account for truncated/expanded static files

When running a static file server, we must account for filesystem
activity outside of our control where files may grow/shrink as
they're being served.

For truncated files, we must abort any persistent connections
downloading a truncated file to avoid confusing clients because
the Content-Length header was already set to the big value.

We also must ensure (we already did so before this commit,
this just adds a test for it) we do not send additional data
when a file grows on us after we've started sending the response.

1 files changed, 14 insertions, 0 deletions

diff --git a/test/server_helper.rb b/test/server_helper.rb
index 52b08c7..2f9266a 100644
--- a/test/server_helper.rb
+++ b/test/server_helper.rb
@@ -78,6 +78,20 @@ module ServerHelper
       Yahns::Server.new(cfg).start.join
     end
   end
+
+  def wait_for_full(c)
+    prev = 0
+    prev_time = Time.now
+    begin
+      nr = c.nread
+      break if nr > 0 && nr == prev && (Time.now - prev_time) > 0.5
+      if nr != prev
+        prev = nr
+        prev_time = Time.now
+      end
+      Thread.pass
+    end while sleep(0.1)
+  end
 end
 
 module TrywriteBlocked