From c56c18320506152db25277f49c05733c73a1043a Mon Sep 17 00:00:00 2001
From: bryan newbold <bnewbold@snark.mit.edu>
Date: Tue, 29 Jul 2008 02:32:16 -0400
Subject: initialization of repo

---
 first_try.py | 269 +++++++++++++++++++++++++++++++++++++++
 nsfs.py      | 401 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 670 insertions(+)
 create mode 100644 first_try.py
 create mode 100644 nsfs.py

diff --git a/first_try.py b/first_try.py
new file mode 100644
index 0000000..04a831e
--- /dev/null
+++ b/first_try.py
@@ -0,0 +1,269 @@
+#!/usr/bin/env python
+
+# July 2008: Bryan Newbold <bryannewbold.com>
+#            Based on xmp.py
+
+import os, sys
+from errno import *
+from stat import *
+import fcntl
+# pull in some spaghetti to make this stuff work without fuse-py being installed
+try:
+    import _find_fuse_parts
+except ImportError:
+    pass
+import fuse
+from fuse import Fuse
+
+
+if not hasattr(fuse, '__version__'):
+    raise RuntimeError, \
+        "your fuse-py doesn't know of fuse.__version__, probably it's too old."
+
+fuse.fuse_python_api = (0, 2)
+
+fuse.feature_assert('stateful_files', 'has_init')
+
+
+def flag2mode(flags):
+    md = {os.O_RDONLY: 'r', os.O_WRONLY: 'w', os.O_RDWR: 'w+'}
+    m = md[flags & (os.O_RDONLY | os.O_WRONLY | os.O_RDWR)]
+
+    if flags | os.O_APPEND:
+        m = m.replace('w', 'a', 1)
+
+    return m
+
+
+class PyNamespace(Fuse):
+
+    def __init__(self, *args, **kw):
+
+        Fuse.__init__(self, *args, **kw)
+
+        # do stuff to set up your filesystem here, if you want
+        #import thread
+        #thread.start_new_thread(self.mythread, ())
+        #self.root = '/'
+
+#    def mythread(self):
+#
+#        """
+#        The beauty of the FUSE python implementation is that with the python interp
+#        running in foreground, you can have threads
+#        """
+#        print "mythread: started"
+#        while 1:
+#            time.sleep(120)
+#            print "mythread: ticking"
+
+    def getattr(self, path):
+        return locals()[path].__repr__
+
+    def readlink(self, path):
+        return str(path)
+
+    def readdir(self, path, offset):
+        for e in os.listdir("." + path):
+            yield fuse.Direntry(e)
+
+    def unlink(self, path):
+        del locals()[path]
+
+    def rmdir(self, path):
+        del locals()[path]
+
+    def symlink(self, path, path1):
+        locals()[path1] = locals()[path]
+
+    def rename(self, path, path1):
+        locals()[path1] = locals()[path]
+        del locals()[path]
+
+    def link(self, path, path1):
+        locals()[path1] = locals()[path]
+
+    def chmod(self, path, mode):
+        return -EPFNOSUPPORT
+
+    def chown(self, path, user, group):
+        return -EPFNOSUPPORT
+
+    def truncate(self, path, len):
+        return -EPFNOSUPPORT
+
+    def mknod(self, path, mode, dev):
+        return -EPFNOSUPPORT
+
+    def mkdir(self, path, mode):
+        return -EPFNOSUPPORT
+
+    def utime(self, path, times):
+        return -EPFNOSUPPORT
+
+#    The following utimens method would do the same as the above utime method.
+#    We can't make it better though as the Python stdlib doesn't know of
+#    subsecond preciseness in acces/modify times.
+#  
+#    def utimens(self, path, ts_acc, ts_mod):
+#      os.utime("." + path, (ts_acc.tv_sec, ts_mod.tv_sec))
+
+    def access(self, path, mode):
+        if not os.access("." + path, mode):
+            return -EACCES
+
+#    This is how we could add stub extended attribute handlers...
+#    (We can't have ones which aptly delegate requests to the underlying fs
+#    because Python lacks a standard xattr interface.)
+#
+#    def getxattr(self, path, name, size):
+#        val = name.swapcase() + '@' + path
+#        if size == 0:
+#            # We are asked for size of the value.
+#            return len(val)
+#        return val
+#
+#    def listxattr(self, path, size):
+#        # We use the "user" namespace to please XFS utils
+#        aa = ["user." + a for a in ("foo", "bar")]
+#        if size == 0:
+#            # We are asked for size of the attr list, ie. joint size of attrs
+#            # plus null separators.
+#            return len("".join(aa)) + len(aa)
+#        return aa
+
+    def statfs(self):
+        """
+        Should return an object with statvfs attributes (f_bsize, f_frsize...).
+        Eg., the return value of os.statvfs() is such a thing (since py 2.2).
+        If you are not reusing an existing statvfs object, start with
+        fuse.StatVFS(), and define the attributes.
+
+        To provide usable information (ie., you want sensible df(1)
+        output, you are suggested to specify the following attributes:
+
+            - f_bsize - preferred size of file blocks, in bytes
+            - f_frsize - fundamental size of file blcoks, in bytes
+                [if you have no idea, use the same as blocksize]
+            - f_blocks - total number of blocks in the filesystem
+            - f_bfree - number of free blocks
+            - f_files - total number of file inodes
+            - f_ffree - nunber of free file inodes
+        """
+        rval = os.statvfs(".")
+        rval[3] = len(locals())
+        rval[5] = len(locals())
+        return rval
+
+    def fsinit(self):
+        #os.chdir(self.root)
+        pass
+
+    class PyNamespaceFile(object):
+
+        def __init__(self, path, flags, *mode):
+            self.fobject = locals()[path]
+            self.fstr = StringIO(str(self.fobject))
+
+        def read(self, length, offset):
+            return self.fstr.read(length)
+
+        def write(self, buf, offset):
+            self.fstr.seek(offset)
+            self.fstr.write(buf)
+            return len(buf)
+
+        def release(self, flags):
+            self.fstr.close()
+
+        def _fflush(self):
+            if 'w' in self.fstr.mode or 'a' in self.fstr.mode:
+                self.fstr.flush()
+
+        def fsync(self, isfsyncfile):
+            pass
+
+        def flush(self):
+            pass
+
+        def fgetattr(self):
+            pass
+
+        def ftruncate(self, len):
+            self.fstr.truncate(len)
+
+        def lock(self, cmd, owner, **kw):
+            # The code here is much rather just a demonstration of the locking
+            # API than something which actually was seen to be useful.
+
+            # Advisory file locking is pretty messy in Unix, and the Python
+            # interface to this doesn't make it better.
+            # We can't do fcntl(2)/F_GETLK from Python in a platfrom independent
+            # way. The following implementation *might* work under Linux. 
+            #
+            # if cmd == fcntl.F_GETLK:
+            #     import struct
+            # 
+            #     lockdata = struct.pack('hhQQi', kw['l_type'], os.SEEK_SET,
+            #                            kw['l_start'], kw['l_len'], kw['l_pid'])
+            #     ld2 = fcntl.fcntl(self.fd, fcntl.F_GETLK, lockdata)
+            #     flockfields = ('l_type', 'l_whence', 'l_start', 'l_len', 'l_pid')
+            #     uld2 = struct.unpack('hhQQi', ld2)
+            #     res = {}
+            #     for i in xrange(len(uld2)):
+            #          res[flockfields[i]] = uld2[i]
+            #  
+            #     return fuse.Flock(**res)
+
+            # Convert fcntl-ish lock parameters to Python's weird
+            # lockf(3)/flock(2) medley locking API...
+            return -EOPNOTSUPP
+            #op = { fcntl.F_UNLCK : fcntl.LOCK_UN,
+            #       fcntl.F_RDLCK : fcntl.LOCK_SH,
+            #       fcntl.F_WRLCK : fcntl.LOCK_EX }[kw['l_type']]
+            #if cmd == fcntl.F_GETLK:
+            #    return -EOPNOTSUPP
+            #elif cmd == fcntl.F_SETLK:
+            #    if op != fcntl.LOCK_UN:
+            #        op |= fcntl.LOCK_NB
+            #elif cmd == fcntl.F_SETLKW:
+            #    pass
+            #else:
+            #    return -EINVAL
+
+            #fcntl.lockf(self.fd, op, kw['l_start'], kw['l_len'])
+
+
+    def main(self, *a, **kw):
+
+        self.file_class = self.PyNamespaceFile
+
+        return Fuse.main(self, *a, **kw)
+
+
+def main():
+
+    usage = """
+Presents a python namespace as a filesystem for aesthetic reasons
+""" + Fuse.fusage
+
+    server = PyNamespace(version="%prog " + fuse.__version__,
+                 usage=usage,
+                 dash_s_do='setsingle')
+
+    #server.parser.add_option(mountopt="root", metavar="PATH", default='/',
+    #                         help="mirror filesystem from under PATH [default: %default]")
+    #server.parse(values=server, errex=1)
+
+    #try:
+    #    if server.fuse_args.mount_expected():
+    #        os.chdir(server.root)
+    #except OSError:
+    #    print >> sys.stderr, "can't enter root of underlying filesystem"
+    #    sys.exit(1)
+
+    server.main()
+
+
+if __name__ == '__main__':
+    main()
diff --git a/nsfs.py b/nsfs.py
new file mode 100644
index 0000000..740598a
--- /dev/null
+++ b/nsfs.py
@@ -0,0 +1,401 @@
+#!/usr/bin/python
+
+from time import time
+from StringIO import StringIO
+
+import stat    # for file properties
+import os      # for filesystem modes (O_RDONLY, etc)
+import errno   # for error number codes (ENOENT, etc)
+               # - note: these must be returned as negatives
+
+
+# pull in some spaghetti to make this stuff work without fuse-py being installed
+try:
+    import _find_fuse_parts
+except ImportError:
+    pass
+import fuse
+from fuse import Fuse
+
+if not hasattr(fuse, '__version__'):
+    raise RuntimeError, \
+        "your fuse-py doesn't know of fuse.__version__, probably it's too old."
+
+fuse.fuse_python_api = (0, 2)
+
+class DefaultStat(fuse.Stat):
+    def __init__(self):
+        self.st_mode = 0
+        self.st_ino = 0
+        self.st_dev = 0
+        self.st_nlink = 0
+        self.st_uid = 0
+        self.st_gid = 0
+        self.st_size = 0
+        self.st_atime = 0
+        self.st_mtime = 0
+        self.st_ctime = 0
+
+class DefaultStatVfs(fuse.StatVfs):
+    def __init__(self):
+        self.f_bavail = 0
+        self.f_bfree = 0
+        self.f_blocks = 0
+        self.f_bsize = 0
+        self.f_favail = 0
+        self.f_ffree = 0
+        self.f_files = 0
+        self.f_flag = 0
+        self.f_frsize = 0
+        self.f_namemax = 0
+        self.n_fields = 0
+        self.n_sequence_fields = 0
+        self.n_unamed_fields = 0
+
+class NamespaceFS(Fuse):
+    """Generates a file system from a python namespace, for kicks.
+    """
+
+    def __init__(self, *args, **kw):
+        Fuse.__init__(self, *args, **kw)
+
+        self.context = self.GetContext()
+        #self.file_class = NsfsFile
+        print '*** init complete'
+
+    def getattr(self, path):
+        """
+        - st_mode (protection bits)
+        - st_ino (inode number)
+        - st_dev (device)
+        - st_nlink (number of hard links)
+        - st_uid (user ID of owner)
+        - st_gid (group ID of owner)
+        - st_size (size of file, in bytes)
+        - st_atime (time of most recent access)
+        - st_mtime (time of most recent content modification)
+        - st_ctime (platform dependent; time of most recent metadata change on 
+                    Unix, or the time of creation on Windows).
+        """
+        print '*** getattr', path
+
+        st = DefaultStat()
+        #st.st_uid = self.context['uid']
+        #st.st_gid = self.context['gid']
+       
+        if path == '/':
+            # root directory
+            st.st_mode = stat.S_IFDIR | 0755
+            st.st_nlink = 2 
+            return st 
+
+        # we want this in the form 'module/submod/stuff'
+        l = path.strip('/').split('/')
+        
+        # recursively check the namespace
+        try:
+            l[0] = globals()[l[0]] 
+            if len(l) > 1:
+                thing = reduce(getattr, l)
+            else:
+                thing = l[0]
+        except:
+            return -errno.ENOENT # nope, not there
+       
+        # for now, only modules are directories 
+        if isinstance(thing, type(fuse)):
+            st.st_mode = stat.S_IFDIR | 0755
+            st.st_nlink = 2 
+        else:
+            st.st_mode = stat.S_IFREG | 0444
+            st.st_size = len(str(thing))  # how big?
+            st.st_nlink = 1
+        return st 
+
+    def readdir(self, path, offset):
+        print '*** readdir', path, offset
+        if path == '/':
+            retl = globals().keys()
+        else:
+            # we want this in the form 'module/submod/stuff'
+            l = path.strip('/').split('/')
+
+            # recursively check the namespace
+            try:
+                print '* trying ', l
+                l[0] = globals()[l[0]]
+                if len(l) == 1:
+                    retl = l[0].__dict__.keys()
+                else:
+                    retl = reduce(getattr, l).__dict__.keys()
+            except:
+                raise IOError(-errno.ENOENT) # nope, not there
+
+        retl.insert(0, '..')
+        retl.insert(0, '.')
+        for r in retl:
+            yield fuse.Direntry(r)
+
+    def open ( self, path, flags ):
+        print '*** open', path, flags
+
+        # we want this in the form 'module/submod/stuff'
+        l = path.strip('/').split('/')
+
+        # recursively check the namespace
+        try:
+            print '* trying ', l
+            l[0] = globals()[l[0]]
+            if len(l) == 1:
+                thing = l[0]
+            else:
+                thing = reduce(getattr, l)
+        except:
+            raise IOError(-errno.ENOENT) # nope, not there
+
+        # only allow read unless it's a string
+        writeok = False
+        if isinstance(thing, type(".")):
+            writeok = True
+        accmode = os.O_RDONLY | os.O_WRONLY | os.O_RDWR
+        if (flags & accmode) and writeok:
+            return
+        elif (flags & accmode) != os.O_RDONLY:
+            return -errno.EACCES
+
+    def read ( self, path, length, offset ):
+        print '*** read', path, length, offset
+        # we want this in the form 'module/submod/stuff'
+        l = path.strip('/').split('/')
+
+        # recursively check the namespace
+        try:
+            print '* trying ', l
+            l[0] = globals()[l[0]]
+            if len(l) == 1:
+                thing = l[0]
+            else:
+                thing = reduce(getattr, l)
+        except:
+            raise IOError(-errno.ENOENT) # nope, not there
+
+        tstr = str(thing)
+        slen = len(tstr)
+        if offset < tstr:
+            if offset + length > slen:
+                size = slen - offset
+            buf = tstr[offset:offset+length]
+        else:
+            buf = ''
+        return buf
+
+    def statfs ( self ):
+        print '*** statfs'
+        #return -errno.ENOSYS
+        fst = DefaultStatVfs()
+        fst.f_namemax = 256
+        return fst
+
+    def link ( self, targetPath, linkPath ):
+        print '*** link', targetPath, linkPath
+        t = targetPath.strip('/').split('/')
+
+        # recursively check the namespace; target can't be / for now
+        try:
+            print '* trying ', t
+            t[0] = globals()[t[0]]
+            if len(t) == 1:
+                target = t[0]
+            else:
+                target = reduce(getattr, t)
+        except:
+            return -errno.ENOENT # nope, not there
+
+        l = linkPath.strip('/').split('/')
+        if (len(l) == 1) and (l[0] != '') and not (l[0] in globals().keys()):
+            # easy, good to go
+            globals()[l[0]] = target
+            print '* trying easy ', l[0], target
+            return
+
+        # otherwise...
+        # recursively check the namespace; link can't be /
+        try:
+            print '* trying ', l
+            l[0] = globals()[l[0]]
+            if len(l) == 1:
+                raise IOError(-errno.ENOENT) # can't do root or existing
+            elif len(l) == 2:
+                lp = l[0]
+            else:
+                lp = reduce(getattr, l[:-1]) # want the parent of the link
+        except:
+            return -errno.ENOENT # nope, not there
+       
+        # if that all worked out with no errors...
+        lp.__setattr__(l[-1], target)
+
+    def unlink ( self, path ):
+        print '*** unlink', path
+
+        l = path.strip('/').split('/')
+        if (len(l) == 1) and (l[0] != '') and (l[0] in globals().keys()):
+            # easy, good to go
+            del globals()[l[0]]
+            return
+
+        try:
+            print '* trying ', l
+            l[0] = globals()[l[0]]
+            if len(l) == 1:
+                return -errno.ENOENT # something is wrong, shouldn't get here
+            elif len(l) == 2:
+                lp = l[0]
+            else:
+                lp = reduce(getattr, l[:-1]) # want the parent of the link
+        except:
+            return -errno.ENOENT # nope, not there
+        lp.__delattr__(l[-1])
+
+    def write ( self, path, buf, offset ):
+        print '*** write', path, buf, offset
+        # we want this in the form 'module/submod/stuff'
+        l = path.strip('/').split('/')
+
+        # recursively check the namespace
+        try:
+            print '* trying ', l
+            l[0] = globals()[l[0]]
+            if len(l) == 1:
+                thing = l[0]
+            else:
+                thing = reduce(getattr, l)
+        except:
+            print '* ACTUALLY CAN\'T FIND'
+            raise IOError(-errno.ENOENT) # nope, not there
+        
+        if not isinstance(thing, type(".")):
+            print '* WRONG TYPE'
+            raise IOError(-errno.ENOENT) # wrong file type
+ 
+        # Kind of a slow way to go?
+        sfile = StringIO(thing)
+        sfile.seek(offset)
+        sfile.write(buf)
+        sfile.flush()
+        thing = sfile.getvalue()
+        sfile.close()
+
+        # recursively check the namespace
+        l = path.strip('/').split('/')
+        #try:
+        if len(l) == 1:
+            globals()[l[0]] = thing
+            return len(buf)
+        l[0] = globals()[l[0]]
+        tp = reduce(getattr, l[:-1])
+        tp.__setattr__(l[-1], thing)
+        print '* TRIED ', thing
+        return len(buf)
+        #except: #    raise IOError(-errno.ENOENT) # nope, not there
+
+    def release ( self, path, flags ):
+        print '*** release', path, flags
+        return -errno.ENOSYS
+
+    def fsync ( self, path, isFsyncFile ):
+        print '*** fsync', path, isFsyncFile
+        return -errno.ENOSYS
+
+    def mknod ( self, path, mode, dev ):
+        print '*** mknod', path, oct(mode), dev
+        return -errno.ENOSYS
+
+    def rmdir ( self, path ):
+        print '*** rmdir', path
+        return -errno.ENOSYS
+
+    def getdir(self, path):
+        print '*** getdir', path
+        return self.readdir(path, 0)
+
+    def mythread ( self ):
+        print '*** mythread'
+        return -errno.ENOSYS
+
+    def chmod ( self, path, mode ):
+        print '*** chmod', path, oct(mode)
+        return -errno.ENOSYS
+
+    def chown ( self, path, uid, gid ):
+        print '*** chown', path, uid, gid
+        return -errno.ENOSYS
+
+    def mkdir ( self, path, mode ):
+        print '*** mkdir', path, oct(mode)
+        return -errno.ENOSYS
+
+    def readlink ( self, path ):
+        print '*** readlink', path
+        return -errno.ENOSYS
+
+    def rename ( self, oldPath, newPath ):
+        print '*** rename', oldPath, newPath
+        globals()[path1] = globals()[path]
+        del globals()[path]
+        #return -errno.ENOSYS
+
+    def symlink ( self, targetPath, linkPath ):
+        print '*** symlink', targetPath, linkPath
+        return -errno.ENOSYS
+
+    def truncate ( self, path, size ):
+        print '*** truncate', path, size
+        return -errno.ENOSYS
+
+    def utime ( self, path, times ):
+        print '*** utime', path, times
+        return -errno.ENOSYS
+
+# This isn't actually used yet
+class NsfsFile(object):
+
+    def init(self, path, flags, mode=None):
+
+        # if mode != None: NEW FILE
+
+        # we want this in the form 'module/submod/stuff'
+        l = path.strip('/').split('/')
+
+        # recursively check the namespace
+        try:
+            l[0] = globals()[l[0]]
+            self.thing = reduce(getattr, l)
+        except:
+            return -errno.ENOENT # nope, not there
+        self.tstr = str(self.thing)
+        self.tfile = StringIO(self.tfile)
+
+    def read(self, len, offset):
+        #return -errno.ENOSYS
+        return read(self.tfile, len, offset)
+
+    def release(self, flags):
+        self.tfile.close()
+
+def main():
+    usage="""
+Experimental Python Namespace Filesystem
+
+""" + Fuse.fusage
+    server = NamespaceFS(version="%prog " + fuse.__version__,
+        usage=usage,
+        dash_s_do='setsingle')
+    server.parse(errex=1)
+    server.flags = 0
+    server.multithreaded = 0
+    print "let's go!"
+    server.main()
+
+if __name__ == '__main__':
+    main()
-- 
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