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#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"
#include "sha1-lookup.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 int rerere_dir_nr;
static int rerere_dir_alloc;
#define RR_HAS_POSTIMAGE 1
#define RR_HAS_PREIMAGE 2
static struct rerere_dir {
unsigned char sha1[20];
int status_alloc, status_nr;
unsigned char *status;
} **rerere_dir;
static void free_rerere_dirs(void)
{
int i;
for (i = 0; i < rerere_dir_nr; i++) {
free(rerere_dir[i]->status);
free(rerere_dir[i]);
}
free(rerere_dir);
rerere_dir_nr = rerere_dir_alloc = 0;
rerere_dir = NULL;
}
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 sha1_to_hex(id->collection->sha1);
}
static void fit_variant(struct rerere_dir *rr_dir, int variant)
{
variant++;
ALLOC_GROW(rr_dir->status, variant, rr_dir->status_alloc);
if (rr_dir->status_nr < variant) {
memset(rr_dir->status + rr_dir->status_nr,
'\0', variant - rr_dir->status_nr);
rr_dir->status_nr = variant;
}
}
static void assign_variant(struct rerere_id *id)
{
int variant;
struct rerere_dir *rr_dir = id->collection;
variant = id->variant;
if (variant < 0) {
for (variant = 0; variant < rr_dir->status_nr; variant++)
if (!rr_dir->status[variant])
break;
}
fit_variant(rr_dir, variant);
id->variant = variant;
}
const char *rerere_path(const struct rerere_id *id, const char *file)
{
if (!file)
return git_path("rr-cache/%s", rerere_id_hex(id));
if (id->variant <= 0)
return git_path("rr-cache/%s/%s", rerere_id_hex(id), file);
return git_path("rr-cache/%s/%s.%d",
rerere_id_hex(id), file, id->variant);
}
static int is_rr_file(const char *name, const char *filename, int *variant)
{
const char *suffix;
char *ep;
if (!strcmp(name, filename)) {
*variant = 0;
return 1;
}
if (!skip_prefix(name, filename, &suffix) || *suffix != '.')
return 0;
errno = 0;
*variant = strtol(suffix + 1, &ep, 10);
if (errno || *ep)
return 0;
return 1;
}
static void scan_rerere_dir(struct rerere_dir *rr_dir)
{
struct dirent *de;
DIR *dir = opendir(git_path("rr-cache/%s", sha1_to_hex(rr_dir->sha1)));
if (!dir)
return;
while ((de = readdir(dir)) != NULL) {
int variant;
if (is_rr_file(de->d_name, "postimage", &variant)) {
fit_variant(rr_dir, variant);
rr_dir->status[variant] |= RR_HAS_POSTIMAGE;
} else if (is_rr_file(de->d_name, "preimage", &variant)) {
fit_variant(rr_dir, variant);
rr_dir->status[variant] |= RR_HAS_PREIMAGE;
}
}
closedir(dir);
}
static const unsigned char *rerere_dir_sha1(size_t i, void *table)
{
struct rerere_dir **rr_dir = table;
return rr_dir[i]->sha1;
}
static struct rerere_dir *find_rerere_dir(const char *hex)
{
unsigned char sha1[20];
struct rerere_dir *rr_dir;
int pos;
if (get_sha1_hex(hex, sha1))
return NULL; /* BUG */
pos = sha1_pos(sha1, rerere_dir, rerere_dir_nr, rerere_dir_sha1);
if (pos < 0) {
rr_dir = xmalloc(sizeof(*rr_dir));
hashcpy(rr_dir->sha1, sha1);
rr_dir->status = NULL;
rr_dir->status_nr = 0;
rr_dir->status_alloc = 0;
pos = -1 - pos;
/* Make sure the array is big enough ... */
ALLOC_GROW(rerere_dir, rerere_dir_nr + 1, rerere_dir_alloc);
/* ... and add it in. */
rerere_dir_nr++;
memmove(rerere_dir + pos + 1, rerere_dir + pos,
(rerere_dir_nr - pos - 1) * sizeof(*rerere_dir));
rerere_dir[pos] = rr_dir;
scan_rerere_dir(rr_dir);
}
return rerere_dir[pos];
}
static int has_rerere_resolution(const struct rerere_id *id)
{
const int both = RR_HAS_POSTIMAGE|RR_HAS_PREIMAGE;
int variant = id->variant;
if (variant < 0)
return 0;
return ((id->collection->status[variant] & both) == both);
}
static struct rerere_id *new_rerere_id_hex(char *hex)
{
struct rerere_id *id = xmalloc(sizeof(*id));
id->collection = find_rerere_dir(hex);
id->variant = -1; /* not known yet */
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;
int variant;
/* 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] != '.') {
variant = 0;
path = buf.buf + 40;
} else {
errno = 0;
variant = strtol(buf.buf + 41, &path, 10);
if (errno)
die("corrupt MERGE_RR");
}
if (*(path++) != '\t')
die("corrupt MERGE_RR");
buf.buf[40] = '\0';
id = new_rerere_id_hex(buf.buf);
id->variant = variant;
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;
assert(id->variant >= 0);
if (0 < id->variant)
strbuf_addf(&buf, "%s.%d\t%s%c",
rerere_id_hex(id), id->variant,
rr->items[i].string, 0);
else
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 {
int (*getline)(struct strbuf *, struct rerere_io *);
FILE *output;
int wrerror;
/* some more stuff */
};
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;
}
/*
* 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;
}
/*
* Try using the given conflict resolution "ID" to see
* if that recorded conflict resolves cleanly what we
* got in the "cur".
*/
static int try_merge(const struct rerere_id *id, const char *path,
mmfile_t *cur, mmbuffer_t *result)
{
int ret;
mmfile_t base = {NULL, 0}, other = {NULL, 0};
if (read_mmfile(&base, rerere_path(id, "preimage")) ||
read_mmfile(&other, rerere_path(id, "postimage")))
ret = 1;
else
/*
* 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);
free(base.ptr);
free(other.ptr);
return ret;
}
/*
* 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};
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) ||
read_mmfile(&cur, rerere_path(id, "thisimage"))) {
ret = 1;
goto out;
}
ret = try_merge(id, path, &cur, &result);
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(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);
}
static void remove_variant(struct rerere_id *id)
{
unlink_or_warn(rerere_path(id, "postimage"));
unlink_or_warn(rerere_path(id, "preimage"));
id->collection->status[id->variant] = 0;
}
/*
* 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;
struct rerere_id *id = rr_item->util;
struct rerere_dir *rr_dir = id->collection;
int variant;
variant = id->variant;
/* Has the user resolved it already? */
if (variant >= 0) {
if (!handle_file(path, NULL, NULL)) {
copy_file(rerere_path(id, "postimage"), path, 0666);
id->collection->status[variant] |= RR_HAS_POSTIMAGE;
fprintf(stderr, "Recorded resolution for '%s'.\n", path);
free_rerere_id(rr_item);
rr_item->util = NULL;
return;
}
/*
* There may be other variants that can cleanly
* replay. Try them and update the variant number for
* this one.
*/
}
/* Does any existing resolution apply cleanly? */
for (variant = 0; variant < rr_dir->status_nr; variant++) {
const int both = RR_HAS_PREIMAGE | RR_HAS_POSTIMAGE;
struct rerere_id vid = *id;
if ((rr_dir->status[variant] & both) != both)
continue;
vid.variant = variant;
if (merge(&vid, path))
continue; /* failed to replay */
/*
* If there already is a different variant that applies
* cleanly, there is no point maintaining our own variant.
*/
if (0 <= id->variant && id->variant != variant)
remove_variant(id);
if (rerere_autoupdate)
string_list_insert(update, path);
else
fprintf(stderr,
"Resolved '%s' using previous resolution.\n",
path);
free_rerere_id(rr_item);
rr_item->util = NULL;
return;
}
/* None of the existing one applies; we need a new variant */
assign_variant(id);
variant = id->variant;
handle_file(path, NULL, rerere_path(id, "preimage"));
if (id->collection->status[variant] & RR_HAS_POSTIMAGE) {
const char *path = rerere_path(id, "postimage");
if (unlink(path))
die_errno("cannot unlink stray '%s'", path);
id->collection->status[variant] &= ~RR_HAS_POSTIMAGE;
}
id->collection->status[variant] |= RR_HAS_PREIMAGE;
fprintf(stderr, "Recorded preimage for '%s'\n", path);
}
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;
/* Ensure that the directory exists. */
mkdir_in_gitdir(rerere_path(id, NULL));
}
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, status;
fd = setup_rerere(&merge_rr, flags);
if (fd < 0)
return 0;
status = do_plain_rerere(&merge_rr, fd);
free_rerere_dirs();
return status;
}
/*
* 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;
}
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);
for (id->variant = 0;
id->variant < id->collection->status_nr;
id->variant++) {
mmfile_t cur = { NULL, 0 };
mmbuffer_t result = {NULL, 0};
int cleanly_resolved;
if (!has_rerere_resolution(id))
continue;
handle_cache(path, sha1, rerere_path(id, "thisimage"));
if (read_mmfile(&cur, rerere_path(id, "thisimage"))) {
free(cur.ptr);
return error("Failed to update conflicted state in '%s'",
path);
}
cleanly_resolved = !try_merge(id, path, &cur, &result);
free(result.ptr);
free(cur.ptr);
if (cleanly_resolved)
break;
}
if (id->collection->status_nr <= id->variant)
return error("no remembered resolution for '%s'", path);
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
*/
static time_t rerere_created_at(struct rerere_id *id)
{
struct stat st;
return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
}
static time_t rerere_last_used_at(struct rerere_id *id)
{
struct stat st;
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_or_warn(rerere_path(id, "thisimage"));
remove_variant(id);
id->collection->status[id->variant] = 0;
}
static void prune_one(struct rerere_id *id, time_t now,
int cutoff_resolve, int cutoff_noresolve)
{
time_t then;
int cutoff;
then = rerere_last_used_at(id);
if (then)
cutoff = cutoff_resolve;
else {
then = rerere_created_at(id);
if (!then)
return;
cutoff = cutoff_noresolve;
}
if (then < now - cutoff * 86400)
unlink_rr_item(id);
}
void rerere_gc(struct string_list *rr)
{
struct string_list to_remove = STRING_LIST_INIT_DUP;
DIR *dir;
struct dirent *e;
int i;
time_t now = time(NULL);
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))) {
struct rerere_dir *rr_dir;
struct rerere_id id;
int now_empty;
if (is_dot_or_dotdot(e->d_name))
continue;
rr_dir = find_rerere_dir(e->d_name);
if (!rr_dir)
continue; /* or should we remove e->d_name? */
now_empty = 1;
for (id.variant = 0, id.collection = rr_dir;
id.variant < id.collection->status_nr;
id.variant++) {
prune_one(&id, now, cutoff_resolve, cutoff_noresolve);
if (id.collection->status[id.variant])
now_empty = 0;
}
if (now_empty)
string_list_append(&to_remove, e->d_name);
}
closedir(dir);
/* ... and then remove the empty directories */
for (i = 0; i < to_remove.nr; i++)
rmdir(git_path("rr-cache/%s", 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;
for (i = 0; i < merge_rr->nr; i++) {
struct rerere_id *id = merge_rr->items[i].util;
if (!has_rerere_resolution(id)) {
unlink_rr_item(id);
rmdir(rerere_path(id, NULL));
}
}
unlink_or_warn(git_path_merge_rr());
rollback_lock_file(&write_lock);
}
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