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Posted to github@arrow.apache.org by GitBox <gi...@apache.org> on 2022/04/07 14:18:29 UTC
[GitHub] [arrow] davisusanibar commented on a diff in pull request #12794: ARROW-15578: [Java][Doc] - Document C Data and how to interface with other languages
davisusanibar commented on code in PR #12794:
URL: https://github.com/apache/arrow/pull/12794#discussion_r845193872
##########
docs/source/java/cdata.rst:
##########
@@ -0,0 +1,213 @@
+.. Licensed to the Apache Software Foundation (ASF) under one
+.. or more contributor license agreements. See the NOTICE file
+.. distributed with this work for additional information
+.. regarding copyright ownership. The ASF licenses this file
+.. to you under the Apache License, Version 2.0 (the
+.. "License"); you may not use this file except in compliance
+.. with the License. You may obtain a copy of the License at
+
+.. http://www.apache.org/licenses/LICENSE-2.0
+
+.. Unless required by applicable law or agreed to in writing,
+.. software distributed under the License is distributed on an
+.. "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+.. KIND, either express or implied. See the License for the
+.. specific language governing permissions and limitations
+.. under the License.
+
+================
+C Data Interface
+================
+
+.. contents::
+
+Arrow supports exchanging data without copying or serialization within the same process
+through the :ref:`c-data-interface`, even between different language runtimes.
+
+Java to Python
+--------------
+
+Use this guide to implement :doc:`Java to Python <../python/integration/python_java.rst>`
+communication using the C Data Interface.
+
+Java to C++
+-----------
+
+Example: Share an Int64 array from C++ to Java:
+
+**C++ Side**
+
+Use this guide to :doc:`compile arrow <../developers/cpp/building.rst>` library:
+
+.. code-block:: shell
+
+ git clone https://github.com/apache/arrow.git
+ cd arrow/cpp
+ cmake --preset -N ninja-debug-minimal
+ mkdir build # from inside the `cpp` subdirectory
+ cd build
+ cmake .. --preset ninja-debug-minimal
+ cmake --build .
+ tree debug/
+ debug/
+ ├── libarrow.800.0.0.dylib
+ ├── libarrow.800.dylib -> libarrow.800.0.0.dylib
+ └── libarrow.dylib -> libarrow.800.dylib
+
+Define C++ code CDataCppBridge.h that export function **fillCArray** for third party
Review Comment:
Changed to *.cpp for more readable, and yes it is used by javacpp generated sources
##########
docs/source/java/cdata.rst:
##########
@@ -0,0 +1,213 @@
+.. Licensed to the Apache Software Foundation (ASF) under one
+.. or more contributor license agreements. See the NOTICE file
+.. distributed with this work for additional information
+.. regarding copyright ownership. The ASF licenses this file
+.. to you under the Apache License, Version 2.0 (the
+.. "License"); you may not use this file except in compliance
+.. with the License. You may obtain a copy of the License at
+
+.. http://www.apache.org/licenses/LICENSE-2.0
+
+.. Unless required by applicable law or agreed to in writing,
+.. software distributed under the License is distributed on an
+.. "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+.. KIND, either express or implied. See the License for the
+.. specific language governing permissions and limitations
+.. under the License.
+
+================
+C Data Interface
+================
+
+.. contents::
+
+Arrow supports exchanging data without copying or serialization within the same process
+through the :ref:`c-data-interface`, even between different language runtimes.
+
+Java to Python
+--------------
+
+Use this guide to implement :doc:`Java to Python <../python/integration/python_java.rst>`
+communication using the C Data Interface.
+
+Java to C++
+-----------
+
+Example: Share an Int64 array from C++ to Java:
+
+**C++ Side**
+
+Use this guide to :doc:`compile arrow <../developers/cpp/building.rst>` library:
+
+.. code-block:: shell
+
+ git clone https://github.com/apache/arrow.git
+ cd arrow/cpp
+ cmake --preset -N ninja-debug-minimal
+ mkdir build # from inside the `cpp` subdirectory
+ cd build
+ cmake .. --preset ninja-debug-minimal
+ cmake --build .
+ tree debug/
+ debug/
+ ├── libarrow.800.0.0.dylib
+ ├── libarrow.800.dylib -> libarrow.800.0.0.dylib
+ └── libarrow.dylib -> libarrow.800.dylib
+
+Define C++ code CDataCppBridge.h that export function **fillCArray** for third party
+consumers like Java:
+
+.. code-block:: cpp
+
+ #include <iostream>
+ #include <arrow/api.h>
+ #include <arrow/c/bridge.h>
+
+ using arrow::Int64Builder;
+
+ void fillCArray(const uintptr_t c_schema_ptr, const uintptr_t c_array_ptr){
+ arrow::Int64Builder builder;
+ builder.Append(1);
+ builder.Append(2);
+ builder.Append(3);
+ builder.AppendNull();
+ builder.Append(5);
+ builder.Append(6);
+ builder.Append(7);
+ builder.Append(8);
+ builder.Append(9);
+ builder.Append(10);
+ std::shared_ptr<arrow::Array> array = *builder.Finish();;
+
+ struct ArrowSchema* c_schema = reinterpret_cast<struct ArrowSchema*>(c_schema_ptr);
+ auto c_schema_status = arrow::ExportType(*array->type(), c_schema);
+ if (!c_schema_status.ok()) c_schema_status.Abort();
+
+ struct ArrowArray* c_array = reinterpret_cast<struct ArrowArray*>(c_array_ptr);
+ auto c_array_status = arrow::ExportArray(*array, c_array);
+ if (!c_array_status.ok()) c_array_status.Abort();
+ }
+
+**Java Side**
+
+For this example, we will use `JavaCPP`_ to call our main C++ **fillCArray** function from Java,
+without writing JNI bindings ourselves.
+
+.. code-block:: xml
+
+ <?xml version="1.0" encoding="UTF-8"?>
+ <project xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+
+ <groupId>org.example</groupId>
+ <artifactId>cdatav2</artifactId>
Review Comment:
Changed
##########
docs/source/java/cdata.rst:
##########
@@ -0,0 +1,213 @@
+.. Licensed to the Apache Software Foundation (ASF) under one
+.. or more contributor license agreements. See the NOTICE file
+.. distributed with this work for additional information
+.. regarding copyright ownership. The ASF licenses this file
+.. to you under the Apache License, Version 2.0 (the
+.. "License"); you may not use this file except in compliance
+.. with the License. You may obtain a copy of the License at
+
+.. http://www.apache.org/licenses/LICENSE-2.0
+
+.. Unless required by applicable law or agreed to in writing,
+.. software distributed under the License is distributed on an
+.. "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+.. KIND, either express or implied. See the License for the
+.. specific language governing permissions and limitations
+.. under the License.
+
+================
+C Data Interface
+================
+
+.. contents::
+
+Arrow supports exchanging data without copying or serialization within the same process
+through the :ref:`c-data-interface`, even between different language runtimes.
+
+Java to Python
+--------------
+
+Use this guide to implement :doc:`Java to Python <../python/integration/python_java.rst>`
+communication using the C Data Interface.
+
+Java to C++
+-----------
+
+Example: Share an Int64 array from C++ to Java:
+
+**C++ Side**
+
+Use this guide to :doc:`compile arrow <../developers/cpp/building.rst>` library:
+
+.. code-block:: shell
+
+ git clone https://github.com/apache/arrow.git
+ cd arrow/cpp
+ cmake --preset -N ninja-debug-minimal
+ mkdir build # from inside the `cpp` subdirectory
+ cd build
+ cmake .. --preset ninja-debug-minimal
+ cmake --build .
+ tree debug/
+ debug/
+ ├── libarrow.800.0.0.dylib
+ ├── libarrow.800.dylib -> libarrow.800.0.0.dylib
+ └── libarrow.dylib -> libarrow.800.dylib
+
+Define C++ code CDataCppBridge.h that export function **fillCArray** for third party
+consumers like Java:
+
+.. code-block:: cpp
+
+ #include <iostream>
+ #include <arrow/api.h>
+ #include <arrow/c/bridge.h>
+
+ using arrow::Int64Builder;
+
+ void fillCArray(const uintptr_t c_schema_ptr, const uintptr_t c_array_ptr){
+ arrow::Int64Builder builder;
+ builder.Append(1);
+ builder.Append(2);
+ builder.Append(3);
+ builder.AppendNull();
+ builder.Append(5);
+ builder.Append(6);
+ builder.Append(7);
+ builder.Append(8);
+ builder.Append(9);
+ builder.Append(10);
+ std::shared_ptr<arrow::Array> array = *builder.Finish();;
+
+ struct ArrowSchema* c_schema = reinterpret_cast<struct ArrowSchema*>(c_schema_ptr);
+ auto c_schema_status = arrow::ExportType(*array->type(), c_schema);
+ if (!c_schema_status.ok()) c_schema_status.Abort();
+
+ struct ArrowArray* c_array = reinterpret_cast<struct ArrowArray*>(c_array_ptr);
+ auto c_array_status = arrow::ExportArray(*array, c_array);
+ if (!c_array_status.ok()) c_array_status.Abort();
+ }
+
+**Java Side**
+
+For this example, we will use `JavaCPP`_ to call our main C++ **fillCArray** function from Java,
+without writing JNI bindings ourselves.
+
+.. code-block:: xml
+
+ <?xml version="1.0" encoding="UTF-8"?>
+ <project xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+
+ <groupId>org.example</groupId>
+ <artifactId>cdatav2</artifactId>
+ <version>1.0-SNAPSHOT</version>
+
+ <properties>
+ <maven.compiler.source>8</maven.compiler.source>
+ <maven.compiler.target>8</maven.compiler.target>
+ <arrow.version>8.0.0.dev254</arrow.version>
Review Comment:
Changed
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