#include "cache.h"

#include "lockfile.h"

#include "string-list.h"

#include "rerere.h"

#include "xdiff-interface.h"

#include "dir.h"

#include "resolve-undo.h"

#include "ll-merge.h"

#include "attr.h"

#include "pathspec.h"

#define RESOLVED 0

#define PUNTED 1

#define THREE_STAGED 2

void *RERERE_RESOLVED = &RERERE_RESOLVED;

/* 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 void free_rerere_id(struct string_list_item *item)

{

free(item->util);

}

static const char *rerere_id_hex(const struct rerere_id *id)

{

return id->hex;

}

const char *rerere_path(const struct rerere_id *id, const char *file)

{

if (!file)

return git_path("rr-cache/%s", rerere_id_hex(id));

return git_path("rr-cache/%s/%s", rerere_id_hex(id), file);

}

static int has_rerere_resolution(const struct rerere_id *id)

{

struct stat st;

return !stat(rerere_path(id, "postimage"), &st);

}

static struct rerere_id *new_rerere_id_hex(char *hex)

{

struct rerere_id *id = xmalloc(sizeof(*id));

strcpy(id->hex, hex);

return id;

}

static struct rerere_id *new_rerere_id(unsigned char *sha1)

{

return new_rerere_id_hex(sha1_to_hex(sha1));

}

/*

* $GIT_DIR/MERGE_RR file is a collection of records, each of which is

* "conflict ID", a HT and pathname, terminated with a NUL, and is

* used to keep track of the set of paths that "rerere" may need to

* work on (i.e. what is left by the previous invocation of "git

* rerere" during the current conflict resolution session).

*/

static void read_rr(struct string_list *rr)

{

struct strbuf buf = STRBUF_INIT;

FILE *in = fopen(git_path_merge_rr(), "r");

if (!in)

return;

while (!strbuf_getwholeline(&buf, in, '\0')) {

char *path;

unsigned char sha1[20];

struct rerere_id *id;

/* There has to be the hash, tab, path and then NUL */

if (buf.len < 42 || get_sha1_hex(buf.buf, sha1))

die("corrupt MERGE_RR");

if (buf.buf[40] != '\t')

die("corrupt MERGE_RR");

buf.buf[40] = '\0';

path = buf.buf + 41;

id = new_rerere_id_hex(buf.buf);

string_list_insert(rr, path)->util = id;

}

strbuf_release(&buf);

fclose(in);

}

static struct lock_file write_lock;

static int write_rr(struct string_list *rr, int out_fd)

{

int i;

for (i = 0; i < rr->nr; i++) {

struct strbuf buf = STRBUF_INIT;

struct rerere_id *id;

assert(rr->items[i].util != RERERE_RESOLVED);

id = rr->items[i].util;

if (!id)

continue;

strbuf_addf(&buf, "%s\t%s%c",

rerere_id_hex(id),

rr->items[i].string, 0);

if (write_in_full(out_fd, buf.buf, buf.len) != buf.len)

die("unable to write rerere record");

strbuf_release(&buf);

}

if (commit_lock_file(&write_lock) != 0)

die("unable to write rerere record");

return 0;

}

/*

* "rerere" interacts with conflicted file contents using this I/O

* abstraction. It reads a conflicted contents from one place via

* "getline()" method, and optionally can write it out after

* normalizing the conflicted hunks to the "output". Subclasses of

* rerere_io embed this structure at the beginning of their own

* rerere_io object.

*/

struct rerere_io {

};

static void ferr_write(const void *p, size_t count, FILE *fp, int *err)

{

if (!count || *err)

return;

if (fwrite(p, count, 1, fp) != 1)

*err = errno;

}

static inline void ferr_puts(const char *s, FILE *fp, int *err)

{

ferr_write(s, strlen(s), fp, err);

}

static void rerere_io_putstr(const char *str, struct rerere_io *io)

{

if (io->output)

ferr_puts(str, io->output, &io->wrerror);

}

/*

* Write a conflict marker to io->output (if defined).

*/

static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)

{

char buf[64];

while (size) {

if (size <= sizeof(buf) - 2) {

memset(buf, ch, size);

buf[size] = '\n';

buf[size + 1] = '\0';

size = 0;

} else {

int sz = sizeof(buf) - 1;

/*

* Make sure we will not write everything out

* in this round by leaving at least 1 byte

* for the next round, giving the next round

* a chance to add the terminating LF. Yuck.

*/

if (size <= sz)

sz -= (sz - size) + 1;

memset(buf, ch, sz);

buf[sz] = '\0';

size -= sz;

}

rerere_io_putstr(buf, io);

}

}

static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)

{

if (io->output)

ferr_write(mem, sz, io->output, &io->wrerror);

}

/*

* Subclass of rerere_io that reads from an on-disk file

*/

struct rerere_io_file {

struct rerere_io io;

FILE *input;

};

/*

* ... and its getline() method implementation

*/

static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)

{

struct rerere_io_file *io = (struct rerere_io_file *)io_;

return strbuf_getwholeline(sb, io->input, '\n');

}

/*

* Require the exact number of conflict marker letters, no more, no

* less, followed by SP or any whitespace

* (including LF).

*/

static int is_cmarker(char *buf, int marker_char, int marker_size)

{

int want_sp;

/*

* The beginning of our version and the end of their version

* always are labeled like "<<<<< ours" or ">>>>> theirs",

* hence we set want_sp for them. Note that the version from

* the common ancestor in diff3-style output is not always

* labelled (e.g. "||||| common" is often seen but "|||||"

* alone is also valid), so we do not set want_sp.

*/

want_sp = (marker_char == '<') || (marker_char == '>');

while (marker_size--)

if (*buf++ != marker_char)

return 0;

if (want_sp && *buf != ' ')

return 0;

return isspace(*buf);

}

/*

* Read contents a file with conflicts, normalize the conflicts

* by (1) discarding the common ancestor version in diff3-style,

* (2) reordering our side and their side so that whichever sorts

* alphabetically earlier comes before the other one, while

* computing the "conflict ID", which is just an SHA-1 hash of

* one side of the conflict, NUL, the other side of the conflict,

* and NUL concatenated together.

*

* Return the number of conflict hunks found.

*

* NEEDSWORK: the logic and theory of operation behind this conflict

* normalization may deserve to be documented somewhere, perhaps in

* Documentation/technical/rerere.txt.

*/

static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)

{

git_SHA_CTX ctx;

int hunk_no = 0;

enum {

RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL

} hunk = RR_CONTEXT;

struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;

struct strbuf buf = STRBUF_INIT;

if (sha1)

git_SHA1_Init(&ctx);

while (!io->getline(&buf, io)) {

if (is_cmarker(buf.buf, '<', marker_size)) {

if (hunk != RR_CONTEXT)

goto bad;

hunk = RR_SIDE_1;

} else if (is_cmarker(buf.buf, '|', marker_size)) {

if (hunk != RR_SIDE_1)

goto bad;

hunk = RR_ORIGINAL;

} else if (is_cmarker(buf.buf, '=', marker_size)) {

if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)

goto bad;

hunk = RR_SIDE_2;

} else if (is_cmarker(buf.buf, '>', marker_size)) {

if (hunk != RR_SIDE_2)

goto bad;

if (strbuf_cmp(&one, &two) > 0)

strbuf_swap(&one, &two);

hunk_no++;

hunk = RR_CONTEXT;

rerere_io_putconflict('<', marker_size, io);

rerere_io_putmem(one.buf, one.len, io);

rerere_io_putconflict('=', marker_size, io);

rerere_io_putmem(two.buf, two.len, io);

rerere_io_putconflict('>', marker_size, io);

if (sha1) {

git_SHA1_Update(&ctx, one.buf ? one.buf : "",

one.len + 1);

git_SHA1_Update(&ctx, two.buf ? two.buf : "",

two.len + 1);

}

strbuf_reset(&one);

strbuf_reset(&two);

} else if (hunk == RR_SIDE_1)

strbuf_addbuf(&one, &buf);

else if (hunk == RR_ORIGINAL)

; /* discard */

else if (hunk == RR_SIDE_2)

strbuf_addbuf(&two, &buf);

else

rerere_io_putstr(buf.buf, io);

continue;

bad:

hunk = 99; /* force error exit */

break;

}

strbuf_release(&one);

strbuf_release(&two);

strbuf_release(&buf);

if (sha1)

git_SHA1_Final(sha1, &ctx);

if (hunk != RR_CONTEXT)

return -1;

return hunk_no;

}

/*

* Scan the path for conflicts, do the "handle_path()" thing above, and

* return the number of conflict hunks found.

*/

static int handle_file(const char *path, unsigned char *sha1, const char *output)

{

int hunk_no = 0;

struct rerere_io_file io;

int marker_size = ll_merge_marker_size(path);

memset(&io, 0, sizeof(io));

io.io.getline = rerere_file_getline;

io.input = fopen(path, "r");

io.io.wrerror = 0;

if (!io.input)

return error("Could not open %s", path);

if (output) {

io.io.output = fopen(output, "w");

if (!io.io.output) {

fclose(io.input);

return error("Could not write %s", output);

}

}

hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);

fclose(io.input);

if (io.io.wrerror)

error("There were errors while writing %s (%s)",

path, strerror(io.io.wrerror));

if (io.io.output && fclose(io.io.output))

io.io.wrerror = error("Failed to flush %s: %s",

path, strerror(errno));

if (hunk_no < 0) {

if (output)

unlink_or_warn(output);

return error("Could not parse conflict hunks in %s", path);

}

if (io.io.wrerror)

return -1;

return hunk_no;

}

/*

* Subclass of rerere_io that reads from an in-core buffer that is a

* strbuf

*/

struct rerere_io_mem {

struct rerere_io io;

struct strbuf input;

};

/*

* ... and its getline() method implementation

*/

static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)

{

struct rerere_io_mem *io = (struct rerere_io_mem *)io_;

char *ep;

size_t len;

strbuf_release(sb);

if (!io->input.len)

return -1;

ep = memchr(io->input.buf, '\n', io->input.len);

if (!ep)

ep = io->input.buf + io->input.len;

else if (*ep == '\n')

ep++;

len = ep - io->input.buf;

strbuf_add(sb, io->input.buf, len);

strbuf_remove(&io->input, 0, len);

return 0;

}

static int handle_cache(const char *path, unsigned char *sha1, const char *output)

{

mmfile_t mmfile[3] = {{NULL}};

mmbuffer_t result = {NULL, 0};

const struct cache_entry *ce;

int pos, len, i, hunk_no;

struct rerere_io_mem io;

int marker_size = ll_merge_marker_size(path);

/*

* Reproduce the conflicted merge in-core

*/

len = strlen(path);

pos = cache_name_pos(path, len);

if (0 <= pos)

return -1;

pos = -pos - 1;

while (pos < active_nr) {

enum object_type type;

unsigned long size;

ce = active_cache[pos++];

if (ce_namelen(ce) != len || memcmp(ce->name, path, len))

break;

i = ce_stage(ce) - 1;

if (!mmfile[i].ptr) {

mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);

mmfile[i].size = size;

}

}

for (i = 0; i < 3; i++)

if (!mmfile[i].ptr && !mmfile[i].size)

mmfile[i].ptr = xstrdup("");

/*

* NEEDSWORK: handle conflicts from merges with

* merge.renormalize set, too

*/

ll_merge(&result, path, &mmfile[0], NULL,

&mmfile[1], "ours",

&mmfile[2], "theirs", NULL);

for (i = 0; i < 3; i++)

free(mmfile[i].ptr);

memset(&io, 0, sizeof(io));

io.io.getline = rerere_mem_getline;

if (output)

io.io.output = fopen(output, "w");

else

io.io.output = NULL;

strbuf_init(&io.input, 0);

strbuf_attach(&io.input, result.ptr, result.size, result.size);

/*

* Grab the conflict ID and optionally write the original

* contents with conflict markers out.

*/

hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);

strbuf_release(&io.input);

if (io.io.output)

fclose(io.io.output);

return hunk_no;

}

/*

* Look at a cache entry at "i" and see if it is not conflicting,

* conflicting and we are willing to handle, or conflicting and

* we are unable to handle, and return the determination in *type.

* Return the cache index to be looked at next, by skipping the

* stages we have already looked at in this invocation of this

* function.

*/

static int check_one_conflict(int i, int *type)

{

const struct cache_entry *e = active_cache[i];

if (!ce_stage(e)) {

*type = RESOLVED;

return i + 1;

}

*type = PUNTED;

while (ce_stage(active_cache[i]) == 1)

i++;

/* Only handle regular files with both stages #2 and #3 */

if (i + 1 < active_nr) {

const struct cache_entry *e2 = active_cache[i];

const struct cache_entry *e3 = active_cache[i + 1];

if (ce_stage(e2) == 2 &&

ce_stage(e3) == 3 &&

ce_same_name(e, e3) &&

S_ISREG(e2->ce_mode) &&

S_ISREG(e3->ce_mode))

*type = THREE_STAGED;

}

/* Skip the entries with the same name */

while (i < active_nr && ce_same_name(e, active_cache[i]))

i++;

return i;

}

/*

* Scan the index and find paths that have conflicts that rerere can

* handle, i.e. the ones that has both stages #2 and #3.

*

* NEEDSWORK: we do not record or replay a previous "resolve by

* deletion" for a delete-modify conflict, as that is inherently risky

* without knowing what modification is being discarded. The only

* safe case, i.e. both side doing the deletion and modification that

* are identical to the previous round, might want to be handled,

* though.

*/

static int find_conflict(struct string_list *conflict)

{

int i;

if (read_cache() < 0)

return error("Could not read index");

for (i = 0; i < active_nr;) {

int conflict_type;

const struct cache_entry *e = active_cache[i];

i = check_one_conflict(i, &conflict_type);

if (conflict_type == THREE_STAGED)

string_list_insert(conflict, (const char *)e->name);

}

return 0;

}

/*

* The merge_rr list is meant to hold outstanding conflicted paths

* that rerere could handle. Abuse the list by adding other types of

* entries to allow the caller to show "rerere remaining".

*

* - Conflicted paths that rerere does not handle are added

* - Conflicted paths that have been resolved are marked as such

* by storing RERERE_RESOLVED to .util field (where conflict ID

* is expected to be stored).

*

* Do *not* write MERGE_RR file out after calling this function.

*

* NEEDSWORK: we may want to fix the caller that implements "rerere

* remaining" to do this without abusing merge_rr.

*/

int rerere_remaining(struct string_list *merge_rr)

{

int i;

if (setup_rerere(merge_rr, RERERE_READONLY))

return 0;

if (read_cache() < 0)

return error("Could not read index");

for (i = 0; i < active_nr;) {

int conflict_type;

const struct cache_entry *e = active_cache[i];

i = check_one_conflict(i, &conflict_type);

if (conflict_type == PUNTED)

string_list_insert(merge_rr, (const char *)e->name);

else if (conflict_type == RESOLVED) {

struct string_list_item *it;

it = string_list_lookup(merge_rr, (const char *)e->name);

if (it != NULL) {

free_rerere_id(it);

it->util = RERERE_RESOLVED;

}

}

}

return 0;

}

/*

* Find the conflict identified by "id"; the change between its

* "preimage" (i.e. a previous contents with conflict markers) and its

* "postimage" (i.e. the corresponding contents with conflicts

* resolved) may apply cleanly to the contents stored in "path", i.e.

* the conflict this time around.

*

* Returns 0 for successful replay of recorded resolution, or non-zero

* for failure.

*/

static int merge(const struct rerere_id *id, const char *path)

{

FILE *f;

int ret;

mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};

mmbuffer_t result = {NULL, 0};

/*

* Normalize the conflicts in path and write it out to

* "thisimage" temporary file.

*/

if (handle_file(path, NULL, rerere_path(id, "thisimage")) < 0) {

ret = 1;

goto out;

}

if (read_mmfile(&cur, rerere_path(id, "thisimage")) ||

read_mmfile(&base, rerere_path(id, "preimage")) ||

read_mmfile(&other, rerere_path(id, "postimage"))) {

ret = 1;

goto out;

}

/*

* A three-way merge. Note that this honors user-customizable

* low-level merge driver settings.

*/

ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);

if (ret)

goto out;

/*

* A successful replay of recorded resolution.

* Mark that "postimage" was used to help gc.

*/

if (utime(rerere_path(id, "postimage"), NULL) < 0)

warning("failed utime() on %s: %s",

rerere_path(id, "postimage"),

strerror(errno));

/* Update "path" with the resolution */

f = fopen(path, "w");

if (!f)

return error("Could not open %s: %s", path,

strerror(errno));

if (fwrite(result.ptr, result.size, 1, f) != 1)

error("Could not write %s: %s", path, strerror(errno));

if (fclose(f))

return error("Writing %s failed: %s", path,

strerror(errno));

out:

free(cur.ptr);

free(base.ptr);

free(other.ptr);

free(result.ptr);

return ret;

}

static struct lock_file index_lock;

static void update_paths(struct string_list *update)

{

int i;

hold_locked_index(&index_lock, 1);

for (i = 0; i < update->nr; i++) {

struct string_list_item *item = &update->items[i];

if (add_file_to_cache(item->string, 0))

exit(128);

fprintf(stderr, "Staged '%s' using previous resolution.\n",

item->string);

}

if (active_cache_changed) {

if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))

die("Unable to write new index file");

} else

rollback_lock_file(&index_lock);

}

/*

* The path indicated by rr_item may still have conflict for which we

* have a recorded resolution, in which case replay it and optionally

* update it. Or it may have been resolved by the user and we may

* only have the preimage for that conflict, in which case the result

* needs to be recorded as a resolution in a postimage file.

*/

static void do_rerere_one_path(struct string_list_item *rr_item,

struct string_list *update)

{

const char *path = rr_item->string;

const struct rerere_id *id = rr_item->util;

/* Is there a recorded resolution we could attempt to apply? */

if (has_rerere_resolution(id)) {

if (merge(id, path))

return; /* failed to replay */

if (rerere_autoupdate)

string_list_insert(update, path);

else

fprintf(stderr,

"Resolved '%s' using previous resolution.\n",

path);

} else if (!handle_file(path, NULL, NULL)) {

/* The user has resolved it. */

copy_file(rerere_path(id, "postimage"), path, 0666);

fprintf(stderr, "Recorded resolution for '%s'.\n", path);

} else {

return;

}

free_rerere_id(rr_item);

rr_item->util = NULL;

}

static int do_plain_rerere(struct string_list *rr, int fd)

{

struct string_list conflict = STRING_LIST_INIT_DUP;

struct string_list update = STRING_LIST_INIT_DUP;

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++) {

struct rerere_id *id;

unsigned char sha1[20];

const char *path = conflict.items[i].string;

int ret;

if (string_list_has_string(rr, path))

continue;

/*

* Ask handle_file() to scan and assign a

* conflict ID. No need to write anything out

* yet.

*/

ret = handle_file(path, sha1, NULL);

if (ret < 1)

continue;

id = new_rerere_id(sha1);

string_list_insert(rr, path)->util = id;

/*

* If the directory does not exist, create

* it. mkdir_in_gitdir() will fail with

* EEXIST if there already is one.

*

* NEEDSWORK: make sure "gc" does not remove

* preimage without removing the directory.

*/

if (mkdir_in_gitdir(rerere_path(id, NULL)))

continue;

/*

* We are the first to encounter this

* conflict. Ask handle_file() to write the

* normalized contents to the "preimage" file.

*/

handle_file(path, NULL, rerere_path(id, "preimage"));

fprintf(stderr, "Recorded preimage for '%s'\n", path);

}

for (i = 0; i < rr->nr; i++)

do_rerere_one_path(&rr->items[i], &update);

if (update.nr)

update_paths(&update);

return write_rr(rr, fd);

}

static void git_rerere_config(void)

{

git_config_get_bool("rerere.enabled", &rerere_enabled);

git_config_get_bool("rerere.autoupdate", &rerere_autoupdate);

git_config(git_default_config, NULL);

}

static GIT_PATH_FUNC(git_path_rr_cache, "rr-cache")

static int is_rerere_enabled(void)

{

int rr_cache_exists;

if (!rerere_enabled)

return 0;

rr_cache_exists = is_directory(git_path_rr_cache());

if (rerere_enabled < 0)

return rr_cache_exists;

if (!rr_cache_exists && mkdir_in_gitdir(git_path_rr_cache()))

die("Could not create directory %s", git_path_rr_cache());

return 1;

}

int setup_rerere(struct string_list *merge_rr, int flags)

{

int fd;

git_rerere_config();

if (!is_rerere_enabled())

return -1;

if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))

rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);

if (flags & RERERE_READONLY)

fd = 0;

else

fd = hold_lock_file_for_update(&write_lock, git_path_merge_rr(),

LOCK_DIE_ON_ERROR);

read_rr(merge_rr);

return fd;

}

/*

* The main entry point that is called internally from codepaths that

* perform mergy operations, possibly leaving conflicted index entries

* and working tree files.

*/

int rerere(int flags)

{

struct string_list merge_rr = STRING_LIST_INIT_DUP;

int fd;

fd = setup_rerere(&merge_rr, flags);

if (fd < 0)

return 0;

return do_plain_rerere(&merge_rr, fd);

}

static int rerere_forget_one_path(const char *path, struct string_list *rr)

{

const char *filename;

struct rerere_id *id;

unsigned char sha1[20];

int ret;

struct string_list_item *item;

/*

* Recreate the original conflict from the stages in the

* index and compute the conflict ID

*/

ret = handle_cache(path, sha1, NULL);

if (ret < 1)

return error("Could not parse conflict hunks in '%s'", path);

/* Nuke the recorded resolution for the conflict */

id = new_rerere_id(sha1);

filename = rerere_path(id, "postimage");

if (unlink(filename))

return (errno == ENOENT

? error("no remembered resolution for %s", path)

: error("cannot unlink %s: %s", filename, strerror(errno)));

/*

* Update the preimage so that the user can resolve the

* conflict in the working tree, run us again to record

* the postimage.

*/

handle_cache(path, sha1, rerere_path(id, "preimage"));

fprintf(stderr, "Updated preimage for '%s'\n", path);

/*

* And remember that we can record resolution for this

* conflict when the user is done.

*/

item = string_list_insert(rr, path);

free_rerere_id(item);

item->util = id;

fprintf(stderr, "Forgot resolution for %s\n", path);

return 0;

}

int rerere_forget(struct pathspec *pathspec)

{

int i, fd;

struct string_list conflict = STRING_LIST_INIT_DUP;

struct string_list merge_rr = STRING_LIST_INIT_DUP;

if (read_cache() < 0)

return error("Could not read index");

fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);

if (fd < 0)

return 0;

/*

* The paths may have been resolved (incorrectly);

* recover the original conflicted state and then

* find the conflicted paths.

*/

unmerge_cache(pathspec);

find_conflict(&conflict);

for (i = 0; i < conflict.nr; i++) {

struct string_list_item *it = &conflict.items[i];

if (!match_pathspec(pathspec, it->string,

strlen(it->string), 0, NULL, 0))

continue;

rerere_forget_one_path(it->string, &merge_rr);

}

return write_rr(&merge_rr, fd);

}

/*

* Garbage collection support

*/

/*

* Note that this is not reentrant but is used only one-at-a-time

* so it does not matter right now.

*/

static struct rerere_id *dirname_to_id(const char *name)

{

static struct rerere_id id;

strcpy(id.hex, name);

return &id;

}

static time_t rerere_created_at(const char *dir_name)

{

struct stat st;

struct rerere_id *id = dirname_to_id(dir_name);

return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime;

}

static time_t rerere_last_used_at(const char *dir_name)

{

struct stat st;

struct rerere_id *id = dirname_to_id(dir_name);

return stat(rerere_path(id, "postimage"), &st) ? (time_t) 0 : st.st_mtime;

}

/*

* Remove the recorded resolution for a given conflict ID

*/

static void unlink_rr_item(struct rerere_id *id)

{

unlink(rerere_path(id, "thisimage"));

unlink(rerere_path(id, "preimage"));

unlink(rerere_path(id, "postimage"));

/*

* NEEDSWORK: what if this rmdir() fails? Wouldn't we then

* assume that we already have preimage recorded in

* do_plain_rerere()?

*/

rmdir(rerere_path(id, NULL));

}

void rerere_gc(struct string_list *rr)

{

struct string_list to_remove = STRING_LIST_INIT_DUP;

DIR *dir;

struct dirent *e;

int i, cutoff;

time_t now = time(NULL), then;

int cutoff_noresolve = 15;

int cutoff_resolve = 60;

if (setup_rerere(rr, 0) < 0)

return;

git_config_get_int("gc.rerereresolved", &cutoff_resolve);

git_config_get_int("gc.rerereunresolved", &cutoff_noresolve);

git_config(git_default_config, NULL);

dir = opendir(git_path("rr-cache"));

if (!dir)

die_errno("unable to open rr-cache directory");

/* Collect stale conflict IDs ... */

while ((e = readdir(dir))) {

if (is_dot_or_dotdot(e->d_name))

continue;

then = rerere_last_used_at(e->d_name);

if (then) {

cutoff = cutoff_resolve;

} else {

then = rerere_created_at(e->d_name);

if (!then)

continue;

cutoff = cutoff_noresolve;

}

if (then < now - cutoff * 86400)

string_list_append(&to_remove, e->d_name);

}

closedir(dir);

/* ... and then remove them one-by-one */

for (i = 0; i < to_remove.nr; i++)

unlink_rr_item(dirname_to_id(to_remove.items[i].string));

string_list_clear(&to_remove, 0);

rollback_lock_file(&write_lock);

}

/*

* During a conflict resolution, after "rerere" recorded the

* preimages, abandon them if the user did not resolve them or

* record their resolutions. And drop $GIT_DIR/MERGE_RR.

*

* NEEDSWORK: shouldn't we be calling this from "reset --hard"?

*/

void rerere_clear(struct string_list *merge_rr)

{

int i;

if (setup_rerere(merge_rr, 0) < 0)

return;