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@othiym23 othiym23/hapi.js Secret
Last active Dec 31, 2015

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Hapi auto-instrumentation from New Relic. See `newrelic/lib/tracer.js` and `newrelic/lib/shimmer.js` for the pieces used by this instrumentation.
'use strict';
var path = require('path')
, shimmer = require(path.join(__dirname, '..', 'shimmer.js'))
, urltils = require(path.join(__dirname, '..', 'util', 'urltils.js'))
, logger = require(path.join(__dirname, '..', 'logger.js'))
.child({component : 'hapi'})
, record = require(path.join(__dirname, '..', 'metrics', 'recorders', 'generic.js'))
, NAMES = require(path.join(__dirname, '..', 'metrics', 'names.js'))
, VIEW = NAMES.VIEW
;
function nameFromRequest(segment, request) {
if (!segment) return logger.error("No New Relic context to set Hapi route name on.");
if (!request) return logger.debug("No Hapi request to use for naming.");
var transaction = segment.trace.transaction
, path = request.route && request.route.path
;
if (!path) return logger.debug({request : request}, "No path found on Hapi route.");
urltils.copyParameters(transaction.agent.config, request.params, segment.parameters);
transaction.partialName = NAMES.HAPI.PREFIX + transaction.verb +
NAMES.ACTION_DELIMITER + path;
}
function setDispatcher(agent) {
agent.environment.setDispatcher('hapi');
agent.environment.setFramework('hapi');
}
module.exports = function initialize(agent, hapi) {
if (!agent) return logger.error("Hapi instrumentation bootstrapped without agent");
if (!hapi) return logger.error("Hapi instrumentation applied without module");
var tracer = agent.tracer;
function wrapRender(render) {
return function wrappedRender(filename, context, options, callback) {
var wrapped = callback;
// FIXME: this is going to be the most recent segment, which may not be right
var segment = tracer.getSegment();
if (segment && callback) {
wrapped = tracer.callbackProxy(function () {
segment.end();
return callback.apply(this, arguments);
});
}
return render.call(this, filename, context, options, wrapped);
};
}
function wrapStart(start) {
return function wrappedStart() {
setDispatcher(agent);
/* The patched module loader doesn't access the filesystem itself, so
* lazily apply the patch to Views.prototype.render only once a Views
* object has been assigned as the view manager.
*/
if (this._views) {
logger.debug('Hapi view manager set; instrumenting render.');
var proto = this._views.constructor.prototype;
shimmer.wrapMethod(proto, 'hapi.Views.prototype', 'render', wrapRender);
}
return start.apply(this, arguments);
};
}
function wrapViews(views) {
return function wrappedViews() {
var returned = views.apply(this, arguments);
/* The patched module loader doesn't access the filesystem itself, so
* lazily apply the patch to Views.prototype.render only once a Views
* object has been assigned as the view manager.
*/
if (this._views) {
var proto = this._views.constructor.prototype;
shimmer.wrapMethod(proto, 'hapi.Views.prototype', 'render', wrapRender);
}
else {
logger.warn('Hapi view manager set without manager actually being created.');
}
return returned;
};
}
function wrapReplyView(reply) {
var view = reply.view;
reply.view = function (template) {
var name = VIEW.PREFIX + template + VIEW.RENDER;
tracer.addSegment(name, record);
return view.apply(this, arguments);
};
}
function wrapHandler(handler) {
return function (request, reply) {
if (!tracer.getTransaction()) {
logger.trace("Hapi route handler called outside transaction.");
return handler.apply(this, arguments);
}
nameFromRequest(tracer.getSegment(), request);
if (reply && reply.view) wrapReplyView(reply);
return handler.apply(this, arguments);
};
}
function tableVisitor(before, after, vhost, visit) {
if (!vhost) vhost = '*';
if (after) {
Object.keys(after).forEach(function (method) {
var beforeHandlers = before && before[method];
var afterHandlers = after[method];
for (var i = 0; i < afterHandlers.length; i++) {
var route = afterHandlers[i];
logger.debug('Instrumented hapi route [host %s] %s %s',
vhost, method, route.path);
if (!beforeHandlers || beforeHandlers.indexOf(route) === -1) {
route.settings.handler = visit(route.settings.handler);
}
}
});
}
}
function wrapRoute(_route) {
return function wrappedRoute(configs, env) {
var server = this;
var router = server._router;
if (!router) return logger.warn("no router found on hapi server");
var vhosts = router.vhosts;
var beforeHosts;
if (vhosts) {
logger.debug("capturing vhosts on hapi router");
Object.keys(vhosts).forEach(function (host) {
beforeHosts[host] = {};
Object.keys(vhosts[host]).forEach(function (method) {
beforeHosts[host][method] = vhosts[host][method].slice();
});
});
}
var table = router.table;
var beforeTable = {};
if (table) {
Object.keys(table).forEach(function (method) {
beforeTable[method] = table[method].slice();
});
}
var returned = _route.call(this, configs, env);
vhosts = router.vhosts;
if (vhosts) {
Object.keys(vhosts).forEach(function (host) {
tableVisitor(beforeHosts[host], vhosts[host], host, wrapHandler);
});
}
table = router.table;
if (table) tableVisitor(beforeTable, table, undefined, wrapHandler);
return returned;
};
}
var proto = hapi && hapi.Server && hapi.Server.prototype;
if (proto) {
shimmer.wrapMethod(proto, 'hapi.Server.prototype', 'start', wrapStart);
shimmer.wrapMethod(proto, 'hapi.Server.prototype', 'views', wrapViews);
shimmer.wrapMethod(proto, 'hapi.Server.prototype', '_route', wrapRoute);
}
else {
logger.warn('hapi Server constructor not found; can\'t instrument');
}
};
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