Compressed activity log database storage

chrome/browser/extensions/activity_log/activity_log_policy.h

 // Copyright 2013 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 CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_POLICY_H_
 #define CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_POLICY_H_
 
+#include <set>
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/activity_log/activity_actions.h"
 #include "chrome/browser/extensions/activity_log/activity_database.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 26 matching lines @@
 // is responsible for queueing) be flushed to storage.
 //
 // Since every policy implementation might summarize data differently, the
 // database implementation is policy-specific and therefore completely
 // encapsulated in the policy class.  All the member functions can be called
 // on the UI thread.
 class ActivityLogPolicy {
  public:
   enum PolicyType {
     POLICY_FULLSTREAM,
-    POLICY_NOARGS,
+    POLICY_COUNTS,
     POLICY_INVALID,
   };
 
-  // For all subclasses, add all the key types they might support here.
-  // The actual key is returned by calling GetKey(KeyType).  The subclasses
-  // are free to return an empty string for keys they don't support.
-  // For every key added here, you should update the GetKey member function
-  // for at least one policy.
-  enum KeyType {
-    PARAM_KEY_REASON,      // Why an action was blocked
-    PARAM_KEY_DOM_ACTION,  // Getter, Setter, Method,...
-    PARAM_KEY_URL_TITLE,
-    PARAM_KEY_DETAILS_STRING,
-    PARAM_KEY_EXTRA,
-  };
-
   // Parameters are the profile and the thread that will be used to execute
   // the callback when ReadData is called.
   // TODO(felt,dbabic)  Since only ReadData uses thread_id, it would be
   // cleaner to pass thread_id as a param of ReadData directly.
   explicit ActivityLogPolicy(Profile* profile);
 
   // Instead of a public destructor, ActivityLogPolicy objects have a Close()
   // method which will cause the object to be deleted (but may do so on another
   // thread or in a deferred fashion).
   virtual void Close() = 0;
@@ skipping 11 matching lines @@
   // TODO(felt,dbabic) This is overly specific to the current implementation of
   // the FullStreamUIPolicy.  We should refactor it to use a more generic read
   // function, for example one that takes a dictionary of query parameters
   // (extension_id, time range, etc.).
   virtual void ReadData(
       const std::string& extension_id,
       const int day,
       const base::Callback
           <void(scoped_ptr<Action::ActionVector>)>& callback) = 0;
 
-  virtual std::string GetKey(KeyType key_id) const;
+  // For unit testing only.
+  void SetClockForTesting(scoped_ptr<base::Clock> clock);
 
-  // For unit testing only.
-  void SetClockForTesting(base::Clock* clock) { testing_clock_ = clock; }
+  // A collection of methods that are useful for implementing policies.  These
+  // are all static methods; the ActivityLogPolicy::Util class cannot be
+  // instantiated.  This is nested within ActivityLogPolicy to make calling
+  // these methods more convenient from within a policy, but they are public.
+  class Util {
+   public:
+    // Serialize a Value as a JSON string.  Returns an empty string if value is
+    // null.
+    static std::string Serialize(const base::Value* value);
+
+    // Removes potentially privacy-sensitive data that should not be logged.
+    // This should generally be called on an Action before logging, unless
+    // debugging flags are enabled.  Modifies the Action object in place; if
+    // the action might be shared with other users, it is up to the caller to
+    // call ->Clone() first.
+    static void StripPrivacySensitiveFields(scoped_refptr<Action> action);
+
+    // Strip arguments from most API actions, preserving actions only for a
+    // whitelisted set.  Modifies the Action object in-place.
+    static void StripArguments(const std::set<std::string>& api_whitelist,
+                               scoped_refptr<Action> action);
+
+    // Given a base day (timestamp at local midnight), computes the timestamp
+    // at midnight the given number of days before or after.
+    static base::Time AddDays(const base::Time& base_date, int days);
+
+    // Compute the time bounds that should be used for a database query to
+    // cover a time range days_ago days in the past, relative to the specified
+    // time.
+    static void ComputeDatabaseTimeBounds(const base::Time& now,
+                                          int days_ago,
+                                          int64* early_bound,
+                                          int64* late_bound);
+
+    // Deletes obsolete database tables from an activity log database.  This
+    // can be used in InitDatabase() methods of ActivityLogDatabasePolicy
+    // subclasses to clean up data from old versions of the activity logging
+    // code.  Returns true on success, false on database error.
+    static bool DropObsoleteTables(sql::Connection* db);
+
+   private:
+    DISALLOW_IMPLICIT_CONSTRUCTORS(Util);
+  };
 
  protected:
   // An ActivityLogPolicy is not directly destroyed.  Instead, call Close()
   // which will cause the object to be deleted when it is safe.
   virtual ~ActivityLogPolicy();
 
   // Returns Time::Now() unless a mock clock has been installed with
   // SetClockForTesting, in which case the time according to that clock is used
   // instead.
   base::Time Now() const;
 
  private:
   // Support for a mock clock for testing purposes.  This is used by ReadData
   // to determine the date for "today" when when interpreting date ranges to
   // fetch.  This has no effect on batching of writes to the database.
-  base::Clock* testing_clock_;
+  scoped_ptr<base::Clock> testing_clock_;
 
   DISALLOW_COPY_AND_ASSIGN(ActivityLogPolicy);
 };
 
 // A subclass of ActivityLogPolicy which is designed for policies that use
 // database storage; it contains several useful helper methods.
 class ActivityLogDatabasePolicy : public ActivityLogPolicy,
                                   public ActivityDatabase::Delegate {
  public:
   ActivityLogDatabasePolicy(Profile* profile,
@@ skipping 37 matching lines @@
 
  private:
   // See the comments for the ActivityDatabase class for a discussion of how
   // database cleanup runs.
   ActivityDatabase* db_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_POLICY_H_