alloc: allow arbitrary repositories for alloc functions

We have to convert all of the alloc functions at once, because alloc_report
uses a funky macro for reporting. It is better for the sake of mechanical
conversion to convert multiple functions at once rather than changing the
structure of the reporting function.

We record all memory allocation in alloc.c, and free them in
clear_alloc_state, which is called for all repositories except
the_repository.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: stefanbeller

alloc.c

@@ -4,8 +4,7 @@
  * Copyright (C) 2006 Linus Torvalds
  *
  * The standard malloc/free wastes too much space for objects, partly because
- * it maintains all the allocation infrastructure (which isn't needed, since
- * we never free an object descriptor anyway), but even more because it ends
+ * it maintains all the allocation infrastructure, but even more because it ends
  * up with maximal alignment because it doesn't know what the object alignment
  * for the new allocation is.
  */
@@ -15,6 +14,7 @@
 #include "tree.h"
 #include "commit.h"
 #include "tag.h"
+#include "alloc.h"
 
 #define BLOCKING 1024
 
@@ -30,69 +30,85 @@ struct alloc_state {
 	int count; /* total number of nodes allocated */
 	int nr;    /* number of nodes left in current allocation */
 	void *p;   /* first free node in current allocation */
+
+	/* bookkeeping of allocations */
+	void **slabs;
+	int slab_nr, slab_alloc;
 };
 
+void *allocate_alloc_state(void)
+{
+	return xcalloc(1, sizeof(struct alloc_state));
+}
+
+void clear_alloc_state(struct alloc_state *s)
+{
+	while (s->slab_nr > 0) {
+		s->slab_nr--;
+		free(s->slabs[s->slab_nr]);
+	}
+
+	FREE_AND_NULL(s->slabs);
+}
+
 static inline void *alloc_node(struct alloc_state *s, size_t node_size)
 {
 	void *ret;
 
 	if (!s->nr) {
 		s->nr = BLOCKING;
 		s->p = xmalloc(BLOCKING * node_size);
+
+		ALLOC_GROW(s->slabs, s->slab_nr + 1, s->slab_alloc);
+		s->slabs[s->slab_nr++] = s->p;
 	}
 	s->nr--;
 	s->count++;
 	ret = s->p;
 	s->p = (char *)s->p + node_size;
 	memset(ret, 0, node_size);
+
 	return ret;
 }
 
-static struct alloc_state blob_state;
-void *alloc_blob_node_the_repository(void)
+void *alloc_blob_node(struct repository *r)
 {
-	struct blob *b = alloc_node(&blob_state, sizeof(struct blob));
+	struct blob *b = alloc_node(r->parsed_objects->blob_state, sizeof(struct blob));
 	b->object.type = OBJ_BLOB;
 	return b;
 }
 
-static struct alloc_state tree_state;
-void *alloc_tree_node_the_repository(void)
+void *alloc_tree_node(struct repository *r)
 {
-	struct tree *t = alloc_node(&tree_state, sizeof(struct tree));
+	struct tree *t = alloc_node(r->parsed_objects->tree_state, sizeof(struct tree));
 	t->object.type = OBJ_TREE;
 	return t;
 }
 
-static struct alloc_state tag_state;
-void *alloc_tag_node_the_repository(void)
+void *alloc_tag_node(struct repository *r)
 {
-	struct tag *t = alloc_node(&tag_state, sizeof(struct tag));
+	struct tag *t = alloc_node(r->parsed_objects->tag_state, sizeof(struct tag));
 	t->object.type = OBJ_TAG;
 	return t;
 }
 
-static struct alloc_state object_state;
-void *alloc_object_node_the_repository(void)
+void *alloc_object_node(struct repository *r)
 {
-	struct object *obj = alloc_node(&object_state, sizeof(union any_object));
+	struct object *obj = alloc_node(r->parsed_objects->object_state, sizeof(union any_object));
 	obj->type = OBJ_NONE;
 	return obj;
 }
 
-static struct alloc_state commit_state;
-
-unsigned int alloc_commit_index_the_repository(void)
+unsigned int alloc_commit_index(struct repository *r)
 {
-	static unsigned int count;
-	return count++;
+	return r->parsed_objects->commit_count++;
 }
 
-void *alloc_commit_node_the_repository(void)
+void *alloc_commit_node(struct repository *r)
 {
-	struct commit *c = alloc_node(&commit_state, sizeof(struct commit));
+	struct commit *c = alloc_node(r->parsed_objects->commit_state, sizeof(struct commit));
 	c->object.type = OBJ_COMMIT;
-	c->index = alloc_commit_index(the_repository);
+	c->index = alloc_commit_index(r);
 	return c;
 }
 
@@ -103,9 +119,10 @@ static void report(const char *name, unsigned int count, size_t size)
 }
 
 #define REPORT(name, type)	\
-    report(#name, name##_state.count, name##_state.count * sizeof(type) >> 10)
+    report(#name, r->parsed_objects->name##_state->count, \
+		  r->parsed_objects->name##_state->count * sizeof(type) >> 10)
 
-void alloc_report_the_repository(void)
+void alloc_report(struct repository *r)
 {
 	REPORT(blob, struct blob);
 	REPORT(tree, struct tree);

alloc.h

@@ -0,0 +1,19 @@
+#ifndef ALLOC_H
+#define ALLOC_H
+
+struct tree;
+struct commit;
+struct tag;
+
+void *alloc_blob_node(struct repository *r);
+void *alloc_tree_node(struct repository *r);
+void *alloc_commit_node(struct repository *r);
+void *alloc_tag_node(struct repository *r);
+void *alloc_object_node(struct repository *r);
+void alloc_report(struct repository *r);
+unsigned int alloc_commit_index(struct repository *r);
+
+void *allocate_alloc_state(void);
+void clear_alloc_state(struct alloc_state *s);
+
+#endif

blame.c

@@ -6,6 +6,7 @@
 #include "diffcore.h"
 #include "tag.h"
 #include "blame.h"
+#include "alloc.h"
 
 void blame_origin_decref(struct blame_origin *o)
 {

blob.c

@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "blob.h"
 #include "repository.h"
+#include "alloc.h"
 
 const char *blob_type = "blob";
 

cache.h

@@ -1763,22 +1763,6 @@ extern const char *excludes_file;
 int decode_85(char *dst, const char *line, int linelen);
 void encode_85(char *buf, const unsigned char *data, int bytes);
 
-/* alloc.c */
-#define alloc_blob_node(r) alloc_blob_node_##r()
-extern void *alloc_blob_node_the_repository(void);
-#define alloc_tree_node(r) alloc_tree_node_##r()
-extern void *alloc_tree_node_the_repository(void);
-#define alloc_commit_node(r) alloc_commit_node_##r()
-extern void *alloc_commit_node_the_repository(void);
-#define alloc_tag_node(r) alloc_tag_node_##r()
-extern void *alloc_tag_node_the_repository(void);
-#define alloc_object_node(r) alloc_object_node_##r()
-extern void *alloc_object_node_the_repository(void);
-#define alloc_report(r) alloc_report_##r()
-extern void alloc_report_the_repository(void);
-#define alloc_commit_index(r) alloc_commit_index_##r()
-extern unsigned int alloc_commit_index_the_repository(void);
-
 /* pkt-line.c */
 void packet_trace_identity(const char *prog);
 

commit.c

@@ -6,6 +6,7 @@
 #include "diff.h"
 #include "revision.h"
 #include "notes.h"
+#include "alloc.h"
 #include "gpg-interface.h"
 #include "mergesort.h"
 #include "commit-slab.h"
@@ -296,6 +297,17 @@ void free_commit_buffer(struct commit *commit)
 	}
 }
 
+void release_commit_memory(struct commit *c)
+{
+	c->tree = NULL;
+	c->index = 0;
+	free_commit_buffer(c);
+	free_commit_list(c->parents);
+	/* TODO: what about commit->util? */
+
+	c->object.parsed = 0;
+}
+
 const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
 {
 	struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);

commit.h

@@ -99,6 +99,12 @@ void unuse_commit_buffer(const struct commit *, const void *buffer);
  */
 void free_commit_buffer(struct commit *);
 
+/*
+ * Release memory related to a commit, including the parent list and
+ * any cached object buffer.
+ */
+void release_commit_memory(struct commit *c);
+
 /*
  * Disassociate any cached object buffer from the commit, but do not free it.
  * The buffer (or NULL, if none) is returned.

merge-recursive.c

@@ -15,6 +15,7 @@
 #include "diff.h"
 #include "diffcore.h"
 #include "tag.h"
+#include "alloc.h"
 #include "unpack-trees.h"
 #include "string-list.h"
 #include "xdiff-interface.h"

object.c

@@ -5,6 +5,7 @@
 #include "tree.h"
 #include "commit.h"
 #include "tag.h"
+#include "alloc.h"
 #include "object-store.h"
 #include "packfile.h"
 
@@ -455,6 +456,13 @@ struct parsed_object_pool *parsed_object_pool_new(void)
 {
 	struct parsed_object_pool *o = xmalloc(sizeof(*o));
 	memset(o, 0, sizeof(*o));
+
+	o->blob_state = allocate_alloc_state();
+	o->tree_state = allocate_alloc_state();
+	o->commit_state = allocate_alloc_state();
+	o->tag_state = allocate_alloc_state();
+	o->object_state = allocate_alloc_state();
+
 	return o;
 }
 
@@ -501,9 +509,39 @@ void raw_object_store_clear(struct raw_object_store *o)
 void parsed_object_pool_clear(struct parsed_object_pool *o)
 {
 	/*
-	 * TOOD free objects in o->obj_hash.
-	 *
 	 * As objects are allocated in slabs (see alloc.c), we do
 	 * not need to free each object, but each slab instead.
+	 *
+	 * Before doing so, we need to free any additional memory
+	 * the objects may hold.
 	 */
+	unsigned i;
+
+	for (i = 0; i < o->obj_hash_size; i++) {
+		struct object *obj = o->obj_hash[i];
+
+		if (!obj)
+			continue;
+
+		if (obj->type == OBJ_TREE)
+			free_tree_buffer((struct tree*)obj);
+		else if (obj->type == OBJ_COMMIT)
+			release_commit_memory((struct commit*)obj);
+		else if (obj->type == OBJ_TAG)
+			release_tag_memory((struct tag*)obj);
+	}
+
+	FREE_AND_NULL(o->obj_hash);
+	o->obj_hash_size = 0;
+
+	clear_alloc_state(o->blob_state);
+	clear_alloc_state(o->tree_state);
+	clear_alloc_state(o->commit_state);
+	clear_alloc_state(o->tag_state);
+	clear_alloc_state(o->object_state);
+	FREE_AND_NULL(o->blob_state);
+	FREE_AND_NULL(o->tree_state);
+	FREE_AND_NULL(o->commit_state);
+	FREE_AND_NULL(o->tag_state);
+	FREE_AND_NULL(o->object_state);
 }

object.h

@@ -4,6 +4,14 @@
 struct parsed_object_pool {
 	struct object **obj_hash;
 	int nr_objs, obj_hash_size;
+
+	/* TODO: migrate alloc_states to mem-pool? */
+	struct alloc_state *blob_state;
+	struct alloc_state *tree_state;
+	struct alloc_state *commit_state;
+	struct alloc_state *tag_state;
+	struct alloc_state *object_state;
+	unsigned commit_count;
 };
 
 struct parsed_object_pool *parsed_object_pool_new(void);