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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:34:27 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:34:27 +0000
commit4dbdc42d9e7c3968ff7f690d00680419c9b8cb0f (patch)
tree47c1d492e9c956c1cd2b74dbd3b9d8b0db44dc4e /object-store-ll.h
parentInitial commit. (diff)
downloadgit-4dbdc42d9e7c3968ff7f690d00680419c9b8cb0f.tar.xz
git-4dbdc42d9e7c3968ff7f690d00680419c9b8cb0f.zip
Adding upstream version 1:2.43.0.upstream/1%2.43.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'object-store-ll.h')
-rw-r--r--object-store-ll.h533
1 files changed, 533 insertions, 0 deletions
diff --git a/object-store-ll.h b/object-store-ll.h
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+#ifndef OBJECT_STORE_LL_H
+#define OBJECT_STORE_LL_H
+
+#include "hashmap.h"
+#include "object.h"
+#include "list.h"
+#include "thread-utils.h"
+#include "oidset.h"
+
+struct oidmap;
+struct oidtree;
+struct strbuf;
+
+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;
+};
+
+void prepare_alt_odb(struct repository *r);
+int has_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;
+ size_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;
+ struct kh_odb_path_map *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
+ * repo_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 *repo_read_object_file(struct repository *r,
+ const struct object_id *oid,
+ enum object_type *type,
+ unsigned long *size);
+
+/* 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);
+
+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 attempt to fetch the object if missing (even if fetch_is_missing is
+ * nonzero).
+ */
+#define OBJECT_INFO_SKIP_FETCH_OBJECT 16
+/*
+ * 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)
+
+/* Die if object corruption (not just an object being missing) was detected. */
+#define OBJECT_INFO_DIE_IF_CORRUPT 32
+
+int oid_object_info_extended(struct repository *r,
+ const struct object_id *,
+ struct object_info *, unsigned flags);
+
+/*
+ * 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);
+
+/*
+ * 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 "<type> <obj-len>" 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_with_reference(), 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);
+}
+
+/*
+ * 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_LL_H */