From c8bae7493d2f2910b57f13ded012e86bdcfb0532 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 16:47:53 +0200 Subject: Adding upstream version 1:2.39.2. Signed-off-by: Daniel Baumann --- object-store.h | 550 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 550 insertions(+) create mode 100644 object-store.h (limited to 'object-store.h') diff --git a/object-store.h b/object-store.h new file mode 100644 index 0000000..1be57ab --- /dev/null +++ b/object-store.h @@ -0,0 +1,550 @@ +#ifndef OBJECT_STORE_H +#define OBJECT_STORE_H + +#include "cache.h" +#include "oidmap.h" +#include "list.h" +#include "oid-array.h" +#include "strbuf.h" +#include "thread-utils.h" +#include "khash.h" +#include "dir.h" +#include "oidtree.h" +#include "oidset.h" + +struct object_directory { + struct object_directory *next; + + /* + * Used to store the results of readdir(3) calls when we are OK + * sacrificing accuracy due to races for speed. That includes + * object existence with OBJECT_INFO_QUICK, as well as + * our search for unique abbreviated hashes. Don't use it for tasks + * requiring greater accuracy! + * + * Be sure to call odb_load_loose_cache() before using. + */ + uint32_t loose_objects_subdir_seen[8]; /* 256 bits */ + struct oidtree *loose_objects_cache; + + /* + * This is a temporary object store created by the tmp_objdir + * facility. Disable ref updates since the objects in the store + * might be discarded on rollback. + */ + int disable_ref_updates; + + /* + * This object store is ephemeral, so there is no need to fsync. + */ + int will_destroy; + + /* + * Path to the alternative object store. If this is a relative path, + * it is relative to the current working directory. + */ + char *path; +}; + +struct input_stream { + const void *(*read)(struct input_stream *, unsigned long *len); + void *data; + int is_finished; +}; + +KHASH_INIT(odb_path_map, const char * /* key: odb_path */, + struct object_directory *, 1, fspathhash, fspatheq) + +void prepare_alt_odb(struct repository *r); +char *compute_alternate_path(const char *path, struct strbuf *err); +struct object_directory *find_odb(struct repository *r, const char *obj_dir); +typedef int alt_odb_fn(struct object_directory *, void *); +int foreach_alt_odb(alt_odb_fn, void*); +typedef void alternate_ref_fn(const struct object_id *oid, void *); +void for_each_alternate_ref(alternate_ref_fn, void *); + +/* + * Add the directory to the on-disk alternates file; the new entry will also + * take effect in the current process. + */ +void add_to_alternates_file(const char *dir); + +/* + * Add the directory to the in-memory list of alternates (along with any + * recursive alternates it points to), but do not modify the on-disk alternates + * file. + */ +void add_to_alternates_memory(const char *dir); + +/* + * Replace the current writable object directory with the specified temporary + * object directory; returns the former primary object directory. + */ +struct object_directory *set_temporary_primary_odb(const char *dir, int will_destroy); + +/* + * Restore a previous ODB replaced by set_temporary_main_odb. + */ +void restore_primary_odb(struct object_directory *restore_odb, const char *old_path); + +/* + * Populate and return the loose object cache array corresponding to the + * given object ID. + */ +struct oidtree *odb_loose_cache(struct object_directory *odb, + const struct object_id *oid); + +/* Empty the loose object cache for the specified object directory. */ +void odb_clear_loose_cache(struct object_directory *odb); + +/* Clear and free the specified object directory */ +void free_object_directory(struct object_directory *odb); + +struct packed_git { + struct hashmap_entry packmap_ent; + struct packed_git *next; + struct list_head mru; + struct pack_window *windows; + off_t pack_size; + const void *index_data; + size_t index_size; + uint32_t num_objects; + uint32_t crc_offset; + struct oidset bad_objects; + int index_version; + time_t mtime; + int pack_fd; + int index; /* for builtin/pack-objects.c */ + unsigned pack_local:1, + pack_keep:1, + pack_keep_in_core:1, + freshened:1, + do_not_close:1, + pack_promisor:1, + multi_pack_index:1, + is_cruft:1; + unsigned char hash[GIT_MAX_RAWSZ]; + struct revindex_entry *revindex; + const uint32_t *revindex_data; + const uint32_t *revindex_map; + size_t revindex_size; + /* + * mtimes_map points at the beginning of the memory mapped region of + * this pack's corresponding .mtimes file, and mtimes_size is the size + * of that .mtimes file + */ + const uint32_t *mtimes_map; + size_t mtimes_size; + /* something like ".git/objects/pack/xxxxx.pack" */ + char pack_name[FLEX_ARRAY]; /* more */ +}; + +struct multi_pack_index; + +static inline int pack_map_entry_cmp(const void *cmp_data UNUSED, + const struct hashmap_entry *entry, + const struct hashmap_entry *entry2, + const void *keydata) +{ + const char *key = keydata; + const struct packed_git *pg1, *pg2; + + pg1 = container_of(entry, const struct packed_git, packmap_ent); + pg2 = container_of(entry2, const struct packed_git, packmap_ent); + + return strcmp(pg1->pack_name, key ? key : pg2->pack_name); +} + +struct raw_object_store { + /* + * Set of all object directories; the main directory is first (and + * cannot be NULL after initialization). Subsequent directories are + * alternates. + */ + struct object_directory *odb; + struct object_directory **odb_tail; + kh_odb_path_map_t *odb_by_path; + + int loaded_alternates; + + /* + * A list of alternate object directories loaded from the environment; + * this should not generally need to be accessed directly, but will + * populate the "odb" list when prepare_alt_odb() is run. + */ + char *alternate_db; + + /* + * Objects that should be substituted by other objects + * (see git-replace(1)). + */ + struct oidmap *replace_map; + unsigned replace_map_initialized : 1; + pthread_mutex_t replace_mutex; /* protect object replace functions */ + + struct commit_graph *commit_graph; + unsigned commit_graph_attempted : 1; /* if loading has been attempted */ + + /* + * private data + * + * should only be accessed directly by packfile.c and midx.c + */ + struct multi_pack_index *multi_pack_index; + + /* + * private data + * + * should only be accessed directly by packfile.c + */ + + struct packed_git *packed_git; + /* A most-recently-used ordered version of the packed_git list. */ + struct list_head packed_git_mru; + + struct { + struct packed_git **packs; + unsigned flags; + } kept_pack_cache; + + /* + * A map of packfiles to packed_git structs for tracking which + * packs have been loaded already. + */ + struct hashmap pack_map; + + /* + * A fast, rough count of the number of objects in the repository. + * These two fields are not meant for direct access. Use + * approximate_object_count() instead. + */ + unsigned long approximate_object_count; + unsigned approximate_object_count_valid : 1; + + /* + * Whether packed_git has already been populated with this repository's + * packs. + */ + unsigned packed_git_initialized : 1; +}; + +struct raw_object_store *raw_object_store_new(void); +void raw_object_store_clear(struct raw_object_store *o); + +/* + * Put in `buf` the name of the file in the local object database that + * would be used to store a loose object with the specified oid. + */ +const char *loose_object_path(struct repository *r, struct strbuf *buf, + const struct object_id *oid); + +void *map_loose_object(struct repository *r, const struct object_id *oid, + unsigned long *size); + +void *read_object_file_extended(struct repository *r, + const struct object_id *oid, + enum object_type *type, + unsigned long *size, int lookup_replace); +static inline void *repo_read_object_file(struct repository *r, + const struct object_id *oid, + enum object_type *type, + unsigned long *size) +{ + return read_object_file_extended(r, oid, type, size, 1); +} +#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS +#define read_object_file(oid, type, size) repo_read_object_file(the_repository, oid, type, size) +#endif + +/* Read and unpack an object file into memory, write memory to an object file */ +int oid_object_info(struct repository *r, const struct object_id *, unsigned long *); + +void hash_object_file(const struct git_hash_algo *algo, const void *buf, + unsigned long len, enum object_type type, + struct object_id *oid); + +int write_object_file_flags(const void *buf, unsigned long len, + enum object_type type, struct object_id *oid, + unsigned flags); +static inline int write_object_file(const void *buf, unsigned long len, + enum object_type type, struct object_id *oid) +{ + return write_object_file_flags(buf, len, type, oid, 0); +} + +int write_object_file_literally(const void *buf, unsigned long len, + const char *type, struct object_id *oid, + unsigned flags); +int stream_loose_object(struct input_stream *in_stream, size_t len, + struct object_id *oid); + +/* + * Add an object file to the in-memory object store, without writing it + * to disk. + * + * Callers are responsible for calling write_object_file to record the + * object in persistent storage before writing any other new objects + * that reference it. + */ +int pretend_object_file(void *, unsigned long, enum object_type, + struct object_id *oid); + +int force_object_loose(const struct object_id *oid, time_t mtime); + +/* + * Open the loose object at path, check its hash, and return the contents, + * use the "oi" argument to assert things about the object, or e.g. populate its + * type, and size. If the object is a blob, then "contents" may return NULL, + * to allow streaming of large blobs. + * + * Returns 0 on success, negative on error (details may be written to stderr). + */ +int read_loose_object(const char *path, + const struct object_id *expected_oid, + struct object_id *real_oid, + void **contents, + struct object_info *oi); + +/* Retry packed storage after checking packed and loose storage */ +#define HAS_OBJECT_RECHECK_PACKED 1 + +/* + * Returns 1 if the object exists. This function will not lazily fetch objects + * in a partial clone. + */ +int has_object(struct repository *r, const struct object_id *oid, + unsigned flags); + +/* + * These macros and functions are deprecated. If checking existence for an + * object that is likely to be missing and/or whose absence is relatively + * inconsequential (or is consequential but the caller is prepared to handle + * it), use has_object(), which has better defaults (no lazy fetch in a partial + * clone and no rechecking of packed storage). In the unlikely event that a + * caller needs to assert existence of an object that it fully expects to + * exist, and wants to trigger a lazy fetch in a partial clone, use + * oid_object_info_extended() with a NULL struct object_info. + * + * These functions can be removed once all callers have migrated to + * has_object() and/or oid_object_info_extended(). + */ +int repo_has_object_file(struct repository *r, const struct object_id *oid); +int repo_has_object_file_with_flags(struct repository *r, + const struct object_id *oid, int flags); +#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS +#define has_object_file(oid) repo_has_object_file(the_repository, oid) +#define has_object_file_with_flags(oid, flags) repo_has_object_file_with_flags(the_repository, oid, flags) +#endif + +/* + * Return true iff an alternate object database has a loose object + * with the specified name. This function does not respect replace + * references. + */ +int has_loose_object_nonlocal(const struct object_id *); + +int has_loose_object(const struct object_id *); + +/** + * format_object_header() is a thin wrapper around s xsnprintf() that + * writes the initial " " part of the loose object + * header. It returns the size that snprintf() returns + 1. + */ +int format_object_header(char *str, size_t size, enum object_type type, + size_t objsize); + +void assert_oid_type(const struct object_id *oid, enum object_type expect); + +/* + * Enabling the object read lock allows multiple threads to safely call the + * following functions in parallel: repo_read_object_file(), read_object_file(), + * read_object_file_extended(), read_object_with_reference(), read_object(), + * oid_object_info() and oid_object_info_extended(). + * + * obj_read_lock() and obj_read_unlock() may also be used to protect other + * section which cannot execute in parallel with object reading. Since the used + * lock is a recursive mutex, these sections can even contain calls to object + * reading functions. However, beware that in these cases zlib inflation won't + * be performed in parallel, losing performance. + * + * TODO: oid_object_info_extended()'s call stack has a recursive behavior. If + * any of its callees end up calling it, this recursive call won't benefit from + * parallel inflation. + */ +void enable_obj_read_lock(void); +void disable_obj_read_lock(void); + +extern int obj_read_use_lock; +extern pthread_mutex_t obj_read_mutex; + +static inline void obj_read_lock(void) +{ + if(obj_read_use_lock) + pthread_mutex_lock(&obj_read_mutex); +} + +static inline void obj_read_unlock(void) +{ + if(obj_read_use_lock) + pthread_mutex_unlock(&obj_read_mutex); +} + +struct object_info { + /* Request */ + enum object_type *typep; + unsigned long *sizep; + off_t *disk_sizep; + struct object_id *delta_base_oid; + struct strbuf *type_name; + void **contentp; + + /* Response */ + enum { + OI_CACHED, + OI_LOOSE, + OI_PACKED, + OI_DBCACHED + } whence; + union { + /* + * struct { + * ... Nothing to expose in this case + * } cached; + * struct { + * ... Nothing to expose in this case + * } loose; + */ + struct { + struct packed_git *pack; + off_t offset; + unsigned int is_delta; + } packed; + } u; +}; + +/* + * Initializer for a "struct object_info" that wants no items. You may + * also memset() the memory to all-zeroes. + */ +#define OBJECT_INFO_INIT { 0 } + +/* Invoke lookup_replace_object() on the given hash */ +#define OBJECT_INFO_LOOKUP_REPLACE 1 +/* Allow reading from a loose object file of unknown/bogus type */ +#define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2 +/* Do not retry packed storage after checking packed and loose storage */ +#define OBJECT_INFO_QUICK 8 +/* Do not check loose object */ +#define OBJECT_INFO_IGNORE_LOOSE 16 +/* + * Do not attempt to fetch the object if missing (even if fetch_is_missing is + * nonzero). + */ +#define OBJECT_INFO_SKIP_FETCH_OBJECT 32 +/* + * This is meant for bulk prefetching of missing blobs in a partial + * clone. Implies OBJECT_INFO_SKIP_FETCH_OBJECT and OBJECT_INFO_QUICK + */ +#define OBJECT_INFO_FOR_PREFETCH (OBJECT_INFO_SKIP_FETCH_OBJECT | OBJECT_INFO_QUICK) + +int oid_object_info_extended(struct repository *r, + const struct object_id *, + struct object_info *, unsigned flags); + +/* + * Iterate over the files in the loose-object parts of the object + * directory "path", triggering the following callbacks: + * + * - loose_object is called for each loose object we find. + * + * - loose_cruft is called for any files that do not appear to be + * loose objects. Note that we only look in the loose object + * directories "objects/[0-9a-f]{2}/", so we will not report + * "objects/foobar" as cruft. + * + * - loose_subdir is called for each top-level hashed subdirectory + * of the object directory (e.g., "$OBJDIR/f0"). It is called + * after the objects in the directory are processed. + * + * Any callback that is NULL will be ignored. Callbacks returning non-zero + * will end the iteration. + * + * In the "buf" variant, "path" is a strbuf which will also be used as a + * scratch buffer, but restored to its original contents before + * the function returns. + */ +typedef int each_loose_object_fn(const struct object_id *oid, + const char *path, + void *data); +typedef int each_loose_cruft_fn(const char *basename, + const char *path, + void *data); +typedef int each_loose_subdir_fn(unsigned int nr, + const char *path, + void *data); +int for_each_file_in_obj_subdir(unsigned int subdir_nr, + struct strbuf *path, + each_loose_object_fn obj_cb, + each_loose_cruft_fn cruft_cb, + each_loose_subdir_fn subdir_cb, + void *data); +int for_each_loose_file_in_objdir(const char *path, + each_loose_object_fn obj_cb, + each_loose_cruft_fn cruft_cb, + each_loose_subdir_fn subdir_cb, + void *data); +int for_each_loose_file_in_objdir_buf(struct strbuf *path, + each_loose_object_fn obj_cb, + each_loose_cruft_fn cruft_cb, + each_loose_subdir_fn subdir_cb, + void *data); + +/* Flags for for_each_*_object() below. */ +enum for_each_object_flags { + /* Iterate only over local objects, not alternates. */ + FOR_EACH_OBJECT_LOCAL_ONLY = (1<<0), + + /* Only iterate over packs obtained from the promisor remote. */ + FOR_EACH_OBJECT_PROMISOR_ONLY = (1<<1), + + /* + * Visit objects within a pack in packfile order rather than .idx order + */ + FOR_EACH_OBJECT_PACK_ORDER = (1<<2), + + /* Only iterate over packs that are not marked as kept in-core. */ + FOR_EACH_OBJECT_SKIP_IN_CORE_KEPT_PACKS = (1<<3), + + /* Only iterate over packs that do not have .keep files. */ + FOR_EACH_OBJECT_SKIP_ON_DISK_KEPT_PACKS = (1<<4), +}; + +/* + * Iterate over all accessible loose objects without respect to + * reachability. By default, this includes both local and alternate objects. + * The order in which objects are visited is unspecified. + * + * Any flags specific to packs are ignored. + */ +int for_each_loose_object(each_loose_object_fn, void *, + enum for_each_object_flags flags); + +/* + * Iterate over all accessible packed objects without respect to reachability. + * By default, this includes both local and alternate packs. + * + * Note that some objects may appear twice if they are found in multiple packs. + * Each pack is visited in an unspecified order. By default, objects within a + * pack are visited in pack-idx order (i.e., sorted by oid). + */ +typedef int each_packed_object_fn(const struct object_id *oid, + struct packed_git *pack, + uint32_t pos, + void *data); +int for_each_object_in_pack(struct packed_git *p, + each_packed_object_fn, void *data, + enum for_each_object_flags flags); +int for_each_packed_object(each_packed_object_fn, void *, + enum for_each_object_flags flags); + +#endif /* OBJECT_STORE_H */ -- cgit v1.2.3