results.h

Go to the documentation of this file.

// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_RESULTS_H
#define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_RESULTS_H

#include "google/cloud/spanner/row.h"
#include "google/cloud/spanner/timestamp.h"
#include "google/cloud/optional.h"
#include <google/spanner/v1/spanner.pb.h>
#include <memory>
#include <string>
#include <unordered_map>

namespace google {
namespace cloud {
namespace spanner {
inline namespace SPANNER_CLIENT_NS {

using ExecutionPlan = ::google::spanner::v1::QueryPlan;

namespace internal {
class ResultSourceInterface {
 public:
  virtual ~ResultSourceInterface() = default;
  // Returns OK Status with an empty Row to indicate end-of-stream.
  virtual StatusOr<Row> NextRow() = 0;
  virtual optional<google::spanner::v1::ResultSetMetadata> Metadata() = 0;
  virtual optional<google::spanner::v1::ResultSetStats> Stats() const = 0;
};
}  // namespace internal

class RowStream {
 public:
  RowStream() = default;
  explicit RowStream(std::unique_ptr<internal::ResultSourceInterface> source)
      : source_(std::move(source)) {}

  // This class is movable but not copyable.
  RowStream(RowStream&&) = default;
  RowStream& operator=(RowStream&&) = default;

  RowStreamIterator begin() {
    return RowStreamIterator([this]() mutable { return source_->NextRow(); });
  }

  // NOLINTNEXTLINE(readability-convert-member-functions-to-static)
  RowStreamIterator end() { return {}; }

  optional<Timestamp> ReadTimestamp() const;

 private:
  std::unique_ptr<internal::ResultSourceInterface> source_;
};

class DmlResult {
 public:
  DmlResult() = default;
  explicit DmlResult(std::unique_ptr<internal::ResultSourceInterface> source)
      : source_(std::move(source)) {}

  // This class is movable but not copyable.
  DmlResult(DmlResult&&) = default;
  DmlResult& operator=(DmlResult&&) = default;

  std::int64_t RowsModified() const;

 private:
  std::unique_ptr<internal::ResultSourceInterface> source_;
};

class ProfileQueryResult {
 public:
  ProfileQueryResult() = default;
  explicit ProfileQueryResult(
      std::unique_ptr<internal::ResultSourceInterface> source)
      : source_(std::move(source)) {}

  // This class is movable but not copyable.
  ProfileQueryResult(ProfileQueryResult&&) = default;
  ProfileQueryResult& operator=(ProfileQueryResult&&) = default;

  RowStreamIterator begin() {
    return RowStreamIterator([this]() mutable { return source_->NextRow(); });
  }

  // NOLINTNEXTLINE(readability-convert-member-functions-to-static)
  RowStreamIterator end() { return {}; }

  optional<Timestamp> ReadTimestamp() const;

  optional<std::unordered_map<std::string, std::string>> ExecutionStats() const;

  optional<spanner::ExecutionPlan> ExecutionPlan() const;

 private:
  std::unique_ptr<internal::ResultSourceInterface> source_;
};

class ProfileDmlResult {
 public:
  ProfileDmlResult() = default;
  explicit ProfileDmlResult(
      std::unique_ptr<internal::ResultSourceInterface> source)
      : source_(std::move(source)) {}

  // This class is movable but not copyable.
  ProfileDmlResult(ProfileDmlResult&&) = default;
  ProfileDmlResult& operator=(ProfileDmlResult&&) = default;

  std::int64_t RowsModified() const;

  optional<std::unordered_map<std::string, std::string>> ExecutionStats() const;

  optional<spanner::ExecutionPlan> ExecutionPlan() const;

 private:
  std::unique_ptr<internal::ResultSourceInterface> source_;
};
}  // namespace SPANNER_CLIENT_NS
}  // namespace spanner
}  // namespace cloud
}  // namespace google

#endif  // GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_SPANNER_RESULTS_H