Reporting: Implement cache.

net/reporting/reporting_cache.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 NET_REPORTING_REPORTING_CACHE_H_
+#define NET_REPORTING_REPORTING_CACHE_H_
+
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/stl_util.h"
+#include "base/time/time.h"
+#include "base/values.h"
+#include "net/base/net_export.h"
+#include "net/reporting/reporting_client.h"
+#include "url/gurl.h"
+#include "url/origin.h"
+
+namespace net {
+
+struct ReportingReport;
+
+// The cache holds undelivered reports and clients (per-origin endpoint
+// configurations) in memory. (It is not responsible for persisting them.)
+//
+// This corresponds roughly to the "Reporting cache" in the spec, except that
+// endpoints and clients are stored in a more structurally-convenient way, and
+// endpoint failures/retry-after are tracked elsewhere.
+class NET_EXPORT ReportingCache {
+ public:
+  ReportingCache();
+
+  ~ReportingCache();
+
+  // Adds a report to the cache.
+  //
+  // All parameters correspond to the desired values for the relevant fields in
+  // |Report|.
+  void AddReport(const GURL& url,
+                 const std::string& group,
+                 const std::string& type,
+                 std::unique_ptr<const base::Value> body,
+                 base::TimeTicks queued,
+                 int attempts);
+
+  // Gets all reports in the cache. The returned pointers are valid as long as
+  // either no calls to |RemoveReports| have happened or the reports' |pending|
+  // flag has been set to true using |SetReportsPending|. Does not return
+  // doomed reports (pending reports for which removal has been requested).
+  //
+  // (Clears any existing data in |*reports_out|.)
+  void GetReports(std::vector<const ReportingReport*>* reports_out) const;
+
+  // Sets |pending| on a set of reports.
+  void SetReportsPending(const std::vector<const ReportingReport*>& reports);
+
+  // Clear |pending| on a set of reports.
+  void ClearReportsPending(const std::vector<const ReportingReport*>& reports);
+
+  // Increments |attempts| on a set of reports.
+  void IncrementReportsAttempts(
+      const std::vector<const ReportingReport*>& reports);
+
+  // Removes a set of reports. Any reports that are pending will not be removed
+  // immediately, but rather marked doomed and removed once they are no longer
+  // pending.
+  void RemoveReports(const std::vector<const ReportingReport*>& reports);
+
+  // Creates or updates a client for a particular origin and a particular
+  // endpoint.
+  //
+  // All parameters correspond to the desired values for the fields in
+  // |Client|.
+  //
+  // |endpoint| must use a cryptographic scheme.
+  void SetClient(const url::Origin& origin,
+                 const GURL& endpoint,
+                 ReportingClient::Subdomains subdomains,
+                 const std::string& group,
+                 base::TimeTicks expires);
+
+  // Gets all of the clients in the cache, regardless of origin or group.
+  //
+  // (Clears any existing data in |*clients_out|.)
+  void GetClients(std::vector<const ReportingClient*>* clients_out) const;
+
+  // Gets all of the clients configured for a particular origin in a particular
+  // group. The returned pointers are only guaranteed to be valid if no calls
+  // have been made to |SetClient| or |RemoveEndpoint| in between.
+  //
+  // (Clears any existing data in |*clients_out|.)
+  void GetClientsForOriginAndGroup(
+      const url::Origin& origin,
+      const std::string& group,
+      std::vector<const ReportingClient*>* clients_out) const;
+
+  // Removes a set of clients.
+  //
+  // May invalidate ReportingClient pointers returned by |GetClients| or
+  // |GetClientsForOriginAndGroup|.
+  void RemoveClients(const std::vector<const ReportingClient*>& clients);
+
+  // Removes a client for a particular origin and a particular endpoint.
+  void RemoveClientForOriginAndEndpoint(const url::Origin& origin,
+                                        const GURL& endpoint);
+
+  // Removes all clients whose endpoint is |endpoint|.
+  //
+  // May invalidate ReportingClient pointers returned by |GetClients| or
+  // |GetClientsForOriginAndGroup|.
+  void RemoveClientsForEndpoint(const GURL& endpoint);
+
+  // Gets the count of reports in the cache, *including* doomed reports.
+  //
+  // Needed to ensure that doomed reports are eventually deleted, since no
+  // method provides a view of *every* report in the cache, just non-doomed
+  // ones.
+  size_t GetFullReportCountForTesting() const { return reports_.size(); }
+
+  bool IsReportPendingForTesting(const ReportingReport* report) const {
+    return base::ContainsKey(pending_reports_, report);
+  }
+
+  bool IsReportDoomedForTesting(const ReportingReport* report) const {
+    return base::ContainsKey(doomed_reports_, report);
+  }
+
+ private:
+  // Map from origin to map from endpoint to unique_ptr-to-Client.

[jkarlin, 2017/03/17 15:07:02]

This comment is just spelling out the type and seems unnecessary. Instead,
describe its purpose. E.g., Stores all of the clients, arranged by origin and
endpoint.

[Julia Tuttle, 2017/03/21 18:41:02]

Done.

+  std::map<url::Origin, std::map<GURL, std::unique_ptr<ReportingClient>>>

[jkarlin, 2017/03/17 15:07:02]

Prefer unordered_map, unless you need the ordering?

[Julia Tuttle, 2017/03/21 18:41:02]

I don't, but GURL and url::Origin don't have hash functions.

+      clients_;
+
+  // Map from raw-pointer-to-Report to unique_ptr-to-Report.
+  std::map<const ReportingReport*, std::unique_ptr<ReportingReport>> reports_;

[jkarlin, 2017/03/17 15:07:02]

Ditto. Perhaps: owns all active reports, indexed by raw pointer.

[jkarlin, 2017/03/17 15:07:02]

prefer unordered_map, unless you need the ordering?

[Julia Tuttle, 2017/03/21 18:41:02]

Done.

[Julia Tuttle, 2017/03/21 18:41:02]

Done.

+
+  // Reports that have been marked "pending" (in use elsewhere and should not be
+  // deleted until no longer pending).
+  std::set<const ReportingReport*> pending_reports_;

[jkarlin, 2017/03/17 15:07:02]

prefer unordered_set

[Julia Tuttle, 2017/03/21 18:41:02]

Done.

+
+  // Reports that have been marked "doomed" (would have been deleted, but were
+  // pending when the deletion was requested).
+  std::set<const ReportingReport*> doomed_reports_;

[jkarlin, 2017/03/17 15:07:02]

prefer unordered_set

[Julia Tuttle, 2017/03/21 18:41:02]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(ReportingCache);
+};
+
+}  // namespace net
+
+#endif  // NET_REPORTING_REPORTING_CACHE_H_