const struct string_list *extras,
const struct string_list *skip);
-int rename_ref_available(const char *oldname, const char *newname);
+/*
+ * Check whether an attempt to rename old_refname to new_refname would
+ * cause a D/F conflict with any existing reference (other than
+ * possibly old_refname). If there would be a conflict, emit an error
+ * message and return false; otherwise, return true.
+ *
+ * Note that this function is not safe against all races with other
+ * processes (though rename_ref() catches some races that might get by
+ * this check).
+ */
+int rename_ref_available(const char *old_refname, const char *new_refname);
/* We allow "recursive" symbolic refs. Only within reason, though */
#define SYMREF_MAXDEPTH 5
#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
/*
- * The common backend for the for_each_*ref* functions
+ * Reference iterators
+ *
+ * A reference iterator encapsulates the state of an in-progress
+ * iteration over references. Create an instance of `struct
+ * ref_iterator` via one of the functions in this module.
+ *
+ * A freshly-created ref_iterator doesn't yet point at a reference. To
+ * advance the iterator, call ref_iterator_advance(). If successful,
+ * this sets the iterator's refname, oid, and flags fields to describe
+ * the next reference and returns ITER_OK. The data pointed at by
+ * refname and oid belong to the iterator; if you want to retain them
+ * after calling ref_iterator_advance() again or calling
+ * ref_iterator_abort(), you must make a copy. When the iteration has
+ * been exhausted, ref_iterator_advance() releases any resources
+ * assocated with the iteration, frees the ref_iterator object, and
+ * returns ITER_DONE. If you want to abort the iteration early, call
+ * ref_iterator_abort(), which also frees the ref_iterator object and
+ * any associated resources. If there was an internal error advancing
+ * to the next entry, ref_iterator_advance() aborts the iteration,
+ * frees the ref_iterator, and returns ITER_ERROR.
+ *
+ * The reference currently being looked at can be peeled by calling
+ * ref_iterator_peel(). This function is often faster than peel_ref(),
+ * so it should be preferred when iterating over references.
+ *
+ * Putting it all together, a typical iteration looks like this:
+ *
+ * int ok;
+ * struct ref_iterator *iter = ...;
+ *
+ * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
+ * if (want_to_stop_iteration()) {
+ * ok = ref_iterator_abort(iter);
+ * break;
+ * }
+ *
+ * // Access information about the current reference:
+ * if (!(iter->flags & REF_ISSYMREF))
+ * printf("%s is %s\n", iter->refname, oid_to_hex(&iter->oid));
+ *
+ * // If you need to peel the reference:
+ * ref_iterator_peel(iter, &oid);
+ * }
+ *
+ * if (ok != ITER_DONE)
+ * handle_error();
+ */
+struct ref_iterator {
+ struct ref_iterator_vtable *vtable;
+ const char *refname;
+ const struct object_id *oid;
+ unsigned int flags;
+};
+
+/*
+ * Advance the iterator to the first or next item and return ITER_OK.
+ * If the iteration is exhausted, free the resources associated with
+ * the ref_iterator and return ITER_DONE. On errors, free the iterator
+ * resources and return ITER_ERROR. It is a bug to use ref_iterator or
+ * call this function again after it has returned ITER_DONE or
+ * ITER_ERROR.
+ */
+int ref_iterator_advance(struct ref_iterator *ref_iterator);
+
+/*
+ * If possible, peel the reference currently being viewed by the
+ * iterator. Return 0 on success.
+ */
+int ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled);
+
+/*
+ * End the iteration before it has been exhausted, freeing the
+ * reference iterator and any associated resources and returning
+ * ITER_DONE. If the abort itself failed, return ITER_ERROR.
+ */
+int ref_iterator_abort(struct ref_iterator *ref_iterator);
+
+/*
+ * An iterator over nothing (its first ref_iterator_advance() call
+ * returns ITER_DONE).
+ */
+struct ref_iterator *empty_ref_iterator_begin(void);
+
+/*
+ * Return true iff ref_iterator is an empty_ref_iterator.
+ */
+int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
+
+/*
+ * A callback function used to instruct merge_ref_iterator how to
+ * interleave the entries from iter0 and iter1. The function should
+ * return one of the constants defined in enum iterator_selection. It
+ * must not advance either of the iterators itself.
+ *
+ * The function must be prepared to handle the case that iter0 and/or
+ * iter1 is NULL, which indicates that the corresponding sub-iterator
+ * has been exhausted. Its return value must be consistent with the
+ * current states of the iterators; e.g., it must not return
+ * ITER_SKIP_1 if iter1 has already been exhausted.
+ */
+typedef enum iterator_selection ref_iterator_select_fn(
+ struct ref_iterator *iter0, struct ref_iterator *iter1,
+ void *cb_data);
+
+/*
+ * Iterate over the entries from iter0 and iter1, with the values
+ * interleaved as directed by the select function. The iterator takes
+ * ownership of iter0 and iter1 and frees them when the iteration is
+ * over.
*/
-int do_for_each_ref(const char *submodule, const char *base,
- each_ref_fn fn, int trim, int flags, void *cb_data);
+struct ref_iterator *merge_ref_iterator_begin(
+ struct ref_iterator *iter0, struct ref_iterator *iter1,
+ ref_iterator_select_fn *select, void *cb_data);
/*
- * Read the specified reference from the filesystem or packed refs
- * file, non-recursively. Set type to describe the reference, and:
+ * An iterator consisting of the union of the entries from front and
+ * back. If there are entries common to the two sub-iterators, use the
+ * one from front. Each iterator must iterate over its entries in
+ * strcmp() order by refname for this to work.
+ *
+ * The new iterator takes ownership of its arguments and frees them
+ * when the iteration is over. As a convenience to callers, if front
+ * or back is an empty_ref_iterator, then abort that one immediately
+ * and return the other iterator directly, without wrapping it.
+ */
+struct ref_iterator *overlay_ref_iterator_begin(
+ struct ref_iterator *front, struct ref_iterator *back);
+
+/*
+ * Wrap iter0, only letting through the references whose names start
+ * with prefix. If trim is set, set iter->refname to the name of the
+ * reference with that many characters trimmed off the front;
+ * otherwise set it to the full refname. The new iterator takes over
+ * ownership of iter0 and frees it when iteration is over. It makes
+ * its own copy of prefix.
+ *
+ * As an convenience to callers, if prefix is the empty string and
+ * trim is zero, this function returns iter0 directly, without
+ * wrapping it.
+ */
+struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
+ const char *prefix,
+ int trim);
+
+/* Internal implementation of reference iteration: */
+
+/*
+ * Base class constructor for ref_iterators. Initialize the
+ * ref_iterator part of iter, setting its vtable pointer as specified.
+ * This is meant to be called only by the initializers of derived
+ * classes.
+ */
+void base_ref_iterator_init(struct ref_iterator *iter,
+ struct ref_iterator_vtable *vtable);
+
+/*
+ * Base class destructor for ref_iterators. Destroy the ref_iterator
+ * part of iter and shallow-free the object. This is meant to be
+ * called only by the destructors of derived classes.
+ */
+void base_ref_iterator_free(struct ref_iterator *iter);
+
+/* Virtual function declarations for ref_iterators: */
+
+typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
+
+typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
+ struct object_id *peeled);
+
+/*
+ * Implementations of this function should free any resources specific
+ * to the derived class, then call base_ref_iterator_free() to clean
+ * up and free the ref_iterator object.
+ */
+typedef int ref_iterator_abort_fn(struct ref_iterator *ref_iterator);
+
+struct ref_iterator_vtable {
+ ref_iterator_advance_fn *advance;
+ ref_iterator_peel_fn *peel;
+ ref_iterator_abort_fn *abort;
+};
+
+/*
+ * current_ref_iter is a performance hack: when iterating over
+ * references using the for_each_ref*() functions, current_ref_iter is
+ * set to the reference iterator before calling the callback function.
+ * If the callback function calls peel_ref(), then peel_ref() first
+ * checks whether the reference to be peeled is the one referred to by
+ * the iterator (it usually is) and if so, asks the iterator for the
+ * peeled version of the reference if it is available. This avoids a
+ * refname lookup in a common case. current_ref_iter is set to NULL
+ * when the iteration is over.
+ */
+extern struct ref_iterator *current_ref_iter;
+
+/*
+ * The common backend for the for_each_*ref* functions. Call fn for
+ * each reference in iter. If the iterator itself ever returns
+ * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
+ * the iteration and return that value. Otherwise, return 0. In any
+ * case, free the iterator when done. This function is basically an
+ * adapter between the callback style of reference iteration and the
+ * iterator style.
+ */
+int do_for_each_ref_iterator(struct ref_iterator *iter,
+ each_ref_fn fn, void *cb_data);
+
+/* refs backends */
+
+struct ref_store;
+
+/*
+ * Initialize the ref_store for the specified submodule, or for the
+ * main repository if submodule == NULL. These functions should call
+ * base_ref_store_init() to initialize the shared part of the
+ * ref_store and to record the ref_store for later lookup.
+ */
+typedef struct ref_store *ref_store_init_fn(const char *submodule);
+
+typedef int ref_transaction_commit_fn(struct ref_store *refs,
+ struct ref_transaction *transaction,
+ struct strbuf *err);
+
+typedef int pack_refs_fn(struct ref_store *ref_store, unsigned int flags);
+typedef int peel_ref_fn(struct ref_store *ref_store,
+ const char *refname, unsigned char *sha1);
+typedef int create_symref_fn(struct ref_store *ref_store,
+ const char *ref_target,
+ const char *refs_heads_master,
+ const char *logmsg);
+typedef int delete_refs_fn(struct ref_store *ref_store,
+ struct string_list *refnames, unsigned int flags);
+
+/*
+ * Iterate over the references in the specified ref_store that are
+ * within find_containing_dir(prefix). If prefix is NULL or the empty
+ * string, iterate over all references in the submodule.
+ */
+typedef struct ref_iterator *ref_iterator_begin_fn(
+ struct ref_store *ref_store,
+ const char *prefix, unsigned int flags);
+
+/* reflog functions */
+
+/*
+ * Iterate over the references in the specified ref_store that have a
+ * reflog. The refs are iterated over in arbitrary order.
+ */
+typedef struct ref_iterator *reflog_iterator_begin_fn(
+ struct ref_store *ref_store);
+
+typedef int for_each_reflog_ent_fn(struct ref_store *ref_store,
+ const char *refname,
+ each_reflog_ent_fn fn,
+ void *cb_data);
+typedef int for_each_reflog_ent_reverse_fn(struct ref_store *ref_store,
+ const char *refname,
+ each_reflog_ent_fn fn,
+ void *cb_data);
+typedef int reflog_exists_fn(struct ref_store *ref_store, const char *refname);
+typedef int create_reflog_fn(struct ref_store *ref_store, const char *refname,
+ int force_create, struct strbuf *err);
+typedef int delete_reflog_fn(struct ref_store *ref_store, const char *refname);
+typedef int reflog_expire_fn(struct ref_store *ref_store,
+ const char *refname, const unsigned char *sha1,
+ unsigned int flags,
+ reflog_expiry_prepare_fn prepare_fn,
+ reflog_expiry_should_prune_fn should_prune_fn,
+ reflog_expiry_cleanup_fn cleanup_fn,
+ void *policy_cb_data);
+
+/*
+ * Read a reference from the specified reference store, non-recursively.
+ * Set type to describe the reference, and:
*
* - If refname is the name of a normal reference, fill in sha1
* (leaving referent unchanged).
* - in all other cases, referent will be untouched, and therefore
* refname will still be valid and unchanged.
*/
-int read_raw_ref(const char *refname, unsigned char *sha1,
- struct strbuf *referent, unsigned int *type);
+typedef int read_raw_ref_fn(struct ref_store *ref_store,
+ const char *refname, unsigned char *sha1,
+ struct strbuf *referent, unsigned int *type);
+
+typedef int verify_refname_available_fn(struct ref_store *ref_store,
+ const char *newname,
+ const struct string_list *extras,
+ const struct string_list *skip,
+ struct strbuf *err);
+
+struct ref_storage_be {
+ struct ref_storage_be *next;
+ const char *name;
+ ref_store_init_fn *init;
+ ref_transaction_commit_fn *transaction_commit;
+ ref_transaction_commit_fn *initial_transaction_commit;
+
+ pack_refs_fn *pack_refs;
+ peel_ref_fn *peel_ref;
+ create_symref_fn *create_symref;
+ delete_refs_fn *delete_refs;
+
+ ref_iterator_begin_fn *iterator_begin;
+ read_raw_ref_fn *read_raw_ref;
+ verify_refname_available_fn *verify_refname_available;
+
+ reflog_iterator_begin_fn *reflog_iterator_begin;
+ for_each_reflog_ent_fn *for_each_reflog_ent;
+ for_each_reflog_ent_reverse_fn *for_each_reflog_ent_reverse;
+ reflog_exists_fn *reflog_exists;
+ create_reflog_fn *create_reflog;
+ delete_reflog_fn *delete_reflog;
+ reflog_expire_fn *reflog_expire;
+};
+
+extern struct ref_storage_be refs_be_files;
+
+/*
+ * A representation of the reference store for the main repository or
+ * a submodule. The ref_store instances for submodules are kept in a
+ * linked list.
+ */
+struct ref_store {
+ /* The backend describing this ref_store's storage scheme: */
+ const struct ref_storage_be *be;
+
+ /*
+ * The name of the submodule represented by this object, or
+ * the empty string if it represents the main repository's
+ * reference store:
+ */
+ const char *submodule;
+
+ /*
+ * Submodule reference store instances are stored in a linked
+ * list using this pointer.
+ */
+ struct ref_store *next;
+};
+
+/*
+ * Fill in the generic part of refs for the specified submodule and
+ * add it to our collection of reference stores.
+ */
+void base_ref_store_init(struct ref_store *refs,
+ const struct ref_storage_be *be,
+ const char *submodule);
+
+/*
+ * Create, record, and return a ref_store instance for the specified
+ * submodule (or the main repository if submodule is NULL).
+ *
+ * For backwards compatibility, submodule=="" is treated the same as
+ * submodule==NULL.
+ */
+struct ref_store *ref_store_init(const char *submodule);
+
+/*
+ * Return the ref_store instance for the specified submodule (or the
+ * main repository if submodule is NULL). If that ref_store hasn't
+ * been initialized yet, return NULL.
+ *
+ * For backwards compatibility, submodule=="" is treated the same as
+ * submodule==NULL.
+ */
+struct ref_store *lookup_ref_store(const char *submodule);
+
+/*
+ * Return the ref_store instance for the specified submodule. For the
+ * main repository, use submodule==NULL; such a call cannot fail. For
+ * a submodule, the submodule must exist and be a nonbare repository,
+ * otherwise return NULL. If the requested reference store has not yet
+ * been initialized, initialize it first.
+ *
+ * For backwards compatibility, submodule=="" is treated the same as
+ * submodule==NULL.
+ */
+struct ref_store *get_ref_store(const char *submodule);
+
+/*
+ * Die if refs is for a submodule (i.e., not for the main repository).
+ * caller is used in any necessary error messages.
+ */
+void assert_main_repository(struct ref_store *refs, const char *caller);
#endif /* REFS_REFS_INTERNAL_H */
projects / thirdparty / git.git / blobdiff