Google API地理编码OVER_QUERY_LIMIT，每秒5个地址？

Question

First of all, I didn't reach the maximum daily limit of 2,500 addresses.

I have 25 addresses, and I already set the sleep time in JavaScript between each address to 5 seconds. I always get OVER_QUERY_LIMIT error after 18 or 19 addresses are geocoded. The rest 7 or 6 address always not get geocoded.

Google API Geocoding as limit of 5 addresses per second, or they have increased?

Thanks.

Code

function geocodeAddress(geocoder, addresses ) {

    var arrayLength = addresses.length;

    for (var i = 0; i < arrayLength; i++) {
        var address = String(addresses[i]);
   // alert(address)
    sleep(5000) 
        geocoder.geocode({'address': address}, function (results, status) 
    {
            if (status === google.maps.GeocoderStatus.OK) {
                var result = results[0].geometry.location;
                var name = results[0].formatted_address;
                writeFile(geocode_file_path, name + ',' + result.toString());
            } else {
                alert('Geocode was not successful for the following reason: ' + status);
            }
        });
    }
}

function sleep(milliseconds) {
var start = new Date().getTime();
for (var i = 0; i < 1e7; i++) {
        if ((new Date().getTime() - start) > milliseconds){
        break;
        }
}   
}

Answer 1

This is a complex problem. Async is very tricky to get your head around.

Having said that, here's a solution that would work. I would prefer a Promise based solution but Promises are another issue that takes time to understand.

function geocodeAddresses(geocoder, addresses, callback){

    var result = [];

    // this internal function does the hard work
    function geocode(address) {
        // get timestamp so we can use it to throttle later
        var lastCall = Date.now();
        // call google function asynchronously
        geocoder.geocode({'address': address}, function (results, status) {
            // process the return data here
            if (status === google.maps.GeocoderStatus.OK) {
                result.push({
                    location: results[0].geometry.location,
                    address: results[0].formatted_address
                });
            } else {
                result.push({ error: status });
            }

            // check to see if there are any more addresses to geocode
            if (addresses.length) {
                // calculate when next call can be made. 200ms is 5 req / second
                var throttleTime = 200 - (lastCall - Date.now());
                setTimeout(function(){      // create timeout to run in 'throttletime` ms
                    // call this function with next address
                    geocode(addresses.shift());
                }, throttleTime);

            } else {        // all done return result
                callback(result);
            }

        });
    }

    // start the process - geocode will call itself for any remaining addresses
    geocode(addresses.shift());
}

Since this function is asynchronous, you have to use it asynchronously ... hence the callback. So you use it as follows:

geocodeAddresses(geocoder, addresses, function(result){
    // do what you need with the result here
    console.log(result);
});

This is about as simple as I can make it. I've created a jsbin that mocks out the geocoder call and shows real results. Change the throttleTime to bigger numbers to see it slow down.

I hope this helps.