lib/s3io/read_wrapper.rb in s3io-1.1.1 vs lib/s3io/read_wrapper.rb in s3io-1.1.4

@@ -28,34 +28,34 @@
     end
 
     # Reads data from S3 object.
     #
     # @param [Integer] bytes number of bytes to read
-    def read(bytes = nil)
-      content_length = @s3object.content_length
+    def read(bytes = nil, outbuf = nil)
+      @content_length ||= @s3object.content_length
 
-      return '' if (@pos >= content_length) || (bytes == 0)
+      return '' if (@pos >= @content_length) || (bytes == 0)
 
-      bytes ||= content_length
+      bytes ||= @content_length
 
       upper_bound = @pos + bytes - 1
-      upper_bound = (content_length - 1) if upper_bound >= content_length
+      upper_bound = (@content_length - 1) if upper_bound >= @content_length
 
-      data = @s3object.read :range => @pos..upper_bound
+      data = @s3object.read :range => @pos..upper_bound, :if_unmodified_since => @last_modified
 
-      last_modified = @s3object.last_modified
-      unless last_modified == @last_modified
-        fail ReadModifiedError, "S3 object #{@s3object.key} was updated during read, last_modified=#{last_modified.to_s} (was #{@last_modified.to_s})"
-      end
-
       @pos = upper_bound + 1
 
+      outbuf.replace data if outbuf 
+
       return data
+
+    rescue ::AWS::S3::Errors::PreconditionFailed
+      fail ReadModifiedError, "S3 object #{@s3object.key} was updated during read (modified since #{@last_modified.to_s})"
     end
 
     def eof?
-      @pos >= @s3object.content_length
+      (@content_length = @s3object.content_length) && (@pos >= @content_length)
     end
 
     # Rewinds position to the very beginning of S3 object.
     def rewind
       @pos = 0
@@ -90,7 +90,17 @@
 
       return self
     end
     alias lines each
     alias each_line each
+
+    # Returns one string at a time.
+    #
+    # @param [String] separator line separator string
+    def gets(separator = $/)
+      @_gets ||= enum_for(:each, separator)
+      @_gets.next
+    rescue StopIteration
+      nil
+    end
   end
 end