The code was using two string_lists, one for the directories and one for the files. The code never checks the lists independently so we should be able to only use one list. The string_list also is a O(log n) for lookup and insertion. Switching this to use a hashmap will give O(1) which will save some time when there are millions of paths that will be checked.
Signed-off-by: Kevin Willford <kewillf@microsoft.com>
---
merge-recursive.c | 56 ++++++++++++++++++++++++++++++++++++++++++++-----------
merge-recursive.h | 3 +--
2 files changed, 46 insertions(+), 13 deletions(-)
Show changes to 2 files +46 −13
merge-recursive.c, merge-recursive.h
diff --git a/merge-recursive.c b/merge-recursive.c
index d47f40ea81..35af3761ba 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -24,6 +24,31 @@
#include "dir.h"
#include "submodule.h"
+struct path_hashmap_entry {
+ struct hashmap_entry e;
+ char path[FLEX_ARRAY];
+};
+
+static int path_hashmap_cmp(const void *cmp_data,
+ const void *entry,
+ const void *entry_or_key,
+ const void *keydata)
+{
+ const struct path_hashmap_entry *a = entry;
+ const struct path_hashmap_entry *b = entry_or_key;
+ const char *key = keydata;
+
+ if (ignore_case)
+ return strcasecmp(a->path, key ? key : b->path);
+ else
+ return strcmp(a->path, key ? key : b->path);
+}
+
+static unsigned int path_hash(const char *path)
+{
+ return ignore_case ? strihash(path) : strhash(path);
+}
+
static void flush_output(struct merge_options *o)
{
if (o->buffer_output < 2 && o->obuf.len) {
@@ -314,15 +339,15 @@ static int save_files_dirs(const unsigned char *sha1,
struct strbuf *base, const char *path,
unsigned int mode, int stage, void *context)
{
+ struct path_hashmap_entry *entry;
int baselen = base->len;
struct merge_options *o = context;
strbuf_addstr(base, path);
- if (S_ISDIR(mode))
- string_list_insert(&o->current_directory_set, base->buf);
- else
- string_list_insert(&o->current_file_set, base->buf);
+ FLEX_ALLOC_MEM(entry, path, base->buf, base->len);
+ hashmap_entry_init(entry, path_hash(entry->path));
+ hashmap_add(&o->current_file_dir_set, entry);
strbuf_setlen(base, baselen);
return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
@@ -642,6 +667,7 @@ static void add_flattened_path(struct strbuf *out, const char *s)
static char *unique_path(struct merge_options *o, const char *path, const char *branch)
{
+ struct path_hashmap_entry *entry;
struct strbuf newpath = STRBUF_INIT;
int suffix = 0;
size_t base_len;
@@ -650,14 +676,16 @@ static char *unique_path(struct merge_options *o, const char *path, const char *
add_flattened_path(&newpath, branch);
base_len = newpath.len;
- while (string_list_has_string(&o->current_file_set, newpath.buf) ||
- string_list_has_string(&o->current_directory_set, newpath.buf) ||
+ while (hashmap_get_from_hash(&o->current_file_dir_set,
+ path_hash(newpath.buf), newpath.buf) ||
(!o->call_depth && file_exists(newpath.buf))) {
strbuf_setlen(&newpath, base_len);
strbuf_addf(&newpath, "_%d", suffix++);
}
- string_list_insert(&o->current_file_set, newpath.buf);
+ FLEX_ALLOC_MEM(entry, path, newpath.buf, newpath.len);
+ hashmap_entry_init(entry, path_hash(entry->path));
+ hashmap_add(&o->current_file_dir_set, entry);
return strbuf_detach(&newpath, NULL);
}
@@ -1941,8 +1969,14 @@ int merge_trees(struct merge_options *o,
if (unmerged_cache()) {
struct string_list *entries, *re_head, *re_merge;
int i;
- string_list_clear(&o->current_file_set, 1);
- string_list_clear(&o->current_directory_set, 1);
+ /*
+ * Only need the hashmap while processing entries, so
+ * initialize it here and free it when we are done running
+ * through the entries. Keeping it in the merge_options as
+ * opposed to decaring a local hashmap is for convenience
+ * so that we don't have to pass it to around.
+ */
+ hashmap_init(&o->current_file_dir_set, path_hashmap_cmp, NULL, 512);
get_files_dirs(o, head);
get_files_dirs(o, merge);
@@ -1978,6 +2012,8 @@ int merge_trees(struct merge_options *o,
string_list_clear(re_head, 0);
string_list_clear(entries, 1);
+ hashmap_free(&o->current_file_dir_set, 1);
+
free(re_merge);
free(re_head);
free(entries);
@@ -2179,8 +2215,6 @@ void init_merge_options(struct merge_options *o)
if (o->verbosity >= 5)
o->buffer_output = 0;
strbuf_init(&o->obuf, 0);
- string_list_init(&o->current_file_set, 1);
- string_list_init(&o->current_directory_set, 1);
string_list_init(&o->df_conflict_file_set, 1);
}
diff --git a/merge-recursive.h b/merge-recursive.h
index 735343b413..80d69d1401 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -25,8 +25,7 @@ struct merge_options {
int show_rename_progress;
int call_depth;
struct strbuf obuf;
- struct string_list current_file_set;
- struct string_list current_directory_set;
+ struct hashmap current_file_dir_set;
struct string_list df_conflict_file_set;
};