Multi-strategy based tracking.

chrome/browser/prefs/tracked/tracked_split_preference.cc

+// Copyright 2014 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.
+
+#include "chrome/browser/prefs/tracked/tracked_split_preference.h"
+
+#include <vector>
+
+#include "base/logging.h"
+#include "base/values.h"
+#include "chrome/browser/prefs/pref_hash_store.h"
+
+TrackedSplitPreference::TrackedSplitPreference(
+    const std::string& pref_path,
+    size_t reporting_id,
+    size_t reporting_ids_count,
+    PrefHashFilter::EnforcementLevel enforcement_level,
+    PrefHashStore* pref_hash_store)
+    : pref_path_(pref_path),
+      helper_(pref_path, reporting_id, reporting_ids_count, enforcement_level),
+      pref_hash_store_(pref_hash_store) {
+}
+
+void TrackedSplitPreference::OnNewValue(const base::Value* value) const {
+  const base::DictionaryValue* dict_value = NULL;
+  if (value && !value->GetAsDictionary(&dict_value)) {
+    NOTREACHED();
+    return;
+  }
+  pref_hash_store_->StoreSplitHash(pref_path_, dict_value);
+}
+
+void TrackedSplitPreference::EnforceAndReport(
+    base::DictionaryValue* pref_store_contents) const {
+  base::DictionaryValue* dict_value = NULL;
+  if (!pref_store_contents->GetDictionary(pref_path_, &dict_value) &&
+      pref_store_contents->Get(pref_path_, NULL)) {
+    // There should be a dictionary or nothing at |pref_path_|.
+    NOTREACHED();
+    return;
+  }
+
+  std::vector<std::string> invalid_keys;
+  PrefHashStore::ValueState value_state =
+      pref_hash_store_->CheckSplitValue(pref_path_, dict_value, &invalid_keys);
+
+  if (value_state == PrefHashStore::CHANGED)
+    helper_.ReportSplitPreferenceChangedCount(invalid_keys.size());
+
+  helper_.ReportValidationResult(value_state);
+
+  TrackedPreferenceHelper::ResetAction reset_action =
+      helper_.GetAction(value_state);
+  helper_.ReportAction(reset_action);
+
+  if (reset_action == TrackedPreferenceHelper::DO_RESET) {
+    if (value_state == PrefHashStore::CHANGED) {
+      DCHECK(!invalid_keys.empty());
+
+      for (std::vector<std::string>::const_iterator it =
+               invalid_keys.begin(); it != invalid_keys.end(); ++it) {
+        dict_value->Remove(*it, NULL);
+      }
+    } else {
+      pref_store_contents->RemovePath(pref_path_, NULL);
+    }
+  }
+
+  if (value_state != PrefHashStore::UNCHANGED) {
+    // Store the hash for the new value (whether it was reset or not).
+    const base::DictionaryValue* new_dict_value = NULL;
+    pref_store_contents->GetDictionary(pref_path_, &new_dict_value);
+    pref_hash_store_->StoreSplitHash(pref_path_, new_dict_value);
+  }
+}