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authorKarsten Blees <karsten.blees@gmail.com>2013-11-14 20:19:34 +0100
committerJunio C Hamano <gitster@pobox.com>2013-11-18 13:04:23 -0800
commit7c85f8acb2282e3ed108c46b59fd5daa78bf17db (patch)
tree10eb91593d592c1a76ed0a4eeba12b74ee5598c0 /diffcore-rename.c
parent48f6407ffec1db18f5ef3316f0d761965bb17f1e (diff)
downloadgit-7c85f8acb2282e3ed108c46b59fd5daa78bf17db.tar.gz
diffcore-rename.c: simplify finding exact renames
The find_exact_renames function currently only uses the hash table for grouping, i.e.: 1. add sources 2. add destinations 3. iterate all buckets, per bucket: 4. split sources from destinations 5. iterate destinations, per destination: 6. iterate sources to find best match This can be simplified by utilizing the lookup functionality of the hash table, i.e.: 1. add sources 2. iterate destinations, per destination: 3. lookup sources matching the current destination 4. iterate sources to find best match This saves several iterations and file_similarity allocations for the destinations. Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'diffcore-rename.c')
-rw-r--r--diffcore-rename.c75
1 files changed, 20 insertions, 55 deletions
diff --git a/diffcore-rename.c b/diffcore-rename.c
index 008a60c09d..cfeb408ea7 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -243,7 +243,7 @@ static int score_compare(const void *a_, const void *b_)
}
struct file_similarity {
- int src_dst, index;
+ int index;
struct diff_filespec *filespec;
struct file_similarity *next;
};
@@ -260,25 +260,21 @@ static unsigned int hash_filespec(struct diff_filespec *filespec)
return hash;
}
-static int find_identical_files(struct file_similarity *src,
- struct file_similarity *dst,
+static int find_identical_files(struct hash_table *srcs,
+ int dst_index,
struct diff_options *options)
{
int renames = 0;
- /*
- * Walk over all the destinations ...
- */
- do {
- struct diff_filespec *target = dst->filespec;
+ struct diff_filespec *target = rename_dst[dst_index].two;
struct file_similarity *p, *best;
int i = 100, best_score = -1;
/*
- * .. to find the best source match
+ * Find the best source match for specified destination.
*/
best = NULL;
- for (p = src; p; p = p->next) {
+ for (p = lookup_hash(hash_filespec(target), srcs); p; p = p->next) {
int score;
struct diff_filespec *source = p->filespec;
@@ -307,61 +303,28 @@ static int find_identical_files(struct file_similarity *src,
break;
}
if (best) {
- record_rename_pair(dst->index, best->index, MAX_SCORE);
+ record_rename_pair(dst_index, best->index, MAX_SCORE);
renames++;
}
- } while ((dst = dst->next) != NULL);
return renames;
}
-static void free_similarity_list(struct file_similarity *p)
+static int free_similarity_list(void *p, void *unused)
{
while (p) {
struct file_similarity *entry = p;
- p = p->next;
+ p = entry->next;
free(entry);
}
+ return 0;
}
-static int find_same_files(void *ptr, void *data)
-{
- int ret;
- struct file_similarity *p = ptr;
- struct file_similarity *src = NULL, *dst = NULL;
- struct diff_options *options = data;
-
- /* Split the hash list up into sources and destinations */
- do {
- struct file_similarity *entry = p;
- p = p->next;
- if (entry->src_dst < 0) {
- entry->next = src;
- src = entry;
- } else {
- entry->next = dst;
- dst = entry;
- }
- } while (p);
-
- /*
- * If we have both sources *and* destinations, see if
- * we can match them up
- */
- ret = (src && dst) ? find_identical_files(src, dst, options) : 0;
-
- /* Free the hashes and return the number of renames found */
- free_similarity_list(src);
- free_similarity_list(dst);
- return ret;
-}
-
-static void insert_file_table(struct hash_table *table, int src_dst, int index, struct diff_filespec *filespec)
+static void insert_file_table(struct hash_table *table, int index, struct diff_filespec *filespec)
{
void **pos;
unsigned int hash;
struct file_similarity *entry = xmalloc(sizeof(*entry));
- entry->src_dst = src_dst;
entry->index = index;
entry->filespec = filespec;
entry->next = NULL;
@@ -385,24 +348,26 @@ static void insert_file_table(struct hash_table *table, int src_dst, int index,
*/
static int find_exact_renames(struct diff_options *options)
{
- int i;
+ int i, renames = 0;
struct hash_table file_table;
+ /* Add all sources to the hash table */
init_hash(&file_table);
- preallocate_hash(&file_table, rename_src_nr + rename_dst_nr);
+ preallocate_hash(&file_table, rename_src_nr);
for (i = 0; i < rename_src_nr; i++)
- insert_file_table(&file_table, -1, i, rename_src[i].p->one);
+ insert_file_table(&file_table, i, rename_src[i].p->one);
+ /* Walk the destinations and find best source match */
for (i = 0; i < rename_dst_nr; i++)
- insert_file_table(&file_table, 1, i, rename_dst[i].two);
+ renames += find_identical_files(&file_table, i, options);
- /* Find the renames */
- i = for_each_hash(&file_table, find_same_files, options);
+ /* Free source file_similarity chains */
+ for_each_hash(&file_table, free_similarity_list, options);
/* .. and free the hash data structure */
free_hash(&file_table);
- return i;
+ return renames;
}
#define NUM_CANDIDATE_PER_DST 4