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Merge branch 'ps/avoid-unnecessary-hook-invocation-with-packed-refs'
[thirdparty/git.git] / refs / refs-internal.h
CommitLineData
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1#ifndef REFS_REFS_INTERNAL_H
2#define REFS_REFS_INTERNAL_H
3
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RJ
4#include "cache.h"
5#include "refs.h"
13f925f3 6#include "iterator.h"
91c2f204 7
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8struct ref_transaction;
9
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10/*
11 * Data structures and functions for the internal use of the refs
12 * module. Code outside of the refs module should use only the public
13 * functions defined in "refs.h", and should *not* include this file.
14 */
15
16/*
5ac95fee 17 * The following flags can appear in `ref_update::flags`. Their
91774afc 18 * numerical values must not conflict with those of REF_NO_DEREF and
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19 * REF_FORCE_CREATE_REFLOG, which are also stored in
20 * `ref_update::flags`.
4cb77009 21 */
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22
23/*
78fb4579 24 * The reference should be updated to new_oid.
4cb77009 25 */
5ac95fee 26#define REF_HAVE_NEW (1 << 2)
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27
28/*
5ac95fee 29 * The current reference's value should be checked to make sure that
78fb4579 30 * it agrees with old_oid.
4cb77009 31 */
5ac95fee 32#define REF_HAVE_OLD (1 << 3)
44639777 33
63c05673
HWN
34/*
35 * Used as a flag in ref_update::flags when we want to log a ref
36 * update but not actually perform it. This is used when a symbolic
37 * ref update is split up.
38 */
39#define REF_LOG_ONLY (1 << 7)
40
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41/*
42 * Return the length of time to retry acquiring a loose reference lock
43 * before giving up, in milliseconds:
44 */
45long get_files_ref_lock_timeout_ms(void);
46
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47/*
48 * Return true iff refname is minimally safe. "Safe" here means that
49 * deleting a loose reference by this name will not do any damage, for
50 * example by causing a file that is not a reference to be deleted.
51 * This function does not check that the reference name is legal; for
52 * that, use check_refname_format().
53 *
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54 * A refname that starts with "refs/" is considered safe iff it
55 * doesn't contain any "." or ".." components or consecutive '/'
56 * characters, end with '/', or (on Windows) contain any '\'
57 * characters. Names that do not start with "refs/" are considered
58 * safe iff they consist entirely of upper case characters and '_'
59 * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR").
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60 */
61int refname_is_safe(const char *refname);
62
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63/*
64 * Helper function: return true if refname, which has the specified
65 * oid and flags, can be resolved to an object in the database. If the
66 * referred-to object does not exist, emit a warning and return false.
67 */
68int ref_resolves_to_object(const char *refname,
9bc45a28 69 struct repository *repo,
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70 const struct object_id *oid,
71 unsigned int flags);
72
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73enum peel_status {
74 /* object was peeled successfully: */
75 PEEL_PEELED = 0,
76
77 /*
78 * object cannot be peeled because the named object (or an
79 * object referred to by a tag in the peel chain), does not
80 * exist.
81 */
82 PEEL_INVALID = -1,
83
84 /* object cannot be peeled because it is not a tag: */
85 PEEL_NON_TAG = -2,
86
87 /* ref_entry contains no peeled value because it is a symref: */
88 PEEL_IS_SYMREF = -3,
89
90 /*
91 * ref_entry cannot be peeled because it is broken (i.e., the
92 * symbolic reference cannot even be resolved to an object
93 * name):
94 */
95 PEEL_BROKEN = -4
96};
97
98/*
99 * Peel the named object; i.e., if the object is a tag, resolve the
100 * tag recursively until a non-tag is found. If successful, store the
ac2ed0d7 101 * result to oid and return PEEL_PEELED. If the object is not a tag
4cb77009 102 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
78fb4579 103 * and leave oid unchanged.
4cb77009 104 */
ac2ed0d7 105enum peel_status peel_object(const struct object_id *name, struct object_id *oid);
4cb77009 106
4cb77009 107/**
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108 * Information needed for a single ref update. Set new_oid to the new
109 * value or to null_oid to delete the ref. To check the old value
110 * while the ref is locked, set (flags & REF_HAVE_OLD) and set old_oid
111 * to the old value, or to null_oid to ensure the ref does not exist
112 * before update.
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113 */
114struct ref_update {
115 /*
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116 * If (flags & REF_HAVE_NEW), set the reference to this value
117 * (or delete it, if `new_oid` is `null_oid`).
4cb77009 118 */
98491298 119 struct object_id new_oid;
6e30b2f6 120
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121 /*
122 * If (flags & REF_HAVE_OLD), check that the reference
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123 * previously had this value (or didn't previously exist, if
124 * `old_oid` is `null_oid`).
4cb77009 125 */
98491298 126 struct object_id old_oid;
6e30b2f6 127
4cb77009 128 /*
91774afc 129 * One or more of REF_NO_DEREF, REF_FORCE_CREATE_REFLOG,
5ac95fee 130 * REF_HAVE_NEW, REF_HAVE_OLD, or backend-specific flags.
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131 */
132 unsigned int flags;
6e30b2f6 133
7d618264 134 void *backend_data;
92b1551b 135 unsigned int type;
4cb77009 136 char *msg;
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137
138 /*
139 * If this ref_update was split off of a symref update via
140 * split_symref_update(), then this member points at that
141 * update. This is used for two purposes:
142 * 1. When reporting errors, we report the refname under which
143 * the update was originally requested.
144 * 2. When we read the old value of this reference, we
145 * propagate it back to its parent update for recording in
146 * the latter's reflog.
147 */
148 struct ref_update *parent_update;
149
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150 const char refname[FLEX_ARRAY];
151};
152
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153int refs_read_raw_ref(struct ref_store *ref_store, const char *refname,
154 struct object_id *oid, struct strbuf *referent,
155 unsigned int *type, int *failure_errno);
470be518 156
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157/*
158 * Write an error to `err` and return a nonzero value iff the same
159 * refname appears multiple times in `refnames`. `refnames` must be
160 * sorted on entry to this function.
161 */
162int ref_update_reject_duplicates(struct string_list *refnames,
163 struct strbuf *err);
164
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165/*
166 * Add a ref_update with the specified properties to transaction, and
167 * return a pointer to the new object. This function does not verify
78fb4579 168 * that refname is well-formed. new_oid and old_oid are only
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169 * dereferenced if the REF_HAVE_NEW and REF_HAVE_OLD bits,
170 * respectively, are set in flags.
171 */
172struct ref_update *ref_transaction_add_update(
173 struct ref_transaction *transaction,
174 const char *refname, unsigned int flags,
89f3bbdd 175 const struct object_id *new_oid,
176 const struct object_id *old_oid,
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177 const char *msg);
178
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179/*
180 * Transaction states.
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181 *
182 * OPEN: The transaction is initialized and new updates can still be
183 * added to it. An OPEN transaction can be prepared,
184 * committed, freed, or aborted (freeing and aborting an open
185 * transaction are equivalent).
186 *
187 * PREPARED: ref_transaction_prepare(), which locks all of the
188 * references involved in the update and checks that the
189 * update has no errors, has been called successfully for the
190 * transaction. A PREPARED transaction can be committed or
191 * aborted.
192 *
193 * CLOSED: The transaction is no longer active. A transaction becomes
194 * CLOSED if there is a failure while building the transaction
195 * or if a transaction is committed or aborted. A CLOSED
196 * transaction can only be freed.
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197 */
198enum ref_transaction_state {
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199 REF_TRANSACTION_OPEN = 0,
200 REF_TRANSACTION_PREPARED = 1,
201 REF_TRANSACTION_CLOSED = 2
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202};
203
204/*
205 * Data structure for holding a reference transaction, which can
206 * consist of checks and updates to multiple references, carried out
207 * as atomically as possible. This structure is opaque to callers.
208 */
209struct ref_transaction {
c0fe4e8b 210 struct ref_store *ref_store;
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211 struct ref_update **updates;
212 size_t alloc;
213 size_t nr;
214 enum ref_transaction_state state;
3bf4f561 215 void *backend_data;
fbe73f61 216 unsigned int flags;
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217};
218
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219/*
220 * Check for entries in extras that are within the specified
221 * directory, where dirname is a reference directory name including
222 * the trailing slash (e.g., "refs/heads/foo/"). Ignore any
223 * conflicting references that are found in skip. If there is a
224 * conflicting reference, return its name.
225 *
226 * extras and skip must be sorted lists of reference names. Either one
227 * can be NULL, signifying the empty list.
228 */
229const char *find_descendant_ref(const char *dirname,
230 const struct string_list *extras,
231 const struct string_list *skip);
232
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233/* We allow "recursive" symbolic refs. Only within reason, though */
234#define SYMREF_MAXDEPTH 5
93770590 235
bf708add 236/*
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237 * These flags are passed to refs_ref_iterator_begin() (and do_for_each_ref(),
238 * which feeds it).
bf708add 239 */
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240enum do_for_each_ref_flags {
241 /*
242 * Include broken references in a do_for_each_ref*() iteration, which
243 * would normally be omitted. This includes both refs that point to
244 * missing objects (a true repository corruption), ones with illegal
245 * names (which we prefer not to expose to callers), as well as
246 * dangling symbolic refs (i.e., those that point to a non-existent
247 * ref; this is not a corruption, but as they have no valid oid, we
248 * omit them from normal iteration results).
249 */
250 DO_FOR_EACH_INCLUDE_BROKEN = (1 << 0),
251
252 /*
253 * Only include per-worktree refs in a do_for_each_ref*() iteration.
254 * Normally this will be used with a files ref_store, since that's
255 * where all reference backends will presumably store their
256 * per-worktree refs.
257 */
258 DO_FOR_EACH_PER_WORKTREE_ONLY = (1 << 1),
8dccb224
JK
259
260 /*
261 * Omit dangling symrefs from output; this only has an effect with
262 * INCLUDE_BROKEN, since they are otherwise not included at all.
263 */
264 DO_FOR_EACH_OMIT_DANGLING_SYMREFS = (1 << 2),
9aab952e 265};
93770590 266
3bc581b9
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267/*
268 * Reference iterators
269 *
270 * A reference iterator encapsulates the state of an in-progress
271 * iteration over references. Create an instance of `struct
272 * ref_iterator` via one of the functions in this module.
273 *
274 * A freshly-created ref_iterator doesn't yet point at a reference. To
275 * advance the iterator, call ref_iterator_advance(). If successful,
276 * this sets the iterator's refname, oid, and flags fields to describe
277 * the next reference and returns ITER_OK. The data pointed at by
278 * refname and oid belong to the iterator; if you want to retain them
279 * after calling ref_iterator_advance() again or calling
280 * ref_iterator_abort(), you must make a copy. When the iteration has
281 * been exhausted, ref_iterator_advance() releases any resources
15beaaa3 282 * associated with the iteration, frees the ref_iterator object, and
3bc581b9
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283 * returns ITER_DONE. If you want to abort the iteration early, call
284 * ref_iterator_abort(), which also frees the ref_iterator object and
285 * any associated resources. If there was an internal error advancing
286 * to the next entry, ref_iterator_advance() aborts the iteration,
287 * frees the ref_iterator, and returns ITER_ERROR.
288 *
289 * The reference currently being looked at can be peeled by calling
290 * ref_iterator_peel(). This function is often faster than peel_ref(),
291 * so it should be preferred when iterating over references.
292 *
293 * Putting it all together, a typical iteration looks like this:
294 *
295 * int ok;
296 * struct ref_iterator *iter = ...;
297 *
298 * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
299 * if (want_to_stop_iteration()) {
300 * ok = ref_iterator_abort(iter);
301 * break;
302 * }
303 *
304 * // Access information about the current reference:
305 * if (!(iter->flags & REF_ISSYMREF))
7b6057c8 306 * printf("%s is %s\n", iter->refname, oid_to_hex(iter->oid));
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307 *
308 * // If you need to peel the reference:
309 * ref_iterator_peel(iter, &oid);
310 * }
311 *
312 * if (ok != ITER_DONE)
313 * handle_error();
314 */
315struct ref_iterator {
316 struct ref_iterator_vtable *vtable;
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317
318 /*
319 * Does this `ref_iterator` iterate over references in order
320 * by refname?
321 */
322 unsigned int ordered : 1;
323
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324 const char *refname;
325 const struct object_id *oid;
326 unsigned int flags;
327};
328
329/*
330 * Advance the iterator to the first or next item and return ITER_OK.
331 * If the iteration is exhausted, free the resources associated with
332 * the ref_iterator and return ITER_DONE. On errors, free the iterator
333 * resources and return ITER_ERROR. It is a bug to use ref_iterator or
334 * call this function again after it has returned ITER_DONE or
335 * ITER_ERROR.
336 */
337int ref_iterator_advance(struct ref_iterator *ref_iterator);
338
339/*
340 * If possible, peel the reference currently being viewed by the
341 * iterator. Return 0 on success.
342 */
343int ref_iterator_peel(struct ref_iterator *ref_iterator,
344 struct object_id *peeled);
345
346/*
347 * End the iteration before it has been exhausted, freeing the
348 * reference iterator and any associated resources and returning
349 * ITER_DONE. If the abort itself failed, return ITER_ERROR.
350 */
351int ref_iterator_abort(struct ref_iterator *ref_iterator);
352
353/*
354 * An iterator over nothing (its first ref_iterator_advance() call
355 * returns ITER_DONE).
356 */
357struct ref_iterator *empty_ref_iterator_begin(void);
358
359/*
360 * Return true iff ref_iterator is an empty_ref_iterator.
361 */
362int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
363
e121b9cb
MH
364/*
365 * Return an iterator that goes over each reference in `refs` for
366 * which the refname begins with prefix. If trim is non-zero, then
84ee4ca1 367 * trim that many characters off the beginning of each refname.
9aab952e 368 * The output is ordered by refname.
e121b9cb
MH
369 */
370struct ref_iterator *refs_ref_iterator_begin(
371 struct ref_store *refs,
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372 const char *prefix, int trim,
373 enum do_for_each_ref_flags flags);
e121b9cb 374
3bc581b9
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375/*
376 * A callback function used to instruct merge_ref_iterator how to
377 * interleave the entries from iter0 and iter1. The function should
378 * return one of the constants defined in enum iterator_selection. It
379 * must not advance either of the iterators itself.
380 *
381 * The function must be prepared to handle the case that iter0 and/or
382 * iter1 is NULL, which indicates that the corresponding sub-iterator
383 * has been exhausted. Its return value must be consistent with the
384 * current states of the iterators; e.g., it must not return
385 * ITER_SKIP_1 if iter1 has already been exhausted.
386 */
387typedef enum iterator_selection ref_iterator_select_fn(
388 struct ref_iterator *iter0, struct ref_iterator *iter1,
389 void *cb_data);
390
391/*
392 * Iterate over the entries from iter0 and iter1, with the values
393 * interleaved as directed by the select function. The iterator takes
394 * ownership of iter0 and iter1 and frees them when the iteration is
8738a8a4
MH
395 * over. A derived class should set `ordered` to 1 or 0 based on
396 * whether it generates its output in order by reference name.
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397 */
398struct ref_iterator *merge_ref_iterator_begin(
8738a8a4 399 int ordered,
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400 struct ref_iterator *iter0, struct ref_iterator *iter1,
401 ref_iterator_select_fn *select, void *cb_data);
402
403/*
404 * An iterator consisting of the union of the entries from front and
405 * back. If there are entries common to the two sub-iterators, use the
406 * one from front. Each iterator must iterate over its entries in
407 * strcmp() order by refname for this to work.
408 *
409 * The new iterator takes ownership of its arguments and frees them
410 * when the iteration is over. As a convenience to callers, if front
411 * or back is an empty_ref_iterator, then abort that one immediately
412 * and return the other iterator directly, without wrapping it.
413 */
414struct ref_iterator *overlay_ref_iterator_begin(
415 struct ref_iterator *front, struct ref_iterator *back);
416
417/*
418 * Wrap iter0, only letting through the references whose names start
419 * with prefix. If trim is set, set iter->refname to the name of the
420 * reference with that many characters trimmed off the front;
421 * otherwise set it to the full refname. The new iterator takes over
422 * ownership of iter0 and frees it when iteration is over. It makes
423 * its own copy of prefix.
424 *
425 * As an convenience to callers, if prefix is the empty string and
426 * trim is zero, this function returns iter0 directly, without
427 * wrapping it.
8738a8a4
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428 *
429 * The resulting ref_iterator is ordered if iter0 is.
3bc581b9
MH
430 */
431struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
432 const char *prefix,
433 int trim);
434
3bc581b9
MH
435/* Internal implementation of reference iteration: */
436
437/*
438 * Base class constructor for ref_iterators. Initialize the
439 * ref_iterator part of iter, setting its vtable pointer as specified.
8738a8a4
MH
440 * `ordered` should be set to 1 if the iterator will iterate over
441 * references in order by refname; otherwise it should be set to 0.
3bc581b9
MH
442 * This is meant to be called only by the initializers of derived
443 * classes.
444 */
445void base_ref_iterator_init(struct ref_iterator *iter,
8738a8a4
MH
446 struct ref_iterator_vtable *vtable,
447 int ordered);
3bc581b9
MH
448
449/*
450 * Base class destructor for ref_iterators. Destroy the ref_iterator
451 * part of iter and shallow-free the object. This is meant to be
452 * called only by the destructors of derived classes.
453 */
454void base_ref_iterator_free(struct ref_iterator *iter);
455
456/* Virtual function declarations for ref_iterators: */
457
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HWN
458/*
459 * backend-specific implementation of ref_iterator_advance. For symrefs, the
460 * function should set REF_ISSYMREF, and it should also dereference the symref
9aab952e
JK
461 * to provide the OID referent. It should respect do_for_each_ref_flags
462 * that were passed to refs_ref_iterator_begin().
84ee4ca1 463 */
3bc581b9
MH
464typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
465
617480d7
HWN
466/*
467 * Peels the current ref, returning 0 for success or -1 for failure.
468 */
3bc581b9
MH
469typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
470 struct object_id *peeled);
471
472/*
473 * Implementations of this function should free any resources specific
474 * to the derived class, then call base_ref_iterator_free() to clean
475 * up and free the ref_iterator object.
476 */
477typedef int ref_iterator_abort_fn(struct ref_iterator *ref_iterator);
478
479struct ref_iterator_vtable {
480 ref_iterator_advance_fn *advance;
481 ref_iterator_peel_fn *peel;
482 ref_iterator_abort_fn *abort;
483};
484
93770590 485/*
4c4de895
MH
486 * current_ref_iter is a performance hack: when iterating over
487 * references using the for_each_ref*() functions, current_ref_iter is
488 * set to the reference iterator before calling the callback function.
489 * If the callback function calls peel_ref(), then peel_ref() first
490 * checks whether the reference to be peeled is the one referred to by
491 * the iterator (it usually is) and if so, asks the iterator for the
492 * peeled version of the reference if it is available. This avoids a
493 * refname lookup in a common case. current_ref_iter is set to NULL
494 * when the iteration is over.
495 */
496extern struct ref_iterator *current_ref_iter;
497
498/*
499 * The common backend for the for_each_*ref* functions. Call fn for
500 * each reference in iter. If the iterator itself ever returns
501 * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
502 * the iteration and return that value. Otherwise, return 0. In any
503 * case, free the iterator when done. This function is basically an
504 * adapter between the callback style of reference iteration and the
505 * iterator style.
506 */
4a6067cd
SB
507int do_for_each_repo_ref_iterator(struct repository *r,
508 struct ref_iterator *iter,
509 each_repo_ref_fn fn, void *cb_data);
2d0663b2 510
1a769003
MH
511struct ref_store;
512
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DT
513/* refs backends */
514
9e7ec634
NTND
515/* ref_store_init flags */
516#define REF_STORE_READ (1 << 0)
517#define REF_STORE_WRITE (1 << 1) /* can perform update operations */
518#define REF_STORE_ODB (1 << 2) /* has access to object database */
519#define REF_STORE_MAIN (1 << 3)
0d8a814d
NTND
520#define REF_STORE_ALL_CAPS (REF_STORE_READ | \
521 REF_STORE_WRITE | \
522 REF_STORE_ODB | \
523 REF_STORE_MAIN)
9e7ec634 524
e1e33b72 525/*
5d0bc90e
NTND
526 * Initialize the ref_store for the specified gitdir. These functions
527 * should call base_ref_store_init() to initialize the shared part of
528 * the ref_store and to record the ref_store for later lookup.
e1e33b72 529 */
34224e14
JT
530typedef struct ref_store *ref_store_init_fn(struct repository *repo,
531 const char *gitdir,
9e7ec634 532 unsigned int flags);
e1e33b72 533
6fb5acfd
DT
534typedef int ref_init_db_fn(struct ref_store *refs, struct strbuf *err);
535
30173b88
MH
536typedef int ref_transaction_prepare_fn(struct ref_store *refs,
537 struct ref_transaction *transaction,
538 struct strbuf *err);
539
540typedef int ref_transaction_finish_fn(struct ref_store *refs,
541 struct ref_transaction *transaction,
542 struct strbuf *err);
543
544typedef int ref_transaction_abort_fn(struct ref_store *refs,
545 struct ref_transaction *transaction,
546 struct strbuf *err);
547
e1e33b72
MH
548typedef int ref_transaction_commit_fn(struct ref_store *refs,
549 struct ref_transaction *transaction,
550 struct strbuf *err);
551
8231527e 552typedef int pack_refs_fn(struct ref_store *ref_store, unsigned int flags);
284689ba
MH
553typedef int create_symref_fn(struct ref_store *ref_store,
554 const char *ref_target,
555 const char *refs_heads_master,
556 const char *logmsg);
64da4199 557typedef int delete_refs_fn(struct ref_store *ref_store, const char *msg,
a27dcf89 558 struct string_list *refnames, unsigned int flags);
9b6b40d9
DT
559typedef int rename_ref_fn(struct ref_store *ref_store,
560 const char *oldref, const char *newref,
561 const char *logmsg);
52d59cc6
SD
562typedef int copy_ref_fn(struct ref_store *ref_store,
563 const char *oldref, const char *newref,
564 const char *logmsg);
8231527e 565
1a769003 566/*
e1860571
MH
567 * Iterate over the references in `ref_store` whose names start with
568 * `prefix`. `prefix` is matched as a literal string, without regard
569 * for path separators. If prefix is NULL or the empty string, iterate
8738a8a4
MH
570 * over all references in `ref_store`. The output is ordered by
571 * refname.
1a769003
MH
572 */
573typedef struct ref_iterator *ref_iterator_begin_fn(
574 struct ref_store *ref_store,
575 const char *prefix, unsigned int flags);
576
e3688bd6
DT
577/* reflog functions */
578
579/*
580 * Iterate over the references in the specified ref_store that have a
581 * reflog. The refs are iterated over in arbitrary order.
582 */
583typedef struct ref_iterator *reflog_iterator_begin_fn(
584 struct ref_store *ref_store);
585
586typedef int for_each_reflog_ent_fn(struct ref_store *ref_store,
587 const char *refname,
588 each_reflog_ent_fn fn,
589 void *cb_data);
590typedef int for_each_reflog_ent_reverse_fn(struct ref_store *ref_store,
591 const char *refname,
592 each_reflog_ent_fn fn,
593 void *cb_data);
594typedef int reflog_exists_fn(struct ref_store *ref_store, const char *refname);
595typedef int create_reflog_fn(struct ref_store *ref_store, const char *refname,
7b089120 596 struct strbuf *err);
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597typedef int delete_reflog_fn(struct ref_store *ref_store, const char *refname);
598typedef int reflog_expire_fn(struct ref_store *ref_store,
cc40b5ce 599 const char *refname,
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600 unsigned int flags,
601 reflog_expiry_prepare_fn prepare_fn,
602 reflog_expiry_should_prune_fn should_prune_fn,
603 reflog_expiry_cleanup_fn cleanup_fn,
604 void *policy_cb_data);
605
cf596442 606/*
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607 * Read a reference from the specified reference store, non-recursively.
608 * Set type to describe the reference, and:
cf596442 609 *
99afe91a 610 * - If refname is the name of a normal reference, fill in oid
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611 * (leaving referent unchanged).
612 *
613 * - If refname is the name of a symbolic reference, write the full
614 * name of the reference to which it refers (e.g.
615 * "refs/heads/master") to referent and set the REF_ISSYMREF bit in
99afe91a 616 * type (leaving oid unchanged). The caller is responsible for
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617 * validating that referent is a valid reference name.
618 *
619 * WARNING: refname might be used as part of a filename, so it is
620 * important from a security standpoint that it be safe in the sense
621 * of refname_is_safe(). Moreover, for symrefs this function sets
622 * referent to whatever the repository says, which might not be a
623 * properly-formatted or even safe reference name. NEITHER INPUT NOR
624 * OUTPUT REFERENCE NAMES ARE VALIDATED WITHIN THIS FUNCTION.
625 *
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626 * Return 0 on success, or -1 on failure. If the ref exists but is neither a
627 * symbolic ref nor an object ID, it is broken. In this case set REF_ISBROKEN in
628 * type, and return -1 (failure_errno should not be ENOENT)
629 *
630 * failure_errno provides errno codes that are interpreted beyond error
631 * reporting. The following error codes have special meaning:
632 * * ENOENT: the ref doesn't exist
633 * * EISDIR: ref name is a directory
634 * * ENOTDIR: ref prefix is not a directory
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635 *
636 * Backend-specific flags might be set in type as well, regardless of
637 * outcome.
638 *
639 * It is OK for refname to point into referent. If so:
640 *
641 * - if the function succeeds with REF_ISSYMREF, referent will be
642 * overwritten and the memory formerly pointed to by it might be
643 * changed or even freed.
644 *
645 * - in all other cases, referent will be untouched, and therefore
646 * refname will still be valid and unchanged.
647 */
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648typedef int read_raw_ref_fn(struct ref_store *ref_store, const char *refname,
649 struct object_id *oid, struct strbuf *referent,
650 unsigned int *type, int *failure_errno);
127b42a1 651
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652struct ref_storage_be {
653 struct ref_storage_be *next;
654 const char *name;
00eebe35 655 ref_store_init_fn *init;
6fb5acfd 656 ref_init_db_fn *init_db;
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MH
657
658 ref_transaction_prepare_fn *transaction_prepare;
659 ref_transaction_finish_fn *transaction_finish;
660 ref_transaction_abort_fn *transaction_abort;
fc681463 661 ref_transaction_commit_fn *initial_transaction_commit;
e1e33b72 662
8231527e 663 pack_refs_fn *pack_refs;
284689ba 664 create_symref_fn *create_symref;
a27dcf89 665 delete_refs_fn *delete_refs;
9b6b40d9 666 rename_ref_fn *rename_ref;
52d59cc6 667 copy_ref_fn *copy_ref;
8231527e 668
1a769003 669 ref_iterator_begin_fn *iterator_begin;
e1e33b72 670 read_raw_ref_fn *read_raw_ref;
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DT
671
672 reflog_iterator_begin_fn *reflog_iterator_begin;
673 for_each_reflog_ent_fn *for_each_reflog_ent;
674 for_each_reflog_ent_reverse_fn *for_each_reflog_ent_reverse;
675 reflog_exists_fn *reflog_exists;
676 create_reflog_fn *create_reflog;
677 delete_reflog_fn *delete_reflog;
678 reflog_expire_fn *reflog_expire;
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679};
680
681extern struct ref_storage_be refs_be_files;
e0cc8ac8 682extern struct ref_storage_be refs_be_packed;
3dce444f 683
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684/*
685 * A representation of the reference store for the main repository or
686 * a submodule. The ref_store instances for submodules are kept in a
4877c6c7 687 * hash map; see get_submodule_ref_store() for more info.
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688 */
689struct ref_store {
690 /* The backend describing this ref_store's storage scheme: */
691 const struct ref_storage_be *be;
5085aef4 692
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693 struct repository *repo;
694
695 /*
696 * The gitdir that this ref_store applies to. Note that this is not
697 * necessarily repo->gitdir if the repo has multiple worktrees.
698 */
5085aef4 699 char *gitdir;
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700};
701
e39620f0 702/*
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703 * Parse contents of a loose ref file. *failure_errno maybe be set to EINVAL for
704 * invalid contents.
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705 */
706int parse_loose_ref_contents(const char *buf, struct object_id *oid,
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707 struct strbuf *referent, unsigned int *type,
708 int *failure_errno);
e39620f0 709
00eebe35 710/*
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711 * Fill in the generic part of refs and add it to our collection of
712 * reference stores.
00eebe35 713 */
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714void base_ref_store_init(struct ref_store *refs, struct repository *repo,
715 const char *path, const struct ref_storage_be *be);
00eebe35 716
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717/*
718 * Support GIT_TRACE_REFS by optionally wrapping the given ref_store instance.
719 */
720struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_store *store);
721
4cb77009 722#endif /* REFS_REFS_INTERNAL_H */