thodg/got/lib/repository.c

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• Hash : eb77ee11
  Author :
  Date : 2018-07-08T18:06:36
  

  add an object id cache which backs the object cache

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• lib/repository.c

• /*
   * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #include <sys/queue.h>
  #include <sys/stat.h>
  
  #include <limits.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <sha1.h>
  #include <string.h>
  #include <zlib.h>
  
  #include "got_error.h"
  #include "got_reference.h"
  #include "got_repository.h"
  #include "got_worktree.h"
  #include "got_object.h"
  
  #include "got_lib_path.h"
  #include "got_lib_delta.h"
  #include "got_lib_zbuf.h"
  #include "got_lib_object.h"
  #include "got_lib_pack.h"
  #include "got_lib_repository.h"
  #include "got_lib_worktree.h"
  #include "got_lib_object_idcache.h"
  
  #ifndef nitems
  #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
  #endif
  
  #define GOT_GIT_DIR	".git"
  
  /* Mandatory files and directories inside the git directory. */
  #define GOT_OBJECTS_DIR		"objects"
  #define GOT_REFS_DIR		"refs"
  #define GOT_HEAD_FILE		"HEAD"
  
  /* Other files and directories inside the git directory. */
  #define GOT_FETCH_HEAD_FILE	"FETCH_HEAD"
  #define GOT_ORIG_HEAD_FILE	"ORIG_HEAD"
  #define GOT_OBJECTS_PACK_DIR	"objects/pack"
  
  char *
  got_repo_get_path(struct got_repository *repo)
  {
  	return strdup(repo->path);
  }
  
  char *
  got_repo_get_path_git_dir(struct got_repository *repo)
  {
  	return strdup(repo->path_git_dir);
  }
  
  static char *
  get_path_git_child(struct got_repository *repo, const char *basename)
  {
  	char *path_child;
  	
  	if (asprintf(&path_child, "%s/%s", repo->path_git_dir,
  	    basename) == -1)
  		return NULL;
  
  	return path_child;
  }
  
  char *
  got_repo_get_path_objects(struct got_repository *repo)
  {
  	return get_path_git_child(repo, GOT_OBJECTS_DIR);
  }
  
  char *
  got_repo_get_path_objects_pack(struct got_repository *repo)
  {
  	return get_path_git_child(repo, GOT_OBJECTS_PACK_DIR);
  }
  
  char *
  got_repo_get_path_refs(struct got_repository *repo)
  {
  	return get_path_git_child(repo, GOT_REFS_DIR);
  }
  
  static char *
  get_path_head(struct got_repository *repo)
  {
  	return get_path_git_child(repo, GOT_HEAD_FILE);
  }
  
  static int
  is_git_repo(struct got_repository *repo)
  {
  	char *path_git = got_repo_get_path_git_dir(repo);
  	char *path_objects = got_repo_get_path_objects(repo);
  	char *path_refs = got_repo_get_path_refs(repo);
  	char *path_head = get_path_head(repo);
  	int ret = 0;
  	struct stat sb;
  	struct got_reference *head_ref;
  
  	if (lstat(path_git, &sb) == -1)
  		goto done;
  	if (!S_ISDIR(sb.st_mode))
  		goto done;
  
  	if (lstat(path_objects, &sb) == -1)
  		goto done;
  	if (!S_ISDIR(sb.st_mode))
  		goto done;
  
  	if (lstat(path_refs, &sb) == -1)
  		goto done;
  	if (!S_ISDIR(sb.st_mode))
  		goto done;
  
  	if (lstat(path_head, &sb) == -1)
  		goto done;
  	if (!S_ISREG(sb.st_mode))
  		goto done;
  
  	/* Check if the HEAD reference can be opened. */
  	if (got_ref_open(&head_ref, repo, GOT_REF_HEAD) != NULL)
  		goto done;
  	got_ref_close(head_ref);
  
  	ret = 1;
  done:
  	free(path_git);
  	free(path_objects);
  	free(path_refs);
  	free(path_head);
  	return ret;
  
  }
  
  static const struct got_error *
  cache_add(struct got_object_cache *cache, struct got_object_id *id, void *item)
  {
  	const struct got_error *err = NULL;
  	struct got_object_cache_entry *ce;
  	int nelem;
  
  	nelem = got_object_idcache_num_elements(cache->idcache);
  	if (nelem >= cache->size) {
  		err = got_object_idcache_remove_least_used((void **)&ce,
  		    cache->idcache);
  		if (err)
  			return err;
  		switch (cache->type) {
  		case GOT_OBJECT_CACHE_TYPE_OBJ:
  			got_object_close(ce->data.obj);
  			break;
  		case GOT_OBJECT_CACHE_TYPE_TREE:
  			got_object_tree_close(ce->data.tree);
  			break;
  		case GOT_OBJECT_CACHE_TYPE_COMMIT:
  			got_object_commit_close(ce->data.commit);
  			break;
  		}
  		free(ce);
  	}
  
  	ce = calloc(1, sizeof(*ce));
  	if (ce == NULL)
  		return got_error_from_errno();
  	memcpy(&ce->id, id, sizeof(ce->id));
  	switch (cache->type) {
  	case GOT_OBJECT_CACHE_TYPE_OBJ:
  		ce->data.obj = (struct got_object *)item;
  		break;
  	case GOT_OBJECT_CACHE_TYPE_TREE:
  		ce->data.tree = (struct got_tree_object *)item;
  		break;
  	case GOT_OBJECT_CACHE_TYPE_COMMIT:
  		ce->data.commit = (struct got_commit_object *)item;
  		break;
  	}
  	err = got_object_idcache_add(cache->idcache, id, ce);
  	if (err) {
  		if (err->code == GOT_ERR_OBJ_EXISTS) {
  			free(ce);
  			err = NULL;
  		}
  	}
  
  	return err;
  }
  
  const struct got_error *
  got_repo_cache_object(struct got_repository *repo, struct got_object_id *id,
      struct got_object *obj)
  {
  	const struct got_error *err = NULL;
  
  	err = cache_add(&repo->objcache, id, obj);
  	if (err)
  		return err;
  
  	obj->refcnt++;
  	return NULL;
  }
  
  struct got_object *
  got_repo_get_cached_object(struct got_repository *repo,
      struct got_object_id *id)
  {
  	struct got_object_cache_entry *ce;
  
  	ce = got_object_idcache_get(repo->objcache.idcache, id);
  	if (ce) {
  		repo->objcache.cache_hit++;
  		return ce->data.obj;
  	}
  
  	repo->objcache.cache_miss++;
  	return NULL;
  }
  
  const struct got_error *
  got_repo_cache_tree(struct got_repository *repo, struct got_object_id *id,
      struct got_tree_object *tree)
  {
  	const struct got_error *err = NULL;
  
  	err = cache_add(&repo->treecache, id, tree);
  	if (err)
  		return err;
  
  	tree->refcnt++;
  	return NULL;
  }
  
  struct got_tree_object *
  got_repo_get_cached_tree(struct got_repository *repo,
      struct got_object_id *id)
  {
  	struct got_object_cache_entry *ce;
  
  	ce = got_object_idcache_get(repo->treecache.idcache, id);
  	if (ce) {
  		repo->treecache.cache_hit++;
  		return ce->data.tree;
  	}
  
  	repo->treecache.cache_miss++;
  	return NULL;
  }
  
  const struct got_error *
  got_repo_cache_commit(struct got_repository *repo, struct got_object_id *id,
      struct got_commit_object *commit)
  {
  	const struct got_error *err = NULL;
  
  	err = cache_add(&repo->commitcache, id, commit);
  	if (err)
  		return err;
  
  	commit->refcnt++;
  	return NULL;
  }
  
  struct got_commit_object *
  got_repo_get_cached_commit(struct got_repository *repo,
      struct got_object_id *id)
  {
  	struct got_object_cache_entry *ce;
  
  	ce = got_object_idcache_get(repo->commitcache.idcache, id);
  	if (ce) {
  		repo->commitcache.cache_hit++;
  		return ce->data.commit;
  	}
  
  	repo->commitcache.cache_miss++;
  	return NULL;
  }
  
  const struct got_error *
  got_repo_open(struct got_repository **ret, const char *path)
  {
  	struct got_repository *repo = NULL;
  	const struct got_error *err = NULL;
  	char *abspath;
  
  	if (got_path_is_absolute(path))
  		abspath = strdup(path);
  	else
  		abspath = got_path_get_absolute(path);
  	if (abspath == NULL)
  		return got_error(GOT_ERR_BAD_PATH);
  
  	repo = calloc(1, sizeof(*repo));
  	if (repo == NULL) {
  		err = got_error_from_errno();
  		goto done;
  	}
  
  	repo->objcache.type = GOT_OBJECT_CACHE_TYPE_OBJ;
  	repo->objcache.size = GOT_OBJECT_CACHE_SIZE_OBJ;
  	repo->objcache.idcache = got_object_idcache_alloc(repo->objcache.size);
  	if (repo->objcache.idcache == NULL) {
  		err = got_error_from_errno();
  		goto done;
  	}
  
  	repo->treecache.type = GOT_OBJECT_CACHE_TYPE_TREE;
  	repo->treecache.size = GOT_OBJECT_CACHE_SIZE_TREE;
  	repo->treecache.idcache =
  	    got_object_idcache_alloc(repo->treecache.size);
  	if (repo->treecache.idcache == NULL) {
  		err = got_error_from_errno();
  		goto done;
  	}
  
  	repo->commitcache.type = GOT_OBJECT_CACHE_TYPE_COMMIT;
  	repo->commitcache.size = GOT_OBJECT_CACHE_SIZE_COMMIT;
  	repo->commitcache.idcache =
  	    got_object_idcache_alloc(repo->commitcache.size);
  	if (repo->commitcache.idcache == NULL) {
  		err = got_error_from_errno();
  		goto done;
  	}
  
  	repo->path = got_path_normalize(abspath);
  	if (repo->path == NULL) {
  		err = got_error(GOT_ERR_BAD_PATH);
  		goto done;
  	}
  
  	repo->path_git_dir = strdup(repo->path);
  	if (repo->path_git_dir == NULL) {
  		err = got_error_from_errno();
  		goto done;
  	}
  	if (!is_git_repo(repo)) {
  		free(repo->path_git_dir);
  		if (asprintf(&repo->path_git_dir, "%s/%s", repo->path,
  		    GOT_GIT_DIR) == -1) {
  			err = got_error_from_errno();
  			goto done;
  		}
  		if (!is_git_repo(repo)) {
  			struct got_worktree *worktree;
  			if (got_worktree_open(&worktree, repo->path) == NULL) {
  				free(repo->path_git_dir);
  				repo->path_git_dir =
  				    strdup(worktree->repo_path);
  				if (repo->path_git_dir == NULL) {
  					err = got_error_from_errno();
  					goto done;
  				}
  				if (!is_git_repo(repo)) {
  					free(repo->path_git_dir);
  					if (asprintf(&repo->path_git_dir,
  					    "%s/%s", worktree->repo_path,
  					    GOT_GIT_DIR) == -1) {
  						err = got_error_from_errno();
  						goto done;
  					}
  				}
  				got_worktree_close(worktree);
  			}
  		}
  		if (!is_git_repo(repo)) {
  			err = got_error(GOT_ERR_NOT_GIT_REPO);
  			goto done;
  		}
  	}
  		
  	*ret = repo;
  done:
  	if (err)
  		got_repo_close(repo);
  	free(abspath);
  	return err;
  }
  
  #if 0
  static void
  print_cache_stats(struct got_object_cache *cache, const char *name)
  {
  	fprintf(stderr, "%s cache: %d elements, %d hits, %d missed\n",
  	    name, got_object_idcache_num_elements(cache->idcache),
  	    cache->cache_hit, cache->cache_miss);
  }
  
  void check_refcount(struct got_object_id *id, void *data, void *arg)
  {
  	struct got_object_cache *cache = arg;
  	struct got_object_cache_entry *ce = data;
  	struct got_object *obj;
  	struct got_tree_object *tree;
  	struct got_commit_object *commit;
  	char *id_str;
  
  	if (got_object_id_str(&id_str, id) != NULL)
  		return;
  
  	switch (cache->type) {
  	case GOT_OBJECT_CACHE_TYPE_OBJ:
  		obj = ce->data.obj;
  		if (obj->refcnt == 1)
  			break;
  		fprintf(stderr, "object %s has %d unclaimed references\n",
  		    id_str, obj->refcnt - 1);
  		break;
  	case GOT_OBJECT_CACHE_TYPE_TREE:
  		tree = ce->data.tree;
  		if (tree->refcnt == 1)
  			break;
  		fprintf(stderr, "tree %s has %d unclaimed references\n",
  		    id_str, tree->refcnt - 1);
  		break;
  	case GOT_OBJECT_CACHE_TYPE_COMMIT:
  		commit = ce->data.commit;
  		if (commit->refcnt == 1)
  			break;
  		fprintf(stderr, "commit %s has %d unclaimed references\n",
  		    id_str, commit->refcnt);
  		break;
  	}
  	free(id_str);
  }
  #endif
  
  void
  got_repo_close(struct got_repository *repo)
  {
  	int i;
  
  	for (i = 0; i < nitems(repo->packidx_cache); i++) {
  		if (repo->packidx_cache[i] == NULL)
  			break;
  		got_packidx_close(repo->packidx_cache[i]);
  	}
  
  	for (i = 0; i < nitems(repo->packs); i++) {
  		if (repo->packs[i].path_packfile == NULL)
  			break;
  		got_pack_close(&repo->packs[i]);
  	}
  
  	free(repo->path);
  	free(repo->path_git_dir);
  
  #if 0
  	print_cache_stats(&repo->objcache, "object");
  	print_cache_stats(&repo->treecache, "tree");
  	print_cache_stats(&repo->commitcache, "commit");
  	got_object_idcache_for_each(repo->objcache.idcache, check_refcount,
  	    &repo->objcache);
  	got_object_idcache_for_each(repo->treecache.idcache, check_refcount,
  	    &repo->treecache);
  	got_object_idcache_for_each(repo->commitcache.idcache, check_refcount,
  	    &repo->commitcache);
  #endif
  
  	if (repo->objcache.idcache)
  		got_object_idcache_free(repo->objcache.idcache);
  	if (repo->treecache.idcache)
  		got_object_idcache_free(repo->treecache.idcache);
  	if (repo->commitcache.idcache)
  		got_object_idcache_free(repo->commitcache.idcache);
  	free(repo);
  }
  

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