analyzer/store/report_store.h - cobalt - Git at Google

 // Copyright 2017 The Fuchsia Authors
 //
 // 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 COBALT_ANALYZER_STORE_REPORT_STORE_H_
 #define COBALT_ANALYZER_STORE_REPORT_STORE_H_

 #include <memory>
 #include <string>
 #include <vector>

 #include "analyzer/report_master/report_internal.pb.h"
 #include "analyzer/report_master/report_master.pb.h"
 #include "analyzer/store/data_store.h"
 #include "util/clock.h"

 namespace cobalt {
 namespace analyzer {
 namespace store {

 // A ReportStore is used for storing and retrieving Cobalt reports. A
 // report is the final output of the Cobalt pipeline--the result of the privacy-
 // preserving analysis.
 class ReportStore {
  public:
   // Constructs a ReportStore that wraps an underlying data store.
   explicit ReportStore(std::shared_ptr<DataStore> store);

   // Generates a new ReportId and writes information into the ReportStore to
   // indicate that the report with that ID is in the IN_PROGRESS state. This
   // method should be invoked prior to starting to add new rows to a report
   // via the AddReportRow() method. The report being started is associated
   // with a ReportConfig and it may be either the primary report specified
   // by the ReportConfig or it may be an auxilliary report being automatically
   // generated by the system in support of the primary report. The group of
   // reports--primary and auxilliary--associated with a ReportConfig are known
   // as a report dependency group. This method should be used on the *first*
   // report in a dependency group. The other reports in the dependency group are
   // created in the WAITING_TO_START state via the method CreateDependentReport
   // and later started via the method StartDependentReport.
   //
   // |first_day_index| and |last_day_index| specify the range of day indices
   // for which Observations will be analyzed for this report.
   //
   // |one_off| indicates whether this report is being explicitly requested
   // as opposed to being generated by a regular schedule.
   //
   // |export_name| specifies the location to where this report will be exported.
   // See the comments on the |export_name| field of ReportMetadataLite.
   //
   // |in_store| specifies whether or not the rows of this report will be
   // stored in the ReportStore. See the comments on the |in_store| field of
   // ReportMetadataLite. Note that if |report_type| is RAW_DUMP then this
   // value must be false or kInvalidArguments, will be returned.
   //
   // |report_type| indicates which type of report is being started. The
   // associated ReportConfig already specifies a ReportType. This |report_type|
   // should be the same as that ReportType if the report being started is the
   // primary report associated with the ReportConfig. But in case the report
   // being started is an auxiallary report being automatically generated by the
   // system, this |report_type| may be different from the primary ReportType.
   // For example if the primary ReportType is JOINT the report being started
   // may be one of the automatically generated one-way marginal reports in which
   // case this |report_type| would be  HISTOGRAM.
   //
   // |variable_indices| indicates which of the variables specified in the
   // ReportConfig are being analyzed by the report being started. It consists
   // of zero-based indices into the |variable| list in the ReportConfig.
   //
   // |report_id| is used for both input and output. On input all fields other
   // than the |instance_id| and |creation_time_seconds| should be set. This
   // method will set those fields thereby forming a new unique ReportId.
   // Note that in |report_id| the |sequence_num| field should be set by the
   // caller to be 0 (the default value) to indicate that the report is either
   // not part of a dependency group of reports or else that it is the first
   // report in its dependency group to be started.
   Status StartNewReport(uint32_t first_day_index, uint32_t last_day_index,
                         bool one_off, const std::string& export_name,
                         bool in_store, ReportType report_type,
                         const std::vector<uint32_t>& variable_indices,
                         ReportId* report_id);

   // Writes information into the ReportStore to indicate that a dependent report
   // is in the WAITING_TO_START state. This method is in support of report
   // dependency groups. StartNewReport() is used to start the first report
   // in the group and this method is used to *create* but *not start* all
   // subsequent reports. This method may be invoked at any time
   // after StartNewReport() has been invoked for the first report. This
   // is useful so that the later reports are registered in the ReportStore
   // before the actual generation of the first report begins. The
   // method StartDependentReport() should later be invoked when it is time
   // to put the dependent report into the IN_PROGRESS_STATE which must be done
   // before the generation of the dependent report begins.
   //
   // squence_number: The identifier of this report within its dependency group.
   // The first report in the group has sequence_number 0 so this one should have
   // a positive sequence number.
   //
   // |export_name| specifies the location to where this report will be exported.
   // See the comments on the |export_name| field of ReportMetadataLite.
   //
   // |in_store| specifies whether or not the rows of this report will be
   // stored in the ReportStore. See the comments on the |in_store| field of
   // ReportMetadataLite.  Note that if |report_type| is RAW_DUMP then this
   // value must be false or kInvalidArguments will be returned.
   //
   // |report_type| indicates which type of report is being created. Note that
   // different reports in a dependency group may have different ReportTypes.
   //
   // |variable_indices| indicates which of the variables specified in the
   // ReportConfig associated with the dependency group are being analyzed by the
   // report being created. It consists of zero-based indices into the
   // |variable| list in the ReportConfig. Note that different reports in a
   // dependency group may analyze different subsets of the variables.
   //
   // report_id: This is used for both input and output. On input this should be
   // the complete ReportId for some earlier member of the dependency group.
   // This id should have been previously returned from StartNewReport() for
   // the first member of the group or from this method for a later member
   // of the group. The |sequence_number| field of |report_id| will be
   // updated to be equal to the given |sequence_number|, thereby forming a new
   // ReportId which must not yet exist in the ReportStore. The
   // |first_day_index|,
   // |last_day_index|, and |one_off| fields of ReportMetadataLite will be
   // copied from the existing report into the new report.
   //
   // Returns kOK on success, kNotFound if there is no existing report with
   // the ReportId passed in, and kAlreadyExists if there is already a
   // report with an ID of the new value of report_id obtained by setting the
   // |sequence_number| field to the given |sequence_number|.
   Status CreateDependentReport(uint32_t sequence_number,
                                const std::string& export_name, bool in_store,
                                ReportType report_type,
                                const std::vector<uint32_t>& variable_indices,
                                ReportId* report_id);

   // Writes information into the ReportStore to indicate that the dependent
   // report with the given |report_id| is transitioning from the
   // WAITING_TO_START state into the IN_PROGRESS state. The report must
   // already exist in the ReportStore and it must be in the
   // WAITING_TO_START state.
   //
   // report_id: The ID of the dependent report to be started. This should have
   // been returned from CreateDependentReport.
   //
   // Returns kOK on success, kNotFound if there is no existing report with
   // the ReportId passed in, and kPreconditionFailed if the report is not
   // in the WAITING_TO_START state.
   Status StartDependentReport(const ReportId& report_id);

   // Writes information into the ReportStore to indicate that the report with
   // the given |report_id| has ended. If |success| is true then the report
   // will now be in the COMPLETED_SUCCESSFULLY state, otherwise it will now be
   // in the TERMINATED state. The |message| may hold additional information
   // about the report  such as an error message in the case |successful| is
   // false. Returns kOK on success or kNotFound if there is no report with
   // the given report_id.
   Status EndReport(const ReportId& report_id, bool success,
                    std::string message);

   // Adds ReportRows to the ReportStore for the report with the given id.
   // This method should be invoked only after StartNewReport (or
   // StartDependentReport as appropriate) has been invoked and the ReportId is
   // therefore complete and the report is in the IN_PROGRESS state. This method
   // is invoked repeatedly in order to output the results of an analysis. After
   // all of the rows have been added with this method, the method EndReport()
   // should be invoked.
   //
   // Note that the report with the given |report_id| is associated with a
   // particular list of variables, namely those specified in the invocation
   // of StartNewReport or CreateDependentReport. The values specified in
   // |report_rows| must be for the appropriate list of variables.  Returns
   // kInvalidArguments if not.
   //
   // This method should only be invoked on a report for which |in_store| was
   // set true when the metadata was created via StartNewReport or
   // StartDependentReport. Otherwise INVALID_ARGUMENT is returned.
   Status AddReportRows(const ReportId& report_id,
                        const std::vector<ReportRow>& report_rows);

   // Gets the ReportMetadataLite for the report with the specified id.
   Status GetMetadata(const ReportId& report_id,
                      ReportMetadataLite* metadata_out);

   // Gets the Report with the specified id. If this method is invoked on a
   // report for which |in_store| is not true then |report_out| will contain
   // zero rows.
   // TODO(rudominer) Consider not assuming a report fits in memory.
   Status GetReport(const ReportId& report_id, ReportMetadataLite* metadata_out,
                    ReportRows* report_out);

   // A ReportRecord is one of the results contained in the QueryReportsResponse
   // returned from QueryReports(). It contains only meta-data. The report data
   // is represented by ReportRows. This is a move-only type.
   struct ReportRecord {
     // Default constructor
     ReportRecord() {}

     // Move constructor.
     ReportRecord(ReportRecord&& other) {
       report_id.Swap(&other.report_id);
       report_metadata.Swap(&other.report_metadata);
     }

     ReportId report_id;
     ReportMetadataLite report_metadata;
   };

   // A QueryReportsResponse is returned from QueryReports().
   struct QueryReportsResponse {
     // status will be kOK on success or an error status on failure.
     // If there was an error then the other fields of QueryReportsResponse
     // should be ignored.
     Status status;

     // If status is kOK then this is the list of results of the query.
     std::vector<ReportRecord> results;

     // If status is kOK and pagination_token is not empty, it indicates that
     // there were more results than could be returned in a single invocation
     // of QueryReports(). Use this token as an input to another invocation
     // of QueryReports() in order to obtain the next batch of results.
     // Note that it is possible for pagination_token to be non-empty even if the
     // number of results returned is fewer than the |max_results| specified in
     // the query.
     std::string pagination_token;
   };

   // Queries the ReportStore for the list of reports that exist for the
   // given |customer_id|, |project_id|, |report_config_id|.
   //
   // |interval_start_time_seconds| and |interval_end_time_seconds| specify
   // a half-open interval of |creation_time_seconds| that the query is
   // restricted to. That is, the query will only return ReportRecords for which
   // the |creation_time_seconds| field of the |report_id| is in the range
   // [interval_start_time_seconds, interval_end_time_seconds).
   //
   // |max_results| must be positive and at most |max_results| will be returned.
   // The number of returned results may be less than |max_results| for
   // several reasons. The caller must look at whether or not the
   // |pagination_token| in the returned QueryReportsResponse is empty in order
   // to determine if there are further results that may be queried.
   //
   // If |pagination_token| is not empty then it should be the pagination_token
   // from a QueryReportsResponse that was returned from a previous invocation of
   // of this method with the same values for all of the other arguments.
   // This query will be restricted to start after the last result returned from
   // that previous query. A typical pattern is to invoke this method in a
   // loop passing the pagination_token returned from one invocation into
   // the following invocation. If pagination_token is not consistent with
   // the other arguments then the returned status will be kInvalidArguments.
   //
   // See the comments on |QueryReportsResponse| for an explanation of how
   // to interpret the response.
   QueryReportsResponse QueryReports(uint32_t customer_id, uint32_t project_id,
                                     uint32_t report_config_id,
                                     int64_t interval_start_time_seconds,
                                     int64_t interval_end_time_seconds,
                                     size_t max_results,
                                     std::string pagination_token);

   // Permanently deletes all data in the ReportStore corresponding to the given
   // report config.
   Status DeleteAllForReportConfig(uint32_t customer_id, uint32_t project_id,
                                   uint32_t report_config_id);

   static std::string ToString(const ReportId& report_id);

   // Sets the clock used by the ReportStore for obtaining the current time.
   // Mostly useful for tests.
   void set_clock(std::shared_ptr<util::ClockInterface> clock) {
     clock_ = clock;
   }

  private:
   friend class ReportStorePrivateTest;
   friend class ReportStoreTestUtils;

   // Makes all instantiations of ReportStoreAbstractTest friends.
   template <class X>
   friend class ReportStoreAbstractTest;

   // Makes the row key for the report_metadata table that corresponds to the
   // given |report_id|.
   static std::string MakeMetadataRowKey(const ReportId& report_id);

   // Makes the first possible row key for the report_metadata table for the
   // given data.
   static std::string MetadataRangeStartKey(uint32_t customer_id,
                                            uint32_t project_id,
                                            uint32_t report_config_id,
                                            int64_t creation_time_seconds);

   // Makes the first possible row key for the report_rows table for
   // the given |report_id|.
   static std::string ReportStartRowKey(const ReportId& report_id);

   // Makes the last possible row key for the report_rows table for
   // the given |report_id|.
   static std::string ReportEndRowKey(const ReportId& report_id);

   // Generates a new row key for the report_rows table for the report with
   // the given report_id. Each time this method is invoked a new row key
   // is generated.
   static std::string GenerateReportRowKey(const ReportId& report_id);

   // Makes the DataStore::Row that represents the arguments.
   DataStore::Row MakeDataStoreRow(const ReportId& report_id,
                                   const ReportMetadataLite& metadata);

   // Write a row into the report_metadata table to represent the arguemnts.
   Status WriteMetadata(const ReportId& report_id,
                        const ReportMetadataLite& metadata);

   // Write many rows into the report_metadata table to represent the arguments.
   // CHECK fails if |report_ids| and |metadata| do not have the same length.
   Status WriteBulkMetadata(const std::vector<ReportId>& report_ids,
                            const std::vector<ReportMetadataLite>& metadata);

   // The underlying data store.
   const std::shared_ptr<DataStore> store_;

   std::shared_ptr<util::ClockInterface> clock_;
 };

 }  // namespace store
 }  // namespace analyzer
 }  // namespace cobalt

 #endif  // COBALT_ANALYZER_STORE_REPORT_STORE_H_
	// Copyright 2017 The Fuchsia Authors
	//
	// 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 COBALT_ANALYZER_STORE_REPORT_STORE_H_
	#define COBALT_ANALYZER_STORE_REPORT_STORE_H_

	#include <memory>
	#include <string>
	#include <vector>

	#include "analyzer/report_master/report_internal.pb.h"
	#include "analyzer/report_master/report_master.pb.h"
	#include "analyzer/store/data_store.h"
	#include "util/clock.h"

	namespace cobalt {
	namespace analyzer {
	namespace store {

	// A ReportStore is used for storing and retrieving Cobalt reports. A
	// report is the final output of the Cobalt pipeline--the result of the privacy-
	// preserving analysis.
	class ReportStore {
	public:
	// Constructs a ReportStore that wraps an underlying data store.
	explicit ReportStore(std::shared_ptr<DataStore> store);

	// Generates a new ReportId and writes information into the ReportStore to
	// indicate that the report with that ID is in the IN_PROGRESS state. This
	// method should be invoked prior to starting to add new rows to a report
	// via the AddReportRow() method. The report being started is associated
	// with a ReportConfig and it may be either the primary report specified
	// by the ReportConfig or it may be an auxilliary report being automatically
	// generated by the system in support of the primary report. The group of
	// reports--primary and auxilliary--associated with a ReportConfig are known
	// as a report dependency group. This method should be used on the first
	// report in a dependency group. The other reports in the dependency group are
	// created in the WAITING_TO_START state via the method CreateDependentReport
	// and later started via the method StartDependentReport.
	//
	// \|first_day_index\| and \|last_day_index\| specify the range of day indices
	// for which Observations will be analyzed for this report.
	//
	// \|one_off\| indicates whether this report is being explicitly requested
	// as opposed to being generated by a regular schedule.
	//
	// \|export_name\| specifies the location to where this report will be exported.
	// See the comments on the \|export_name\| field of ReportMetadataLite.
	//
	// \|in_store\| specifies whether or not the rows of this report will be
	// stored in the ReportStore. See the comments on the \|in_store\| field of
	// ReportMetadataLite. Note that if \|report_type\| is RAW_DUMP then this
	// value must be false or kInvalidArguments, will be returned.
	//
	// \|report_type\| indicates which type of report is being started. The
	// associated ReportConfig already specifies a ReportType. This \|report_type\|
	// should be the same as that ReportType if the report being started is the
	// primary report associated with the ReportConfig. But in case the report
	// being started is an auxiallary report being automatically generated by the
	// system, this \|report_type\| may be different from the primary ReportType.
	// For example if the primary ReportType is JOINT the report being started
	// may be one of the automatically generated one-way marginal reports in which
	// case this \|report_type\| would be HISTOGRAM.
	//
	// \|variable_indices\| indicates which of the variables specified in the
	// ReportConfig are being analyzed by the report being started. It consists
	// of zero-based indices into the \|variable\| list in the ReportConfig.
	//
	// \|report_id\| is used for both input and output. On input all fields other
	// than the \|instance_id\| and \|creation_time_seconds\| should be set. This
	// method will set those fields thereby forming a new unique ReportId.
	// Note that in \|report_id\| the \|sequence_num\| field should be set by the
	// caller to be 0 (the default value) to indicate that the report is either
	// not part of a dependency group of reports or else that it is the first
	// report in its dependency group to be started.
	Status StartNewReport(uint32_t first_day_index, uint32_t last_day_index,
	bool one_off, const std::string& export_name,
	bool in_store, ReportType report_type,
	const std::vector<uint32_t>& variable_indices,
	ReportId* report_id);

	// Writes information into the ReportStore to indicate that a dependent report
	// is in the WAITING_TO_START state. This method is in support of report
	// dependency groups. StartNewReport() is used to start the first report
	// in the group and this method is used to create but not start all
	// subsequent reports. This method may be invoked at any time
	// after StartNewReport() has been invoked for the first report. This
	// is useful so that the later reports are registered in the ReportStore
	// before the actual generation of the first report begins. The
	// method StartDependentReport() should later be invoked when it is time
	// to put the dependent report into the IN_PROGRESS_STATE which must be done
	// before the generation of the dependent report begins.
	//
	// squence_number: The identifier of this report within its dependency group.
	// The first report in the group has sequence_number 0 so this one should have
	// a positive sequence number.
	//
	// \|export_name\| specifies the location to where this report will be exported.
	// See the comments on the \|export_name\| field of ReportMetadataLite.
	//
	// \|in_store\| specifies whether or not the rows of this report will be
	// stored in the ReportStore. See the comments on the \|in_store\| field of
	// ReportMetadataLite. Note that if \|report_type\| is RAW_DUMP then this
	// value must be false or kInvalidArguments will be returned.
	//
	// \|report_type\| indicates which type of report is being created. Note that
	// different reports in a dependency group may have different ReportTypes.
	//
	// \|variable_indices\| indicates which of the variables specified in the
	// ReportConfig associated with the dependency group are being analyzed by the
	// report being created. It consists of zero-based indices into the
	// \|variable\| list in the ReportConfig. Note that different reports in a
	// dependency group may analyze different subsets of the variables.
	//
	// report_id: This is used for both input and output. On input this should be
	// the complete ReportId for some earlier member of the dependency group.
	// This id should have been previously returned from StartNewReport() for
	// the first member of the group or from this method for a later member
	// of the group. The \|sequence_number\| field of \|report_id\| will be
	// updated to be equal to the given \|sequence_number\|, thereby forming a new
	// ReportId which must not yet exist in the ReportStore. The
	// \|first_day_index\|,
	// \|last_day_index\|, and \|one_off\| fields of ReportMetadataLite will be
	// copied from the existing report into the new report.
	//
	// Returns kOK on success, kNotFound if there is no existing report with
	// the ReportId passed in, and kAlreadyExists if there is already a
	// report with an ID of the new value of report_id obtained by setting the
	// \|sequence_number\| field to the given \|sequence_number\|.
	Status CreateDependentReport(uint32_t sequence_number,
	const std::string& export_name, bool in_store,
	ReportType report_type,
	const std::vector<uint32_t>& variable_indices,
	ReportId* report_id);

	// Writes information into the ReportStore to indicate that the dependent
	// report with the given \|report_id\| is transitioning from the
	// WAITING_TO_START state into the IN_PROGRESS state. The report must
	// already exist in the ReportStore and it must be in the
	// WAITING_TO_START state.
	//
	// report_id: The ID of the dependent report to be started. This should have
	// been returned from CreateDependentReport.
	//
	// Returns kOK on success, kNotFound if there is no existing report with
	// the ReportId passed in, and kPreconditionFailed if the report is not
	// in the WAITING_TO_START state.
	Status StartDependentReport(const ReportId& report_id);

	// Writes information into the ReportStore to indicate that the report with
	// the given \|report_id\| has ended. If \|success\| is true then the report
	// will now be in the COMPLETED_SUCCESSFULLY state, otherwise it will now be
	// in the TERMINATED state. The \|message\| may hold additional information
	// about the report such as an error message in the case \|successful\| is
	// false. Returns kOK on success or kNotFound if there is no report with
	// the given report_id.
	Status EndReport(const ReportId& report_id, bool success,
	std::string message);

	// Adds ReportRows to the ReportStore for the report with the given id.
	// This method should be invoked only after StartNewReport (or
	// StartDependentReport as appropriate) has been invoked and the ReportId is
	// therefore complete and the report is in the IN_PROGRESS state. This method
	// is invoked repeatedly in order to output the results of an analysis. After
	// all of the rows have been added with this method, the method EndReport()
	// should be invoked.
	//
	// Note that the report with the given \|report_id\| is associated with a
	// particular list of variables, namely those specified in the invocation
	// of StartNewReport or CreateDependentReport. The values specified in
	// \|report_rows\| must be for the appropriate list of variables. Returns
	// kInvalidArguments if not.
	//
	// This method should only be invoked on a report for which \|in_store\| was
	// set true when the metadata was created via StartNewReport or
	// StartDependentReport. Otherwise INVALID_ARGUMENT is returned.
	Status AddReportRows(const ReportId& report_id,
	const std::vector<ReportRow>& report_rows);

	// Gets the ReportMetadataLite for the report with the specified id.
	Status GetMetadata(const ReportId& report_id,
	ReportMetadataLite* metadata_out);

	// Gets the Report with the specified id. If this method is invoked on a
	// report for which \|in_store\| is not true then \|report_out\| will contain
	// zero rows.
	// TODO(rudominer) Consider not assuming a report fits in memory.
	Status GetReport(const ReportId& report_id, ReportMetadataLite* metadata_out,
	ReportRows* report_out);

	// A ReportRecord is one of the results contained in the QueryReportsResponse
	// returned from QueryReports(). It contains only meta-data. The report data
	// is represented by ReportRows. This is a move-only type.
	struct ReportRecord {
	// Default constructor
	ReportRecord() {}

	// Move constructor.
	ReportRecord(ReportRecord&& other) {
	report_id.Swap(&other.report_id);
	report_metadata.Swap(&other.report_metadata);
	}

	ReportId report_id;
	ReportMetadataLite report_metadata;
	};

	// A QueryReportsResponse is returned from QueryReports().
	struct QueryReportsResponse {
	// status will be kOK on success or an error status on failure.
	// If there was an error then the other fields of QueryReportsResponse
	// should be ignored.
	Status status;

	// If status is kOK then this is the list of results of the query.
	std::vector<ReportRecord> results;

	// If status is kOK and pagination_token is not empty, it indicates that
	// there were more results than could be returned in a single invocation
	// of QueryReports(). Use this token as an input to another invocation
	// of QueryReports() in order to obtain the next batch of results.
	// Note that it is possible for pagination_token to be non-empty even if the
	// number of results returned is fewer than the \|max_results\| specified in
	// the query.
	std::string pagination_token;
	};

	// Queries the ReportStore for the list of reports that exist for the
	// given \|customer_id\|, \|project_id\|, \|report_config_id\|.
	//
	// \|interval_start_time_seconds\| and \|interval_end_time_seconds\| specify
	// a half-open interval of \|creation_time_seconds\| that the query is
	// restricted to. That is, the query will only return ReportRecords for which
	// the \|creation_time_seconds\| field of the \|report_id\| is in the range
	// [interval_start_time_seconds, interval_end_time_seconds).
	//
	// \|max_results\| must be positive and at most \|max_results\| will be returned.
	// The number of returned results may be less than \|max_results\| for
	// several reasons. The caller must look at whether or not the
	// \|pagination_token\| in the returned QueryReportsResponse is empty in order
	// to determine if there are further results that may be queried.
	//
	// If \|pagination_token\| is not empty then it should be the pagination_token
	// from a QueryReportsResponse that was returned from a previous invocation of
	// of this method with the same values for all of the other arguments.
	// This query will be restricted to start after the last result returned from
	// that previous query. A typical pattern is to invoke this method in a
	// loop passing the pagination_token returned from one invocation into
	// the following invocation. If pagination_token is not consistent with
	// the other arguments then the returned status will be kInvalidArguments.
	//
	// See the comments on \|QueryReportsResponse\| for an explanation of how
	// to interpret the response.
	QueryReportsResponse QueryReports(uint32_t customer_id, uint32_t project_id,
	uint32_t report_config_id,
	int64_t interval_start_time_seconds,
	int64_t interval_end_time_seconds,
	size_t max_results,
	std::string pagination_token);

	// Permanently deletes all data in the ReportStore corresponding to the given
	// report config.
	Status DeleteAllForReportConfig(uint32_t customer_id, uint32_t project_id,
	uint32_t report_config_id);

	static std::string ToString(const ReportId& report_id);

	// Sets the clock used by the ReportStore for obtaining the current time.
	// Mostly useful for tests.
	void set_clock(std::shared_ptr<util::ClockInterface> clock) {
	clock_ = clock;
	}

	private:
	friend class ReportStorePrivateTest;
	friend class ReportStoreTestUtils;

	// Makes all instantiations of ReportStoreAbstractTest friends.
	template <class X>
	friend class ReportStoreAbstractTest;

	// Makes the row key for the report_metadata table that corresponds to the
	// given \|report_id\|.
	static std::string MakeMetadataRowKey(const ReportId& report_id);

	// Makes the first possible row key for the report_metadata table for the
	// given data.
	static std::string MetadataRangeStartKey(uint32_t customer_id,
	uint32_t project_id,
	uint32_t report_config_id,
	int64_t creation_time_seconds);

	// Makes the first possible row key for the report_rows table for
	// the given \|report_id\|.
	static std::string ReportStartRowKey(const ReportId& report_id);

	// Makes the last possible row key for the report_rows table for
	// the given \|report_id\|.
	static std::string ReportEndRowKey(const ReportId& report_id);

	// Generates a new row key for the report_rows table for the report with
	// the given report_id. Each time this method is invoked a new row key
	// is generated.
	static std::string GenerateReportRowKey(const ReportId& report_id);

	// Makes the DataStore::Row that represents the arguments.
	DataStore::Row MakeDataStoreRow(const ReportId& report_id,
	const ReportMetadataLite& metadata);

	// Write a row into the report_metadata table to represent the arguemnts.
	Status WriteMetadata(const ReportId& report_id,
	const ReportMetadataLite& metadata);

	// Write many rows into the report_metadata table to represent the arguments.
	// CHECK fails if \|report_ids\| and \|metadata\| do not have the same length.
	Status WriteBulkMetadata(const std::vector<ReportId>& report_ids,
	const std::vector<ReportMetadataLite>& metadata);

	// The underlying data store.
	const std::shared_ptr<DataStore> store_;

	std::shared_ptr<util::ClockInterface> clock_;
	};

	} // namespace store
	} // namespace analyzer
	} // namespace cobalt

	#endif // COBALT_ANALYZER_STORE_REPORT_STORE_H_