components/previews/core/previews_decider.h

// 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.

#ifndef COMPONENTS_PREVIEWS_CORE_PREVIEWS_DECIDER_H_
#define COMPONENTS_PREVIEWS_CORE_PREVIEWS_DECIDER_H_

#include "components/previews/core/previews_experiments.h"

#include <string>
#include <vector>

#include "base/strings/string_piece.h"
#include "net/nqe/effective_connection_type.h"

namespace net {
class URLRequest;
}

namespace previews {

class PreviewsDecider {
 public:
  // Whether |request| is allowed to show a preview of |type|. If the current
  // ECT is strictly faster than |effective_connection_type_threshold|, the
  // preview will be disallowed; preview types that check network quality before
  // calling ShouldAllowPreviewAtECT should pass in
  // EFFECTIVE_CONNECTION_TYPE_4G.
  virtual bool ShouldAllowPreviewAtECT(
      const net::URLRequest& request,
      PreviewsType type,
      net::EffectiveConnectionType effective_connection_type_threshold,
      const std::vector<std::string>& host_blacklist_from_finch,
      bool ignore_long_term_black_list_rules) const = 0;

  // Same as ShouldAllowPreviewAtECT, but uses the previews default
  // EffectiveConnectionType and no blacklisted hosts from the server.
  virtual bool ShouldAllowPreview(const net::URLRequest& request,
                                  PreviewsType type) const = 0;

  // Whether the URL in |request| is allowed to show a preview of |type|.
  // This only considers whether the URL is constrained/allowed in
  // blacklists/whitelists. It does not include other constraints such
  // as the effective connection type.
  virtual bool IsURLAllowedForPreview(const net::URLRequest& request,
                                      PreviewsType type) const = 0;

  // Requests that any applicable detailed resource hints be loaded.
  virtual void LoadResourceHints(const net::URLRequest& request) = 0;

 protected:
  PreviewsDecider() {}
  virtual ~PreviewsDecider() {}
};

}  // namespace previews

#endif  // COMPONENTS_PREVIEWS_CORE_PREVIEWS_DECIDER_H_