I am writing a Bittorrent client in Go and I would like to save the progress of the download by writing a bitfield to the file headers/metadata. This allows me to cancel the download and restart from where I left off the next time I start downloading.
However, I could not find any standard or third party libraries that allow me to write to file metadata. The closest I have gotten was printing the FileInfo struct returned by os.Stat. I am not sure how to add/edit the FileInfo struct.
I realized there are no library functions in Golang like that because metadata is a filesystem specific implementation. So, I have decided to hide my metadata in a hidden file like .filename.meta
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I'm trying to implement file download directly via Browser. Our company uses Protocol Buffer as data communication format. So how can I download the file once I open the web page?
I tried to user bytes and stream of Protocol Buffer. But the result is
{"result":{"data":"Cw4ODg4ODgsMCw4ODg4ODgsMTUwMCwwLDE1MDAsNDAwMDAsMTAwMDAsMzAwMDAKMDMvMTEvMjAxNSxVbmtub3duIEl0ZW0sUHJlIFJvbGwgVmlkZW8gKG1heCAwOjMwKSw2MDAwMCwzMTAwMCwyOTAwMCw1MDAwMCwyNDAwMCwyNjAwMCwyMC4wMCUsODQ0NCwwLDQwMDAsNDQ0NCw4OTAzODgsMCwwLDAsODg4ODg4LDAsODg4ODg4LDE1MDAsMCwxNTAwLDQwMDAwLDIxMDAwLDE5MDAwCg=="}}
Protobuf is good for structured communication but http provides the perfect protocol for downloading files. The right headers need to be set and the browser will download the file.
If you really have to use protobuf to transfer files, then you need to add some javascript that is parsing the protobuf first and then turns it into a file that can be downloaded. See How to create a dynamic file + link for download in Javascript? for reference.
So, send the message as bytes, add the javascript that parses the protobuf message to extract the bytes, and then create the file download like on the linked answer.
I was just wondering something and I could not find it.
Is it possible to make a custom file format that is searchable by Windows? Like Word or HTML files are searchable.
I've written a program that has a custom file format (extension) associated. It would be nice if windows could search inside that file.
It looks rather involved. Essentially, you provide an implementation of a COM interface for your file type, which lets the search indexer discover what's in your file.
From MSDN:
You can extend Windows Search to index the contents and properties of new file formats, and data stores using data add-in interfaces. To create Windows Search add-ins, third-party developers must first implement a Shell data store, and then develop a protocol handler so that Windows Search can access the data for indexing. If you have a custom file format, you must develop a filter handler to index file contents, and a property handler for every file type to index properties.
I am trying do play songs from soundcloud, which is working fine for one exception: when the response handler is called, the download of the file is allready complete. I'd like to start playing the file directly after the download started, but i have no clue how to access the data before the response handler gets called. Accessing the data ln the progress handler would be nice, but i need a hint on how to do it.
If you write your own download code using NSURLConnection and
initWithRequest:delegate:startImmediately:, the delegate methods (e.g.
connection:didReceiveData:) will be called as the data becomes available.
You risk running out of data if you try to play the sound as it is downloaded. You should probably implement a buffering system where you download enough extra data for several seconds of playback before you start playing. That way you can smooth over short "stutters" in the download.
I suggest you at least two options to perform what you want:
1. AVPlayer supports playing a file from http. If you download a static file - you can just ask a player to stream over http.
2. You can download a small chunks of file (5 MB at once, for example) and append them to the result file or write directly into memory buffer. You can download a file chunk of specified size by just adding a Content-Range header with an offset you need. (see RFC, 14.16 Content-Range for more specific info). This method requires server to support partial downloads, but in nowadays it is harder to find a sever that does not support this =) Alamofire easily allows you to do that.
I'm developing an API Server in Go and the server (at the moment) handles all translations for clients. When an API client fetches particular data it also asks for the translations that are available for the given section.
Ideally I want to have the following folder structure:
/messages
/home.en
/home.fr
/home.sv
/news.en
/news.fr
/news.sv
Where news and home are distinct modules.
Now the question I have for Revel is is it possible to fetch ALL language strings for a given module and given locale? For example pull all home strings for en-US.
EDIT:
I would like the output (something I can return to the client) a key:value string of translations.
Any guidance would be appreciated.
It seems to me that revel uses messaged based translation (just like gettext does), so you need
the original string to get the translation. These strings are stored in Config objects,
which are themselves stored in messages of i18n.go, sorted by language.
As you can see, this mapping is not exported, so you can't access it. The best way
to fix this is to write a function for what you want (getting the config by supplying a language)
or exporting one of the existing functions and create a pull request for revel.
You may workaround this by copying the code of loadMessageFile or by forking your version
of revel and exporting loadMessageFile or parseMessagesFile. This also is a great opportunity
to create a pull request.
Note that the localizations are stored in a INI file format parsed by robfig/config,
so manually parsing is also an option (although not recommended).
What is the best way to find the file mime type of remote file in ruby on rails application (eg. I have a file located in s3 and want to check its file type, I don't think checking extension of file is a good idea).
To be specific, I want to find whether the given media is video or audio.
There's a library called ruby-filemagic that can check the content of the file and return the mime type. However, it required to access and read the file and it can be an issue if you need to fetch the content of the file from a remote source.
Please note that in the specific Amazon S3 case, you can also store the mime type of the file to Amazon S£ as object metadata when you upload the file itself. I strongly recommend you to do this, so that you can easily retrieve the metadata and search for the given attribute, instead of guessing it from the file.