components/optimization_guide/core/optimization_guide_util.h

// Copyright 2019 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_OPTIMIZATION_GUIDE_CORE_OPTIMIZATION_GUIDE_UTIL_H_
#define COMPONENTS_OPTIMIZATION_GUIDE_CORE_OPTIMIZATION_GUIDE_UTIL_H_

#include <string>

#include "base/files/file_path.h"
#include "base/strings/string_split.h"
#include "components/optimization_guide/core/optimization_guide_enums.h"
#include "components/optimization_guide/proto/common_types.pb.h"
#include "components/optimization_guide/proto/models.pb.h"
#include "third_party/abseil-cpp/absl/types/optional.h"

namespace optimization_guide {

// Returns the string than can be used to record histograms for the optimization
// target. If adding a histogram to use the string or adding an optimization
// target, update the OptimizationGuide.OptimizationTargets histogram suffixes
// in histograms.xml.
std::string GetStringNameForOptimizationTarget(
    proto::OptimizationTarget optimization_target);

// Returns false if the host is an IP address, localhosts, or an invalid
// host that is not supported by the remote optimization guide.
bool IsHostValidToFetchFromRemoteOptimizationGuide(const std::string& host);

// Returns the set of active field trials that are allowed to be sent to the
// remote Optimization Guide Service.
google::protobuf::RepeatedPtrField<proto::FieldTrial>
GetActiveFieldTrialsAllowedForFetch();

// Returns the file path that holds the model file for |model|, if applicable.
absl::optional<base::FilePath> GetFilePathFromPredictionModel(
    const proto::PredictionModel& model);

// Fills |model| with the path for which the corresponding model file can be
// found.
void SetFilePathInPredictionModel(const base::FilePath& file_path,
                                  proto::PredictionModel* model);

// Validates that the metadata stored in |any_metadata_| is of the same type
// and is parseable as |T|. Will return metadata if all checks pass.
template <class T,
          class = typename std::enable_if<
              std::is_convertible<T*, google::protobuf::MessageLite*>{}>::type>
absl::optional<T> ParsedAnyMetadata(const proto::Any& any_metadata) {
  // Verify type is the same - the Any type URL should be wrapped as:
  // "type.googleapis.com/com.foo.Name".
  std::vector<std::string> any_type_parts =
      base::SplitString(any_metadata.type_url(), ".", base::TRIM_WHITESPACE,
                        base::SPLIT_WANT_NONEMPTY);
  if (any_type_parts.empty())
    return absl::nullopt;
  T metadata;
  std::vector<std::string> type_parts =
      base::SplitString(metadata.GetTypeName(), ".", base::TRIM_WHITESPACE,
                        base::SPLIT_WANT_NONEMPTY);
  if (type_parts.empty())
    return absl::nullopt;
  std::string any_type_name = any_type_parts.back();
  std::string type_name = type_parts.back();
  if (type_name != any_type_name)
    return absl::nullopt;

  // Return metadata if parseable.
  if (metadata.ParseFromString(any_metadata.value()))
    return metadata;
  return absl::nullopt;
}

}  // namespace optimization_guide

#endif  // COMPONENTS_OPTIMIZATION_GUIDE_CORE_OPTIMIZATION_GUIDE_UTIL_H_