#include "ll-merge.h"
#include "attr.h"
#include "pathspec.h"
+#include "sha1-lookup.h"
#define RESOLVED 0
#define PUNTED 1
/* automatically update cleanly resolved paths to the index */
static int rerere_autoupdate;
-const char *rerere_path(const char *hex, const char *file)
+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)
{
- return git_path("rr-cache/%s/%s", hex, file);
+ 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 int has_rerere_resolution(const char *hex)
+static void free_rerere_id(struct string_list_item *item)
{
- struct stat st;
- return !stat(rerere_path(hex, "postimage"), &st);
+ free(item->util);
}
-static void read_rr(struct string_list *rr)
+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];
- char buf[PATH_MAX];
+ 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 (fread(buf, 40, 1, in) == 1) {
- int i;
- char *name;
- if (get_sha1_hex(buf, sha1))
+ 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");
- buf[40] = '\0';
- name = xstrdup(buf);
- if (fgetc(in) != '\t')
- die("corrupt MERGE_RR");
- for (i = 0; i < sizeof(buf); i++) {
- int c = fgetc(in);
- if (c < 0)
+
+ 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");
- buf[i] = c;
- if (c == 0)
- break;
}
- if (i == sizeof(buf))
- die("filename too long");
- string_list_insert(rr, buf)->util = name;
+ 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);
}
{
int i;
for (i = 0; i < rr->nr; i++) {
- const char *path;
- int length;
- if (!rr->items[i].util)
+ struct strbuf buf = STRBUF_INIT;
+ struct rerere_id *id;
+
+ assert(rr->items[i].util != RERERE_RESOLVED);
+
+ id = rr->items[i].util;
+ if (!id)
continue;
- path = rr->items[i].string;
- length = strlen(path) + 1;
- if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
- write_str_in_full(out_fd, "\t") != 1 ||
- write_in_full(out_fd, path, length) != length)
+ 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)
ferr_write(s, strlen(s), fp, err);
}
-struct rerere_io {
- int (*getline)(struct strbuf *, struct rerere_io *);
- FILE *output;
- int wrerror;
- /* some more stuff */
-};
-
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) {
+ 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);
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');
}
-static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
+/*
+ * 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;
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;
git_SHA1_Init(&ctx);
while (!io->getline(&buf, io)) {
- if (is_cmarker(buf.buf, '<', marker_size, 1)) {
+ 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, 0)) {
+ } 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, 0)) {
+ } 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, 1)) {
+ } else if (is_cmarker(buf.buf, '>', marker_size)) {
if (hunk != RR_SIDE_2)
goto bad;
if (strbuf_cmp(&one, &two) > 0)
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;
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));
+ io.io.wrerror = error_errno("Failed to flush %s", path);
if (hunk_no < 0) {
if (output)
return hunk_no;
}
-struct rerere_io_mem {
- struct rerere_io io;
- struct strbuf input;
-};
-
-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;
-
- for (i = 0; i < 3; i++) {
- enum object_type type;
- unsigned long size;
- int j;
-
- if (active_nr <= pos)
- break;
- ce = active_cache[pos++];
- if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
- continue;
- j = ce_stage(ce) - 1;
- mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size);
- mmfile[j].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);
-
- 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];
}
*type = PUNTED;
- if (ce_stage(e) == 1) {
- if (active_nr <= ++i)
- return i + 1;
- }
+ while (ce_stage(active_cache[i]) == 1)
+ i++;
/* Only handle regular files with both stages #2 and #3 */
if (i + 1 < active_nr) {
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;
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;
struct string_list_item *it;
it = string_list_lookup(merge_rr, (const char *)e->name);
if (it != NULL) {
- free(it->util);
+ free_rerere_id(it);
it->util = RERERE_RESOLVED;
}
}
return 0;
}
-static int merge(const char *name, const char *path)
+/*
+ * 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 cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
- mmbuffer_t result = {NULL, 0};
+ mmfile_t base = {NULL, 0}, other = {NULL, 0};
- if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
- return 1;
+ 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};
- if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
- read_mmfile(&base, rerere_path(name, "preimage")) ||
- read_mmfile(&other, rerere_path(name, "postimage"))) {
+ /*
+ * 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 = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
- if (!ret) {
- FILE *f;
-
- if (utime(rerere_path(name, "postimage"), NULL) < 0)
- warning("failed utime() on %s: %s",
- rerere_path(name, "postimage"),
- strerror(errno));
- 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));
- }
+
+ 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_errno("failed utime() on %s",
+ rerere_path(id, "postimage"));
+
+ /* Update "path" with the resolution */
+ f = fopen(path, "w");
+ if (!f)
+ return error_errno("Could not open %s", path);
+ if (fwrite(result.ptr, result.size, 1, f) != 1)
+ error_errno("Could not write %s", path);
+ if (fclose(f))
+ return error_errno("Writing %s failed", path);
out:
free(cur.ptr);
- free(base.ptr);
- free(other.ptr);
free(result.ptr);
return ret;
{
int i;
- hold_locked_index(&index_lock, 1);
+ hold_locked_index(&index_lock, LOCK_DIE_ON_ERROR);
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) {
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;
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.
+ * 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;
- if (!string_list_has_string(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));
- string_list_insert(rr, path)->util = hex;
- if (mkdir_in_gitdir(git_path("rr-cache/%s", hex)))
- continue;
- handle_file(path, NULL, rerere_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].string;
- const char *name = (const char *)rr->items[i].util;
-
- if (has_rerere_resolution(name)) {
- if (!merge(name, path)) {
- const char *msg;
- if (rerere_autoupdate) {
- string_list_insert(&update, path);
- msg = "Staged '%s' using previous resolution.\n";
- } else
- msg = "Resolved '%s' using previous resolution.\n";
- fprintf(stderr, msg, path);
- goto mark_resolved;
- }
- }
- /* Let's see if we have resolved it. */
- ret = handle_file(path, NULL, NULL);
- if (ret)
+ if (string_list_has_string(rr, path))
continue;
- fprintf(stderr, "Recorded resolution for '%s'.\n", path);
- copy_file(rerere_path(name, "postimage"), path, 0666);
- mark_resolved:
- rr->items[i].util = NULL;
+ /*
+ * 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 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;
+ int fd, status;
fd = setup_rerere(&merge_rr, flags);
if (fd < 0)
return 0;
- return do_plain_rerere(&merge_rr, fd);
+ 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->oid.hash, &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;
- char *hex;
+ 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);
- hex = xstrdup(sha1_to_hex(sha1));
- filename = rerere_path(hex, "postimage");
- if (unlink(filename))
- return (errno == ENOENT
- ? error("no remembered resolution for %s", path)
- : error("cannot unlink %s: %s", filename, strerror(errno)));
-
- handle_cache(path, sha1, rerere_path(hex, "preimage"));
- fprintf(stderr, "Updated preimage for '%s'\n", 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);
+ error("Failed to update conflicted state in '%s'", path);
+ goto fail_exit;
+ }
+ 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) {
+ error("no remembered resolution for '%s'", path);
+ goto fail_exit;
+ }
+
+ filename = rerere_path(id, "postimage");
+ if (unlink(filename)) {
+ if (errno == ENOENT)
+ error("no remembered resolution for %s", path);
+ else
+ error_errno("cannot unlink %s", filename);
+ goto fail_exit;
+ }
+
+ /*
+ * 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);
- string_list_insert(rr, path)->util = hex;
+ /*
+ * 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;
+
+fail_exit:
+ free(id);
+ return -1;
}
int rerere_forget(struct pathspec *pathspec)
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++) {
return write_rr(&merge_rr, fd);
}
-static time_t rerere_created_at(const char *name)
+/*
+ * Garbage collection support
+ */
+
+static time_t rerere_created_at(struct rerere_id *id)
{
struct stat st;
- return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
+
+ return stat(rerere_path(id, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
}
-static time_t rerere_last_used_at(const char *name)
+static time_t rerere_last_used_at(struct rerere_id *id)
{
struct stat st;
- return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
+
+ 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 unlink_rr_item(const char *name)
+static void prune_one(struct rerere_id *id, time_t now,
+ int cutoff_resolve, int cutoff_noresolve)
{
- unlink(rerere_path(name, "thisimage"));
- unlink(rerere_path(name, "preimage"));
- unlink(rerere_path(name, "postimage"));
- rmdir(git_path("rr-cache/%s", name));
+ 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, cutoff;
- time_t now = time(NULL), then;
+ int i;
+ time_t now = time(NULL);
int cutoff_noresolve = 15;
int cutoff_resolve = 60;
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;
-
- 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;
+ 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 (then < now - cutoff * 86400)
+ 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++)
- unlink_rr_item(to_remove.items[i].string);
+ 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;
return;
for (i = 0; i < merge_rr->nr; i++) {
- const char *name = (const char *)merge_rr->items[i].util;
- if (!has_rerere_resolution(name))
- unlink_rr_item(name);
+ 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);