Patch by Eric Raymond: add an optional 'seekable' flag to the
MultiFile constructor, and only do the posstack bookkeeping when it is
true.
diff --git a/Lib/multifile.py b/Lib/multifile.py
index 8ba88e4..6c80c43 100644
--- a/Lib/multifile.py
+++ b/Lib/multifile.py
@@ -21,6 +21,11 @@
# Note that if a nested multipart message is terminated by a separator
# for an outer message, this is not reported, even though it is really
# illegal input.
+#
+# If seekable is given as 0, the class code will not do the bookeeping
+# it normally attempts in order to make seeks relative to the beginning of the
+# current file part. This may be useful when using MultiFile with a non-
+# seekable stream object.
import sys
import string
@@ -31,13 +36,16 @@
class MultiFile:
#
- def __init__(self, fp):
+ seekable = 0
+ def __init__(self, fp, seekable=1):
self.fp = fp
self.stack = [] # Grows down
self.level = 0
self.last = 0
- self.start = self.fp.tell()
- self.posstack = [] # Grows down
+ if seekable:
+ self.seekable = 1
+ self.start = self.fp.tell()
+ self.posstack = [] # Grows down
#
def tell(self):
if self.level > 0:
@@ -88,7 +96,8 @@
else:
return line
# Get here after break out of loop
- self.lastpos = self.tell() - len(line)
+ if self.seekable:
+ self.lastpos = self.tell() - len(line)
self.level = i+1
if self.level > 1:
err('*** Missing endmarker in MultiFile.readline()\n')
@@ -111,15 +120,17 @@
return 0
self.level = 0
self.last = 0
- self.start = self.fp.tell()
+ if self.seekable:
+ self.start = self.fp.tell()
return 1
#
def push(self, sep):
if self.level > 0:
raise Error, 'bad MultiFile.push() call'
self.stack.insert(0, sep)
- self.posstack.insert(0, self.start)
- self.start = self.fp.tell()
+ if self.seekable:
+ self.posstack.insert(0, self.start)
+ self.start = self.fp.tell()
#
def pop(self):
if self.stack == []:
@@ -130,8 +141,9 @@
abslastpos = self.lastpos + self.start
self.level = max(0, self.level - 1)
del self.stack[0]
- self.start = self.posstack[0]
- del self.posstack[0]
- if self.level > 0:
- self.lastpos = abslastpos - self.start
+ if self.seekable:
+ self.start = self.posstack[0]
+ del self.posstack[0]
+ if self.level > 0:
+ self.lastpos = abslastpos - self.start
#