chromium/components/history_clusters/core/history_clusters_service_task_update_clusters.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_HISTORY_CLUSTERS_CORE_HISTORY_CLUSTERS_SERVICE_TASK_UPDATE_CLUSTERS_H_
#define COMPONENTS_HISTORY_CLUSTERS_CORE_HISTORY_CLUSTERS_SERVICE_TASK_UPDATE_CLUSTERS_H_

#include <vector>

#include "base/memory/weak_ptr.h"
#include "base/task/cancelable_task_tracker.h"
#include "base/time/time.h"
#include "components/history/core/browser/history_types.h"
#include "components/history_clusters/core/clustering_backend.h"
#include "components/history_clusters/core/history_clusters_service_task.h"
#include "components/history_clusters/core/history_clusters_types.h"

namespace history {
class HistoryService;
}

namespace history_clusters {

class HistoryClustersService;

// `HistoryClustersServiceTaskUpdateClusters` gets clustered and unclustered
// visits straddling the threshold and clusters them together. It continues
// doing so, moving the threshold forward 1 day each time, until reaching today.
// When re-clustering clustered visits, it takes all visits in their clusters
// and replaces those clusters. This allows existing clusters to grow without
// having to cluster an impractical number of visits simultaneously and without
// creating near-duplicate clusters. The similar
// `HistoryClustersServiceTaskGetMostRecentClusters` will consume the clusters
// this creates. In contrast to this,
// `HistoryClustersServiceTaskGetMostRecentClusters` iterates recent visits 1st
// and does not persist them.
class HistoryClustersServiceTaskUpdateClusters
    : public HistoryClustersServiceTask { … };

}  // namespace history_clusters

#endif  // COMPONENTS_HISTORY_CLUSTERS_CORE_HISTORY_CLUSTERS_SERVICE_TASK_UPDATE_CLUSTERS_H_