bucket: Add clone/staleness operations for ast_bucket/ast_bucket_file

This patch enhances the bucket API in two ways.

First, since ast_bucket and ast_bucket_file instances are immutable, a 'clone'
operation has been added that provides a 'clone' of an existing
ast_bucket/ast_bucket_file object. Note that this makes use of the
ast_sorcery_copy operation, along with the copy callback handler on the
"bucket" and "file" object types for the bucket sorcery instance.

Second, there is a need for the bucket API to ask a wizard if an object
is stale. This is particularly useful with the upcoming media cache
enhancements, where we want to ask the backing data storage if the
object we are currently operating on has known updates. This patch adds
API calls for ast_bucket and ast_bucket_file objects, which callback
into their respective sorcery wizards via the sorcery API.

Unit tests have also been added to cover the respective
ast_bucket/ast_bucket_file clone and staleness operations.

Change-Id: Ib0240ba915ece313f1678a085a716021d75d6b4a

1 files changed, 69 insertions, 0 deletions

diff --git a/include/asterisk/bucket.h b/include/asterisk/bucket.h
index da83759ce..c335fd351 100644
--- a/include/asterisk/bucket.h
+++ b/include/asterisk/bucket.h
@@ -218,6 +218,23 @@ struct ast_bucket *ast_bucket_alloc(const char *uri);
 int ast_bucket_create(struct ast_bucket *bucket);
 
 /*!
+ * \brief Clone a bucket
+ *
+ * This will create a copy of the passed in \c ast_bucket structure. While
+ * all properties of the \c ast_bucket structure are copied, any metadata
+ * in the original structure simply has its reference count increased.
+ *
+ * \param file The bucket to clone
+ *
+ * \retval non-NULL success
+ * \retval NULL failure
+ *
+ * \note This operation should be called prior to updating a bucket
+ * object, as \c ast_bucket instances are immutable
+ */
+struct ast_bucket *ast_bucket_clone(struct ast_bucket *bucket);
+
+/*!
  * \brief Delete a bucket from backend storage
  *
  * \param bucket The bucket
@@ -240,6 +257,23 @@ int ast_bucket_delete(struct ast_bucket *bucket);
 struct ast_bucket *ast_bucket_retrieve(const char *uri);
 
 /*!
+ * \brief Retrieve whether or not the backing datastore views the bucket as stale
+ * \since 14.0.0
+ *
+ * This function will ask whatever data storage backs the bucket's schema
+ * type if the current instance of the object is stale. It will not
+ * update the bucket object itself, as said objects are immutable. If the
+ * caller of this function would like to update the object, it should perform
+ * a retrieve operation.
+ *
+ * \param bucket The bucket object to check
+ *
+ * \retval 0 if \c bucket is not stale
+ * \retval 1 if \c bucket is stale
+ */
+int ast_bucket_is_stale(struct ast_bucket *bucket);
+
+/*!
  * \brief Add an observer for bucket creation and deletion operations
  *
  * \param callbacks Implementation of the sorcery observer interface
@@ -309,6 +343,24 @@ int ast_bucket_file_create(struct ast_bucket_file *file);
 struct ast_bucket_file *ast_bucket_file_copy(struct ast_bucket_file *file, const char *uri);
 
 /*!
+ * \brief Clone a bucket file
+ *
+ * This will create a copy of the passed in \c ast_bucket_file structure. While
+ * all properties of the \c ast_bucket_file structure are copied, any metadata
+ * in the original structure simply has its reference count increased. Note that
+ * this copies the structure, not the underlying file.
+ *
+ * \param file The bucket file to clone
+ *
+ * \retval non-NULL success
+ * \retval NULL failure
+ *
+ * \note This operation should be called prior to updating a bucket file
+ * object, as \c ast_bucket_file instances are immutable
+ */
+struct ast_bucket_file *ast_bucket_file_clone(struct ast_bucket_file *file);
+
+/*!
  * \brief Update an existing bucket file in backend storage
  *
  * \param file The bucket file
@@ -343,6 +395,23 @@ int ast_bucket_file_delete(struct ast_bucket_file *file);
 struct ast_bucket_file *ast_bucket_file_retrieve(const char *uri);
 
 /*!
+ * \brief Retrieve whether or not the backing datastore views the bucket file as stale
+ * \since 14.0.0
+ *
+ * This function will ask whatever data storage backs the bucket file's schema
+ * type if the current instance of the object is stale. It will not
+ * update the bucket file object itself, as said objects are immutable. If the
+ * caller of this function would like to update the object, it should perform
+ * a retrieve operation.
+ *
+ * \param bucket_file The bucket file object to check
+ *
+ * \retval 0 if \c bucket_file is not stale
+ * \retval 1 if \c bucket_file is stale
+ */
+int ast_bucket_file_is_stale(struct ast_bucket_file *file);
+
+/*!
  * \brief Add an observer for bucket file creation and deletion operations
  *
  * \param callbacks Implementation of the sorcery observer interface