Merge pull request #2414 from lrtfm/load-binary-gmsh-file

Load binary gmsh file

Author: dham

firedrake/mesh.py

@@ -232,9 +232,21 @@ def _from_gmsh(filename, comm=None):
         COMM_WORLD).
     """
     comm = comm or COMM_WORLD
+    # check the filetype of the gmsh file
+    filetype = None
+    if comm.rank == 0:
+        with open(filename, 'rb') as fid:
+            header = fid.readline().rstrip(b'\n\r')
+            version = fid.readline().rstrip(b'\n\r')
+        assert header == b'$MeshFormat'
+        if version.split(b' ')[1] == b'1':
+            filetype = "binary"
+        else:
+            filetype = "ascii"
+    filetype = comm.bcast(filetype, root=0)
     # Create a read-only PETSc.Viewer
     gmsh_viewer = PETSc.Viewer().create(comm=comm)
-    gmsh_viewer.setType("ascii")
+    gmsh_viewer.setType(filetype)
     gmsh_viewer.setFileMode("r")
     gmsh_viewer.setFileName(filename)
     gmsh_plex = PETSc.DMPlex().createGmsh(gmsh_viewer, comm=comm)

tests/meshes/square_binary.msh

@@ -0,0 +1,20 @@
+from firedrake import *
+import numpy as np
+import pytest
+from os.path import abspath, dirname, join
+
+
+path = join(abspath(dirname(__file__)), '..', 'meshes')
+
+
+def load_mesh(filename):
+    m = Mesh(join(path, filename))
+    return m
+
+
+@pytest.mark.parametrize(
+    'filename', ['square.msh', 'square_binary.msh'])
+def test_load_mesh(filename):
+    m = load_mesh(filename)
+    v = assemble(1*dx(domain=m))
+    assert np.allclose(v, 1)