Documentation of RsyncOSX source

This is documentation of the design and code of RsyncOSX. I have just commenced the process (June 2017) and it will take time to complete. Why am I doing it? Well, primary for fun but i might learn something from it as well. The design of RsyncOSX is based upon ideas of the MVC pattern. One of the objectives in MVC is to separate the views and models.

First will the data model and some of the methods operating on the data be documented. After that some of the high level details about how RsyncOSX is working. RsyncOSX kicks off the rsync utility to do the real work. The rsync is executed in a Process object.

Every time RsyncOSX executes a command, RsyncOSX is listening for two notifications didTerminateNotification and NSFileHandleDataAvailable. Those two notifications kicks of other functions depended upon the state of RsyncOSX.

I am also adapting most of the code to SwiftLint guidelines for code. Most of the classes are compliant and a few are not. The main reason for this is I discovered SwiftLint to late in development. This project commenced because I wanted to learn Swift. And the codebase from beginning until now is quite different.

Data model

The views has no knowledge about the models or data stored about configurations, schedules and logdata. Data presented in RsyncOSX are mostly table data. Presenting table data in all views utilizes the NSTableViewDelegate. All data which are saved to permanent storage (configurations, schedules, logs and userconfig) are stored as xml-files (plist files). RsyncOSX does not utilize the Core Data because the data about configurations, schedules and logs are simple and there is no need for a complex datamodel.

Data is read from permanent store and loaded when RsyncOSX either starts or if a new profile is either selected or created. The Execute view loads and holds the data objects during lifetime of data. There are two main objects which holds the data about configurations and schedules including logdata. The objects lives during lifetime of RsyncOSX or until a profile is either selected or created.

Classes in Swift are by reference and both the configurations and schedules objects are created in the Execute view of RsyncOSX. Other objects utilizing data and methods in configurations and schedules objects are by protocol functions, getting the reference for the data objects. The references to configurations and schedules are weak to avoid strong references and memory leaks.

Configurations

The class Configurations (plural) holds required data, as an Array<Configuration>, about all tasks including all parameters for rsync and user selected parameters. Adding a task results in two new Configuration objects, one for backup and for restore. All Configuration objects, which is a struct about one task, are stored in memory in an Array<Configuration> in order loaded from permanent storage. Last timestamp for execution is also stored in the configuration object.

Documentation of Configurations.

Scheduled tasks and log records

All log records are stored in a Schedule record. For one task it might be several schedule records depended upon type of schedule and start of scheduled task. Only backup tasks can be scheduled, not restore task. The type of schedules are manual,once, daily and monthly. If Schedules is not used meaning only manually executed tasks, one Schedule record is created with type manual. All log records for this manually executed tasks are added to this record.

Documentation of scheduled tasks and log records.

Reading and writing data to permanent storage

One object takes care of reading and writing data to permanent storage. The object is also responsible to either read or write data utilizing profiles.

Documentation of reading and writing.

Parameters to rsync

Rsync utilizes a ton of parameters. RsyncOSX let the user pass any parameter to rsync. A few rsync parameters are predefined, both mandatory and user selected. Documentation of rsync parameters in RsyncOSX.

Written on March 10, 2018