Load live version when reloading an offline page on connected network

components/offline_pages/request_header/offline_page_header.cc

+// Copyright 2016 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.
+
+#include "components/offline_pages/request_header/offline_page_header.h"
+
+#include "base/strings/string_tokenizer.h"
+#include "base/strings/string_util.h"
+
+namespace offline_pages {
+
+const char kOfflinePageHeader[] = "X-Chrome-offline";
+const char kOfflinePageHeaderReasonKey[] = "reason";
+const char kOfflinePageHeaderReasonValueDueToNetError[] = "error";
+const char kOfflinePageHeaderReasonValueFromDownload[] = "download";
+const char kOfflinePageHeaderReasonValueReload[] = "reload";
+const char kOfflinePageHeaderPersistKey[] = "persist";
+const char kOfflinePageHeaderIDKey[] = "id";
+
+namespace {
+
+bool ParseOfflineHeaderValue(const std::string& header_value,
+                             bool* need_to_persist,
+                             OfflinePageHeader::Reason* reason,
+                             std::string* id) {
+  // If the offline header is not present, treat it as not parsed successfully.
+  if (header_value.empty())
+    return false;
+
+  bool token_found = false;
+  base::StringTokenizer tokenizer(header_value, ", ");
+  while (tokenizer.GetNext()) {
+    token_found = true;
+    std::string pair = tokenizer.token();
+    std::size_t pos = pair.find('=');
+    if (pos == std::string::npos)
+      return false;
+    std::string key = base::ToLowerASCII(pair.substr(0, pos));
+    std::string value = base::ToLowerASCII(pair.substr(pos + 1));
+    if (key == kOfflinePageHeaderPersistKey) {
+      if (value == "1")
+        *need_to_persist = true;
+      else if (value == "0")
+        *need_to_persist = false;
+      else
+        return false;
+    } else if (key == kOfflinePageHeaderReasonKey) {
+      if (value == kOfflinePageHeaderReasonValueDueToNetError)
+        *reason = OfflinePageHeader::Reason::NET_ERROR;
+      else if (value == kOfflinePageHeaderReasonValueFromDownload)
+        *reason = OfflinePageHeader::Reason::DOWNLOAD;
+      else if (value == kOfflinePageHeaderReasonValueReload)
+        *reason = OfflinePageHeader::Reason::RELOAD;
+      else
+        return false;
+    } else if (key == kOfflinePageHeaderIDKey) {
+      *id = value;
+    } else {
+      return false;
+    }
+  }
+
+  return token_found;
+}
+
+std::string ReasonToString(OfflinePageHeader::Reason reason) {
+  switch (reason) {
+    case OfflinePageHeader::Reason::NET_ERROR:
+      return kOfflinePageHeaderReasonValueDueToNetError;
+    case OfflinePageHeader::Reason::DOWNLOAD:
+      return kOfflinePageHeaderReasonValueFromDownload;
+    case OfflinePageHeader::Reason::RELOAD:
+      return kOfflinePageHeaderReasonValueReload;
+    default:
+      NOTREACHED();
+      return "";
+  }
+}
+
+}  // namespace
+
+OfflinePageHeader::OfflinePageHeader()
+    : did_fail_parsing_for_test(false),
+      need_to_persist(false),
+      reason(Reason::NONE) {
+}
+
+OfflinePageHeader::OfflinePageHeader(const std::string& header_value)
+    : did_fail_parsing_for_test(false),
+      need_to_persist(false),
+      reason(Reason::NONE) {
+  if (!ParseOfflineHeaderValue(header_value, &need_to_persist, &reason, &id)) {
+    did_fail_parsing_for_test = true;
+    Clear();
+  }
+}
+
+OfflinePageHeader::~OfflinePageHeader() {}
+
+std::string OfflinePageHeader::GetCompleteHeaderString() const {
+  if (reason == Reason::NONE)
+    return std::string();
+
+  std::string value(kOfflinePageHeader);
+  value += ": ";
+
+  value += kOfflinePageHeaderPersistKey;
+  value += "=";
+  value += need_to_persist ? "1" : "0";
+
+  value += " " ;
+  value += kOfflinePageHeaderReasonKey;
+  value += "=";
+  value += ReasonToString(reason);
+
+  if (!id.empty()) {
+    value += " " ;
+    value += kOfflinePageHeaderIDKey;
+    value += "=";
+    value += id;
+  }
+
+  return value;
+}
+
+void OfflinePageHeader::Clear() {
+  reason = Reason::NONE;
+  need_to_persist = false;
+  id.clear();
+}
+
+}  // namespace offline_pages