#
#  To start with:
#      python localfs.py mnt
#
#  Stop with Ctrl-C or with
#      lufsumount mnt
#


import lufs, os, thread
from lufs import FileSystem


class Filesystem(FileSystem):
    openfiles = {}
    oflock = thread.allocate_lock()

    def readdir(self, dir):
        flist = os.listdir(dir)
        if not dir.endswith('/'):
            dir += '/'
        #return [(fn, tuple(os.lstat(dir+fn))) for fn in flist]
        return flist

    def stat(self, filename):
        return os.lstat(filename)

    def mkdir(self, dirname, mode):
        os.mkdir(dirname, mode)

    def rmdir(self, dirname):
        os.rmdir(dirname)

    def unlink(self, filename):
        os.unlink(filename)

    def rename(self, fromname, toname):
        os.rename(fromname, toname)

    def create(self, filename, mode):
        fd = os.open(filename, os.O_CREAT|os.O_WRONLY|os.O_TRUNC, mode)
        self.oflock.acquire()
        try:
            fd1 = self.openfiles.pop(filename, None)
            self.openfiles[filename] = fd
        finally:
            self.oflock.release()
        if fd1 is not None:
            os.close(fd1)

    def open(self, filename, flags):
        fd = os.open(filename, flags)
        self.oflock.acquire()
        try:
            fd1 = self.openfiles.pop(filename, None)
            self.openfiles[filename] = fd
        finally:
            self.oflock.release()
        if fd1 is not None:
            os.close(fd1)

    #O_ACCMODE          0003
    #O_RDONLY             00
    #O_WRONLY             01
    #O_RDWR               02
    #O_CREAT            0100
    #O_EXCL             0200
    #O_NOCTTY           0400
    #O_TRUNC           01000
    #O_APPEND          02000
    #O_NONBLOCK        04000
    #O_NDELAY        O_NONBLOCK
    #O_SYNC           010000
    #FASYNC           020000
    #O_DIRECT         040000
    #O_LARGEFILE     0100000
    #O_DIRECTORY     0200000
    #O_NOFOLLOW      0400000

    def release(self, filename):
        self.oflock.acquire()
        try:
            fd = self.openfiles.pop(filename, None)
        finally:
            self.oflock.release()
        if fd is not None:
            os.close(fd)

    def read(self, filename, offset, count):
        self.oflock.acquire()
        try:
            fd = self.openfiles[filename]
            os.lseek(fd, offset, 0)
            return os.read(fd, count)
        finally:
            self.oflock.release()

    def write(self, filename, offset, buf):
        self.oflock.acquire()
        try:
            fd = self.openfiles[filename]
            os.lseek(fd, offset, 0)
            return os.write(fd, buf)
        finally:
            self.oflock.release()

    def readlink(self, link):
        return os.readlink(link)

    def link(self, target, link):
        os.link(target, link)

    def symlink(self, target, link):
        os.symlink(target, link)

    def setattr(self, filename, attribs):
        st = os.lstat(filename)
        mode, nlink, uid, gid, size, atime, mtime, ctime = attribs
        if st.st_size != size is not None:
            fd = os.open(filename, os.O_WRONLY)
            os.ftruncate(fd, size)
            os.close(fd)
            st = os.lstat(filename)
        if st.st_mode != mode is not None:
            os.chmod(filename, mode)
        if (st.st_uid != uid or st.st_gid != gid) and uid is not None:
            os.lchown(filename, uid, gid)
        if (st.st_mtime != mtime or st.st_atime != atime) and mtime is not None:
            os.utime(filename, (atime, mtime))
        #...


# ____________________________________________________________

if __name__ == '__main__':
    import sys
    lufs.mount(Filesystem, sys.argv[1])