@lifi/rpc-wrapper/dist/esm/RPCProviderCache.js

LI.FI rpc-wrapper

import * as providers from '@ethersproject/providers';
export class RPCProviderCache {
    constructor(cacheTTL, pollingInterval) {
        this.cacheTTL = 60 * 60 * 24 * 1000; // ms, defaults to a day
        this.pollingInterval = 8000; // number of ms between polling getBlockNumbers
        this.providerCache = {};
        if (cacheTTL)
            this.cacheTTL = cacheTTL;
        if (pollingInterval)
            this.pollingInterval = pollingInterval;
    }
    /**
     * getProvider is a wrapper around getting a provider. It's mainly repsonsible for
     * writing and reading from the providerCache. This reduces the setup time for each provider.
     * @param providerConfig<string> - the configuration, currently a string
     * @returns a StaticJsonRpcProvider
     */
    getProvider(providerConfig) {
        // create hash of providerConfig
        const hash = providerConfig;
        const providerCache = this.providerCache[hash];
        const timestampMs = Date.now();
        if (providerCache && providerCache.expiresAt > timestampMs) {
            return providerCache.provider;
        }
        else {
            const provider = new providers.StaticJsonRpcProvider(providerConfig);
            provider._pollingInterval = this.pollingInterval;
            const providerCacheObject = {
                provider,
                expiresAt: timestampMs + this.cacheTTL,
            };
            this.providerCache[hash] = providerCacheObject;
            return provider;
        }
    }
}