Merge branch 'tb/pack-bitmap'

Various improvements to the codepath that writes out pack bitmaps.

* tb/pack-bitmap: (24 commits)
  pack-bitmap-write: better reuse bitmaps
  pack-bitmap-write: relax unique revwalk condition
  pack-bitmap-write: use existing bitmaps
  pack-bitmap: factor out 'add_commit_to_bitmap()'
  pack-bitmap: factor out 'bitmap_for_commit()'
  pack-bitmap-write: ignore BITMAP_FLAG_REUSE
  pack-bitmap-write: build fewer intermediate bitmaps
  pack-bitmap.c: check reads more aggressively when loading
  pack-bitmap-write: rename children to reverse_edges
  t5310: add branch-based checks
  commit: implement commit_list_contains()
  bitmap: implement bitmap_is_subset()
  pack-bitmap-write: fill bitmap with commit history
  pack-bitmap-write: pass ownership of intermediate bitmaps
  pack-bitmap-write: reimplement bitmap writing
  ewah: add bitmap_dup() function
  ewah: implement bitmap_or()
  ewah: make bitmap growth less aggressive
  ewah: factor out bitmap growth
  rev-list: die when --test-bitmap detects a mismatch
  ...

Author: gitster

builtin/pack-objects.c

@@ -1104,7 +1104,6 @@ static void write_pack_file(void)
 				stop_progress(&progress_state);
 
 				bitmap_writer_show_progress(progress);
-				bitmap_writer_reuse_bitmaps(&to_pack);
 				bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 				bitmap_writer_build(&to_pack);
 				bitmap_writer_finish(written_list, nr_written,

commit.c

@@ -544,6 +544,17 @@ struct commit_list *commit_list_insert(struct commit *item, struct commit_list *
 	return new_list;
 }
 
+int commit_list_contains(struct commit *item, struct commit_list *list)
+{
+	while (list) {
+		if (list->item == item)
+			return 1;
+		list = list->next;
+	}
+
+	return 0;
+}
+
 unsigned commit_list_count(const struct commit_list *l)
 {
 	unsigned c = 0;

commit.h

@@ -167,6 +167,8 @@ int find_commit_subject(const char *commit_buffer, const char **subject);
 
 struct commit_list *commit_list_insert(struct commit *item,
 					struct commit_list **list);
+int commit_list_contains(struct commit *item,
+			 struct commit_list *list);
 struct commit_list **commit_list_append(struct commit *commit,
 					struct commit_list **next);
 unsigned commit_list_count(const struct commit_list *l);

ewah/bitmap.c

@@ -35,18 +35,26 @@ struct bitmap *bitmap_new(void)
 	return bitmap_word_alloc(32);
 }
 
+struct bitmap *bitmap_dup(const struct bitmap *src)
+{
+	struct bitmap *dst = bitmap_word_alloc(src->word_alloc);
+	COPY_ARRAY(dst->words, src->words, src->word_alloc);
+	return dst;
+}
+
+static void bitmap_grow(struct bitmap *self, size_t word_alloc)
+{
+	size_t old_size = self->word_alloc;
+	ALLOC_GROW(self->words, word_alloc, self->word_alloc);
+	memset(self->words + old_size, 0x0,
+	       (self->word_alloc - old_size) * sizeof(eword_t));
+}
+
 void bitmap_set(struct bitmap *self, size_t pos)
 {
 	size_t block = EWAH_BLOCK(pos);
 
-	if (block >= self->word_alloc) {
-		size_t old_size = self->word_alloc;
-		self->word_alloc = block ? block * 2 : 1;
-		REALLOC_ARRAY(self->words, self->word_alloc);
-		memset(self->words + old_size, 0x0,
-			(self->word_alloc - old_size) * sizeof(eword_t));
-	}
-
+	bitmap_grow(self, block + 1);
 	self->words[block] |= EWAH_MASK(pos);
 }
 
@@ -121,6 +129,15 @@ void bitmap_and_not(struct bitmap *self, struct bitmap *other)
 		self->words[i] &= ~other->words[i];
 }
 
+void bitmap_or(struct bitmap *self, const struct bitmap *other)
+{
+	size_t i;
+
+	bitmap_grow(self, other->word_alloc);
+	for (i = 0; i < other->word_alloc; i++)
+		self->words[i] |= other->words[i];
+}
+
 void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other)
 {
 	size_t original_size = self->word_alloc;
@@ -178,6 +195,27 @@ int bitmap_equals(struct bitmap *self, struct bitmap *other)
 	return 1;
 }
 
+int bitmap_is_subset(struct bitmap *self, struct bitmap *other)
+{
+	size_t common_size, i;
+
+	if (self->word_alloc < other->word_alloc)
+		common_size = self->word_alloc;
+	else {
+		common_size = other->word_alloc;
+		for (i = common_size; i < self->word_alloc; i++) {
+			if (self->words[i])
+				return 1;
+		}
+	}
+
+	for (i = 0; i < common_size; i++) {
+		if (self->words[i] & ~other->words[i])
+			return 1;
+	}
+	return 0;
+}
+
 void bitmap_reset(struct bitmap *bitmap)
 {
 	memset(bitmap->words, 0x0, bitmap->word_alloc * sizeof(eword_t));

ewah/ewah_bitmap.c

@@ -19,6 +19,7 @@
 #include "git-compat-util.h"
 #include "ewok.h"
 #include "ewok_rlw.h"
+#include "cache.h"
 
 static inline size_t min_size(size_t a, size_t b)
 {
@@ -33,20 +34,13 @@ static inline size_t max_size(size_t a, size_t b)
 static inline void buffer_grow(struct ewah_bitmap *self, size_t new_size)
 {
 	size_t rlw_offset = (uint8_t *)self->rlw - (uint8_t *)self->buffer;
-
-	if (self->alloc_size >= new_size)
-		return;
-
-	self->alloc_size = new_size;
-	REALLOC_ARRAY(self->buffer, self->alloc_size);
+	ALLOC_GROW(self->buffer, new_size, self->alloc_size);
 	self->rlw = self->buffer + (rlw_offset / sizeof(eword_t));
 }
 
 static inline void buffer_push(struct ewah_bitmap *self, eword_t value)
 {
-	if (self->buffer_size + 1 >= self->alloc_size)
-		buffer_grow(self, self->buffer_size * 3 / 2);
-
+	buffer_grow(self, self->buffer_size + 1);
 	self->buffer[self->buffer_size++] = value;
 }
 
@@ -137,8 +131,7 @@ void ewah_add_dirty_words(
 
 		rlw_set_literal_words(self->rlw, literals + can_add);
 
-		if (self->buffer_size + can_add >= self->alloc_size)
-			buffer_grow(self, (self->buffer_size + can_add) * 3 / 2);
+		buffer_grow(self, self->buffer_size + can_add);
 
 		if (negate) {
 			size_t i;

ewah/ewok.h

@@ -173,13 +173,14 @@ struct bitmap {
 
 struct bitmap *bitmap_new(void);
 struct bitmap *bitmap_word_alloc(size_t word_alloc);
+struct bitmap *bitmap_dup(const struct bitmap *src);
 void bitmap_set(struct bitmap *self, size_t pos);
 void bitmap_unset(struct bitmap *self, size_t pos);
 int bitmap_get(struct bitmap *self, size_t pos);
 void bitmap_reset(struct bitmap *self);
 void bitmap_free(struct bitmap *self);
 int bitmap_equals(struct bitmap *self, struct bitmap *other);
-int bitmap_is_subset(struct bitmap *self, struct bitmap *super);
+int bitmap_is_subset(struct bitmap *self, struct bitmap *other);
 
 struct ewah_bitmap * bitmap_to_ewah(struct bitmap *bitmap);
 struct bitmap *ewah_to_bitmap(struct ewah_bitmap *ewah);