Dion Moult b1cba757b8 ifcparse: parse instances in parallel
The DATA section is split into one chunk per thread and each worker runs
the same per-instance reader as the serial parse over its own reader,
storage, inverse records and simple-type list; the results are merged in
file order, so instance order, GlobalId precedence and inverse records
are identical to the serial parse. Reference resolution then splits over
the same threads: each instance's slots are its own and the name table
is complete and read-only by then. The default is one thread per core,
capped at 16; IFCOPENSHELL_PARSE_THREADS or file::parse_threads()
overrides it, and 1 parses as before.

The instance headers are read by one loop, for_each_instance_header(),
shared with the lazy index: it looks declarations up once per keyword,
passes over a bypassed instance's attribute list and slides past a stray
keyword the way the serial reader does (the lazy index therefore no
longer falls back on one).

Finding the split points is the one place that looks at raw bytes rather
than tokens, because tokenizing the file serially first would leave
nothing to parallelise. It applies three rules: a string starts and ends
at a quote and cannot span a line, and a comment runs from /* to */; a
split is a '#' that starts a line outside both. Getting a string's end
wrong can only lose a candidate, never accept a wrong one, since no
string contains a newline. The equality test puts a comment holding a
fake instance and a string holding "/*" between the chunks.

file_reader gains for_each_span(), which hands a byte range out span by
span (one span for a buffer, one per page for the paged reader), and
reopen(), a reader over the same file for another thread.

TXG 58 MB / 210_King 147 MB / OKgate22 231 MB, 12 threads: 0.44 / 1.24 /
2.01 s against 1.07 / 2.75 / 5.12 s on one thread; memory after the parse
within 1–4%, peak +5–4%.

This commit was written by an AI coding tool and has not been verified by
a human.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013wcN7XquTfUi4vsKQ4KchL
2026-09-14 19:34:08 +10:00
2026-09-11 19:12:01 +05:00
2025-12-19 18:53:14 +05:00
2026-09-11 19:12:01 +05:00
2026-08-10 06:15:49 +02:00
2026-09-14 19:34:08 +10:00
2026-05-18 19:24:25 +02:00
2026-08-08 03:44:56 +02:00
2026-02-18 09:09:46 +11:00
2026-05-08 16:20:26 +02:00
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2026-08-10 05:19:17 +02:00

IfcOpenShell

IfcOpenShell is an open source (LGPL) software library for working with Industry Foundation Classes (IFC). Complete parsing support is provided for IFC2x3 TC1, IFC4 Add2 TC1, IFC4x1, IFC4x2, and IFC4x3 Add2. Extensive geometric support is implemented for the IFC releases IFC2x3 TC1 and IFC4 Add2 TC1. Extending with support for arbitrary IFC schemas is possible at compile-time when using C++ and at run-time when using Python.

In addition to a C++ and Python API, IfcOpenShell comes with an ecosystem of tools, notably including IfcConvert (an application to convert IFC models to other formats), Bonsai (an add-on to Blender providing a graphical IFC authoring platform), and many other libraries, CLI apps, and more. Support is also provided for auxiliary standards such as BCF and IDS.

For more information, see:

Development is sponsored through your generous donations!

Open Collective Contributors

Contents

Name Description License Service
bcf Library to read and write BCF-XML and query OpenCDE BCF-API modules LGPL-3.0-or-later PyPI Anaconda-Server Badge
bonsai Add-on to Blender providing a graphical native IFC authoring platform GPL-3.0-or-later Official GitHub Unstable Chocolatey
bsdd Library to query the bSDD API LGPL-3.0-or-later PyPI
ifc2ca Utility to convert IFC structural analysis models to Code_Aster LGPL-3.0-or-later
ifc4d Convert to and from IFC and project management software LGPL-3.0-or-later PyPI
ifc5d Report and optimise cost information from IFC LGPL-3.0-or-later PyPI
ifcbimtester Wrapper for Gherkin based unit testing for IFC models LGPL-3.0-or-later
ifcblender Historic Blender IFC import add-on LGPL-3.0-or-later*
ifccityjson Convert CityJSON to IFC LGPL-3.0-or-later PyPI
ifcclash Clash detection library and CLI app LGPL-3.0-or-later PyPI
ifcconvert CLI app to convert IFC to many other formats LGPL-3.0-or-later* Official GitHub
ifccsv Library and CLI app to export and import schedules from IFC LGPL-3.0-or-later PyPI
ifcdiff Compare changes between IFC models LGPL-3.0-or-later PyPI
ifcedit CLI wrapper for ifcopenshell.api IFC model mutation functions LGPL-3.0-or-later PyPI
ifcfm Extract IFC data for FM handover requirements LGPL-3.0-or-later PyPI
ifcmax Historic extension for IFC support in 3DS Max LGPL-3.0-or-later* Official
ifcmcp MCP server for querying and editing IFC building models LGPL-3.0-or-later PyPI
ifcopenshell-python Python library for IFC manipulation LGPL-3.0-or-later* Official GitHub PyPI Anaconda Anaconda Docker AUR AUR Unstable Pyodide WASM Wheels tag
ifcpatch Utility to run pre-packaged scripts to manipulate IFCs LGPL-3.0-or-later PyPI
ifcquery CLI tool for querying and inspecting IFC building models LGPL-3.0-or-later PyPI
ifcsverchok Blender Add-on for visual node programming with IFC GPL-3.0-or-later GitHub
ifctester Library, CLI and webapp for IDS model auditing LGPL-3.0-or-later PyPI

The IfcOpenShell C++ codebase is split into multiple interal libraries:

Name Description License
ifcgeom Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcgeomserver Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcparse Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcwrap Internal library for IfcOpenShell LGPL-3.0-or-later*
serializers Internal library for IfcOpenShell LGPL-3.0-or-later*
S
Description
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Python 36.3%
C 3.9%
Gherkin 0.7%
JavaScript 0.3%
Other 1.3%