1 files changed, 147 insertions, 0 deletions
diff --git a/builtin-rerere.c b/builtin-rerere.c
new file mode 100644
index 0000000000..dd4573fe8d
--- /dev/null
+++ b/builtin-rerere.c
@@ -0,0 +1,147 @@
+#include "builtin.h"
+#include "cache.h"
+#include "string-list.h"
+#include "rerere.h"
+#include "xdiff/xdiff.h"
+#include "xdiff-interface.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 const char *rr_path(const char *name, const char *file)
+{
+	return git_path("rr-cache/%s/%s", name, file);
+}
+
+static time_t rerere_created_at(const char *name)
+{
+	struct stat st;
+	return stat(rr_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
+}
+
+static int has_resolution(const char *name)
+{
+	struct stat st;
+	return !stat(rr_path(name, "postimage"), &st);
+}
+
+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 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 string_list *rr)
+{
+	struct string_list to_remove = { NULL, 0, 0, 1 };
+	DIR *dir;
+	struct dirent *e;
+	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;
+		if (name[0] == '.' &&
+		    (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')))
+			continue;
+		then = rerere_created_at(name);
+		if (!then)
+			continue;
+		cutoff = (has_resolution(name)
+			  ? cutoff_resolve : cutoff_noresolve);
+		if (then < now - cutoff * 86400)
+			string_list_append(name, &to_remove);
+	}
+	for (i = 0; i < to_remove.nr; i++)
+		unlink_rr_item(to_remove.items[i].string);
+	string_list_clear(&to_remove, 0);
+}
+
+static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
+{
+	int i;
+	for (i = 0; i < nbuf; i++)
+		if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
+			return -1;
+	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;
+	memset(&xecfg, 0, sizeof(xecfg));
+	xecfg.ctxlen = 3;
+	ecb.outf = outf;
+	xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
+
+	free(minus.ptr);
+	free(plus.ptr);
+	return 0;
+}
+
+int cmd_rerere(int argc, const char **argv, const char *prefix)
+{
+	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 (!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(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].string);
+	else if (!strcmp(argv[1], "diff"))
+		for (i = 0; i < merge_rr.nr; i++) {
+			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);
+
+	string_list_clear(&merge_rr, 1);
+	return 0;
+}