Rough draft of a client application for the C++ IfcGeomServer binary

src/ifcopenshell-python/ifcopenshell/geom/client.py

@@ -0,0 +1,103 @@
+###############################################################################
+#                                                                             #
+# This file is part of IfcOpenShell.                                          #
+#                                                                             #
+# IfcOpenShell is free software: you can redistribute it and/or modify        #
+# it under the terms of the Lesser GNU General Public License as published by #
+# the Free Software Foundation, either version 3.0 of the License, or         #
+# (at your option) any later version.                                         #
+#                                                                             #
+# IfcOpenShell is distributed in the hope that it will be useful,             #
+# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                #
+# Lesser GNU General Public License for more details.                         #
+#                                                                             #
+# You should have received a copy of the Lesser GNU General Public License    #
+# along with this program. If not, see <http://www.gnu.org/licenses/>.        #
+#                                                                             #
+###############################################################################
+
+"""
+Rough draft of a client application for the C++ IfcGeomServer binary
+"""
+
+import os
+import numpy
+import subprocess
+
+from collections import namedtuple
+
+class message_headers(object):
+    HELLO = 0xff00
+    IFC_MODEL = HELLO + 1
+    GET = IFC_MODEL + 1
+    ENTITY = GET + 1
+    MORE = ENTITY + 1
+    NEXT = MORE + 1
+    BYE = NEXT + 1
+    GET_LOG = BYE + 1
+    LOG = GET_LOG + 1
+    DEFLECTION = LOG + 1
+    SETTING = DEFLECTION + 1
+    
+message = namedtuple("message", ("header", "contents"))
+    
+def process(geomserver_exe, ifc_filename):
+        
+    proc = subprocess.Popen([geomserver_exe], stdout=subprocess.PIPE, stdin=subprocess.PIPE)
+    
+    def cast(data, dtype, n=None):
+        arr = numpy.frombuffer(data, dtype=dtype)
+        if n is None: return arr[0]
+        else: return arr
+
+    def read(dtype, n=None):
+        data = proc.stdout.read(dtype().nbytes * (n or 1))
+        return cast(data, dtype, n)
+        
+    def read_message(header_assertion=None):
+        header, size = read(numpy.int32, 2)
+        assert header_assertion is None or header_assertion == header
+        contents = b""
+        if size > 0:
+            contents = proc.stdout.read(size)
+        return message(header, contents)
+        
+    def write(header, contents=None):
+        if contents is None: contents = []
+        proc.stdin.write(numpy.int32(header).tobytes())
+        integers_as_int32 = list(map(lambda s: numpy.int32(s) if isinstance(s, int) else s, contents))
+        to_bytes = list(map(lambda s: s.tobytes() if hasattr(s, 'tobytes') else s, integers_as_int32))
+        total_length = numpy.int32(sum(map(len, to_bytes)))
+        proc.stdin.write(total_length.tobytes())
+        for b in to_bytes:
+            proc.stdin.write(b)
+        proc.stdin.flush()
+        
+    read_message(message_headers.HELLO)
+    
+    # @todo: no need to read the entire file in memory
+    s = open(ifc_filename, "rb").read()
+    
+    write(message_headers.SETTING, [numpy.int32((1 << 4)), numpy.int32(1)]) 
+    write(message_headers.IFC_MODEL, [numpy.int32(len(s)), s, b"\x00" * ((4 - (len(s) % 4)) % 4)])
+        
+    while True:    
+        has_more = cast(read_message(message_headers.MORE).contents, numpy.int32) == 1        
+        if not has_more: break        
+        write(message_headers.GET)        
+        print(read_message(message_headers.ENTITY).contents)        
+        write(message_headers.NEXT)        
+            
+    write(message_headers.BYE)
+    read_message(message_headers.BYE)
+    proc.wait()
+    assert proc.returncode == 0
+
+if __name__ == "__main__":
+    import sys
+    import platform
+    exe_extension = ".exe" if platform.system() == 'Windows' else ""
+    exe = os.environ.get("IFCGEOMSERVER") or ("IfcGeomServer" + exe_extension)
+    for fn in sys.argv[1:]:
+        process(exe, fn)