Option to bypass storing types when opening model

src/ifcopenshell-python/ifcopenshell/__init__.py

@@ -59,7 +59,7 @@ import sys
 import zipfile
 import tempfile
 from pathlib import Path
-from typing import Optional, Union, TYPE_CHECKING, Any, overload, Literal
+from typing import Optional, Sequence, Union, TYPE_CHECKING, Any, overload, Literal
 
 if TYPE_CHECKING:
     import ifcopenshell.express.schema_class
@@ -138,7 +138,12 @@ def open(
     path: Union[os.PathLike, str], format: Optional[str] = None, *, should_stream: bool = False, readonly: bool = False
 ) -> Union[_file, sqlite, _stream]: ...
 def open(
-    path: Union[os.PathLike, str], format: Optional[str] = None, should_stream: bool = False, readonly: bool = False
+    path: Union[os.PathLike, str],
+    format: Optional[str] = None,
+    should_stream: bool = False,
+    readonly: bool = False,
+    mmap: bool = False,
+    bypass_types: Optional[Sequence[str]] = None,
 ) -> Union[_file, sqlite, _stream]:
     """Loads an IFC dataset from a filepath
 
@@ -186,7 +191,17 @@ def open(
     if should_stream:
         return stream(path)
     if readonly:  # Temporary conditional see #7131. Remove once newer builds don't segfault on Linux.
-        f = ifcopenshell_wrapper.open(str(path.absolute()), readonly)
+        f = ifcopenshell_wrapper.open(str(path.absolute()), readonly=readonly)
+    elif bypass_types:
+        f = ifcopenshell_wrapper.file(ifcopenshell_wrapper.uninitialized_tag())
+        for ty in bypass_types:
+            f.bypass_type(ty)
+        if mmap:
+            f.initialize(str(path.absolute()), mmap=mmap)
+        else:
+            f.initialize(str(path.absolute()))
+    elif mmap:
+        f = ifcopenshell_wrapper.open(str(path.absolute()), mmap=mmap)
     else:
         f = ifcopenshell_wrapper.open(str(path.absolute()))
     return file(f)

src/ifcopenshell-python/ifcopenshell/file.py

@@ -248,6 +248,7 @@ READ_ERROR = ifcopenshell_wrapper.file_open_status.READ_ERROR
 NO_HEADER = ifcopenshell_wrapper.file_open_status.NO_HEADER
 UNSUPPORTED_SCHEMA = ifcopenshell_wrapper.file_open_status.UNSUPPORTED_SCHEMA
 INVALID_SYNTAX = ifcopenshell_wrapper.file_open_status.INVALID_SYNTAX
+UNKNOWN = ifcopenshell_wrapper.file_open_status.UNKNOWN
 
 import struct
 
@@ -586,8 +587,11 @@ class file:
                         "Unsupported schema: %s" % ",".join(self.header.file_schema.schema_identifiers),
                     ),
                     INVALID_SYNTAX: lambda: (Error, "Syntax error during parse, check logs"),
+                    # This is the case when passing uninitialized_tag
+                    UNKNOWN: lambda: (None, None),
                 }[f.good().value()]()
-                raise exc(msg)
+                if exc is not None:
+                    raise exc(msg)
         else:
             args = filter(None, [schema])
             args = map(ifcopenshell_wrapper.schema_by_name, args)

src/ifcopenshell-python/test/test_streaming_rocksdb_and_simpletyperefs.py

@@ -23,6 +23,11 @@ import pytest
 import ifcopenshell
 import tempfile
 
+try:
+    import psutil
+except ImportError:
+    psutil = None
+
 fn = os.path.join(os.path.dirname(__file__), "fixtures/ColumnPSetsOfSets.ifc")
 
 
@@ -32,18 +37,40 @@ def test_stream():
         "value": ({"ref": 136}, {"ref": 138}),
     }
 
+
 def test_chunked_stream():
     assert list(ifcopenshell.stream2(fn)) == list(ifcopenshell.stream2(fn, page_size=1024))
 
+
 def test_mmaped_stream():
     assert list(ifcopenshell.stream2(fn)) == list(ifcopenshell.stream2(fn, mmap=True))
 
+
 def test_file():
     f = ifcopenshell.open(fn)
     assert f[139].RelatingPropertyDefinition.is_a("IfcPropertySetDefinitionSet")
     assert {x.id() for x in f[139].RelatingPropertyDefinition[0]} == {136, 138}
 
 
+def test_partial_open():
+    f = ifcopenshell.open(fn)
+    assert len(f.by_type("ifccartesianpoint"))
+    f = ifcopenshell.open(fn, bypass_types=("IfcRepresentationItem",))
+    assert len(f.by_type("ifccartesianpoint")) == 0
+
+
+@pytest.mark.skipif(psutil is None, reason="psutil not installed")
+def test_memusage_partial_open():
+    m0 = psutil.Process().memory_info().rss
+    f = ifcopenshell.open(fn)
+    m1 = psutil.Process().memory_info().rss
+    g = ifcopenshell.open(fn, bypass_types=("IfcRepresentationItem",))
+    m2 = psutil.Process().memory_info().rss
+    # arbitrary...
+    expected_ratio = 0.75
+    assert (m2 - m1) < (m1 - m0) * expected_ratio
+
+
 def test_rocks():
     with tempfile.TemporaryDirectory() as d:
         rfn = os.path.join(d, os.path.basename(fn))