpparam_t xpp = {XDF_NEED_MINIMAL};
-
-       if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
-               return 1;
-
-       if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
-                       read_mmfile(&base, rr_path(name, "preimage")) ||
-                       read_mmfile(&other, rr_path(name, "postimage")))
-               return 1;
-       ret = xdl_merge(&base, &cur, "", &other, "",
-                       &xpp, XDL_MERGE_ZEALOUS, &result);
-       if (!ret) {
-               FILE *f = fopen(path, "w");
-               if (!f)
-                       return error("Could not write to %s", path);
-               fwrite(result.ptr, result.size, 1, f);
-               fclose(f);
-       }
-
-       free(cur.ptr);
-       free(base.ptr);
-       free(other.ptr);
-       free(result.ptr);
-
-       return ret;
+       struct stat st;
+       return !stat(rr_path(name, "postimage"), &st);
 }
 
 static void unlink_rr_item(const char *name)
@@ -198,40 +38,41 @@ static void unlink_rr_item(const char *name)
        rmdir(git_path("rr-cache/%s", name));
 }
 
-static void garbage_collect(struct path_list *rr)
+static int git_rerere_gc_config(const char *var, const char *value, void *cb)
 {
-       struct path_list to_remove = { NULL, 0, 0, 1 };
-       char buf[1024];
+       if (!strcmp(var, "gc.rerereresolved"))
+               cutoff_resolve = git_config_int(var, value);
+       else if (!strcmp(var, "gc.rerereunresolved"))
+               cutoff_noresolve = git_config_int(var, value);
+       else
+               return git_default_config(var, value, cb);
+       return 0;
+}
+
+static void garbage_collect(struct string_list *rr)
+{
+       struct string_list to_remove = { NULL, 0, 0, 1 };
        DIR *dir;
        struct dirent *e;
-       int len, i, cutoff;
+       int i, cutoff;
        time_t now = time(NULL), then;
 
-       strlcpy(buf, git_path("rr-cache"), sizeof(buf));
-       len = strlen(buf);
-       dir = opendir(buf);
-       strcpy(buf + len++, "/");
+       git_config(git_rerere_gc_config, NULL);
+       dir = opendir(git_path("rr-cache"));
        while ((e = readdir(dir))) {
-               const char *name = e->d_name;
-               struct stat st;
-               if (name[0] == '.' && (name[1] == '\0' ||
-                                       (name[1] == '.' && name[2] == '\0')))
+               if (is_dot_or_dotdot(e->d_name))
                        continue;
-               i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
-               strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
-               if (stat(buf, &st))
+               then = rerere_created_at(e->d_name);
+               if (!then)
                        continue;
-               then = st.st_mtime;
-               strlcpy(buf + len + i, "/postimage", sizeof(buf) - len - i);
-               cutoff = stat(buf, &st) ? cutoff_noresolve : cutoff_resolve;
-               if (then < now - cutoff * 86400) {
-                       buf[len + i] = '\0';
-                       path_list_insert(xstrdup(name), &to_remove);
-               }
+               cutoff = (has_resolution(e->d_name)
+                         ? cutoff_resolve : cutoff_noresolve);
+               if (then < now - cutoff * 86400)
+                       string_list_append(e->d_name, &to_remove);
        }
        for (i = 0; i < to_remove.nr; i++)
-               unlink_rr_item(to_remove.items[i].path);
-       path_list_clear(&to_remove, 0);
+               unlink_rr_item(to_remove.items[i].string);
+       string_list_clear(&to_remove, 0);
 }
 
 static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
@@ -256,6 +97,7 @@ static int diff_two(const char *file1, const char *label1,
 
        printf("--- a/%s\n+++ b/%s\n", label1, label2);
        fflush(stdout);
+       memset(&xpp, 0, sizeof(xpp));
        xpp.flags = XDF_NEED_MINIMAL;
        memset(&xecfg, 0, sizeof(xecfg));
        xecfg.ctxlen = 3;
@@ -267,171 +109,39 @@ static int diff_two(const char *file1, const char *label1,
        return 0;
 }
 
-static int do_plain_rerere(struct path_list *rr, int fd)
-{
-       struct path_list conflict = { NULL, 0, 0, 1 };
-       int i;
-
-       find_conflict(&conflict);
-
-       /*
-        * MERGE_RR records paths with conflicts immediately after merge
-        * failed.  Some of the conflicted paths might have been hand resolved
-        * in the working tree since then, but the initial run would catch all
-        * and register their preimages.
-        */
-
-       for (i = 0; i < conflict.nr; i++) {
-               const char *path = conflict.items[i].path;
-               if (!path_list_has_path(rr, path)) {
-                       unsigned char sha1[20];
-                       char *hex;
-                       int ret;
-                       ret = handle_file(path, sha1, NULL);
-                       if (ret < 1)
-                               continue;
-                       hex = xstrdup(sha1_to_hex(sha1));
-                       path_list_insert(path, rr)->util = hex;
-                       if (mkdir(git_path("rr-cache/%s", hex), 0755))
-                               continue;;
-                       handle_file(path, NULL, rr_path(hex, "preimage"));
-                       fprintf(stderr, "Recorded preimage for '%s'\n", path);
-               }
-       }
-
-       /*
-        * Now some of the paths that had conflicts earlier might have been
-        * hand resolved.  Others may be similar to a conflict already that
-        * was resolved before.
-        */
-
-       for (i = 0; i < rr->nr; i++) {
-               struct stat st;
-               int ret;
-               const char *path = rr->items[i].path;
-               const char *name = (const char *)rr->items[i].util;
-
-               if (!stat(rr_path(name, "preimage"), &st) &&
-                               !stat(rr_path(name, "postimage"), &st)) {
-                       if (!merge(name, path)) {
-                               fprintf(stderr, "Resolved '%s' using "
-                                               "previous resolution.\n", path);
-                               goto tail_optimization;
-                       }
-               }
-
-               /* Let's see if we have resolved it. */
-               ret = handle_file(path, NULL, NULL);
-               if (ret)
-                       continue;
-
-               fprintf(stderr, "Recorded resolution for '%s'.\n", path);
-               copy_file(rr_path(name, "postimage"), path, 0666);
-tail_optimization:
-               if (i < rr->nr - 1)
-                       memmove(rr->items + i,
-                               rr->items + i + 1,
-                               sizeof(rr->items[0]) * (rr->nr - i - 1));
-               rr->nr--;
-               i--;
-       }
-
-       return write_rr(rr, fd);
-}
-
-static int git_rerere_config(const char *var, const char *value, void *cb)
-{
-       if (!strcmp(var, "gc.rerereresolved"))
-               cutoff_resolve = git_config_int(var, value);
-       else if (!strcmp(var, "gc.rerereunresolved"))
-               cutoff_noresolve = git_config_int(var, value);
-       else if (!strcmp(var, "rerere.enabled"))
-               rerere_enabled = git_config_bool(var, value);
-       else
-               return git_default_config(var, value, cb);
-       return 0;
-}
-
-static int is_rerere_enabled(void)
-{
-       struct stat st;
-       const char *rr_cache;
-       int rr_cache_exists;
-
-       if (!rerere_enabled)
-               return 0;
-
-       rr_cache = git_path("rr-cache");
-       rr_cache_exists = !stat(rr_cache, &st) && S_ISDIR(st.st_mode);
-       if (rerere_enabled < 0)
-               return rr_cache_exists;
-
-       if (!rr_cache_exists &&
-           (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
-               die("Could not create directory %s", rr_cache);
-       return 1;
-}
-
-static int setup_rerere(struct path_list *merge_rr)
-{
-       int fd;
-
-       git_config(git_rerere_config, NULL);
-       if (!is_rerere_enabled())
-               return -1;
-
-       merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
-       fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
-       read_rr(merge_rr);
-       return fd;
-}
-
-int rerere(void)
-{
-       struct path_list merge_rr = { NULL, 0, 0, 1 };
-       int fd;
-
-       fd = setup_rerere(&merge_rr);
-       if (fd < 0)
-               return 0;
-       return do_plain_rerere(&merge_rr, fd);
-}
-
 int cmd_rerere(int argc, const char **argv, const char *prefix)
 {
-       struct path_list merge_rr = { NULL, 0, 0, 1 };
+       struct string_list merge_rr = { NULL, 0, 0, 1 };
        int i, fd;
 
+       if (argc < 2)
+               return rerere();
+
        fd = setup_rerere(&merge_rr);
        if (fd < 0)
                return 0;
 
-       if (argc < 2)
-               return do_plain_rerere(&merge_rr, fd);
-       else if (!strcmp(argv[1], "clear")) {
+       if (!strcmp(argv[1], "clear")) {
                for (i = 0; i < merge_rr.nr; i++) {
-                       struct stat st;
                        const char *name = (const char *)merge_rr.items[i].util;
-                       if (!stat(git_path("rr-cache/%s", name), &st) &&
-                                       S_ISDIR(st.st_mode) &&
-                                       stat(rr_path(name, "postimage"), &st))
+                       if (!has_resolution(name))
                                unlink_rr_item(name);
                }
-               unlink(merge_rr_path);
+               unlink(git_path("rr-cache/MERGE_RR"));
        } else if (!strcmp(argv[1], "gc"))
                garbage_collect(&merge_rr);
        else if (!strcmp(argv[1], "status"))
                for (i = 0; i < merge_rr.nr; i++)
-                       printf("%s\n", merge_rr.items[i].path);
+                       printf("%s\n", merge_rr.items[i].string);
        else if (!strcmp(argv[1], "diff"))
                for (i = 0; i < merge_rr.nr; i++) {
-                       const char *path = merge_rr.items[i].path;
+                       const char *path = merge_rr.items[i].string;
                        const char *name = (const char *)merge_rr.items[i].util;
                        diff_two(rr_path(name, "preimage"), path, path, path);
                }
        else
                usage(git_rerere_usage);
 
-       path_list_clear(&merge_rr, 1);
+       string_list_clear(&merge_rr, 1);
        return 0;
 }