# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1252713143 -7200
# Node ID 0cd36671c34eaafa644a3186437ededc50dcd4a9
# Parent  628c5c3881099d567d1232ed5bcc6a04df3682b2
Made the seek method slightly more efficient at reusing cached data.

diff -r 628c5c388109 -r 0cd36671c34e iixr.py
--- a/iixr.py	Sat Sep 12 01:32:19 2009 +0200
+++ b/iixr.py	Sat Sep 12 01:52:23 2009 +0200
@@ -263,16 +263,22 @@
 
         s = self.cache[:n]
         self.cache = self.cache[n:]
-        self.cache_length -= len(s)
+        self.cache_length = len(self.cache)
         return s
 
     def tell(self):
         return self.f.tell() - self.cache_length
 
     def seek(self, offset):
+        current = self.tell()
         self.f.seek(offset)
-        self.cache = ""
-        self.cache_length = 0
+        if offset >= current:
+            discarded = offset - current
+            self.cache = self.cache[discarded:]
+            self.cache_length = len(self.cache)
+        else:
+            self.cache = ""
+            self.cache_length = 0
 
 class FileOpener: