From 3a21e28bf13b5710639337fdc29741e9b6b71405 Mon Sep 17 00:00:00 2001
From: Aldo Cortesi <aldo@nullcube.com>
Date: Mon, 24 Sep 2012 11:10:21 +1200
Subject: [PATCH] Split FileLike into Writer and Reader, and add logging
 functionality.

---
 netlib/tcp.py    | 69 +++++++++++++++++++++++++++++++++++++-----------
 test/test_tcp.py | 34 +++++++++++++++++++++---
 2 files changed, 84 insertions(+), 19 deletions(-)

diff --git a/netlib/tcp.py b/netlib/tcp.py
index 0fed7380d..e1318435b 100644
--- a/netlib/tcp.py
+++ b/netlib/tcp.py
@@ -39,10 +39,11 @@ class NetLibDisconnect(Exception): pass
 class NetLibTimeout(Exception): pass
 
 
-class FileLike:
+class _FileLike:
     BLOCKSIZE = 1024 * 32
     def __init__(self, o):
         self.o = o
+        self._log = None
 
     def set_descriptor(self, o):
         self.o = o
@@ -50,6 +51,37 @@ class FileLike:
     def __getattr__(self, attr):
         return getattr(self.o, attr)
 
+    def start_log(self):
+        """
+            Starts or resets the log.
+
+            This will store all bytes read or written.
+        """
+        self._log = []
+
+    def stop_log(self):
+        """
+            Stops the log.
+        """
+        self._log = None
+
+    def is_logging(self):
+        return self._log is not None
+
+    def get_log(self):
+        """
+            Returns the log as a string.
+        """
+        if not self.is_logging():
+            raise ValueError("Not logging!")
+        return "".join(self._log)
+
+    def add_log(self, v):
+        if self.is_logging():
+            self._log.append(v)
+
+
+class Writer(_FileLike):
     def flush(self):
         try:
             if hasattr(self.o, "flush"):
@@ -57,6 +89,21 @@ class FileLike:
         except socket.error, v:
             raise NetLibDisconnect(str(v))
 
+    def write(self, v):
+        if v:
+            try:
+                if hasattr(self.o, "sendall"):
+                    self.add_log(v)
+                    return self.o.sendall(v)
+                else:
+                    r = self.o.write(v)
+                    self.add_log(v[:r])
+                    return r
+            except (SSL.Error, socket.error):
+                raise NetLibDisconnect()
+
+
+class Reader(_FileLike):
     def read(self, length):
         """
             If length is None, we read until connection closes.
@@ -85,19 +132,9 @@ class FileLike:
             result += data
             if length != -1:
                 length -= len(data)
+        self.add_log(result)
         return result
 
-    def write(self, v):
-        if v:
-            try:
-                if hasattr(self.o, "sendall"):
-                    return self.o.sendall(v)
-                else:
-                    r = self.o.write(v)
-                    return r
-            except (SSL.Error, socket.error):
-                raise NetLibDisconnect()
-
     def readline(self, size = None):
         result = ''
         bytes_read = 0
@@ -151,8 +188,8 @@ class TCPClient:
             addr = socket.gethostbyname(self.host)
             connection = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             connection.connect((addr, self.port))
-            self.rfile = FileLike(connection.makefile('rb', self.rbufsize))
-            self.wfile = FileLike(connection.makefile('wb', self.wbufsize))
+            self.rfile = Reader(connection.makefile('rb', self.rbufsize))
+            self.wfile = Writer(connection.makefile('wb', self.wbufsize))
         except socket.error, err:
             raise NetLibError('Error connecting to "%s": %s' % (self.host, err))
         self.connection = connection
@@ -186,8 +223,8 @@ class BaseHandler:
     wbufsize = -1
     def __init__(self, connection, client_address, server):
         self.connection = connection
-        self.rfile = FileLike(self.connection.makefile('rb', self.rbufsize))
-        self.wfile = FileLike(self.connection.makefile('wb', self.wbufsize))
+        self.rfile = Reader(self.connection.makefile('rb', self.rbufsize))
+        self.wfile = Writer(self.connection.makefile('wb', self.wbufsize))
 
         self.client_address = client_address
         self.server = server
diff --git a/test/test_tcp.py b/test/test_tcp.py
index 67c56a374..9d581939c 100644
--- a/test/test_tcp.py
+++ b/test/test_tcp.py
@@ -228,8 +228,8 @@ class TestTCPClient:
 class TestFileLike:
     def test_wrap(self):
         s = cStringIO.StringIO("foobar\nfoobar")
-        s = tcp.FileLike(s)
         s.flush()
+        s = tcp.Reader(s)
         assert s.readline() == "foobar\n"
         assert s.readline() == "foobar"
         # Test __getattr__
@@ -237,11 +237,39 @@ class TestFileLike:
 
     def test_limit(self):
         s = cStringIO.StringIO("foobar\nfoobar")
-        s = tcp.FileLike(s)
+        s = tcp.Reader(s)
         assert s.readline(3) == "foo"
 
     def test_limitless(self):
         s = cStringIO.StringIO("f"*(50*1024))
-        s = tcp.FileLike(s)
+        s = tcp.Reader(s)
         ret = s.read(-1)
         assert len(ret) == 50 * 1024
+
+    def test_readlog(self):
+        s = cStringIO.StringIO("foobar\nfoobar")
+        s = tcp.Reader(s)
+        assert not s.is_logging()
+        s.start_log()
+        assert s.is_logging()
+        s.readline()
+        assert s.get_log() == "foobar\n"
+        s.read(1)
+        assert s.get_log() == "foobar\nf"
+        s.start_log()
+        assert s.get_log() == ""
+        s.read(1)
+        assert s.get_log() == "o"
+        s.stop_log()
+        tutils.raises(ValueError, s.get_log)
+
+    def test_writelog(self):
+        s = cStringIO.StringIO()
+        s = tcp.Writer(s)
+        s.start_log()
+        assert s.is_logging()
+        s.write("x")
+        assert s.get_log() == "x"
+        s.write("x")
+        assert s.get_log() == "xx"
+