get-npm-pkg.js

var fs = require('fs');
var npm = require("npm");

var npmCntData = [];
var yyyymmAry = [];
var fileName = __dirname + '/npm-pkg-ym.txt';

npm.load(function(err, npm) {
    if (err) throw err;

    npm.commands.find([''], true, 600, function(err, datas) {
        for (var i in datas) {
            setCounts(datas[i]);
        }

        for (var j in yyyymmAry) {
            var a = [];
            a.push([j]);
            a.push([yyyymmAry[j]]);
            npmCntData.push(a);
        }

        fs.writeFile(fileName, JSON.stringify(npmCntData), function(er) {
            if (err) throw err;
            console.log('取得と保存完了');
        });
    });
});

function setCounts(data) {
    var items = data.time.split('-');
    if (isNaN(items[0])) return;
    var ym = '' + items[0] + items[1];
    if (yyyymmAry[ym] === undefined) {
        yyyymmAry[ym] = 0;
    } else {
        yyyymmAry[ym]++;
    }
}

npm.html

<script src="http://ccchart.com/js/ccchart.js" charset="utf-8"></script>
<div class="flex charts">
    <dic class="chart"><canvas id="hoge"></canvas></div>
</div>
<script>
var chartdata = {
    "config": {
        "title"       : "npm パッケージ 月次登録数推移",
        "subTitle"    : "各月毎のNode.js用 npm パッケージ登録数推移 --" + Date(),
        "width"       : (window.innerWidth - 60) / 1,
        "height"      : (window.innerHeigth - 60) / 1.5,
        "type"        : "bar",
        "minY"        : 0,
        "xScaleSkip"  : 2,
        "maxWsColLen" : 25,
        "useVal"      : "yes",
        "bg"          : "#fff",
        "textColors"  : {"title"    : "#555", 
                         "subTitle" : "#555", 
                         "hanrei"   : "#777", 
                         "unit": "#777"},
        "colorSet"    : ["#DDA0DD", "#3CB000"],
        "shadows"     : {"hanrei" : ['#aaa', 5, 5, 5], 
                         "bar"    : ['#bbb', 3, 3, 8]}
    },
    "data": [
        ["年月"],
        ["登録数"]
    ]
}
ccchart
    .init('hoge', chartdata)
    .ws('ws://localhost:8020')
    .on('message', ccchart.wscase.oneColAtATime);
</script>

send-npmdata-to-client

var fs = require('fs');
var WsServer = require('ws').Server;
var ws = new WsServer({port: 8020});
var fileName = __dirname + '/npm-pkg-ym.txt';

ws.on('connection', function(socket) {
    fs.readFile(fileName, function(err, data) {
        if (err) throw err;
        data = JSON.parse(data.toString());
        sendData(socket, data);
    });
});

function sendData(socket, data) {
    var tid = 0;
    var i =0;
    var dly = 100;

    tid = setInterval(function() {
        var d = data[i];
        i++;
        if (i > data.length -1) {
            clearInterval(tid);
        }
        socket.send(JSON.stringify(d));
    }, 100);
}