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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_PREDICTORS_LOADING_PREDICTOR_CONFIG_H_
#define CHROME_BROWSER_PREDICTORS_LOADING_PREDICTOR_CONFIG_H_
#include <cstddef>
#include <string>
class Profile;
namespace predictors {
// Returns whether the Loading Predictor is enabled for the given |profile|. If
// true, the predictor can observe page load events, build historical database
// and perform allowed speculative actions based on this database.
bool IsLoadingPredictorEnabled(Profile* profile);
// Returns whether the current |profile| settings allow to perform preresolve
// and preconnect actions. This setting is controlled by the user, so the return
// value shouldn't be cached.
bool IsPreconnectAllowed(Profile* profile);
// Indicates what caused the page load hint.
enum class HintOrigin {
// Triggered at the start of each navigation.
NAVIGATION,
// Used when a preconnect is triggered by an external Android app.
EXTERNAL,
// Triggered by omnibox.
OMNIBOX,
// Triggered by navigation predictor service.
NAVIGATION_PREDICTOR,
// Used when a prerender initiated by Omnibox is unsuccessful, and instead a
// preconnect is initiated. Preconnect triggered by
// OMNIBOX_PRERENDER_FALLBACK may be handled differently than preconnects
// triggered by OMNIBOX since the former are triggered at higher confidence.
OMNIBOX_PRERENDER_FALLBACK,
// Triggered by optimization guide.
OPTIMIZATION_GUIDE,
// Triggered by bookmark bar.
BOOKMARK_BAR,
// Triggered by New Tab Page.
NEW_TAB_PAGE,
};
// Gets the string that can be used to record histograms for the hint origin.
//
// Keep in sync with LoadingPredictorHintOrigin in histograms.xml. Will DCHECK
// if an origin is added that is not listed in histograms.xml.
std::string GetStringNameForHintOrigin(HintOrigin hint_origin);
// Represents the config for the Loading predictor.
struct LoadingPredictorConfig {
// Initializes the config with default values.
LoadingPredictorConfig();
LoadingPredictorConfig(const LoadingPredictorConfig& other);
~LoadingPredictorConfig();
// If a navigation hasn't seen a load complete event in this much time, it
// is considered abandoned.
size_t max_navigation_lifetime_seconds;
// Size of LRU caches for the host data.
size_t max_hosts_to_track;
// Size of LRU caches for the host data for LCP critical path predictor
// (LCPP).
size_t max_hosts_to_track_for_lcpp;
// The maximum number of origins to store per entry.
size_t max_origins_per_entry;
// The number of consecutive misses after which we stop tracking a resource
// URL.
size_t max_consecutive_misses;
// The number of consecutive misses after which we stop tracking a redirect
// endpoint.
size_t max_redirect_consecutive_misses;
// Delay between writing data to the predictors database memory cache and
// flushing it to disk.
size_t flush_data_to_disk_delay_seconds;
// Parameters for LCPP multiple key support (crbug.com/328487899)
// In LCPP multiple key support, hint data (aka. statistics) are stored not
// per origin but origin + the first-path name.
// In LcppMultipleKeyTypes::kLcppKeyStat option, the number of the first-path
// name per origin is limited and we use the top-k element algorithm
// (https://docs.google.com/document/d/1T80d4xW8xIEqfo792g1nC1deFqzMraunFJW_5ft4ziQ/edit#heading=h.fzlb8kz89fgy)
// to decide an entry to evict.lcpp_multiple_key_histogram_sliding_window_size
// and lcpp_multiple_key_max_histgram_buckets are paraieters used for the
// algorithm. The former is is the virtual sliding window size, and the
// latter is max number of buckets.
size_t lcpp_multiple_key_histogram_sliding_window_size;
size_t lcpp_multiple_key_max_histogram_buckets;
// Parameters for double keyed LCPP (crbug.com/343093433)
// In double keyd LCPP, hint data (aka. statistics) are stored
// per navigation initiator origin + destination origin.
// Initiator origins are kept by the above top-k algorithm too with the below
// two parameters.
// This feature is orthogonal to LCPP multiple key support.
size_t lcpp_initiator_origin_histogram_sliding_window_size;
size_t lcpp_initiator_origin_max_histogram_buckets;
};
} // namespace predictors
#endif // CHROME_BROWSER_PREDICTORS_LOADING_PREDICTOR_CONFIG_H_
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