As part of the interception process, the messages going in either direction can be modified. As well, because the filter is not an endpoint for a request, there is no need for the client to be aware that the filter is even being used. In the. ASPX page, we will take the name of the requested file and perform the necessary authentication and authorization.
Then, as part of the process, the path to the requested file is placed into the headers that are part of the response. The response is then directed back towards the requestor.
It examines the outgoing message looking for a special header…one that contains a path to a file. When that header is detected, it extracts the file path, removes the header from the response and adds the contents of the file path to the response. From the client side, the response now looks exactly like what is expected. From the server side, the request was authenticated and authorized properly. From the performance side, the file was streamed into the response as part of the inetinfo.
And the problem with the momentary memory growth goes away. As part of the investigation process, each of these alternatives was compared from a speed and a memory usage perspective. The results can be found in the table below. Download Technique. Table 1 — Relative Performance of the Different Techniques. Please realize that this is not a formal benchmark. A client application was created that transmitted a request to an appropriate configured server.
The test was run 20 times for each technique, with an IIS Reset and a dummy request used to spin up the IIS process being performed before each of the tests. The numbers in the table represent the averages across all of the tests. One of the challenges of working with technology is that the pace of change frequently causes old ideas to be tossed and new ones embraced.
The introduction of IIS 6. Although IIS 6. As before, a few words on the process isolation architecture are useful. When a request arrives at the web server, it is first processed by HTTP. It is the responsibility of HTTP. If not, then the request is put into the request queue associated with the virtual directory that is the target of the request.
The actual servicing of the request is done by a worker process. The job of the process is to fulfill the request. The worker process listens on the appropriate request queue for the incoming requests the ones placed there by HTTP. The response is generated and sent back to HTTP. Turning our attention back to the problem of large files, remember that the memory growth issue seemed to be rooted in the transfer of files into the InetInfo.
Viewed 9k times. Improve this question. Keith Keith 3, 1 1 gold badge 22 22 silver badges 51 51 bronze badges. For faster loading, turn off header and dynamicTyping; and be sure to use streaming! Right now you're just loading all the data in memory so you're lucky it's not crashing. Add a comment. Active Oldest Votes. If you've never used them before, this site gives a decent rundown, but the key part is: Web Workers mimics multithreading, allowing intensive scripts to be run in the background so they do not block other scripts from running.
Here is my working example: csv. Improve this answer. Keith, I posted an example. Anything else you may want to do via looping through the data can also be used through a worker if you feel it is still taking a while. This was run in Chrome Canary v Awesome answer romellem thanks for putting the work into this one!
This exact example helped me when the worker that comes with Papa Parse was giving me a "window is not defined" error and it was more trouble than it was worth to resolve. So hence writing a custom worker, and I used this exact one as a guide - thanks! Being a customer-focused and technology-driven company, it always helps clients in crafting holistic business value for their software development efforts.
It offers software development and consulting services for cloud computing, enterprise mobility, big data and analytics, user experience and digital commerce. Read more. Hit enter to search or ESC to close. Insights e-Zest members share technology ideas to foster digital transformation.
Similar Blog. The onmessage handler allows us to run some code whenever a message is received, with the message itself being available in the message event's data attribute.
Here we multiply together the two numbers then use postMessage again, to post the result back to the main thread. Back in the main thread, we use onmessage again, to respond to the message sent back from the worker:. Here we grab the message event data and set it as the textContent of the result paragraph, so the user can see the result of the calculation.
Note: Notice that onmessage and postMessage need to be hung off the Worker object when used in the main script thread, but not when used in the worker. This is because, inside the worker, the worker is effectively the global scope. Note: When a message is passed between the main thread and worker, it is copied or "transferred" moved , not shared.
Read Transferring data to and from workers: further details for a much more thorough explanation. If you need to immediately terminate a running worker from the main thread, you can do so by calling the worker's terminate method:. When a runtime error occurs in the worker, its onerror event handler is called. It receives an event named error which implements the ErrorEvent interface. The event doesn't bubble and is cancelable; to prevent the default action from taking place, the worker can call the error event's preventDefault method.
Workers may spawn more workers if they wish. So-called sub-workers must be hosted within the same origin as the parent page. Also, the URIs for subworkers are resolved relative to the parent worker's location rather than that of the owning page. This makes it easier for workers to keep track of where their dependencies are.
Worker threads have access to a global function, importScripts , which lets them import scripts. It accepts zero or more URIs as parameters to resources to import; all of the following examples are valid:. The browser loads each listed script and executes it. Any global objects from each script may then be used by the worker. Previously executed code including code deferred using setTimeout will still be functional though.
Function declarations after the importScripts method are also kept, since these are always evaluated before the rest of the code. Note: Scripts may be downloaded in any order, but will be executed in the order in which you pass the filenames into importScripts. This is done synchronously; importScripts does not return until all the scripts have been loaded and executed. A shared worker is accessible by multiple scripts — even if they are being accessed by different windows, iframes or even workers.
In this section we'll discuss the JavaScript found in our Basic shared worker example run shared worker : This is very similar to the basic dedicated worker example, except that it has two functions available handled by different script files: multiplying two numbers , or squaring a number. Both scripts use the same worker to do the actual calculation required.
Here we'll concentrate on the differences between dedicated and shared workers. Note: If SharedWorker can be accessed from several browsing contexts, all those browsing contexts must share the exact same origin same protocol, host, and port. Note: In Firefox, shared workers cannot be shared between documents loaded in private and non-private windows bug Spawning a new shared worker is pretty much the same as with a dedicated worker, but with a different constructor name see index.
One big difference is that with a shared worker you have to communicate via a port object — an explicit port is opened that the scripts can use to communicate with the worker this is done implicitly in the case of dedicated workers.
The port connection needs to be started either implicitly by use of the onmessage event handler or explicitly with the start method before any messages can be posted. Calling start is only needed if the message event is wired up via the addEventListener method.
0コメント