1 files changed, 84 insertions, 36 deletions

diff --git a/split-index.c b/split-index.c
index 21485e2066..84f067e10d 100644
--- a/split-index.c
+++ b/split-index.c
@@ -18,12 +18,12 @@ int read_link_extension(struct index_state *istate,
 	struct split_index *si;
 	int ret;
 
-	if (sz < 20)
+	if (sz < the_hash_algo->rawsz)
 		return error("corrupt link extension (too short)");
 	si = init_split_index(istate);
-	hashcpy(si->base_sha1, data);
-	data += 20;
-	sz -= 20;
+	hashcpy(si->base_oid.hash, data);
+	data += the_hash_algo->rawsz;
+	sz -= the_hash_algo->rawsz;
 	if (!sz)
 		return 0;
 	si->delete_bitmap = ewah_new();
@@ -41,22 +41,15 @@ int read_link_extension(struct index_state *istate,
 	return 0;
 }
 
-static int write_strbuf(void *user_data, const void *data, size_t len)
-{
-	struct strbuf *sb = user_data;
-	strbuf_add(sb, data, len);
-	return len;
-}
-
 int write_link_extension(struct strbuf *sb,
 			 struct index_state *istate)
 {
 	struct split_index *si = istate->split_index;
-	strbuf_add(sb, si->base_sha1, 20);
+	strbuf_add(sb, si->base_oid.hash, the_hash_algo->rawsz);
 	if (!si->delete_bitmap && !si->replace_bitmap)
 		return 0;
-	ewah_serialize_to(si->delete_bitmap, write_strbuf, sb);
-	ewah_serialize_to(si->replace_bitmap, write_strbuf, sb);
+	ewah_serialize_strbuf(si->delete_bitmap, sb);
+	ewah_serialize_strbuf(si->replace_bitmap, sb);
 	return 0;
 }
 
@@ -67,7 +60,7 @@ static void mark_base_index_entries(struct index_state *base)
 	 * To keep track of the shared entries between
 	 * istate->base->cache[] and istate->cache[], base entry
 	 * position is stored in each base entry. All positions start
-	 * from 1 instead of 0, which is resrved to say "this is a new
+	 * from 1 instead of 0, which is reserved to say "this is a new
 	 * entry".
 	 */
 	for (i = 0; i < base->cache_nr; i++)
@@ -80,18 +73,32 @@ void move_cache_to_base_index(struct index_state *istate)
 	int i;
 
 	/*
-	 * do not delete old si->base, its index entries may be shared
-	 * with istate->cache[]. Accept a bit of leaking here because
-	 * this code is only used by short-lived update-index.
+	 * If there was a previous base index, then transfer ownership of allocated
+	 * entries to the parent index.
 	 */
+	if (si->base &&
+		si->base->ce_mem_pool) {
+
+		if (!istate->ce_mem_pool)
+			mem_pool_init(&istate->ce_mem_pool, 0);
+
+		mem_pool_combine(istate->ce_mem_pool, istate->split_index->base->ce_mem_pool);
+	}
+
 	si->base = xcalloc(1, sizeof(*si->base));
 	si->base->version = istate->version;
 	/* zero timestamp disables racy test in ce_write_index() */
 	si->base->timestamp = istate->timestamp;
 	ALLOC_GROW(si->base->cache, istate->cache_nr, si->base->cache_alloc);
 	si->base->cache_nr = istate->cache_nr;
-	memcpy(si->base->cache, istate->cache,
-	       sizeof(*istate->cache) * istate->cache_nr);
+
+	/*
+	 * The mem_pool needs to move with the allocated entries.
+	 */
+	si->base->ce_mem_pool = istate->ce_mem_pool;
+	istate->ce_mem_pool = NULL;
+
+	COPY_ARRAY(si->base->cache, istate->cache, istate->cache_nr);
 	mark_base_index_entries(si->base);
 	for (i = 0; i < si->base->cache_nr; i++)
 		si->base->cache[i]->ce_flags &= ~CE_UPDATE_IN_BASE;
@@ -131,7 +138,7 @@ static void replace_entry(size_t pos, void *data)
 	src->ce_flags |= CE_UPDATE_IN_BASE;
 	src->ce_namelen = dst->ce_namelen;
 	copy_cache_entry(dst, src);
-	free(src);
+	discard_cache_entry(src);
 	si->nr_replacements++;
 }
 
@@ -148,8 +155,7 @@ void merge_base_index(struct index_state *istate)
 	istate->cache	    = NULL;
 	istate->cache_alloc = 0;
 	ALLOC_GROW(istate->cache, istate->cache_nr, istate->cache_alloc);
-	memcpy(istate->cache, si->base->cache,
-	       sizeof(*istate->cache) * istate->cache_nr);
+	COPY_ARRAY(istate->cache, si->base->cache, istate->cache_nr);
 
 	si->nr_deletions = 0;
 	si->nr_replacements = 0;
@@ -176,10 +182,9 @@ void merge_base_index(struct index_state *istate)
 
 	ewah_free(si->delete_bitmap);
 	ewah_free(si->replace_bitmap);
-	free(si->saved_cache);
+	FREE_AND_NULL(si->saved_cache);
 	si->delete_bitmap  = NULL;
 	si->replace_bitmap = NULL;
-	si->saved_cache	   = NULL;
 	si->saved_cache_nr = 0;
 }
 
@@ -196,7 +201,7 @@ void prepare_to_write_split_index(struct index_state *istate)
 		/* Go through istate->cache[] and mark CE_MATCHED to
 		 * entry with positive index. We'll go through
 		 * base->cache[] later to delete all entries in base
-		 * that are not marked eith either CE_MATCHED or
+		 * that are not marked with either CE_MATCHED or
 		 * CE_UPDATE_IN_BASE. If istate->cache[i] is a
 		 * duplicate, deduplicate it.
 		 */
@@ -234,7 +239,7 @@ void prepare_to_write_split_index(struct index_state *istate)
 			base->ce_flags = base_flags;
 			if (ret)
 				ce->ce_flags |= CE_UPDATE_IN_BASE;
-			free(base);
+			discard_cache_entry(base);
 			si->base->cache[ce->index - 1] = ce;
 		}
 		for (i = 0; i < si->base->cache_nr; i++) {
@@ -248,6 +253,8 @@ void prepare_to_write_split_index(struct index_state *istate)
 				ALLOC_GROW(entries, nr_entries+1, nr_alloc);
 				entries[nr_entries++] = ce;
 			}
+			if (is_null_oid(&ce->oid))
+				istate->drop_cache_tree = 1;
 		}
 	}
 
@@ -309,20 +316,61 @@ void save_or_free_index_entry(struct index_state *istate, struct cache_entry *ce
 	    ce == istate->split_index->base->cache[ce->index - 1])
 		ce->ce_flags |= CE_REMOVE;
 	else
-		free(ce);
+		discard_cache_entry(ce);
 }
 
 void replace_index_entry_in_base(struct index_state *istate,
-				 struct cache_entry *old,
-				 struct cache_entry *new)
+				 struct cache_entry *old_entry,
+				 struct cache_entry *new_entry)
 {
-	if (old->index &&
+	if (old_entry->index &&
 	    istate->split_index &&
 	    istate->split_index->base &&
-	    old->index <= istate->split_index->base->cache_nr) {
-		new->index = old->index;
-		if (old != istate->split_index->base->cache[new->index - 1])
-			free(istate->split_index->base->cache[new->index - 1]);
-		istate->split_index->base->cache[new->index - 1] = new;
+	    old_entry->index <= istate->split_index->base->cache_nr) {
+		new_entry->index = old_entry->index;
+		if (old_entry != istate->split_index->base->cache[new_entry->index - 1])
+			discard_cache_entry(istate->split_index->base->cache[new_entry->index - 1]);
+		istate->split_index->base->cache[new_entry->index - 1] = new_entry;
+	}
+}
+
+void add_split_index(struct index_state *istate)
+{
+	if (!istate->split_index) {
+		init_split_index(istate);
+		istate->cache_changed |= SPLIT_INDEX_ORDERED;
+	}
+}
+
+void remove_split_index(struct index_state *istate)
+{
+	if (istate->split_index) {
+		/*
+		 * When removing the split index, we need to move
+		 * ownership of the mem_pool associated with the
+		 * base index to the main index. There may be cache entries
+		 * allocated from the base's memory pool that are shared with
+		 * the_index.cache[].
+		 */
+		mem_pool_combine(istate->ce_mem_pool, istate->split_index->base->ce_mem_pool);
+
+		/*
+		 * The split index no longer owns the mem_pool backing
+		 * its cache array. As we are discarding this index,
+		 * mark the index as having no cache entries, so it
+		 * will not attempt to clean up the cache entries or
+		 * validate them.
+		 */
+		if (istate->split_index->base)
+			istate->split_index->base->cache_nr = 0;
+
+		/*
+		 * We can discard the split index because its
+		 * memory pool has been incorporated into the
+		 * memory pool associated with the the_index.
+		 */
+		discard_split_index(istate);
+
+		istate->cache_changed |= SOMETHING_CHANGED;
 	}
 }