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-rw-r--r--merge-ort.c331
1 files changed, 319 insertions, 12 deletions
diff --git a/merge-ort.c b/merge-ort.c
index 4a9ce2a822..b954f7184a 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -53,6 +53,8 @@ enum merge_side {
MERGE_SIDE2 = 2
};
+static unsigned RESULT_INITIALIZED = 0x1abe11ed; /* unlikely accidental value */
+
struct traversal_callback_data {
unsigned long mask;
unsigned long dirmask;
@@ -141,6 +143,72 @@ struct rename_info {
char *callback_data_traverse_path;
/*
+ * merge_trees: trees passed to the merge algorithm for the merge
+ *
+ * merge_trees records the trees passed to the merge algorithm. But,
+ * this data also is stored in merge_result->priv. If a sequence of
+ * merges are being done (such as when cherry-picking or rebasing),
+ * the next merge can look at this and re-use information from
+ * previous merges under certain circumstances.
+ *
+ * See also all the cached_* variables.
+ */
+ struct tree *merge_trees[3];
+
+ /*
+ * cached_pairs_valid_side: which side's cached info can be reused
+ *
+ * See the description for merge_trees. For repeated merges, at most
+ * only one side's cached information can be used. Valid values:
+ * MERGE_SIDE2: cached data from side2 can be reused
+ * MERGE_SIDE1: cached data from side1 can be reused
+ * 0: no cached data can be reused
+ */
+ int cached_pairs_valid_side;
+
+ /*
+ * cached_pairs: Caching of renames and deletions.
+ *
+ * These are mappings recording renames and deletions of individual
+ * files (not directories). They are thus a map from an old
+ * filename to either NULL (for deletions) or a new filename (for
+ * renames).
+ */
+ struct strmap cached_pairs[3];
+
+ /*
+ * cached_target_names: just the destinations from cached_pairs
+ *
+ * We sometimes want a fast lookup to determine if a given filename
+ * is one of the destinations in cached_pairs. cached_target_names
+ * is thus duplicative information, but it provides a fast lookup.
+ */
+ struct strset cached_target_names[3];
+
+ /*
+ * cached_irrelevant: Caching of rename_sources that aren't relevant.
+ *
+ * If we try to detect a rename for a source path and succeed, it's
+ * part of a rename. If we try to detect a rename for a source path
+ * and fail, then it's a delete. If we do not try to detect a rename
+ * for a path, then we don't know if it's a rename or a delete. If
+ * merge-ort doesn't think the path is relevant, then we just won't
+ * cache anything for that path. But there's a slight problem in
+ * that merge-ort can think a path is RELEVANT_LOCATION, but due to
+ * commit 9bd342137e ("diffcore-rename: determine which
+ * relevant_sources are no longer relevant", 2021-03-13),
+ * diffcore-rename can downgrade the path to RELEVANT_NO_MORE. To
+ * avoid excessive calls to diffcore_rename_extended() we still need
+ * to cache such paths, though we cannot record them as either
+ * renames or deletes. So we cache them here as a "turned out to be
+ * irrelevant *for this commit*" as they are often also irrelevant
+ * for subsequent commits, though we will have to do some extra
+ * checking to see whether such paths become relevant for rename
+ * detection when cherry-picking/rebasing subsequent commits.
+ */
+ struct strset cached_irrelevant[3];
+
+ /*
* needed_limit: value needed for inexact rename detection to run
*
* If the current rename limit wasn't high enough for inexact
@@ -382,6 +450,8 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
reinitialize ? strmap_partial_clear : strmap_clear;
void (*strintmap_func)(struct strintmap *) =
reinitialize ? strintmap_partial_clear : strintmap_clear;
+ void (*strset_func)(struct strset *) =
+ reinitialize ? strset_partial_clear : strset_clear;
/*
* We marked opti->paths with strdup_strings = 0, so that we
@@ -417,15 +487,21 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
/* Free memory used by various renames maps */
for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) {
strintmap_func(&renames->dirs_removed[i]);
-
- partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
- if (!reinitialize)
- strmap_clear(&renames->dir_rename_count[i], 1);
-
strmap_func(&renames->dir_renames[i], 0);
-
strintmap_func(&renames->relevant_sources[i]);
+ if (!reinitialize)
+ assert(renames->cached_pairs_valid_side == 0);
+ if (i != renames->cached_pairs_valid_side) {
+ strset_func(&renames->cached_target_names[i]);
+ strmap_func(&renames->cached_pairs[i], 1);
+ strset_func(&renames->cached_irrelevant[i]);
+ partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
+ if (!reinitialize)
+ strmap_clear(&renames->dir_rename_count[i], 1);
+ }
}
+ renames->cached_pairs_valid_side = 0;
+ renames->dir_rename_mask = 0;
if (!reinitialize) {
struct hashmap_iter iter;
@@ -448,8 +524,6 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
strmap_clear(&opti->output, 0);
}
- renames->dir_rename_mask = 0;
-
/* Clean out callback_data as well. */
FREE_AND_NULL(renames->callback_data);
renames->callback_data_nr = renames->callback_data_alloc = 0;
@@ -690,15 +764,48 @@ static void add_pair(struct merge_options *opt,
struct rename_info *renames = &opt->priv->renames;
int names_idx = is_add ? side : 0;
- if (!is_add) {
+ if (is_add) {
+ if (strset_contains(&renames->cached_target_names[side],
+ pathname))
+ return;
+ } else {
unsigned content_relevant = (match_mask == 0);
unsigned location_relevant = (dir_rename_mask == 0x07);
+ /*
+ * If pathname is found in cached_irrelevant[side] due to
+ * previous pick but for this commit content is relevant,
+ * then we need to remove it from cached_irrelevant.
+ */
+ if (content_relevant)
+ /* strset_remove is no-op if strset doesn't have key */
+ strset_remove(&renames->cached_irrelevant[side],
+ pathname);
+
+ /*
+ * We do not need to re-detect renames for paths that we already
+ * know the pairing, i.e. for cached_pairs (or
+ * cached_irrelevant). However, handle_deferred_entries() needs
+ * to loop over the union of keys from relevant_sources[side] and
+ * cached_pairs[side], so for simplicity we set relevant_sources
+ * for all the cached_pairs too and then strip them back out in
+ * prune_cached_from_relevant() at the beginning of
+ * detect_regular_renames().
+ */
if (content_relevant || location_relevant) {
/* content_relevant trumps location_relevant */
strintmap_set(&renames->relevant_sources[side], pathname,
content_relevant ? RELEVANT_CONTENT : RELEVANT_LOCATION);
}
+
+ /*
+ * Avoid creating pair if we've already cached rename results.
+ * Note that we do this after setting relevant_sources[side]
+ * as noted in the comment above.
+ */
+ if (strmap_contains(&renames->cached_pairs[side], pathname) ||
+ strset_contains(&renames->cached_irrelevant[side], pathname))
+ return;
}
one = alloc_filespec(pathname);
@@ -2037,6 +2144,9 @@ static int process_renames(struct merge_options *opt,
VERIFY_CI(side2);
if (!strcmp(pathnames[1], pathnames[2])) {
+ struct rename_info *ri = &opt->priv->renames;
+ int j;
+
/* Both sides renamed the same way */
assert(side1 == side2);
memcpy(&side1->stages[0], &base->stages[0],
@@ -2046,6 +2156,16 @@ static int process_renames(struct merge_options *opt,
base->merged.is_null = 1;
base->merged.clean = 1;
+ /*
+ * Disable remembering renames optimization;
+ * rename/rename(1to1) is incredibly rare, and
+ * just disabling the optimization is easier
+ * than purging cached_pairs,
+ * cached_target_names, and dir_rename_counts.
+ */
+ for (j = 0; j < 3; j++)
+ ri->merge_trees[j] = NULL;
+
/* We handled both renames, i.e. i+1 handled */
i++;
/* Move to next rename */
@@ -2273,7 +2393,9 @@ static inline int possible_side_renames(struct rename_info *renames,
static inline int possible_renames(struct rename_info *renames)
{
return possible_side_renames(renames, 1) ||
- possible_side_renames(renames, 2);
+ possible_side_renames(renames, 2) ||
+ !strmap_empty(&renames->cached_pairs[1]) ||
+ !strmap_empty(&renames->cached_pairs[2]);
}
static void resolve_diffpair_statuses(struct diff_queue_struct *q)
@@ -2297,6 +2419,112 @@ static void resolve_diffpair_statuses(struct diff_queue_struct *q)
}
}
+static void prune_cached_from_relevant(struct rename_info *renames,
+ unsigned side)
+{
+ /* Reason for this function described in add_pair() */
+ struct hashmap_iter iter;
+ struct strmap_entry *entry;
+
+ /* Remove from relevant_sources all entries in cached_pairs[side] */
+ strmap_for_each_entry(&renames->cached_pairs[side], &iter, entry) {
+ strintmap_remove(&renames->relevant_sources[side],
+ entry->key);
+ }
+ /* Remove from relevant_sources all entries in cached_irrelevant[side] */
+ strset_for_each_entry(&renames->cached_irrelevant[side], &iter, entry) {
+ strintmap_remove(&renames->relevant_sources[side],
+ entry->key);
+ }
+}
+
+static void use_cached_pairs(struct merge_options *opt,
+ struct strmap *cached_pairs,
+ struct diff_queue_struct *pairs)
+{
+ struct hashmap_iter iter;
+ struct strmap_entry *entry;
+
+ /*
+ * Add to side_pairs all entries from renames->cached_pairs[side_index].
+ * (Info in cached_irrelevant[side_index] is not relevant here.)
+ */
+ strmap_for_each_entry(cached_pairs, &iter, entry) {
+ struct diff_filespec *one, *two;
+ const char *old_name = entry->key;
+ const char *new_name = entry->value;
+ if (!new_name)
+ new_name = old_name;
+
+ /* We don't care about oid/mode, only filenames and status */
+ one = alloc_filespec(old_name);
+ two = alloc_filespec(new_name);
+ diff_queue(pairs, one, two);
+ pairs->queue[pairs->nr-1]->status = entry->value ? 'R' : 'D';
+ }
+}
+
+static void cache_new_pair(struct rename_info *renames,
+ int side,
+ char *old_path,
+ char *new_path,
+ int free_old_value)
+{
+ char *old_value;
+ new_path = xstrdup(new_path);
+ old_value = strmap_put(&renames->cached_pairs[side],
+ old_path, new_path);
+ strset_add(&renames->cached_target_names[side], new_path);
+ if (free_old_value)
+ free(old_value);
+ else
+ assert(!old_value);
+}
+
+static void possibly_cache_new_pair(struct rename_info *renames,
+ struct diff_filepair *p,
+ unsigned side,
+ char *new_path)
+{
+ int dir_renamed_side = 0;
+
+ if (new_path) {
+ /*
+ * Directory renames happen on the other side of history from
+ * the side that adds new files to the old directory.
+ */
+ dir_renamed_side = 3 - side;
+ } else {
+ int val = strintmap_get(&renames->relevant_sources[side],
+ p->one->path);
+ if (val == RELEVANT_NO_MORE) {
+ assert(p->status == 'D');
+ strset_add(&renames->cached_irrelevant[side],
+ p->one->path);
+ }
+ if (val <= 0)
+ return;
+ }
+
+ if (p->status == 'D') {
+ /*
+ * If we already had this delete, we'll just set it's value
+ * to NULL again, so no harm.
+ */
+ strmap_put(&renames->cached_pairs[side], p->one->path, NULL);
+ } else if (p->status == 'R') {
+ if (!new_path)
+ new_path = p->two->path;
+ else
+ cache_new_pair(renames, dir_renamed_side,
+ p->two->path, new_path, 0);
+ cache_new_pair(renames, side, p->one->path, new_path, 1);
+ } else if (p->status == 'A' && new_path) {
+ cache_new_pair(renames, dir_renamed_side,
+ p->two->path, new_path, 0);
+ }
+}
+
static int compare_pairs(const void *a_, const void *b_)
{
const struct diff_filepair *a = *((const struct diff_filepair **)a_);
@@ -2312,6 +2540,7 @@ static void detect_regular_renames(struct merge_options *opt,
struct diff_options diff_opts;
struct rename_info *renames = &opt->priv->renames;
+ prune_cached_from_relevant(renames, side_index);
if (!possible_side_renames(renames, side_index)) {
/*
* No rename detection needed for this side, but we still need
@@ -2322,6 +2551,7 @@ static void detect_regular_renames(struct merge_options *opt,
return;
}
+ partial_clear_dir_rename_count(&renames->dir_rename_count[side_index]);
repo_diff_setup(opt->repo, &diff_opts);
diff_opts.flags.recursive = 1;
diff_opts.flags.rename_empty = 0;
@@ -2339,7 +2569,8 @@ static void detect_regular_renames(struct merge_options *opt,
diffcore_rename_extended(&diff_opts,
&renames->relevant_sources[side_index],
&renames->dirs_removed[side_index],
- &renames->dir_rename_count[side_index]);
+ &renames->dir_rename_count[side_index],
+ &renames->cached_pairs[side_index]);
trace2_region_leave("diff", "diffcore_rename", opt->repo);
resolve_diffpair_statuses(&diff_queued_diff);
@@ -2379,6 +2610,7 @@ static int collect_renames(struct merge_options *opt,
char *new_path; /* non-NULL only with directory renames */
if (p->status != 'A' && p->status != 'R') {
+ possibly_cache_new_pair(renames, p, side_index, NULL);
diff_free_filepair(p);
continue;
}
@@ -2390,6 +2622,7 @@ static int collect_renames(struct merge_options *opt,
&collisions,
&clean);
+ possibly_cache_new_pair(renames, p, side_index, new_path);
if (p->status != 'R' && !new_path) {
diff_free_filepair(p);
continue;
@@ -2445,6 +2678,8 @@ static int detect_and_process_renames(struct merge_options *opt,
trace2_region_enter("merge", "regular renames", opt->repo);
detect_regular_renames(opt, MERGE_SIDE1);
detect_regular_renames(opt, MERGE_SIDE2);
+ use_cached_pairs(opt, &renames->cached_pairs[1], &renames->pairs[1]);
+ use_cached_pairs(opt, &renames->cached_pairs[2], &renames->pairs[2]);
trace2_region_leave("merge", "regular renames", opt->repo);
trace2_region_enter("merge", "directory renames", opt->repo);
@@ -3635,6 +3870,10 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
assert(opt->obuf.len == 0);
assert(opt->priv == NULL);
+ if (result->_properly_initialized != 0 &&
+ result->_properly_initialized != RESULT_INITIALIZED)
+ BUG("struct merge_result passed to merge_incore_*recursive() must be zeroed or filled with values from a previous run");
+ assert(!!result->priv == !!result->_properly_initialized);
if (result->priv) {
opt->priv = result->priv;
result->priv = NULL;
@@ -3674,8 +3913,22 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
NULL, 1);
strmap_init_with_options(&renames->dir_renames[i],
NULL, 0);
+ /*
+ * relevant_sources uses -1 for the default, because we need
+ * to be able to distinguish not-in-strintmap from valid
+ * relevant_source values from enum file_rename_relevance.
+ * In particular, possibly_cache_new_pair() expects a negative
+ * value for not-found entries.
+ */
strintmap_init_with_options(&renames->relevant_sources[i],
- 0, NULL, 0);
+ -1 /* explicitly invalid */,
+ NULL, 0);
+ strmap_init_with_options(&renames->cached_pairs[i],
+ NULL, 1);
+ strset_init_with_options(&renames->cached_irrelevant[i],
+ NULL, 1);
+ strset_init_with_options(&renames->cached_target_names[i],
+ NULL, 0);
}
/*
@@ -3701,6 +3954,50 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
trace2_region_leave("merge", "allocate/init", opt->repo);
}
+static void merge_check_renames_reusable(struct merge_options *opt,
+ struct merge_result *result,
+ struct tree *merge_base,
+ struct tree *side1,
+ struct tree *side2)
+{
+ struct rename_info *renames;
+ struct tree **merge_trees;
+ struct merge_options_internal *opti = result->priv;
+
+ if (!opti)
+ return;
+
+ renames = &opti->renames;
+ merge_trees = renames->merge_trees;
+
+ /*
+ * Handle case where previous merge operation did not want cache to
+ * take effect, e.g. because rename/rename(1to1) makes it invalid.
+ */
+ if (!merge_trees[0]) {
+ assert(!merge_trees[0] && !merge_trees[1] && !merge_trees[2]);
+ renames->cached_pairs_valid_side = 0; /* neither side valid */
+ return;
+ }
+
+ /*
+ * Handle other cases; note that merge_trees[0..2] will only
+ * be NULL if opti is, or if all three were manually set to
+ * NULL by e.g. rename/rename(1to1) handling.
+ */
+ assert(merge_trees[0] && merge_trees[1] && merge_trees[2]);
+
+ /* Check if we meet a condition for re-using cached_pairs */
+ if (oideq(&merge_base->object.oid, &merge_trees[2]->object.oid) &&
+ oideq(&side1->object.oid, &result->tree->object.oid))
+ renames->cached_pairs_valid_side = MERGE_SIDE1;
+ else if (oideq(&merge_base->object.oid, &merge_trees[1]->object.oid) &&
+ oideq(&side2->object.oid, &result->tree->object.oid))
+ renames->cached_pairs_valid_side = MERGE_SIDE2;
+ else
+ renames->cached_pairs_valid_side = 0; /* neither side valid */
+}
+
/*** Function Grouping: merge_incore_*() and their internal variants ***/
/*
@@ -3751,6 +4048,7 @@ static void merge_ort_nonrecursive_internal(struct merge_options *opt,
result->clean &= strmap_empty(&opt->priv->conflicted);
if (!opt->priv->call_depth) {
result->priv = opt->priv;
+ result->_properly_initialized = RESULT_INITIALIZED;
opt->priv = NULL;
}
}
@@ -3848,7 +4146,16 @@ void merge_incore_nonrecursive(struct merge_options *opt,
trace2_region_enter("merge", "merge_start", opt->repo);
assert(opt->ancestor != NULL);
+ merge_check_renames_reusable(opt, result, merge_base, side1, side2);
merge_start(opt, result);
+ /*
+ * Record the trees used in this merge, so if there's a next merge in
+ * a cherry-pick or rebase sequence it might be able to take advantage
+ * of the cached_pairs in that next merge.
+ */
+ opt->priv->renames.merge_trees[0] = merge_base;
+ opt->priv->renames.merge_trees[1] = side1;
+ opt->priv->renames.merge_trees[2] = side2;
trace2_region_leave("merge", "merge_start", opt->repo);
merge_ort_nonrecursive_internal(opt, merge_base, side1, side2, result);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 06:57:57 +0000