make update-server-info more robust
[gitweb.git] / diffcore-rename.c
index d6fd3cacd6de4757994c61903dd07e0c4d74a9e9..2e44a3745939bb75841730ba0cff78ea872df8d9 100644 (file)
@@ -4,7 +4,8 @@
 #include "cache.h"
 #include "diff.h"
 #include "diffcore.h"
-#include "hash.h"
+#include "hashmap.h"
+#include "progress.h"
 
 /* Table of rename/copy destinations */
 
@@ -37,39 +38,36 @@ static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
        if (!insert_ok)
                return NULL;
        /* insert to make it at "first" */
-       if (rename_dst_alloc <= rename_dst_nr) {
-               rename_dst_alloc = alloc_nr(rename_dst_alloc);
-               rename_dst = xrealloc(rename_dst,
-                                     rename_dst_alloc * sizeof(*rename_dst));
-       }
+       ALLOC_GROW(rename_dst, rename_dst_nr + 1, rename_dst_alloc);
        rename_dst_nr++;
        if (first < rename_dst_nr)
                memmove(rename_dst + first + 1, rename_dst + first,
                        (rename_dst_nr - first - 1) * sizeof(*rename_dst));
        rename_dst[first].two = alloc_filespec(two->path);
-       fill_filespec(rename_dst[first].two, two->sha1, two->mode);
+       fill_filespec(rename_dst[first].two, two->sha1, two->sha1_valid, two->mode);
        rename_dst[first].pair = NULL;
        return &(rename_dst[first]);
 }
 
 /* Table of rename/copy src files */
 static struct diff_rename_src {
-       struct diff_filespec *one;
+       struct diff_filepair *p;
        unsigned short score; /* to remember the break score */
 } *rename_src;
 static int rename_src_nr, rename_src_alloc;
 
-static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
-                                                  unsigned short score)
+static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
 {
        int first, last;
+       struct diff_filespec *one = p->one;
+       unsigned short score = p->score;
 
        first = 0;
        last = rename_src_nr;
        while (last > first) {
                int next = (last + first) >> 1;
                struct diff_rename_src *src = &(rename_src[next]);
-               int cmp = strcmp(one->path, src->one->path);
+               int cmp = strcmp(one->path, src->p->one->path);
                if (!cmp)
                        return src;
                if (cmp < 0) {
@@ -80,16 +78,12 @@ static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
        }
 
        /* insert to make it at "first" */
-       if (rename_src_alloc <= rename_src_nr) {
-               rename_src_alloc = alloc_nr(rename_src_alloc);
-               rename_src = xrealloc(rename_src,
-                                     rename_src_alloc * sizeof(*rename_src));
-       }
+       ALLOC_GROW(rename_src, rename_src_nr + 1, rename_src_alloc);
        rename_src_nr++;
        if (first < rename_src_nr)
                memmove(rename_src + first + 1, rename_src + first,
                        (rename_src_nr - first - 1) * sizeof(*rename_src));
-       rename_src[first].one = one;
+       rename_src[first].p = p;
        rename_src[first].score = score;
        return &(rename_src[first]);
 }
@@ -170,7 +164,7 @@ static int estimate_similarity(struct diff_filespec *src,
         * and the final score computation below would not have a
         * divide-by-zero issue.
         */
-       if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
+       if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
                return 0;
 
        if (!src->cnt_data && diff_populate_filespec(src, 0))
@@ -204,7 +198,7 @@ static void record_rename_pair(int dst_index, int src_index, int score)
        if (rename_dst[dst_index].pair)
                die("internal error: dst already matched.");
 
-       src = rename_src[src_index].one;
+       src = rename_src[src_index].p->one;
        src->rename_used++;
        src->count++;
 
@@ -241,133 +235,79 @@ static int score_compare(const void *a_, const void *b_)
 }
 
 struct file_similarity {
-       int src_dst, index;
+       struct hashmap_entry entry;
+       int index;
        struct diff_filespec *filespec;
-       struct file_similarity *next;
 };
 
-static int find_identical_files(struct file_similarity *src,
-                               struct file_similarity *dst)
-{
-       int renames = 0;
-
-       /*
-        * Walk over all the destinations ...
-        */
-       do {
-               struct diff_filespec *target = dst->filespec;
-               struct file_similarity *p, *best;
-               int i = 100, best_score = -1;
-
-               /*
-                * .. to find the best source match
-                */
-               best = NULL;
-               for (p = src; p; p = p->next) {
-                       int score;
-                       struct diff_filespec *source = p->filespec;
-
-                       /* False hash collision? */
-                       if (hashcmp(source->sha1, target->sha1))
-                               continue;
-                       /* Non-regular files? If so, the modes must match! */
-                       if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) {
-                               if (source->mode != target->mode)
-                                       continue;
-                       }
-                       /* Give higher scores to sources that haven't been used already */
-                       score = !source->rename_used;
-                       score += basename_same(source, target);
-                       if (score > best_score) {
-                               best = p;
-                               best_score = score;
-                               if (score == 2)
-                                       break;
-                       }
-
-                       /* Too many identical alternatives? Pick one */
-                       if (!--i)
-                               break;
-               }
-               if (best) {
-                       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 unsigned int hash_filespec(struct diff_filespec *filespec)
 {
-       while (p) {
-               struct file_similarity *entry = p;
-               p = p->next;
-               free(entry);
+       if (!filespec->sha1_valid) {
+               if (diff_populate_filespec(filespec, 0))
+                       return 0;
+               hash_sha1_file(filespec->data, filespec->size, "blob", filespec->sha1);
        }
+       return sha1hash(filespec->sha1);
 }
 
-static int find_same_files(void *ptr)
+static int find_identical_files(struct hashmap *srcs,
+                               int dst_index,
+                               struct diff_options *options)
 {
-       int ret;
-       struct file_similarity *p = ptr;
-       struct file_similarity *src = NULL, *dst = NULL;
-
-       /* 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);
+       int renames = 0;
+
+       struct diff_filespec *target = rename_dst[dst_index].two;
+       struct file_similarity *p, *best = NULL;
+       int i = 100, best_score = -1;
 
        /*
-        * If we have both sources *and* destinations, see if
-        * we can match them up
+        * Find the best source match for specified destination.
         */
-       ret = (src && dst) ? find_identical_files(src, dst) : 0;
+       p = hashmap_get_from_hash(srcs, hash_filespec(target), NULL);
+       for (; p; p = hashmap_get_next(srcs, p)) {
+               int score;
+               struct diff_filespec *source = p->filespec;
 
-       /* Free the hashes and return the number of renames found */
-       free_similarity_list(src);
-       free_similarity_list(dst);
-       return ret;
-}
+               /* False hash collision? */
+               if (hashcmp(source->sha1, target->sha1))
+                       continue;
+               /* Non-regular files? If so, the modes must match! */
+               if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) {
+                       if (source->mode != target->mode)
+                               continue;
+               }
+               /* Give higher scores to sources that haven't been used already */
+               score = !source->rename_used;
+               if (source->rename_used && options->detect_rename != DIFF_DETECT_COPY)
+                       continue;
+               score += basename_same(source, target);
+               if (score > best_score) {
+                       best = p;
+                       best_score = score;
+                       if (score == 2)
+                               break;
+               }
 
-static unsigned int hash_filespec(struct diff_filespec *filespec)
-{
-       unsigned int hash;
-       if (!filespec->sha1_valid) {
-               if (diff_populate_filespec(filespec, 0))
-                       return 0;
-               hash_sha1_file(filespec->data, filespec->size, "blob", filespec->sha1);
+               /* Too many identical alternatives? Pick one */
+               if (!--i)
+                       break;
        }
-       memcpy(&hash, filespec->sha1, sizeof(hash));
-       return hash;
+       if (best) {
+               record_rename_pair(dst_index, best->index, MAX_SCORE);
+               renames++;
+       }
+       return renames;
 }
 
-static void insert_file_table(struct hash_table *table, int src_dst, int index, struct diff_filespec *filespec)
+static void insert_file_table(struct hashmap *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;
 
-       hash = hash_filespec(filespec);
-       pos = insert_hash(hash, entry, table);
-
-       /* We already had an entry there? */
-       if (pos) {
-               entry->next = *pos;
-               *pos = entry;
-       }
+       hashmap_entry_init(entry, hash_filespec(filespec));
+       hashmap_add(table, entry);
 }
 
 /*
@@ -377,25 +317,24 @@ static void insert_file_table(struct hash_table *table, int src_dst, int index,
  * and then during the second round we try to match
  * cache-dirty entries as well.
  */
-static int find_exact_renames(void)
+static int find_exact_renames(struct diff_options *options)
 {
-       int i;
-       struct hash_table file_table;
+       int i, renames = 0;
+       struct hashmap file_table;
 
-       init_hash(&file_table);
+       /* Add all sources to the hash table */
+       hashmap_init(&file_table, NULL, rename_src_nr);
        for (i = 0; i < rename_src_nr; i++)
-               insert_file_table(&file_table, -1, i, rename_src[i].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);
-
-       /* Find the renames */
-       i = for_each_hash(&file_table, find_same_files);
+               renames += find_identical_files(&file_table, i, options);
 
-       /* .. and free the hash data structure */
-       free_hash(&file_table);
+       /* Free the hash data structure and entries */
+       hashmap_free(&file_table, 1);
 
-       return i;
+       return renames;
 }
 
 #define NUM_CANDIDATE_PER_DST 4
@@ -414,16 +353,86 @@ static void record_if_better(struct diff_score m[], struct diff_score *o)
                m[worst] = *o;
 }
 
+/*
+ * Returns:
+ * 0 if we are under the limit;
+ * 1 if we need to disable inexact rename detection;
+ * 2 if we would be under the limit if we were given -C instead of -C -C.
+ */
+static int too_many_rename_candidates(int num_create,
+                                     struct diff_options *options)
+{
+       int rename_limit = options->rename_limit;
+       int num_src = rename_src_nr;
+       int i;
+
+       options->needed_rename_limit = 0;
+
+       /*
+        * This basically does a test for the rename matrix not
+        * growing larger than a "rename_limit" square matrix, ie:
+        *
+        *    num_create * num_src > rename_limit * rename_limit
+        *
+        * but handles the potential overflow case specially (and we
+        * assume at least 32-bit integers)
+        */
+       if (rename_limit <= 0 || rename_limit > 32767)
+               rename_limit = 32767;
+       if ((num_create <= rename_limit || num_src <= rename_limit) &&
+           (num_create * num_src <= rename_limit * rename_limit))
+               return 0;
+
+       options->needed_rename_limit =
+               num_src > num_create ? num_src : num_create;
+
+       /* Are we running under -C -C? */
+       if (!DIFF_OPT_TST(options, FIND_COPIES_HARDER))
+               return 1;
+
+       /* Would we bust the limit if we were running under -C? */
+       for (num_src = i = 0; i < rename_src_nr; i++) {
+               if (diff_unmodified_pair(rename_src[i].p))
+                       continue;
+               num_src++;
+       }
+       if ((num_create <= rename_limit || num_src <= rename_limit) &&
+           (num_create * num_src <= rename_limit * rename_limit))
+               return 2;
+       return 1;
+}
+
+static int find_renames(struct diff_score *mx, int dst_cnt, int minimum_score, int copies)
+{
+       int count = 0, i;
+
+       for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
+               struct diff_rename_dst *dst;
+
+               if ((mx[i].dst < 0) ||
+                   (mx[i].score < minimum_score))
+                       break; /* there is no more usable pair. */
+               dst = &rename_dst[mx[i].dst];
+               if (dst->pair)
+                       continue; /* already done, either exact or fuzzy. */
+               if (!copies && rename_src[mx[i].src].p->one->rename_used)
+                       continue;
+               record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
+               count++;
+       }
+       return count;
+}
+
 void diffcore_rename(struct diff_options *options)
 {
        int detect_rename = options->detect_rename;
        int minimum_score = options->rename_score;
-       int rename_limit = options->rename_limit;
        struct diff_queue_struct *q = &diff_queued_diff;
        struct diff_queue_struct outq;
        struct diff_score *mx;
-       int i, j, rename_count;
-       int num_create, num_src, dst_cnt;
+       int i, j, rename_count, skip_unmodified = 0;
+       int num_create, dst_cnt;
+       struct progress *progress = NULL;
 
        if (!minimum_score)
                minimum_score = DEFAULT_RENAME_SCORE;
@@ -436,10 +445,16 @@ void diffcore_rename(struct diff_options *options)
                        else if (options->single_follow &&
                                 strcmp(options->single_follow, p->two->path))
                                continue; /* not interested */
+                       else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+                                is_empty_blob_sha1(p->two->sha1))
+                               continue;
                        else
                                locate_rename_dst(p->two, 1);
                }
-               else if (!DIFF_FILE_VALID(p->two)) {
+               else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+                        is_empty_blob_sha1(p->one->sha1))
+                       continue;
+               else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
                        /*
                         * If the source is a broken "delete", and
                         * they did not really want to get broken,
@@ -449,7 +464,7 @@ void diffcore_rename(struct diff_options *options)
                         */
                        if (p->broken_pair && !p->score)
                                p->one->rename_used++;
-                       register_rename_src(p->one, p->score);
+                       register_rename_src(p);
                }
                else if (detect_rename == DIFF_DETECT_COPY) {
                        /*
@@ -457,7 +472,7 @@ void diffcore_rename(struct diff_options *options)
                         * one, to indicate ourselves as a user.
                         */
                        p->one->rename_used++;
-                       register_rename_src(p->one, p->score);
+                       register_rename_src(p);
                }
        }
        if (rename_dst_nr == 0 || rename_src_nr == 0)
@@ -467,7 +482,7 @@ void diffcore_rename(struct diff_options *options)
         * We really want to cull the candidates list early
         * with cheap tests in order to avoid doing deltas.
         */
-       rename_count = find_exact_renames();
+       rename_count = find_exact_renames(options);
 
        /* Did we only want exact renames? */
        if (minimum_score == MAX_SCORE)
@@ -478,28 +493,26 @@ void diffcore_rename(struct diff_options *options)
         * files still remain as options for rename/copies!)
         */
        num_create = (rename_dst_nr - rename_count);
-       num_src = rename_src_nr;
 
        /* All done? */
        if (!num_create)
                goto cleanup;
 
-       /*
-        * This basically does a test for the rename matrix not
-        * growing larger than a "rename_limit" square matrix, ie:
-        *
-        *    num_create * num_src > rename_limit * rename_limit
-        *
-        * but handles the potential overflow case specially (and we
-        * assume at least 32-bit integers)
-        */
-       if (rename_limit <= 0 || rename_limit > 32767)
-               rename_limit = 32767;
-       if ((num_create > rename_limit && num_src > rename_limit) ||
-           (num_create * num_src > rename_limit * rename_limit)) {
-               if (options->warn_on_too_large_rename)
-                       warning("too many files (created: %d deleted: %d), skipping inexact rename detection", num_create, num_src);
+       switch (too_many_rename_candidates(num_create, options)) {
+       case 1:
                goto cleanup;
+       case 2:
+               options->degraded_cc_to_c = 1;
+               skip_unmodified = 1;
+               break;
+       default:
+               break;
+       }
+
+       if (options->show_rename_progress) {
+               progress = start_progress_delay(
+                               _("Performing inexact rename detection"),
+                               rename_dst_nr * rename_src_nr, 50, 1);
        }
 
        mx = xcalloc(num_create * NUM_CANDIDATE_PER_DST, sizeof(*mx));
@@ -515,8 +528,13 @@ void diffcore_rename(struct diff_options *options)
                        m[j].dst = -1;
 
                for (j = 0; j < rename_src_nr; j++) {
-                       struct diff_filespec *one = rename_src[j].one;
+                       struct diff_filespec *one = rename_src[j].p->one;
                        struct diff_score this_src;
+
+                       if (skip_unmodified &&
+                           diff_unmodified_pair(rename_src[j].p))
+                               continue;
+
                        this_src.score = estimate_similarity(one, two,
                                                             minimum_score);
                        this_src.name_score = basename_same(one, two);
@@ -531,51 +549,31 @@ void diffcore_rename(struct diff_options *options)
                        diff_free_filespec_blob(two);
                }
                dst_cnt++;
+               display_progress(progress, (i+1)*rename_src_nr);
        }
+       stop_progress(&progress);
 
        /* cost matrix sorted by most to least similar pair */
        qsort(mx, dst_cnt * NUM_CANDIDATE_PER_DST, sizeof(*mx), score_compare);
 
-       for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
-               struct diff_rename_dst *dst;
-
-               if ((mx[i].dst < 0) ||
-                   (mx[i].score < minimum_score))
-                       break; /* there is no more usable pair. */
-               dst = &rename_dst[mx[i].dst];
-               if (dst->pair)
-                       continue; /* already done, either exact or fuzzy. */
-               if (rename_src[mx[i].src].one->rename_used)
-                       continue;
-               record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
-               rename_count++;
-       }
-
-       for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
-               struct diff_rename_dst *dst;
-
-               if ((mx[i].dst < 0) ||
-                   (mx[i].score < minimum_score))
-                       break; /* there is no more usable pair. */
-               dst = &rename_dst[mx[i].dst];
-               if (dst->pair)
-                       continue; /* already done, either exact or fuzzy. */
-               record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
-               rename_count++;
-       }
+       rename_count += find_renames(mx, dst_cnt, minimum_score, 0);
+       if (detect_rename == DIFF_DETECT_COPY)
+               rename_count += find_renames(mx, dst_cnt, minimum_score, 1);
        free(mx);
 
  cleanup:
        /* At this point, we have found some renames and copies and they
         * are recorded in rename_dst.  The original list is still in *q.
         */
-       outq.queue = NULL;
-       outq.nr = outq.alloc = 0;
+       DIFF_QUEUE_CLEAR(&outq);
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
                struct diff_filepair *pair_to_free = NULL;
 
-               if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
+               if (DIFF_PAIR_UNMERGED(p)) {
+                       diff_q(&outq, p);
+               }
+               else if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
                        /*
                         * Creation
                         *