thodg/libgit2/src/odb_mempack.c

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• Hash : 59012bf4
  Author :
  Date : 2018-03-29T09:15:48
  

  odb: mempack: fix leaking objects when freeing mempacks When a ODB mempack gets free'd, we take no measures at all to free its contents, most notably the objects added to the database, resulting in a memory leak. Call `git_mempack_reset` previous to freeing the ODB structures themselves, which takes care of releasing all associated data structures.

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• src/odb_mempack.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "common.h"
  
  #include "git2/object.h"
  #include "git2/sys/odb_backend.h"
  #include "git2/sys/mempack.h"
  #include "fileops.h"
  #include "hash.h"
  #include "odb.h"
  #include "array.h"
  #include "oidmap.h"
  
  #include "git2/odb_backend.h"
  #include "git2/types.h"
  #include "git2/pack.h"
  
  struct memobject {
  	git_oid oid;
  	size_t len;
  	git_otype type;
  	char data[GIT_FLEX_ARRAY];
  };
  
  struct memory_packer_db {
  	git_odb_backend parent;
  	git_oidmap *objects;
  	git_array_t(struct memobject *) commits;
  };
  
  static int impl__write(git_odb_backend *_backend, const git_oid *oid, const void *data, size_t len, git_otype type)
  {
  	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
  	struct memobject *obj = NULL; 
  	khiter_t pos;
  	size_t alloc_len;
  	int rval;
  
  	pos = git_oidmap_put(db->objects, oid, &rval);
  	if (rval < 0)
  		return -1;
  
  	if (rval == 0)
  		return 0;
  
  	GITERR_CHECK_ALLOC_ADD(&alloc_len, sizeof(struct memobject), len);
  	obj = git__malloc(alloc_len);
  	GITERR_CHECK_ALLOC(obj);
  
  	memcpy(obj->data, data, len);
  	git_oid_cpy(&obj->oid, oid);
  	obj->len = len;
  	obj->type = type;
  
  	git_oidmap_set_key_at(db->objects, pos, &obj->oid);
  	git_oidmap_set_value_at(db->objects, pos, obj);
  
  	if (type == GIT_OBJ_COMMIT) {
  		struct memobject **store = git_array_alloc(db->commits);
  		GITERR_CHECK_ALLOC(store);
  		*store = obj;
  	}
  
  	return 0;
  }
  
  static int impl__exists(git_odb_backend *backend, const git_oid *oid)
  {
  	struct memory_packer_db *db = (struct memory_packer_db *)backend;
  
  	return git_oidmap_exists(db->objects, oid);
  }
  
  static int impl__read(void **buffer_p, size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
  {
  	struct memory_packer_db *db = (struct memory_packer_db *)backend;
  	struct memobject *obj = NULL;
  	khiter_t pos;
  
  	pos = git_oidmap_lookup_index(db->objects, oid);
  	if (!git_oidmap_valid_index(db->objects, pos))
  		return GIT_ENOTFOUND;
  
  	obj = git_oidmap_value_at(db->objects, pos);
  
  	*len_p = obj->len;
  	*type_p = obj->type;
  	*buffer_p = git__malloc(obj->len);
  	GITERR_CHECK_ALLOC(*buffer_p);
  
  	memcpy(*buffer_p, obj->data, obj->len);
  	return 0;
  }
  
  static int impl__read_header(size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
  {
  	struct memory_packer_db *db = (struct memory_packer_db *)backend;
  	struct memobject *obj = NULL;
  	khiter_t pos;
  
  	pos = git_oidmap_lookup_index(db->objects, oid);
  	if (!git_oidmap_valid_index(db->objects, pos))
  		return GIT_ENOTFOUND;
  
  	obj = git_oidmap_value_at(db->objects, pos);
  
  	*len_p = obj->len;
  	*type_p = obj->type;
  	return 0;
  }
  
  int git_mempack_dump(git_buf *pack, git_repository *repo, git_odb_backend *_backend)
  {
  	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
  	git_packbuilder *packbuilder;
  	uint32_t i;
  	int err = -1;
  
  	if (git_packbuilder_new(&packbuilder, repo) < 0)
  		return -1;
  
  	for (i = 0; i < db->commits.size; ++i) {
  		struct memobject *commit = db->commits.ptr[i];
  
  		err = git_packbuilder_insert_commit(packbuilder, &commit->oid);
  		if (err < 0)
  			goto cleanup;
  	}
  
  	err = git_packbuilder_write_buf(pack, packbuilder);
  
  cleanup:
  	git_packbuilder_free(packbuilder);
  	return err;
  }
  
  void git_mempack_reset(git_odb_backend *_backend)
  {
  	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
  	struct memobject *object = NULL;
  
  	git_oidmap_foreach_value(db->objects, object, {
  		git__free(object);
  	});
  
  	git_array_clear(db->commits);
  
  	git_oidmap_clear(db->objects);
  }
  
  static void impl__free(git_odb_backend *_backend)
  {
  	struct memory_packer_db *db = (struct memory_packer_db *)_backend;
  
  	git_mempack_reset(_backend);
  	git_oidmap_free(db->objects);
  	git__free(db);
  }
  
  int git_mempack_new(git_odb_backend **out)
  {
  	struct memory_packer_db *db;
  
  	assert(out);
  
  	db = git__calloc(1, sizeof(struct memory_packer_db));
  	GITERR_CHECK_ALLOC(db);
  
  	db->objects = git_oidmap_alloc();
  
  	db->parent.version = GIT_ODB_BACKEND_VERSION;
  	db->parent.read = &impl__read;
  	db->parent.write = &impl__write;
  	db->parent.read_header = &impl__read_header;
  	db->parent.exists = &impl__exists;
  	db->parent.free = &impl__free;
  
  	*out = (git_odb_backend *)db;
  	return 0;
  }
  

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