Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

refs/packed-backend.h

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+#ifndef REFS_PACKED_BACKEND_H
+#define REFS_PACKED_BACKEND_H
+
+struct ref_transaction;
+
+/*
+ * Support for storing references in a `packed-refs` file.
+ *
+ * Note that this backend doesn't check for D/F conflicts, because it
+ * doesn't care about them. But usually it should be wrapped in a
+ * `files_ref_store` that prevents D/F conflicts from being created,
+ * even among packed refs.
+ */
+
+struct ref_store *packed_ref_store_create(const char *path,
+					  unsigned int store_flags);
+
+/*
+ * Lock the packed-refs file for writing. Flags is passed to
+ * hold_lock_file_for_update(). Return 0 on success. On errors, write
+ * an error message to `err` and return a nonzero value.
+ */
+int packed_refs_lock(struct ref_store *ref_store, int flags, struct strbuf *err);
+
+void packed_refs_unlock(struct ref_store *ref_store);
+int packed_refs_is_locked(struct ref_store *ref_store);
+
+/*
+ * Return true if `transaction` really needs to be carried out against
+ * the specified packed_ref_store, or false if it can be skipped
+ * (i.e., because it is an obvious NOOP). `ref_store` must be locked
+ * before calling this function.
+ */
+int is_packed_transaction_needed(struct ref_store *ref_store,
+				 struct ref_transaction *transaction);
+
+#endif /* REFS_PACKED_BACKEND_H */