Merge pull request #1511 from arjun23496/count_in_replace

Fixes #1495 - Added count argument for replacing contents in body

netlib/http/headers.py

@@ -158,7 +158,7 @@ class Headers(multidict.MultiDict):
         else:
             return super(Headers, self).items()
 
-    def replace(self, pattern, repl, flags=0):
+    def replace(self, pattern, repl, flags=0, count=0):
         """
         Replaces a regular expression pattern with repl in each "name: value"
         header line.
@@ -172,10 +172,10 @@ class Headers(multidict.MultiDict):
             repl = strutils.escaped_str_to_bytes(repl)
         pattern = re.compile(pattern, flags)
         replacements = 0
-
+        flag_count = count > 0
         fields = []
         for name, value in self.fields:
-            line, n = pattern.subn(repl, name + b": " + value)
+            line, n = pattern.subn(repl, name + b": " + value, count=count)
             try:
                 name, value = line.split(b": ", 1)
             except ValueError:
@@ -184,6 +184,10 @@ class Headers(multidict.MultiDict):
                 pass
             else:
                 replacements += n
+                if flag_count:
+                    count -= n
+                    if count == 0:
+                        break
             fields.append((name, value))
         self.fields = tuple(fields)
         return replacements

netlib/http/message.py

@@ -260,7 +260,7 @@ class Message(basetypes.Serializable):
         if "content-encoding" not in self.headers:
             raise ValueError("Invalid content encoding {}".format(repr(e)))
 
-    def replace(self, pattern, repl, flags=0):
+    def replace(self, pattern, repl, flags=0, count=0):
         """
         Replaces a regular expression pattern with repl in both the headers
         and the body of the message. Encoded body will be decoded
@@ -276,9 +276,9 @@ class Message(basetypes.Serializable):
         replacements = 0
         if self.content:
             self.content, replacements = re.subn(
-                pattern, repl, self.content, flags=flags
+                pattern, repl, self.content, flags=flags, count=count
             )
-        replacements += self.headers.replace(pattern, repl, flags)
+        replacements += self.headers.replace(pattern, repl, flags=flags, count=count)
         return replacements
 
     # Legacy

netlib/http/request.py

@@ -80,7 +80,7 @@ class Request(message.Message):
             self.method, hostport, path
         )
 
-    def replace(self, pattern, repl, flags=0):
+    def replace(self, pattern, repl, flags=0, count=0):
         """
             Replaces a regular expression pattern with repl in the headers, the
             request path and the body of the request. Encoded content will be
@@ -94,9 +94,9 @@ class Request(message.Message):
         if isinstance(repl, six.text_type):
             repl = strutils.escaped_str_to_bytes(repl)
 
-        c = super(Request, self).replace(pattern, repl, flags)
+        c = super(Request, self).replace(pattern, repl, flags, count)
         self.path, pc = re.subn(
-            pattern, repl, self.data.path, flags=flags
+            pattern, repl, self.data.path, flags=flags, count=count
         )
         c += pc
         return c

test/netlib/http/test_headers.py

@@ -75,6 +75,11 @@ class TestHeaders(object):
         assert replacements == 0
         assert headers["Host"] == "example.com"
 
+    def test_replace_with_count(self):
+        headers = Headers(Host="foobarfoo.com", Accept="foo/bar")
+        replacements = headers.replace("foo", "bar", count=1)
+        assert replacements == 1
+
 
 def test_parse_content_type():
     p = parse_content_type

test/netlib/http/test_message.py

@@ -99,6 +99,16 @@ class TestMessage(object):
     def test_http_version(self):
         _test_decoded_attr(tresp(), "http_version")
 
+    def test_replace(self):
+        r = tresp()
+        r.content = b"foofootoo"
+        r.replace(b"foo", "gg")
+        assert r.content == b"ggggtoo"
+
+        r.content = b"foofootoo"
+        r.replace(b"foo", "gg", count=1)
+        assert r.content == b"ggfootoo"
+
 
 class TestMessageContentEncoding(object):
     def test_simple(self):

test/netlib/http/test_request.py

@@ -26,6 +26,16 @@ class TestRequestCore(object):
         request.host = None
         assert repr(request) == "Request(GET /path)"
 
+    def replace(self):
+        r = treq()
+        r.path = b"foobarfoo"
+        r.replace(b"foo", "bar")
+        assert r.path == b"barbarbar"
+
+        r.path = b"foobarfoo"
+        r.replace(b"foo", "bar", count=1)
+        assert r.path == b"barbarfoo"
+
     def test_first_line_format(self):
         _test_passthrough_attr(treq(), "first_line_format")