import { LogLevel, LogPipe } from './ConsoleOverrides';
/**
 *  LogCachePipe caches up to 'cacheSize' messages,
 *  notifies about cache overflow using 'onCacheSizeReached'
 *  and provides access to the cache.
 */
export interface LogCachePipe extends LogPipe<unknown[]> {
    /** Returns a list of all cached messages. */
    getMessages(): Array<LogCachePipeMessage>;
    /** Clears messages cache. */
    clearMessages(): void;
}
/** Options for 'createLogCachePipe'. */
export interface LogCachePipeOptions {
    /**
     * How many messages to keep in the cache.
     * Once the limit is reached and a new message arrives, 'onCacheSizeReached' is called and
     * the oldest message is removed from the cache.
     *
     * Default: 1000.
     */
    cacheSize: number;
    /**
     * How much data to keep in the cache using 'sum(stringify(...args))' formula.
     * Once the limit is reached and a new message arrives, onCacheSizeReached is called and a set of the oldest
     * messages are removed from the cache to keep the cache size within the limit.
     * The size estimator is optimized for string message parameters (for example, a stringifies JSON messages).
     *
     * Default: not used (-1).
     */
    cacheSizeByStringify: number;
    /**
     * A callback to notify about cache overflow.
     * Called every time the cache is full: count of messages is > cacheSize or 'cacheSizeByStringify' is met.
     *
     * A callee can use 'getMessages' or 'clearMessages' inside the callback to access the current cache state.
     * It is recommended to clear all messages in the callback to avoid callback calls on every new console log event.
     * Default: undefined, no action.
     *
     * Warning: avoid calling console.log from inside 'onCacheSizeReached'.
     * If console log method is called from 'onCacheSizeReached' the pipe will ignore these messages.
     * In order to avoid this problem and still be able to use console in methods called from 'onCacheSizeReached',
     * wrap the code that logs to console into an asynchronous task like a 'setTimeout()' call.
     *
     * Default: undefined.
     */
    onCacheSizeReached?: (pipe: LogCachePipe) => void;
}
/** A cached message model. */
export interface LogCachePipeMessage {
    level: LogLevel;
    /** Time the message was cached. */
    timestamp: number;
    args: unknown[];
}
export declare function getDefaultLogCachePipeOptions(): LogCachePipeOptions;
export declare function createLogCachePipe(inputOptions?: Partial<LogCachePipeOptions>): LogCachePipe;
/** Estimates args array size using simplifyJson call. */
export declare function estimateArgsSizeByStringify(...args: Array<unknown>): number;