The first one won't work. This issue is that the pipe primitive implemented by the OS is fundamentally non-seekable. The reason is supporting seek that would require the OS to buffer the entire pipe "contents" ... until the reading end closes. That is unimplementable unless you place a limit on the amount of data that can be sent through the pipe.
The second one won't work either, for pretty much the same reason. OS-level sockets are not seekable.
At one level, the final idea (a RAM file system) works, modulo that such a capability is supported by the Android OS. (A Ramfs file is seekable, after all.) However, a file stream is not a pipe. In particular the behaviour with respect to the end-of-file is different for a file stream and a pipe. And getting a file stream to look like a pipe stream from the perspective of the reader would entail some special code on that side. (The problem is similar to the problem of running tail -f on a log file ...)
Myloweslife
