[Offline Prefetch] Prefetch request fetcher

components/offline_pages/core/prefetch/prefetch_request_fetcher.h

+// Copyright 2017 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.
+
+#ifndef COMPONENTS_OFFLINE_PAGES_CORE_PREFETCH_PREFETCH_REQUEST_FETCHER_H_
+#define COMPONENTS_OFFLINE_PAGES_CORE_PREFETCH_PREFETCH_REQUEST_FETCHER_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+class GURL;
+namespace net {
+class URLRequestContextGetter;
+}
+
+namespace offline_prefetch {
+
+class PrefetchRequestFetcher : public net::URLFetcherDelegate {
+ public:
+  enum class Status {
+    // Request completed successfully.
+    SUCCESS,
+    // Request failed due to to local network problem, unrelated to server load
+    // levels. The caller will simply reschedule the retry in the next available
+    // WiFi window after 15 minutes have passed.
+    SHOULD_RETRY_WITHOUT_BACKOFF,
+    // Request failed probably related to transient server problems. The caller
+    // will reschedule the retry with backoff included.
+    SHOULD_RETRY_WITH_BACKOFF,
+    // Request failed with error indicating that the server no longer knows how
+    // to service a request. The caller will prevent network requests for the
+    // period of 1 day.
+    SHOULD_SUSPEND
+  };
+
+  using FinishedCallback =
+      base::Callback<void(Status status, const std::string& data)>;
+
+  PrefetchRequestFetcher(
+      const GURL& url,
+      const std::string& message,
+      scoped_refptr<net::URLRequestContextGetter> request_context_getter,
+      const FinishedCallback& callback);
+  ~PrefetchRequestFetcher() override;
+
+  // URLFetcherDelegate implementation.
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
+
+ private:
+  Status ParseResponse(const net::URLFetcher* source, std::string* data);
+
+  scoped_refptr<net::URLRequestContextGetter> request_context_getter_;
+  std::unique_ptr<net::URLFetcher> url_fetcher_;
+  FinishedCallback callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrefetchRequestFetcher);
+};
+
+}  // namespace offline_prefetch
+
+#endif  // COMPONENTS_OFFLINE_PAGES_CORE_PREFETCH_PREFETCH_REQUEST_FETCHER_H_