rippled/src/xrpld/overlay/SquelchStore.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2025 Ripple Labs Inc.

    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

#ifndef RIPPLE_OVERLAY_SQUELCH_H_INCLUDED
#define RIPPLE_OVERLAY_SQUELCH_H_INCLUDED

#include <xrpl/basics/Log.h>
#include <xrpl/beast/utility/Journal.h>
#include <xrpl/protocol/PublicKey.h>

#include <chrono>

namespace ripple {

namespace reduce_relay {

/**
 * @brief Manages the temporary suppression ("squelching") of validators.
 *
 * @details This class provides a mechanism to temporarily ignore messages from
 * specific validators for a defined duration. It tracks which
 * validators are currently squelched and handles the
 * expiration of the squelch period. The use of an
 * abstract clock allows for deterministic testing of time-based
 * squelch logic.
 */
class SquelchStore
{
    using clock_type = beast::abstract_clock<std::chrono::steady_clock>;
    using time_point = typename clock_type::time_point;

public:
    explicit SquelchStore(beast::Journal journal, clock_type& clock)
        : journal_(journal), clock_(clock)
    {
    }
    virtual ~SquelchStore() = default;

    /**
     * @brief Manages the squelch status of a validator.
     *
     * @details This function acts as the primary public interface for
     * controlling a validator's squelch state. Based on the `squelch` flag, it
     * either adds a new squelch entry for the specified duration or removes an
     * existing one. This function also clears all expired squelches.
     *
     * @param validator The public key of the validator to manage.
     * @param squelch If `true`, the validator will be squelched. If `false`,
     * any existing squelch will be removed.
     * @param duration The duration in seconds for the squelch. This value is
     * only used when `squelch` is `true`.
     */
    void
    handleSquelch(
        PublicKey const& validator,
        bool squelch,
        std::chrono::seconds duration);

    /**
     * @brief Checks if a validator is currently squelched.
     *
     * @details This function checks if the validator's squelch has expired.
     *
     * @param validator The public key of the validator to check.
     * @return `true` if a non-expired squelch entry exists for the
     * validator, `false` otherwise.
     */
    bool
    isSquelched(PublicKey const& validator) const;

    // The following field is protected for unit tests.
protected:
    /**
     * @brief The core data structure mapping a validator's public key to the
     * time point when their squelch expires.
     */
    hash_map<PublicKey, time_point> squelched_;

private:
    /**
     * @brief Internal implementation to add or update a squelch entry.
     *
     * @details Calculates the expiration time point by adding the duration to
     * the current time and inserts or overwrites the entry for the validator in
     * the `squelched_` map.
     *
     * @param validator The public key of the validator to squelch.
     * @param squelchDuration The duration for which the validator should be
     * squelched.
     */
    void
    add(PublicKey const& validator,
        std::chrono::seconds const& squelchDuration);

    /**
     * @brief Internal implementation to remove a squelch entry.
     *
     * @details Erases the squelch entry for the given validator from the
     * `squelched_` map, effectively unsquelching it.
     *
     * @param validator The public key of the validator to unsquelch.
     */
    void
    remove(PublicKey const& validator);

    /**
     * @brief Internal implementation to remove all expired squelches.
     *
     * @details Erases all squelch entries whose expiration is in the past.
     */
    void
    removeExpired();

    /**
     * @brief The logging interface used by this store.
     */
    beast::Journal const journal_;

    /**
     * @brief A reference to the clock used for all time-based operations,
     * allowing for deterministic testing via dependency injection.
     */
    clock_type& clock_;
};

}  // namespace reduce_relay

}  // namespace ripple

#endif  // RIPPLED_SQUELCH_H