wrapper.rb in s3io-1.0.0

- old
+ new
@@ -1,88 +1,44 @@
 module S3io
-  # This class wraps an AWS S3 object in order to provide IO-like API.
-  # S3 objects wrapped this way can be used in methods that would otherwise expect an instance of File, StringIO etc.
-  class Wrapper
 
-    # Default buffer size for line parser in bytes
-    LINE_BUFFER_SIZE = 5 * 1024 * 1024 # MiB
+  def self.open(s3object, mode_string = 'r', options = {}, &block)
+    wrapper_class = case mode_string
+    when 'r'
+      ReadWrapper
+    when 'w'
+      WriteWrapper
+    else
+      fail "S3IO only supports 'r' or 'w' as access modes"
+    end
 
-    include Enumerable
+    wrapper = wrapper_class.new(s3object, options)
 
-    # Current byte position in S3 object
-    attr_accessor :pos
+    if block_given?
+      result = yield wrapper if block_given?
+      wrapper.close
 
-    # Options that were passed during initialization
-    attr_reader :options
+      return result
+    else
+      return wrapper
+    end
+  end
 
+  # This class wraps an AWS S3 object in order to provide IO-like API.
+  # S3 objects wrapped this way can be used in methods that would otherwise expect an instance of File, StringIO etc.
+  class Wrapper
+
     # Wraps an AWS::S3::S3Object into IO-like object.
     #
     # @param [AWS::S3::S3Object] s3object an object to wrap
-    # @param [Hash] options options hash
-    # @option options [Integer] :line_buffer_size size of the buffer that is used for reading contents of S3 object when iterating over its lines
-    def initialize(s3object, options = {})
+    def initialize(s3object)
       @s3object = s3object
-      @options = {
-        :line_buffer_size => (options[:line_buffer_size] || LINE_BUFFER_SIZE)
-      }
-
       @pos = 0
     end
 
-    # Reads data from S3 object.
-    #
-    # @param [Integer] bytes number of bytes to read
-    def read(bytes = nil)
-      content_length = @s3object.content_length
-
-      return '' if (@pos >= content_length) || (bytes == 0)
-
-      bytes ||= content_length
-
-      upper_bound = @pos + bytes - 1
-      upper_bound = (content_length - 1) if upper_bound >= content_length
-
-      data = @s3object.read :range => @pos..upper_bound
-      @pos = upper_bound + 1
-
-      return data
-    end
-
-    # Rewinds position to the very beginning of S3 object.
-    def rewind
+    def close
+      @s3object = nil
       @pos = 0
-    end
 
-    # Iterates over S3 object lines.
-    #
-    # @param [String] separator line separator string
-    def each(separator = $/)
-      return enum_for(:each, separator) unless block_given?
-
-      line = ''
-      newline_pos = nil
-
-      # Either trying to parse the remainder or reading some more data
-      while newline_pos || !(buffer = read(@options[:line_buffer_size])).empty?
-        prev_newline_pos = newline_pos || 0
-        newline_pos = buffer.index(separator, prev_newline_pos)
-
-        if newline_pos
-          line << buffer[prev_newline_pos..newline_pos]
-          newline_pos += 1
-          yield line
-          line = ''
-        else
-          line << buffer[prev_newline_pos..-1]
-        end
-      end
-
-      # Flush the remainder if body doesn't end with separator
-      yield line unless line.empty?
-
-      return self
+      return nil
     end
-    alias lines each
-    alias each_line each
-
   end
 end