Prelude
sendfile() is an extremely useful syscall for two reasons:
First, it's less code than a read()/write() (or recv()/send() if you prefer that jive) loop.
Second, it's faster (less syscalls, implementation may copy between devices without buffer, etc...) than the aforementioned methods.
Less code. More efficient. Awesome.
In U...
Hello
Can sendfile() linux syscall be used to send part of file from one mmaped file to other mmaped file?
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Im programming webserver (C), which should send big files. My question is:
What are the main differences in two syscalls: write and sendfile. Does sendfile depends on size of socket system buffer? I noticed that write often writes less then I requested.
For example, if got many requests for one file: should i open it, copy into memory a...
We're benchmarking some code that we've converted to use sendfile(), the linux zero-copy system call. What's the term for the traditional read()/write() loop that sendfile() replaces? I.e., in our report I want to say "zerocopy is X millisecs, and ??? is Y millisecs." What word/phrase should I use?
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I'm trying to test the sendfile() system call under Linux 2.6.32 to zero-copy data between two regular files.
As far as I understand, it should work: ever since 2.6.22, sendfile() has been implemented using splice(), and both the input file and the output file can be either regular files or sockets.
The following is the content of sendf...
I am writing a simple function for downloading a certain file, from the server, to my machine.
The file is unique represented by its id. The file is locatd corectly, and the download is done, but the downloaded file (though named as the one on the server) is empty.
my download function looks like this:
def download_course(request, id):...
Hi There,
Im looking for a way to download a xml file. I use:
file_path = 'folder/' + xml_name + '.xml'
send_file file_path, :type => "text/xml"
but this always downloads me an empty file. The file itself has 16 KB of data in it...
why is that?
Maechi
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As it takes some time to prepare the content of the data to be downloaded, I want to show a message "Preparing file to download" when the user submits the request
Then when the file is ready, I use send_file to send the data
Once it's done, I need to clear the message
Thanks a lot
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Reading through the man page of the Linux system call sendfile, I am wondering whether it is possible for the calling program to know when in_fd is at EOF. Presumably, this could be signaled by a return value of 0, but this leads to the question of what a return value of 0 actually means. If sendfile is like write, then a return value of...