dedup

commit 8f41ac4be4b5c594892b1be8847706db16405c25
parent d3ec97d4abc70c1e5c87f5ff5f7b4800fdf89bcb
Author: sin <sin@2f30.org>
Date:   Mon, 25 Feb 2019 14:00:40 +0000

Wrap cache global state into a cache context structure

Diffstat:
M
cache.c
 | 
40
++++++++++++++++++++++++++++------------
M
dedup.c
 | 
14
++++++++------
M
dedup.h
 | 
10
++++++----

3 files changed, 42 insertions(+), 22 deletions(-)
diff --git a/cache.c b/cache.c
@@ -14,8 +14,11 @@ struct cache_node {
 	struct cache_entry ent;
 	RB_ENTRY(cache_node) e;
 };
+RB_HEAD(cache_head, cache_node);
 
-static RB_HEAD(cache, cache_node) cache_head;
+struct cache {
+	struct cache_head entries;
+};
 
 static int
 cache_node_cmp(struct cache_node *e1, struct cache_node *e2)
@@ -29,8 +32,8 @@ cache_node_cmp(struct cache_node *e1, struct cache_node *e2)
 		return -1;
 	return 0;
 }
-static RB_PROTOTYPE(cache, cache_node, e, cache_node_cmp);
-static RB_GENERATE(cache, cache_node, e, cache_node_cmp);
+static RB_PROTOTYPE(cache_head, cache_node, e, cache_node_cmp);
+static RB_GENERATE(cache_head, cache_node, e, cache_node_cmp);
 
 static struct cache_node *
 alloc_cache_node(struct cache_entry *ent)
@@ -51,21 +54,21 @@ free_cache_node(struct cache_node *node)
 }
 
 void
-add_cache_entry(struct cache_entry *ent)
+add_cache_entry(struct cache *cache, struct cache_entry *ent)
 {
 	struct cache_node *node;
 
 	node = alloc_cache_node(ent);
-	RB_INSERT(cache, &cache_head, node);
+	RB_INSERT(cache_head, &cache->entries, node);
 }
 
 int
-lookup_cache_entry(struct cache_entry *ent)
+lookup_cache_entry(struct cache *cache, struct cache_entry *ent)
 {
 	struct cache_node *node, key;
 
 	key.ent = *ent;
-	node = RB_FIND(cache, &cache_head, &key);
+	node = RB_FIND(cache_head, &cache->entries, &key);
 	if (node != NULL) {
 		*ent = node->ent;
 		return 0;
@@ -74,21 +77,34 @@ lookup_cache_entry(struct cache_entry *ent)
 }
 
 void
-walk_cache(int (*fn)(struct cache_entry *))
+walk_cache(struct cache *cache, int (*fn)(struct cache_entry *))
 {
 	struct cache_node *node;
 
-	RB_FOREACH(node, cache, &cache_head)
+	RB_FOREACH(node, cache_head, &cache->entries)
 		(*fn)(&node->ent);
 }
 
+struct cache *
+alloc_cache(void)
+{
+	struct cache *cache;
+
+	cache = calloc(1, sizeof(*cache));
+	if (cache == NULL)
+		err(1, "malloc");
+	RB_INIT(&cache->entries);
+	return cache;
+}
+
 void
-free_cache(void)
+free_cache(struct cache *cache)
 {
 	struct cache_node *node, *tmp;
 
-	RB_FOREACH_SAFE(node, cache, &cache_head, tmp) {
-		RB_REMOVE(cache, &cache_head, node);
+	RB_FOREACH_SAFE(node, cache_head, &cache->entries, tmp) {
+		RB_REMOVE(cache_head, &cache->entries, node);
 		free_cache_node(node);
 	}
+	free(cache);
 }
diff --git a/dedup.c b/dedup.c
@@ -32,6 +32,7 @@ struct extract_args {
 };
 
 static struct snapshot_hdr snaphdr;
+static struct cache *cache;
 static int ifd;
 static int sfd;
 static int cfd;
@@ -205,7 +206,7 @@ dedup_chunk(struct snapshot *snap, uint8_t *chunkp, size_t chunk_size)
 	snaphdr.st.comp_size += n;
 
 	memcpy(cache_entry.md, md, sizeof(cache_entry.md));
-	if (lookup_cache_entry(&cache_entry) < 0) {
+	if (lookup_cache_entry(cache, &cache_entry) < 0) {
 		struct blk_desc blk_desc;
 
 		memcpy(&blk_desc.md, md, sizeof(blk_desc.md));
@@ -218,7 +219,7 @@ dedup_chunk(struct snapshot *snap, uint8_t *chunkp, size_t chunk_size)
 		cache_entry.offset = blk_desc.offset;
 		cache_entry.size = blk_desc.size;
 		cache_dirty = 1;
-		add_cache_entry(&cache_entry);
+		add_cache_entry(cache, &cache_entry);
 		cache_misses++;
 
 		snaphdr.st.dedup_size += blk_desc.size;
@@ -387,7 +388,7 @@ rebuild_cache(struct snapshot *snap, void *arg)
 		cache_entry.offset = blk_desc->offset;
 		cache_entry.size = blk_desc->size;
 		cache_dirty = 1;
-		add_cache_entry(&cache_entry);
+		add_cache_entry(cache, &cache_entry);
 	}
 	free(buf);
 	return WALK_CONTINUE;
@@ -450,7 +451,7 @@ load_cache(void)
 
 		if (xread(cfd, &cache_entry, sizeof(cache_entry)) == 0)
 			errx(1, "read: unexpected EOF");
-		add_cache_entry(&cache_entry);
+		add_cache_entry(cache, &cache_entry);
 	}
 }
 
@@ -494,6 +495,7 @@ init(void)
 		xwrite(ifd, &snaphdr, sizeof(snaphdr));
 	}
 
+	cache = alloc_cache();
 	if (cache_nr_entries() != 0)
 		load_cache();
 	else
@@ -508,9 +510,9 @@ term(void)
 
 	if (cache_dirty) {
 		xlseek(cfd, 0, SEEK_SET);
-		walk_cache(flush_cache);
+		walk_cache(cache, flush_cache);
 	}
-	free_cache();
+	free_cache(cache);
 
 	fsync(ifd);
 	fsync(sfd);
diff --git a/dedup.h b/dedup.h
@@ -1,13 +1,15 @@
 #include "config.h"
 #include "types.h"
 
+struct cache;
 struct chunker;
 
 /* cache.c */
-void add_cache_entry(struct cache_entry *ent);
-int lookup_cache_entry(struct cache_entry *ent);
-void walk_cache(int (*fn)(struct cache_entry *));
-void free_cache(void);
+void add_cache_entry(struct cache *cache, struct cache_entry *ent);
+int lookup_cache_entry(struct cache *cache, struct cache_entry *ent);
+void walk_cache(struct cache *cache, int (*fn)(struct cache_entry *));
+struct cache *alloc_cache(void);
+void free_cache(struct cache *cache);
 
 /* chunker.c */
 struct chunker *alloc_chunker(size_t cap, int fd);