Class: Configuration::S3SourceStoreBase::CacheRoot::CacheFile

Inherits:
Pathname
  • Object
show all
Defined in:
lib/httpimagestore/configuration/s3.rb

Instance Method Summary collapse

Constructor Details

#initialize(path) ⇒ CacheFile

Returns a new instance of CacheFile.



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# File 'lib/httpimagestore/configuration/s3.rb', line 89

def initialize(path)
	super
	@header = nil
end

Instance Method Details

#header ⇒ Object 



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# File 'lib/httpimagestore/configuration/s3.rb', line 94

def header
	begin
		read(0)
	rescue
		@header = {}
	end unless @header
	@header or fail 'no header data'
end

#read(max_bytes = nil) ⇒ Object 



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# File 'lib/httpimagestore/configuration/s3.rb', line 103

def read(max_bytes = nil)
	open('rb') do |io|
		io.flock(File::LOCK_SH)
		@header = read_header(io)
		return io.read(max_bytes)
	end
end

#write(data) ⇒ Object 



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# File 'lib/httpimagestore/configuration/s3.rb', line 111

def write(data)
	dirname.directory? or dirname.mkpath
	open('ab') do |io|
		# opened but not truncated before lock can be obtained
		io.flock(File::LOCK_EX)

		# now get rid of the old content if any
		io.seek 0, IO::SEEK_SET
		io.truncate 0

		begin
			header = MessagePack.pack(@header)
			io.write [header.length].pack('L') # header length
			io.write header
			io.write data
		rescue => error
			unlink # remove broken cache file
			raise
		end
	end
end