web3.eth.filter.watch該当ソースコード

web3.eth.filter.watch_sources.js

// see https://github.com/ethereum/web3.js/blob/develop/lib/web3/filter.js#L191-L200
Filter.prototype.watch = function (callback) {
    this.callbacks.push(callback);

    if(this.filterId) {
        getLogsAtStart(this, callback);
        pollFilter(this);
    }

    return this;
};

// see https://github.com/ethereum/web3.js/blob/develop/lib/web3/filter.js#L115-L139
var pollFilter = function(self) {

    var onMessage = function (error, messages) {
        if (error) {
            return self.callbacks.forEach(function (callback) {
                callback(error);
            });
        }

        if(utils.isArray(messages)) {
            messages.forEach(function (message) {
                message = self.formatter ? self.formatter(message) : message;
                self.callbacks.forEach(function (callback) {
                    callback(null, message);
                });
            });
        }
    };

    self.requestManager.startPolling({
        method: self.implementation.poll.call,
        params: [self.filterId],
    }, self.filterId, onMessage, self.stopWatching.bind(self));

};

// see https://github.com/ethereum/web3.js/blob/develop/lib/web3/requestmanager.js#L196-L262
RequestManager.prototype.poll = function () {
    /*jshint maxcomplexity: 6 */
    this.timeout = setTimeout(this.poll.bind(this), c.ETH_POLLING_TIMEOUT);

    if (Object.keys(this.polls).length === 0) {
        return;
    }
~~~ snip ~~~

    var self = this;
    this.provider.sendAsync(payload, function (error, results) {


        // TODO: console log?
        if (error) {
            return;
        }

        if (!utils.isArray(results)) {
            throw errors.InvalidResponse(results);
        }
        results.map(function (result) {
            var id = pollsIdMap[result.id];

            // make sure the filter is still installed after arrival of the request
            if (self.polls[id]) {
                result.callback = self.polls[id].callback;
                return result;
            } else
                return false;
        }).filter(function (result) {
            return !!result; 
        }).filter(function (result) {
            var valid = Jsonrpc.isValidResponse(result);
            if (!valid) {
                result.callback(errors.InvalidResponse(result));
            }
            return valid;
        }).forEach(function (result) {
            result.callback(null, result.result);
        });
    });
};