1 files changed, 35 insertions, 0 deletions
diff --git a/retiolum/scripts/adv_graphgen/BackwardsReader.py b/retiolum/scripts/adv_graphgen/BackwardsReader.py
new file mode 100644
index 00000000..6bdbf43c
--- /dev/null
+++ b/retiolum/scripts/adv_graphgen/BackwardsReader.py
@@ -0,0 +1,35 @@
+import sys
+import os
+import string
+
+class BackwardsReader:
+  """ Stripped and stolen from : http://code.activestate.com/recipes/120686-read-a-text-file-backwards/ """
+  def readline(self):
+    while len(self.data) == 1 and ((self.blkcount * self.blksize) < self.size):
+      self.blkcount = self.blkcount + 1
+      line = self.data[0]
+      try:
+        self.f.seek(-self.blksize * self.blkcount, 2) 
+        self.data = string.split(self.f.read(self.blksize) + line, '\n')
+      except IOError:  
+        self.f.seek(0)
+        self.data = string.split(self.f.read(self.size - (self.blksize * (self.blkcount-1))) + line, '\n')
+
+    if len(self.data) == 0:
+      return ""
+
+    line = self.data[-1]
+    self.data = self.data[:-1]
+    return line + '\n'
+
+  def __init__(self, file, blksize=4096):
+    """initialize the internal structures"""
+    self.size = os.stat(file)[6]
+    self.blksize = blksize
+    self.blkcount = 1
+    self.f = open(file, 'rb')
+    if self.size > self.blksize:
+      self.f.seek(-self.blksize * self.blkcount, 2) 
+    self.data = string.split(self.f.read(self.blksize), '\n')
+    if not self.data[-1]:
+      self.data = self.data[:-1]