Introduce SharedTemporaryFile (bis)

fipy/tools/__init__.py

@@ -45,6 +45,7 @@
 from .dimensions.physicalField import PhysicalField
 from fipy.tools.numerix import *
 from fipy.tools.vitals import Vitals
+from fipy.tools.sharedtempfile import SharedTemporaryFile
 
 __all__ = ["serialComm",
            "parallelComm",
@@ -54,7 +55,8 @@
            "PhysicalField",
            "Vitals",
            "serial",
-           "parallel"]
+           "parallel",
+           "SharedTemporaryFile"]
 from future.utils import text_to_native_str
 __all__ = [text_to_native_str(n) for n in __all__]
 

fipy/tools/sharedtempfile.py

@@ -0,0 +1,115 @@
+from future import utils
+from tempfile import NamedTemporaryFile, template, _TemporaryFileWrapper
+
+from fipy.tools import parallelComm
+
+__all__ = ["SharedTemporaryFile"]
+
+if utils.PY3:
+    import io as _io
+
+    def SharedTemporaryFile(mode='w+b', buffering=-1, encoding=None,
+                            newline=None, suffix="", prefix=template,
+                            dir=None, delete=True, communicator=parallelComm):
+        """Create a temporary file shared by all MPI ranks.
+
+        The file is created as `NamedTemporaryFile` would do it.
+        The name of the returned file-like object is accessible as its
+        ``name`` attribute.  The file will be automatically deleted when it
+        is closed unless the `delete` argument is set to False.
+
+        Parameters
+        ----------
+        prefix, suffix, dir : str
+            As for mkstemp
+        mode : str
+            The mode argument to io.open (default "w+b")
+        buffering : int
+            The buffer size argument to io.open (default -1)
+        encoding : str or None
+            The encoding argument to io.open (default None)
+        newline : str or None
+            The newline argument to io.open (default None)
+        delete : bool
+            Whether the file is deleted on close (default True)
+        communicator : ~fipy.tools.comms.commWrapper.CommWrapper
+            MPI communicator describing ranks to share with.  A duck-typed
+            object with `procID` and `Nproc` attributes is sufficient.
+
+        Returns
+        -------
+        file-like object
+
+        See Also
+        --------
+        tempfile.NamedTemporaryFile, tempfile.mkstemp, io.open
+
+        """
+
+        if communicator.procID == 0:
+            f = NamedTemporaryFile(mode=mode, buffering=buffering, encoding=encoding,
+                                   newline=newline, suffix=suffix, prefix=prefix,
+                                   dir=dir, delete=delete)
+            fname = f.name
+        else:
+            fname = None
+
+        fname = communicator.bcast(fname)
+
+        if communicator.procID != 0:
+            f = _io.open(fname, mode, buffering=buffering,
+                         newline=newline, encoding=encoding)
+            # let procID 0 handle delete
+            f = _TemporaryFileWrapper(f, fname, delete=False)
+
+        return f
+else:
+    def SharedTemporaryFile(mode='w+b', bufsize=-1, suffix="",
+                            prefix=template, dir=None, delete=True,
+                            communicator=parallelComm):
+        """Create a temporary file shared by all MPI ranks.
+
+        The file is created as `NamedTemporaryFile` would do it.
+        The name of the returned file-like object is accessible as its
+        ``name`` attribute.  The file will be automatically deleted when it
+        is closed unless the `delete` argument is set to False.
+
+        Parameters
+        ----------
+        prefix, suffix, dir : str
+            As for mkstemp
+        mode : str
+            The mode argument to os.fdopen (default "w+b")
+        bufsize : int
+            The buffer size argument to os.fdopen (default -1)
+        delete : bool
+            Whether the file is deleted on close (default True)
+        communicator : ~fipy.tools.comms.commWrapper.CommWrapper
+            MPI communicator describing ranks to share with.  A duck-typed
+            object with `procID` and `Nproc` attributes is sufficient
+
+        Returns
+        -------
+        file-like object
+
+        See Also
+        --------
+        tempfile.NamedTemporaryFile, tempfile.mkstemp, os.fdopen
+
+        """
+
+        if communicator.procID == 0:
+            f = NamedTemporaryFile(mode=mode, bufsize=bufsize, suffix=suffix,
+                                   prefix=prefix, dir=dir, delete=delete)
+            fname = f.name
+        else:
+            fname = None
+
+        fname = communicator.bcast(fname)
+
+        if communicator.procID != 0:
+            f = open(fname, mode, bufsize)
+            # let procID 0 handle delete
+            f = _TemporaryFileWrapper(f, fname, delete=False)
+
+        return f