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![Elijah Newren](/assets/img/avatar_default.png)
hash.h depends upon and includes repository.h, due to the definition and use of the_hash_algo (defined as the_repository->hash_algo). However, most headers trying to include hash.h are only interested in the layout of the structs like object_id. Move the parts of hash.h that do not depend upon repository.h into a new file hash-ll.h (the "low level" parts of hash.h), and adjust other files to use this new header where the convenience inline functions aren't needed. This allows hash.h and object.h to be fairly small, minimal headers. It also exposes a lot of hidden dependencies on both path.h (which was brought in by repository.h) and repository.h (which was previously implicitly brought in by object.h), so also adjust other files to be more explicit about what they depend upon. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
222 lines
7.8 KiB
C
222 lines
7.8 KiB
C
#ifndef REFS_REF_CACHE_H
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#define REFS_REF_CACHE_H
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#include "hash-ll.h"
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struct ref_dir;
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struct ref_store;
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struct repository;
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/*
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* If this ref_cache is filled lazily, this function is used to load
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* information into the specified ref_dir (shallow or deep, at the
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* option of the ref_store). dirname includes a trailing slash.
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*/
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typedef void fill_ref_dir_fn(struct ref_store *ref_store,
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struct ref_dir *dir, const char *dirname);
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struct ref_cache {
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struct ref_entry *root;
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/* A pointer to the ref_store whose cache this is: */
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struct ref_store *ref_store;
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/*
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* Function used (if necessary) to lazily-fill cache. May be
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* NULL.
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*/
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fill_ref_dir_fn *fill_ref_dir;
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};
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/*
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* Information used (along with the information in ref_entry) to
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* describe a single cached reference. This data structure only
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* occurs embedded in a union in struct ref_entry, and only when
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* (ref_entry->flag & REF_DIR) is zero.
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*/
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struct ref_value {
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/*
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* The name of the object to which this reference resolves
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* (which may be a tag object). If REF_ISBROKEN, this is
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* null. If REF_ISSYMREF, then this is the name of the object
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* referred to by the last reference in the symlink chain.
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*/
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struct object_id oid;
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};
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/*
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* Information used (along with the information in ref_entry) to
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* describe a level in the hierarchy of references. This data
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* structure only occurs embedded in a union in struct ref_entry, and
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* only when (ref_entry.flag & REF_DIR) is set. In that case,
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* (ref_entry.flag & REF_INCOMPLETE) determines whether the references
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* in the directory have already been read:
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*
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* (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
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* or packed references, already read.
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*
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* (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
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* references that hasn't been read yet (nor has any of its
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* subdirectories).
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*
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* Entries within a directory are stored within a growable array of
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* pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
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* sorted are sorted by their component name in strcmp() order and the
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* remaining entries are unsorted.
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*
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* Loose references are read lazily, one directory at a time. When a
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* directory of loose references is read, then all of the references
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* in that directory are stored, and REF_INCOMPLETE stubs are created
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* for any subdirectories, but the subdirectories themselves are not
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* read. The reading is triggered by get_ref_dir().
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*/
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struct ref_dir {
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int nr, alloc;
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/*
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* Entries with index 0 <= i < sorted are sorted by name. New
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* entries are appended to the list unsorted, and are sorted
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* only when required; thus we avoid the need to sort the list
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* after the addition of every reference.
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*/
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int sorted;
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/* The ref_cache containing this entry: */
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struct ref_cache *cache;
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struct ref_entry **entries;
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};
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/*
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* Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
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* REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
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* public values; see refs.h.
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*/
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/* ref_entry represents a directory of references */
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#define REF_DIR 0x10
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/*
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* Entry has not yet been read from disk (used only for REF_DIR
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* entries representing loose references)
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*/
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#define REF_INCOMPLETE 0x20
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/*
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* A ref_entry represents either a reference or a "subdirectory" of
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* references.
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*
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* Each directory in the reference namespace is represented by a
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* ref_entry with (flags & REF_DIR) set and containing a subdir member
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* that holds the entries in that directory that have been read so
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* far. If (flags & REF_INCOMPLETE) is set, then the directory and
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* its subdirectories haven't been read yet. REF_INCOMPLETE is only
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* used for loose reference directories.
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*
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* References are represented by a ref_entry with (flags & REF_DIR)
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* unset and a value member that describes the reference's value. The
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* flag member is at the ref_entry level, but it is also needed to
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* interpret the contents of the value field (in other words, a
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* ref_value object is not very much use without the enclosing
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* ref_entry).
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*
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* Reference names cannot end with slash and directories' names are
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* always stored with a trailing slash (except for the top-level
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* directory, which is always denoted by ""). This has two nice
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* consequences: (1) when the entries in each subdir are sorted
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* lexicographically by name (as they usually are), the references in
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* a whole tree can be generated in lexicographic order by traversing
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* the tree in left-to-right, depth-first order; (2) the names of
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* references and subdirectories cannot conflict, and therefore the
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* presence of an empty subdirectory does not block the creation of a
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* similarly-named reference. (The fact that reference names with the
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* same leading components can conflict *with each other* is a
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* separate issue that is regulated by refs_verify_refname_available().)
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*
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* Please note that the name field contains the fully-qualified
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* reference (or subdirectory) name. Space could be saved by only
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* storing the relative names. But that would require the full names
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* to be generated on the fly when iterating in do_for_each_ref(), and
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* would break callback functions, who have always been able to assume
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* that the name strings that they are passed will not be freed during
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* the iteration.
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*/
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struct ref_entry {
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unsigned char flag; /* ISSYMREF? ISPACKED? */
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union {
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struct ref_value value; /* if not (flags&REF_DIR) */
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struct ref_dir subdir; /* if (flags&REF_DIR) */
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} u;
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/*
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* The full name of the reference (e.g., "refs/heads/master")
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* or the full name of the directory with a trailing slash
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* (e.g., "refs/heads/"):
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*/
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char name[FLEX_ARRAY];
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};
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/*
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* Return the index of the entry with the given refname from the
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* ref_dir (non-recursively), sorting dir if necessary. Return -1 if
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* no such entry is found. dir must already be complete.
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*/
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int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len);
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struct ref_dir *get_ref_dir(struct ref_entry *entry);
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/*
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* Create a struct ref_entry object for the specified dirname.
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* dirname is the name of the directory with a trailing slash (e.g.,
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* "refs/heads/") or "" for the top-level directory.
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*/
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struct ref_entry *create_dir_entry(struct ref_cache *cache,
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const char *dirname, size_t len);
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struct ref_entry *create_ref_entry(const char *refname,
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const struct object_id *oid, int flag);
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/*
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* Return a pointer to a new `ref_cache`. Its top-level starts out
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* marked incomplete. If `fill_ref_dir` is non-NULL, it is the
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* function called to fill in incomplete directories in the
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* `ref_cache` when they are accessed. If it is NULL, then the whole
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* `ref_cache` must be filled (including clearing its directories'
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* `REF_INCOMPLETE` bits) before it is used, and `refs` can be NULL,
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* too.
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*/
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struct ref_cache *create_ref_cache(struct ref_store *refs,
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fill_ref_dir_fn *fill_ref_dir);
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/*
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* Free the `ref_cache` and all of its associated data.
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*/
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void free_ref_cache(struct ref_cache *cache);
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/*
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* Add a ref_entry to the end of dir (unsorted). Entry is always
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* stored directly in dir; no recursion into subdirectories is
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* done.
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*/
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void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry);
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/*
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* Find the value entry with the given name in dir, sorting ref_dirs
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* and recursing into subdirectories as necessary. If the name is not
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* found or it corresponds to a directory entry, return NULL.
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*/
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struct ref_entry *find_ref_entry(struct ref_dir *dir, const char *refname);
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/*
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* Start iterating over references in `cache`. If `prefix` is
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* specified, only include references whose names start with that
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* prefix. If `prime_dir` is true, then fill any incomplete
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* directories before beginning the iteration. The output is ordered
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* by refname.
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*/
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struct ref_iterator *cache_ref_iterator_begin(struct ref_cache *cache,
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const char *prefix,
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struct repository *repo,
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int prime_dir);
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#endif /* REFS_REF_CACHE_H */
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