Http cache: Avoid resuming (and keeping) truncated entries...

net/http/http_response_headers.cc

 // Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // The rules for header parsing were borrowed from Firefox:
 // http://lxr.mozilla.org/seamonkey/source/netwerk/protocol/http/src/nsHttpResponseHead.cpp
 // The rules for parsing content-types were also borrowed from Firefox:
 // http://lxr.mozilla.org/mozilla/source/netwerk/base/src/nsURLHelper.cpp#834
 
 #include "net/http/http_response_headers.h"
@@ skipping 983 matching lines @@
     // HTTP/1.0 responses default to NOT keep-alive
     keep_alive = LowerCaseEqualsASCII(connection_val, "keep-alive");
   } else {
     // HTTP/1.1 responses default to keep-alive
     keep_alive = !LowerCaseEqualsASCII(connection_val, "close");
   }
 
   return keep_alive;
 }
 
+bool HttpResponseHeaders::HasStrongValidators() const {
+  std::string etag_value;
+  EnumerateHeader(NULL, "etag", &etag_value);
+  if (!etag_value.empty()) {
+    size_t slash = etag_value.find('/');
+    if (slash == std::string::npos || slash == 0)
+      return true;
+
+    std::string::const_iterator i = etag_value.begin();
+    std::string::const_iterator j = etag_value.begin() + slash;
+    HttpUtil::TrimLWS(&i, &j);
+    if (!LowerCaseEqualsASCII(i, j, "w"))
+      return true;
+  }
+
+  Time last_modified;
+  if (!GetLastModifiedValue(&last_modified))
+    return false;
+
+  Time date;
+  if (!GetDateValue(&date))
+    return false;
+
+  return ((date - last_modified).InSeconds() >= 60);
+}
+
 // From RFC 2616:
 // Content-Length = "Content-Length" ":" 1*DIGIT
 int64 HttpResponseHeaders::GetContentLength() const {
   void* iter = NULL;
   std::string content_length_val;
   if (!EnumerateHeader(&iter, "content-length", &content_length_val))
     return -1;
 
   if (content_length_val.empty())
     return -1;
@@ skipping 115 matching lines @@
   // We have all the values; let's verify that they make sense for a 206
   // response.
   if (*first_byte_position < 0 || *last_byte_position < 0 ||
       *instance_length < 0 || *instance_length - 1 < *last_byte_position)
     return false;
 
   return true;
 }
 
 }  // namespace net