Make git-rerere a builtin

The perl version used modules which are non-standard in some setups.
This patch brings the full power of rerere to a wider audience.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Makefile b/Makefile
index 76511045a80cf5da72851d8194742de56282d953..154bf4cf52db44088e123b208b2dd07713bcfde1 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -174,7 +174,6 @@ SCRIPT_SH = \
 
 SCRIPT_PERL = \
        git-archimport.perl git-cvsimport.perl git-relink.perl \
-       git-rerere.perl \
        git-cvsserver.perl \
        git-svnimport.perl git-cvsexportcommit.perl \
        git-send-email.perl git-svn.perl
@@ -289,6 +288,7 @@ BUILTIN_OBJS = \
        builtin-push.o \
        builtin-read-tree.o \
        builtin-repo-config.o \
+       builtin-rerere.o \
        builtin-rev-list.o \
        builtin-rev-parse.o \
        builtin-rm.o \

diff --git a/builtin-rerere.c b/builtin-rerere.c
new file mode 100644 (file)
index 0000000..d064bd8
--- /dev/null
+++ b/builtin-rerere.c
@@ -0,0 +1,406 @@
+#include "cache.h"
+#include "path-list.h"
+#include "xdiff/xdiff.h"
+#include "xdiff-interface.h"
+
+#include <time.h>
+
+static const char git_rerere_usage[] =
+"git-rerere [clear | status | diff | gc]";
+
+/* these values are days */
+static int cutoff_noresolve = 15;
+static int cutoff_resolve = 60;
+
+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 = xstrdup(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;
+               write(out_fd, rr->items[i].util, 40);
+               write(out_fd, "\t", 1);
+               write(out_fd, path, strlen(path) + 1);
+       }
+       close(out_fd);
+       return commit_lock_file(&write_lock);
+}
+
+struct buffer {
+       char *ptr;
+       int nr, alloc;
+};
+
+static void append_line(struct buffer *buffer, const char *line)
+{
+       int len = strlen(line);
+
+       if (buffer->nr + len > buffer->alloc) {
+               buffer->alloc = alloc_nr(buffer->nr + len);
+               buffer->ptr = xrealloc(buffer->ptr, buffer->alloc);
+       }
+       memcpy(buffer->ptr + buffer->nr, line, len);
+       buffer->nr += len;
+}
+
+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 buffer minus = { NULL, 0, 0 }, plus = { NULL, 0, 0 };
+       struct buffer *one = &minus, *two = &plus;
+       FILE *f = fopen(path, "r");
+       FILE *out;
+
+       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);
+               }
+       } else
+               out = NULL;
+
+       if (sha1)
+               SHA1_Init(&ctx);
+
+       while (fgets(buf, sizeof(buf), f)) {
+               if (!strncmp("<<<<<<< ", buf, 8))
+                       hunk = 1;
+               else if (!strncmp("=======", buf, 7))
+                       hunk = 2;
+               else if (!strncmp(">>>>>>> ", buf, 8)) {
+                       hunk_no++;
+                       hunk = 0;
+                       if (memcmp(one->ptr, two->ptr, one->nr < two->nr ?
+                                               one->nr : two->nr) > 0) {
+                               struct buffer *swap = one;
+                               one = two;
+                               two = swap;
+                       }
+                       if (out) {
+                               fputs("<<<<<<<\n", out);
+                               fwrite(one->ptr, one->nr, 1, out);
+                               fputs("=======\n", out);
+                               fwrite(two->ptr, two->nr, 1, out);
+                               fputs(">>>>>>>\n", out);
+                       }
+                       if (sha1) {
+                               SHA1_Update(&ctx, one->ptr, one->nr);
+                               SHA1_Update(&ctx, "\0", 1);
+                               SHA1_Update(&ctx, two->ptr, two->nr);
+                               SHA1_Update(&ctx, "\0", 1);
+                       }
+               } else if (hunk == 1)
+                       append_line(one, buf);
+               else if (hunk == 2)
+                       append_line(two, buf);
+               else if (out)
+                       fputs(buf, out);
+       }
+
+       fclose(f);
+       if (out)
+               fclose(out);
+       if (sha1)
+               SHA1_Final(sha1, &ctx);
+       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 + 2 < active_nr; i++) {
+               struct cache_entry *e1 = active_cache[i];
+               struct cache_entry *e2 = active_cache[i + 1];
+               struct cache_entry *e3 = active_cache[i + 2];
+               if (ce_stage(e1) == 1 && ce_stage(e2) == 2 &&
+                               ce_stage(e3) == 3 && ce_same_name(e1, e2) &&
+                               ce_same_name(e1, e3)) {
+                       path_list_insert((const char *)e1->name, conflict);
+                       i += 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"));
+       unlink(rr_path(name, "preimage"));
+       unlink(rr_path(name, "postimage"));
+       rmdir(git_path("rr-cache/%s", name));
+}
+
+static void garbage_collect(struct path_list *rr)
+{
+       struct path_list to_remove = { NULL, 0, 0, 1 };
+       char buf[1024];
+       DIR *dir;
+       struct dirent *e;
+       int len, 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++, "/");
+       while ((e = readdir(dir))) {
+               const char *name = e->d_name;
+               struct stat st;
+               if (name[0] == '.' && (name[1] == '\0' ||
+                                       (name[1] == '.' && name[2] == '\0')))
+                       continue;
+               i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
+               strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
+               if (stat(buf, &st))
+                       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);
+               }
+       }
+       for (i = 0; i < to_remove.nr; i++)
+               unlink_rr_item(to_remove.items[i].path);
+       path_list_clear(&to_remove, 0);
+}
+
+static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
+{
+       int i;
+       for (i = 0; i < nbuf; i++)
+               write(1, ptr[i].ptr, ptr[i].size);
+       return 0;
+}
+
+static int diff_two(const char *file1, const char *label1,
+               const char *file2, const char *label2)
+{
+       xpparam_t xpp;
+       xdemitconf_t xecfg;
+       xdemitcb_t ecb;
+       mmfile_t minus, plus;
+
+       if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
+               return 1;
+
+       printf("--- a/%s\n+++ b/%s\n", label1, label2);
+       fflush(stdout);
+       xpp.flags = XDF_NEED_MINIMAL;
+       xecfg.ctxlen = 3;
+       xecfg.flags = 0;
+       ecb.outf = outf;
+       xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
+
+       free(minus.ptr);
+       free(plus.ptr);
+       return 0;
+}
+
+static int copy_file(const char *src, const char *dest)
+{
+       FILE *in, *out;
+       char buffer[32768];
+       int count;
+
+       if (!(in = fopen(src, "r")))
+               return error("Could not open %s", src);
+       if (!(out = fopen(dest, "w")))
+               return error("Could not open %s", dest);
+       while ((count = fread(buffer, 1, sizeof(buffer), in)))
+               fwrite(buffer, 1, count, out);
+       fclose(in);
+       fclose(out);
+       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(path, rr_path(name, "postimage"));
+tail_optimization:
+               if (i < rr->nr - 1) {
+                       memmove(rr->items + i,
+                                       rr->items + i + 1,
+                                       rr->nr - i - 1);
+               }
+               rr->nr--;
+               i--;
+       }
+
+       return write_rr(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 = -1;
+       struct stat st;
+
+       if (stat(git_path("rr-cache"), &st) || !S_ISDIR(st.st_mode))
+               return 0;
+
+       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);
+
+       if (argc < 2)
+               return do_plain_rerere(&merge_rr, fd);
+       else if (!strcmp(argv[1], "clear")) {
+               for (i = 0; i < merge_rr.nr; i++) {
+                       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))
+                               unlink_rr_item(name);
+               }
+               unlink(merge_rr_path);
+       } 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);
+       else if (!strcmp(argv[1], "diff"))
+               for (i = 0; i < merge_rr.nr; i++) {
+                       const char *path = merge_rr.items[i].path;
+                       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);
+       return 0;
+}
+

diff --git a/builtin.h b/builtin.h
index 08519e7c828b7993a54b4603bf5da0b03b972653..8ffd8b2653a4879f6e5ff59d6ae8a82cae34a2ae 100644 (file)
--- a/builtin.h
+++ b/builtin.h
@@ -52,6 +52,7 @@ extern int cmd_prune_packed(int argc, const char **argv, const char *prefix);
 extern int cmd_push(int argc, const char **argv, const char *prefix);
 extern int cmd_read_tree(int argc, const char **argv, const char *prefix);
 extern int cmd_repo_config(int argc, const char **argv, const char *prefix);
+extern int cmd_rerere(int argc, const char **argv, const char *prefix);
 extern int cmd_rev_list(int argc, const char **argv, const char *prefix);
 extern int cmd_rev_parse(int argc, const char **argv, const char *prefix);
 extern int cmd_rm(int argc, const char **argv, const char *prefix);

diff --git a/git.c b/git.c
index 73cf4d4e019c2c0169e6181b2c557cdeb3f962e7..7a01e02f2b21c029277564ad104c512cbc68b7ba 100644 (file)
--- a/git.c
+++ b/git.c
@@ -245,6 +245,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
                { "push", cmd_push, RUN_SETUP },
                { "read-tree", cmd_read_tree, RUN_SETUP },
                { "repo-config", cmd_repo_config },
+               { "rerere", cmd_rerere, RUN_SETUP },
                { "rev-list", cmd_rev_list, RUN_SETUP },
                { "rev-parse", cmd_rev_parse, RUN_SETUP },
                { "rm", cmd_rm, RUN_SETUP },