Mounting memory buffer as a file without writing to disk - c++

Question

I have a server and needs to feed data from clients to a library; however, that library only supports reading files (it uses open to access the file).
Since the data can get pretty big, I rather not write it out to a temporary file, read it in with the library then delete it afterwards. Instead I would like to do something similar to a ramdisk where there's a file in which the content is actually in memory.
However, there can be multiple clients sending over large data, I don't think constantly calling mount and umount to create a ramdisk for each client is efficient. Is there a way for me to mount an existing memory buffer as a file without writing to disk?
The library does not support taking in a file descriptor nor FILE*. It will only accept a path which it feeds directly to open
I do have the library's source code and attempted to add in a function that uses fmemopen; however, fmemopen returns a FILE* with no file descriptor. The internals of the library works only with file descriptors and it is too complex to change/add support to use FILE*
I looked at mmap, but it appears to be no different than writing out the data to a file
Using mount requires sudo access and I prefer not to run the application as sudo
bool IS_EXITING = false;
ssize_t getDataSize( int clientFD ) { /* ... */}
void handleClient( int clientFD ) {
// Read in messages to get actual data size
ssize_t dataSize = getDataSize( clientFD );
auto* buffer = new char[ dataSize ];
// Read in all the data from the client
ssize_t bytesRead = 0;
while( bytesRead < dataSize ) {
int numRead = read( clientFD, buffer + bytesRead, dataSize - bytesRead );
bytesRead += numRead;
// Error handle if numRead is <= 0
if ( numRead <= 0 ) { /* ... */ }
}
// Mount the buffer and get a file path... How to do this
std::string filePath = mountBuffer( buffer );
// Library call to read the data
readData( filePath );
delete[ ] buffer;
}
void runServer( int socket )
while( !IS_EXITING ) {
auto clientFD = accept( socket, nullptr, nullptr );
// Error handle if clientFD <= 0
if ( clientFD <= 0 ) { /* ... */ }
std::thread clientThread( handleClient, clientFD );
clientThread.detach( );
}
}

Answer 1

Use /dev/fd. Get the file descriptor of the socket, and append that to /dev/fd/ to get the filename.
If the data is in a memory buffer, you could create a thread that writes to a pipe. Use the file descriptor of the read end of the pipe with /dev/fd.