arrow/filesystem/filesystem_library.h

0001 // Licensed to the Apache Software Foundation (ASF) under one
0002 // or more contributor license agreements.  See the NOTICE file
0003 // distributed with this work for additional information
0004 // regarding copyright ownership.  The ASF licenses this file
0005 // to you under the Apache License, Version 2.0 (the
0006 // "License"); you may not use this file except in compliance
0007 // with the License.  You may obtain a copy of the License at
0008 //
0009 //   http://www.apache.org/licenses/LICENSE-2.0
0010 //
0011 // Unless required by applicable law or agreed to in writing,
0012 // software distributed under the License is distributed on an
0013 // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
0014 // KIND, either express or implied.  See the License for the
0015 // specific language governing permissions and limitations
0016 // under the License.
0017
0018 #pragma once
0019
0020 #include "arrow/filesystem/filesystem.h"
0021
0022 namespace arrow::fs {
0023 extern "C" {
0024
0025 // ARROW_FORCE_EXPORT ensures this function's visibility is
0026 // _declspec(dllexport)/[[gnu::visibility("default")]] even when
0027 // this header is #included by a non-arrow source, as in a third
0028 // party filesystem implementation.
0029 ARROW_FORCE_EXPORT void* arrow_filesystem_get_registry() {
0030   // In the case where libarrow is linked statically both to the executable and to a
0031   // dynamically loaded filesystem implementation library, the library contains a
0032   // duplicate definition of the registry into which the library's instances of
0033   // FileSystemRegistrar insert their factories. This function is made accessible to
0034   // dlsym/GetProcAddress to enable detection of such duplicate registries and merging
0035   // into the registry accessible to the executable.
0036   return internal::GetFileSystemRegistry();
0037 }
0038 }
0039 }  // namespace arrow::fs