moviepilot / history_file

A File like class that supports versioning by date and has a fallback to older files

HistoryFile

Behaves like a File class and does some convenience stuff around a HistoryFile::FileDelegator instance. It lets you version files by dates. A date prefix is added to the file name.

If you want to write a file to store data from yesterday, you could write:

> f = HistoryFile[1.day.ago].new("/tmp/foo.txt", "w")
=> #<File:/tmp/2012.11.02-foo.txt>

The returned HistoryFile::FileDelegator object supports all methods that File has, but adds a date prefix to those methods that revolve around a single file (reading, writing, etc.)

If a file for a given date is not available, HistoryFile falls back to the freshest file that is older than the given date.

> f = HistoryFile[3.days.ago].new("test.txt", "w")
=> #<File:./2012.11.12-test.txt>
> f.write("I am old")
=> 8
> f.close
=> nil
> HistoryFile[Date.today].read("test.txt")
=> "I am old"
> HistoryFile[10.days.ago].read("test.txt")
Errno::ENOENT: No such file or directory - ./2012.11.05-test.txt

It does this for every method where a prefix is added and when an Errno::ENOENT is thrown.

Methods that patch all arguments with a date prefix

You can pass an arbitrary amount of arguments to these methods, but all of them are file names. So we'll go ahead and prefix all of them:

• delete
• unlink
• safe_unlink

Methods that patch nothing and just delegate to File

These are mostly methods that are either not HistoryFile specific (i.e. File.join to join components with the OS dependant path separator) or where one can't dumbly prefix filenames.

• absolute_path
• basename
• catname
• chmod
• chown
• compare
• copy
• directory?
• dirname
• expand_path
• extname
• fnmatch
• fnmatch?
• identical?
• install
• join
• lchown
• link
• makedirs
• move
• path
• realdirpath
• realpath
• rename
• split
• umask
• utime

Methods that add a prefix to the filename

All methods not mentioned in the previous two sections

Methods that automatically create a sub directory

If you set HistoryFile.mode = :subdir and you call one of the following methods, Historyfile will create a sub directory for the given date if it does not exist already

• new
• open

Tests

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