ensync/README.md

Table of Contents

1. Demo
2. About
3. Package Contents
4. Issues

Design Goals

• Least possible intrusion.
  • work on top of a FS
  • can be plugged / unpluggen anytime
• Sync, not redundancy, not backup
  • if user deletes File on one system, it will be deleted on all systems
• Pretty simple rules:
  • if same md5 keep older file
  • if diff md5 keep newer file
  • if created, create everywhere
  • if deleted, delete everywhere

Overview

DataRoot                a data root
\_ SyncBundle :         a bundle of directories on the FS to be syncronized.
   \_ SyncDirectory :   a directory on the FS.
      \_ SyncFile :     a file on the FS.

StateFile

• Used for tracking of file deletions.
• Located in each SyncDirectory\state.ensync
• Contains <last edited> <relative file path> for each file in the SyncDirectory.

Demo

About

Sync files across directories.

Package Contents

Path	Comment
doc	Diagrams.
src.com.olexyn.ensync.artifacts	Data Model: Maps, Directories, Files.
src.com.olexyn.ensync.shell	.sh files to ease interaction with the host.
src.com.olexyn.ensync.ui	JavaFX.
src.com.olexyn.ensync.Execute	Issue .sh commands.
src.com.olexyn.ensync.Main	Run from here.
src.com.olexyn.ensync.Flow	Flow of the synchronization.
src.com.olexyn.ensync.	Low level helper methods.

Issues

• Add tests.
• Remove Map entries, once file ops is performed.
• Reduce disk access.
• Add error handling. (i.e. if a web-directory is not available)
• Track files that were modified during the loop.
  • currently writeStateFile just takes from find
  • this means any changes made during the loop will be written to the StateFile
  • and created files are tracked by comparing StateFile (=old state) and State (=new state).
  • because of this it will appear as if the file created while the loop was running was already there.
  • thus the creation of said file will not be replicated to the other directories.
  • to solve this writeStateFile should take the old State and manually add every operation that was performed by the loop (!= user created file while the loop was running).
• File is created in DirB
  • Sync creates the file in DirA
  • Sync creates the file in DirB
    • this means the file in DirB is overwritten with cp for no reason.
    • implement a check to prevent this.