Ticket	Summary	Owner	Status	Type	Component	Priority	Effort	Importance
#169	PRO_CHANGE_REVISION_ACCESS_R0	gogov	closed	planned_task	PRO_LIB_ENTITIES	3	1	0
Reported by Astea, 4 years ago.
Description	wiki page: PRO_CHANGE_REVISION_ACCESS_R0 - effort: 1d
Analysis_owners	gogov
Analysis_score	0
Design_score	0
Imp._score	0
Test_score	0

Analysis

Overview

The goal of this task is to develop a scheme on how to implement a history of changes resulting from the work of the user with Sophie 2 and provide access to any given point in time in this history.
This way a snapshot of the state of Sophie 2 at a given time point could be obtained for various purposes such as:

• debugging
• reverting changes
• feeding the change manager with needed info
• etc.

Task requirements

• Propose ideas for the structure of the history of changes. It should be flexible enough, so the queries as the following could be answered:
  • get a snapshot of the state of all properties at a given time point
  • get the value of a given property at a given time point
  • get a history of all the values of a given property at a given time point
  • get a list of all Changes that affect a given property before and after a given time point
  • get a list of properties which a Change affects
• Since these operations might turn out quite slow, performance should be taken into consideration as early as possible:
  • provide rough ideas on how these operations could be implemented algorithmically efficient
  • also provide ideas for suitable data structures which could improve the performance
• Provide rough implementation of the above ideas, if possible
• Add unit test for the implementation, if possible

Task result

• Design ideas and diagrams of the proposed solutions to the given problems in this page
• New code and unit tests, if any

Implementation idea

• Consider using some data structure which provides logarithmic time for some of the queries
• Try providing ideas for data structures and algorithms which perform at least some of the queries efficiently. Different approaches might be possibly combined to yield good results.

Related

PRO_LIB_CORE_TUTORIAL
PRO_CHANGE_MANAGER_R0
PRO_CHANGE_MERGING_R0
PRO_CHANGE_PRIMITIVES_R0
PRO_CHANGE_UNDO_MANAGER_R0

How to demo

• Show this page and explain the problems and proposed solutions
• Run the unit tests, if any

Design

^{(Describe your design here.)}

Implementation

^{(Describe and link the implementation results here (from the wiki or the repository).)}

Testing

^{(Place the testing results here.)}

Comments

^{(Write comments for this or later revisions here.)}