rerere: Separate libgit and builtin functions

This patch moves rerere()-related functions into a newly created
rerere.c file.
The setup_rerere() function is needed by both rerere() and cmd_rerere(),
so this function is moved to rerere.c and declared non-static (and "extern")
in newly created rerere.h file.

Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Makefile b/Makefile
index 4796565ab3a8e7c9bbe7f6fd092713064dce2c1a..de151638bb5c20fe34a0ca5869652004cd90911d 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -363,6 +363,7 @@ LIB_H += quote.h
 LIB_H += reflog-walk.h
 LIB_H += refs.h
 LIB_H += remote.h
+LIB_H += rerere.h
 LIB_H += revision.h
 LIB_H += run-command.h
 LIB_H += sha1-lookup.h
@@ -447,6 +448,7 @@ LIB_OBJS += read-cache.o
 LIB_OBJS += reflog-walk.o
 LIB_OBJS += refs.o
 LIB_OBJS += remote.o
+LIB_OBJS += rerere.o
 LIB_OBJS += revision.o
 LIB_OBJS += run-command.o
 LIB_OBJS += server-info.o

diff --git a/builtin-commit.c b/builtin-commit.c
index 745c11e7735ffcb070683d1af607b4ad85f48e23..bdc83df55bcaeb51eb51b1a3198033eb69236409 100644 (file)
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -22,6 +22,7 @@
 #include "utf8.h"
 #include "parse-options.h"
 #include "path-list.h"
+#include "rerere.h"
 #include "unpack-trees.h"
 
 static const char * const builtin_commit_usage[] = {

diff --git a/builtin-rerere.c b/builtin-rerere.c
index 69c3a52d5e98818dcd4407e75ae9cfff938710a6..5d40e16932a4d8f3761b9aaebc21b630be904f8a 100644 (file)
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -1,11 +1,10 @@
 #include "builtin.h"
 #include "cache.h"
 #include "path-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]";
 
@@ -13,14 +12,6 @@ static const char git_rerere_usage[] =
 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;
-
-/* automatically update cleanly resolved paths to the index */
-static int rerere_autoupdate;
-
-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);
@@ -38,189 +29,6 @@ static int has_resolution(const char *name)
        return !stat(rr_path(name, "postimage"), &st);
 }
 
-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;
-               int length;
-               if (!rr->items[i].util)
-                       continue;
-               path = rr->items[i].path;
-               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, "<<<<<<< ")) {
-                       if (hunk)
-                               goto bad;
-                       hunk = 1;
-               } else if (!prefixcmp(buf, "=======") && isspace(buf[7])) {
-                       if (hunk != 1)
-                               goto bad;
-                       hunk = 2;
-               } else if (!prefixcmp(buf, ">>>>>>> ")) {
-                       if (hunk != 2)
-                               goto bad;
-                       if (strbuf_cmp(&one, &two) > 0)
-                               strbuf_swap(&one, &two);
-                       hunk_no++;
-                       hunk = 0;
-                       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);
-               continue;
-       bad:
-               hunk = 99; /* force error exit */
-               break;
-       }
-       strbuf_release(&one);
-       strbuf_release(&two);
-
-       fclose(f);
-       if (out)
-               fclose(out);
-       if (sha1)
-               SHA1_Final(sha1, &ctx);
-       if (hunk) {
-               if (output)
-                       unlink(output);
-               return error("Could not parse conflict hunks in %s", path);
-       }
-       return hunk_no;
-}
-
-static int find_conflict(struct path_list *conflict)
-{
-       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;
-}
-
-static int merge(const char *name, const char *path)
-{
-       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;
-}
-
 static void unlink_rr_item(const char *name)
 {
        unlink(rr_path(name, "thisimage"));
@@ -229,6 +37,17 @@ static void unlink_rr_item(const char *name)
        rmdir(git_path("rr-cache/%s", name));
 }
 
+static int git_rerere_gc_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
+               return git_default_config(var, value, cb);
+       return 0;
+}
+
 static void garbage_collect(struct path_list *rr)
 {
        struct path_list to_remove = { NULL, 0, 0, 1 };
@@ -237,6 +56,7 @@ static void garbage_collect(struct path_list *rr)
        int i, cutoff;
        time_t now = time(NULL), then;
 
+       git_config(git_rerere_gc_config, NULL);
        dir = opendir(git_path("rr-cache"));
        while ((e = readdir(dir))) {
                const char *name = e->d_name;
@@ -289,181 +109,25 @@ static int diff_two(const char *file1, const char *label1,
        return 0;
 }
 
-static struct lock_file index_lock;
-
-static int update_paths(struct path_list *update)
-{
-       int i;
-       int fd = hold_locked_index(&index_lock, 0);
-       int status = 0;
-
-       if (fd < 0)
-               return -1;
-
-       for (i = 0; i < update->nr; i++) {
-               struct path_list_item *item = &update->items[i];
-               if (add_file_to_cache(item->path, ADD_CACHE_IGNORE_ERRORS))
-                       status = -1;
-       }
-
-       if (!status && active_cache_changed) {
-               if (write_cache(fd, active_cache, active_nr) ||
-                   commit_locked_index(&index_lock))
-                       die("Unable to write new index file");
-       } else if (fd >= 0)
-               rollback_lock_file(&index_lock);
-       return status;
-}
-
-static int do_plain_rerere(struct path_list *rr, int fd)
-{
-       struct path_list conflict = { NULL, 0, 0, 1 };
-       struct path_list update = { 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++) {
-               int ret;
-               const char *path = rr->items[i].path;
-               const char *name = (const char *)rr->items[i].util;
-
-               if (has_resolution(name)) {
-                       if (!merge(name, path)) {
-                               fprintf(stderr, "Resolved '%s' using "
-                                               "previous resolution.\n", path);
-                               if (rerere_autoupdate)
-                                       path_list_insert(path, &update);
-                               goto mark_resolved;
-                       }
-               }
-
-               /* 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);
-       mark_resolved:
-               rr->items[i].util = NULL;
-       }
-
-       if (update.nr)
-               update_paths(&update);
-
-       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 if (!strcmp(var, "rerere.autoupdate"))
-               rerere_autoupdate = 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 };
        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++) {
                        const char *name = (const char *)merge_rr.items[i].util;
                        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"))

diff --git a/commit.h b/commit.h
index 2d94d4148ed4048469ba79cae4f6ff2a2e3f9bca..fda7ad03c0b1d0f2c2cd1e758dbaecf47742c576 100644 (file)
--- a/commit.h
+++ b/commit.h
@@ -131,7 +131,6 @@ extern struct commit_list *get_shallow_commits(struct object_array *heads,
 int in_merge_bases(struct commit *, struct commit **, int);
 
 extern int interactive_add(int argc, const char **argv, const char *prefix);
-extern int rerere(void);
 
 static inline int single_parent(struct commit *commit)
 {

diff --git a/rerere.c b/rerere.c
new file mode 100644 (file)
index 0000000..eec2b50
--- /dev/null
+++ b/rerere.c
@@ -0,0 +1,360 @@
+#include "cache.h"
+#include "path-list.h"
+#include "rerere.h"
+#include "xdiff/xdiff.h"
+#include "xdiff-interface.h"
+
+/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
+static int rerere_enabled = -1;
+
+/* automatically update cleanly resolved paths to the index */
+static int rerere_autoupdate;
+
+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 int has_resolution(const char *name)
+{
+       struct stat st;
+       return !stat(rr_path(name, "postimage"), &st);
+}
+
+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;
+               int length;
+               if (!rr->items[i].util)
+                       continue;
+               path = rr->items[i].path;
+               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, "<<<<<<< ")) {
+                       if (hunk)
+                               goto bad;
+                       hunk = 1;
+               } else if (!prefixcmp(buf, "=======") && isspace(buf[7])) {
+                       if (hunk != 1)
+                               goto bad;
+                       hunk = 2;
+               } else if (!prefixcmp(buf, ">>>>>>> ")) {
+                       if (hunk != 2)
+                               goto bad;
+                       if (strbuf_cmp(&one, &two) > 0)
+                               strbuf_swap(&one, &two);
+                       hunk_no++;
+                       hunk = 0;
+                       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);
+               continue;
+       bad:
+               hunk = 99; /* force error exit */
+               break;
+       }
+       strbuf_release(&one);
+       strbuf_release(&two);
+
+       fclose(f);
+       if (out)
+               fclose(out);
+       if (sha1)
+               SHA1_Final(sha1, &ctx);
+       if (hunk) {
+               if (output)
+                       unlink(output);
+               return error("Could not parse conflict hunks in %s", path);
+       }
+       return hunk_no;
+}
+
+static int find_conflict(struct path_list *conflict)
+{
+       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;
+}
+
+static int merge(const char *name, const char *path)
+{
+       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;
+}
+
+static struct lock_file index_lock;
+
+static int update_paths(struct path_list *update)
+{
+       int i;
+       int fd = hold_locked_index(&index_lock, 0);
+       int status = 0;
+
+       if (fd < 0)
+               return -1;
+
+       for (i = 0; i < update->nr; i++) {
+               struct path_list_item *item = &update->items[i];
+               if (add_file_to_cache(item->path, ADD_CACHE_IGNORE_ERRORS))
+                       status = -1;
+       }
+
+       if (!status && active_cache_changed) {
+               if (write_cache(fd, active_cache, active_nr) ||
+                   commit_locked_index(&index_lock))
+                       die("Unable to write new index file");
+       } else if (fd >= 0)
+               rollback_lock_file(&index_lock);
+       return status;
+}
+
+static int do_plain_rerere(struct path_list *rr, int fd)
+{
+       struct path_list conflict = { NULL, 0, 0, 1 };
+       struct path_list update = { 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++) {
+               int ret;
+               const char *path = rr->items[i].path;
+               const char *name = (const char *)rr->items[i].util;
+
+               if (has_resolution(name)) {
+                       if (!merge(name, path)) {
+                               fprintf(stderr, "Resolved '%s' using "
+                                               "previous resolution.\n", path);
+                               if (rerere_autoupdate)
+                                       path_list_insert(path, &update);
+                               goto mark_resolved;
+                       }
+               }
+
+               /* 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);
+       mark_resolved:
+               rr->items[i].util = NULL;
+       }
+
+       if (update.nr)
+               update_paths(&update);
+
+       return write_rr(rr, fd);
+}
+
+static int git_rerere_config(const char *var, const char *value, void *cb)
+{
+       if (!strcmp(var, "rerere.enabled"))
+               rerere_enabled = git_config_bool(var, value);
+       else if (!strcmp(var, "rerere.autoupdate"))
+               rerere_autoupdate = 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;
+}
+
+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);
+}

diff --git a/rerere.h b/rerere.h
new file mode 100644 (file)
index 0000000..35b0fa8
--- /dev/null
+++ b/rerere.h
@@ -0,0 +1,9 @@
+#ifndef RERERE_H
+#define RERERE_H
+
+#include "path-list.h"
+
+extern int setup_rerere(struct path_list *);
+extern int rerere(void);
+
+#endif