`module Readable`

Common operations for streaming readable multipart content.

Definitions

`def copy_to(output, chunk_size = 8192)`

Copy the content to a writable object.

Signature

parameter　output　#write: The writable destination.
parameter　chunk_size　Integer: The maximum chunk size.
returns　Integer: The number of bytes copied.

Implementation

def copy_to(output, chunk_size = 8192)
	size = 0
	
	each(chunk_size) do |chunk|
		offset = 0
		
		# A writable object may consume only part of a chunk:
		while offset < chunk.bytesize
			written = output.write(chunk.byteslice(offset, chunk.bytesize - offset))
			
			unless written && written > 0
				raise IOError, "Could not make progress while copying multipart content!"
			end
			
			offset += written
		end
		
		size += chunk.bytesize
	end
	
	return size
end

`def save(path, permissions: 0o600, chunk_size: 8192)`

Save the content to a new local file.

Signature

parameter　path　String, #to_path: The destination path, which must not exist.
parameter　permissions　Integer: The permissions for the new file.
parameter　chunk_size　Integer: The maximum chunk size.
returns　Integer: The number of bytes saved.

Implementation

def save(path, permissions: 0o600, chunk_size: 8192)
	flags = File::WRONLY | File::CREAT | File::EXCL
	created = false
	
	begin
		File.open(path, flags, permissions) do |file|
			created = true
			file.binmode
			return copy_to(file, chunk_size)
		end
	rescue
		# Remove a partial destination created by this operation:
		if created
			File.unlink(path)
		end
		
		raise
	end
end