From: Brian Warner <warner@allmydata.com>
Date: Tue, 4 Nov 2008 22:29:19 +0000 (-0700)
Subject: immutable: tolerate filenode.read() with a size= that's too big, rather than hanging
X-Git-Url: https://git.rkrishnan.org/specifications/-?a=commitdiff_plain;h=6fa41e738b4036efaf128e2b6a9ff284d5c4b0d6;p=tahoe-lafs%2Ftahoe-lafs.git

immutable: tolerate filenode.read() with a size= that's too big, rather than hanging
---

diff --git a/src/allmydata/immutable/filenode.py b/src/allmydata/immutable/filenode.py
index 33395ef9..fbc00d86 100644
--- a/src/allmydata/immutable/filenode.py
+++ b/src/allmydata/immutable/filenode.py
@@ -221,7 +221,7 @@ class FileNode(_ImmutableFileNodeBase):
     def read(self, consumer, offset=0, size=None):
         if size is None:
             size = self.get_size() - offset
-
+        size = min(size, self.get_size() - offset)
 
         if offset == 0 and size == self.get_size():
             # don't use the cache, just do a normal streaming download
diff --git a/src/allmydata/test/test_system.py b/src/allmydata/test/test_system.py
index 5a2fff15..618d4af7 100644
--- a/src/allmydata/test/test_system.py
+++ b/src/allmydata/test/test_system.py
@@ -202,6 +202,11 @@ class SystemTest(SystemTestMixin, unittest.TestCase):
             def _read_tail_done(mc):
                 self.failUnlessEqual("".join(mc.chunks), DATA[2:])
             d.addCallback(_read_tail_done)
+            d.addCallback(lambda ign:
+                          n.read(MemoryConsumer(), size=len(DATA)+1000))
+            def _read_too_much(mc):
+                self.failUnlessEqual("".join(mc.chunks), DATA)
+            d.addCallback(_read_too_much)
 
             return d
         d.addCallback(_test_read)