ARROW-984: [GLib] Add Go examples

c_glib/.gitignore

@@ -41,3 +41,8 @@ Makefile.in
 /example/build
 /example/read-batch
 /example/read-stream
+!/example/go/Makefile
+/example/go/read-batch
+/example/go/read-stream
+/example/go/write-batch
+/example/go/write-stream

c_glib/example/go/Makefile

@@ -0,0 +1,35 @@
+# Licensed 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. See accompanying LICENSE file.
+
+PROGRAMS =					\
+	read-batch				\
+	read-stream				\
+	write-batch				\
+	write-stream
+
+all: build
+
+generate:
+	$$GOPATH/bin/gir-generator		\
+	  -o $$GOPATH/src/gir/arrow-1.0		\
+	  -config arrow-1.0/config.json		\
+	  arrow-1.0/arrow.go.in
+
+build: $(PROGRAMS)
+
+clean:
+	rm -f $(PROGRAMS)
+
+.SUFFIXES: .go
+
+.go:
+	go build -o $@ $<

c_glib/example/go/README.md

@@ -0,0 +1,78 @@
+<!---
+  Licensed 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. See accompanying LICENSE file.
+-->
+
+# Arrow Go example
+
+There are Go example codes in this directory.
+
+## How to run
+
+All example codes use
+[go-gir-generator](https://github.com/linuxdeepin/go-gir-generator) to
+use Arrow GLib based bindings.
+
+See [../../README.md](../../README.md) how to install Arrow GLib. You
+can use packages to install Arrow GLib. The following instructions
+assumes that you've installed Arrow GLib by package. Package name is
+`libarrow-glib-dev` on Debian GNU/Linux and Ubuntu, `arrow-glib-devel`
+on CentOS.
+
+Here are command lines to install go-gir-generator on Debian GNU/Linux
+and Ubuntu:
+
+```text
+% sudo apt install -V -y libarrow-glib-dev golang git libgirepository1.0-dev libgudev-1.0-dev
+% export GOPATH=$HOME
+% go get github.com/linuxdeepin/go-gir-generator
+% cd $GOPATH/src/github.com/linuxdeepin/go-gir-generator
+% make build copyfile
+% mkdir -p $GOPATH/bin/
+% cp -a out/gir-generator $GOPATH/bin/
+% cp -a out/src/gir/ $GOPATH/src/
+```
+
+Now, you can generate Arrow bindings for Go:
+
+```text
+% git clone https://github.com/apache/arrow.git ~/arrow
+% cd ~/arrow/c_glib/example/go
+% make generate
+```
+
+Then you can build all example codes:
+
+```text
+% cd ~/arrow/c_glib/example/go
+% make
+% ./write-batch  # Write data in batch mode
+% ./read-batch   # Read the written batch mode data
+% ./write-stream # Write data in stream mode
+% ./read-stream  # Read the written stream mode data
+```
+
+## Go example codes
+
+Here are example codes in this directory:
+
+  * `write-batch.go`: It shows how to write Arrow array to file in
+    batch mode.
+
+  * `read-batch.go`: It shows how to read Arrow array from file in
+    batch mode.
+
+  * `write-stream.go`: It shows how to write Arrow array to file in
+    stream mode.
+
+  * `read-stream.go`: It shows how to read Arrow array from file in
+    stream mode.

c_glib/example/go/arrow-1.0/arrow.go.in

@@ -0,0 +1,38 @@
+// 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.
+
+package arrow
+
+/*
+#include "arrow.gen.h"
+#cgo pkg-config: arrow-glib
+
+[<.g_list_funcs>]
+[<.g_error_free>]
+[<.g_free>]
+*/
+import "C"
+import "unsafe"
+
+import (
+	"gir/glib-2.0"
+	"gir/gobject-2.0"
+)
+
+[<.go_utils>]
+
+[<.go_bindings>]

c_glib/example/go/arrow-1.0/config.json

@@ -0,0 +1,21 @@
+// 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.
+
+{
+    "namespace": "Arrow",
+    "version": "1.0"
+}

c_glib/example/go/read-batch.go

@@ -0,0 +1,100 @@
+// 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.
+
+package main
+
+import (
+	"os"
+	"log"
+	"fmt"
+	"strings"
+)
+
+import "gir/arrow-1.0"
+
+func PrintColumnValue(column *arrow.Array, i int64) {
+	valueType := column.GetValueType()
+	switch valueType {
+	case arrow.TypeUint8:
+		fmt.Print(arrow.ToUInt8Array(column).GetValue(i))
+	case arrow.TypeUint16:
+		fmt.Print(arrow.ToUInt16Array(column).GetValue(i))
+	case arrow.TypeUint32:
+		fmt.Print(arrow.ToUInt32Array(column).GetValue(i))
+	case arrow.TypeUint64:
+		fmt.Print(arrow.ToUInt64Array(column).GetValue(i))
+	case arrow.TypeInt8:
+		fmt.Print(arrow.ToInt8Array(column).GetValue(i))
+	case arrow.TypeInt16:
+		fmt.Print(arrow.ToInt16Array(column).GetValue(i))
+	case arrow.TypeInt32:
+		fmt.Print(arrow.ToInt32Array(column).GetValue(i))
+	case arrow.TypeInt64:
+		fmt.Print(arrow.ToInt64Array(column).GetValue(i))
+	case arrow.TypeFloat:
+		fmt.Print(arrow.ToFloatArray(column).GetValue(i))
+	case arrow.TypeDouble:
+		fmt.Print(arrow.ToDoubleArray(column).GetValue(i))
+	default:
+		fmt.Printf("unknown(%s)", valueType)
+	}
+}
+
+func PrintRecordBatch(recordBatch *arrow.RecordBatch) {
+	nColumns := recordBatch.GetNColumns()
+	for i := uint32(0); i < nColumns; i++ {
+		column := recordBatch.GetColumn(i)
+		columnName := recordBatch.GetColumnName(i)
+		fmt.Printf("  %s: [", columnName)
+		nRows := recordBatch.GetNRows()
+		for j := int64(0); j < nRows; j++ {
+			if j > 0 {
+				fmt.Print(", ")
+			}
+			PrintColumnValue(column, j)
+		}
+		fmt.Println("]")
+	}
+}
+
+func main() {
+	var path string
+	if len(os.Args) < 2 {
+		path = "/tmp/batch.arrow"
+	} else {
+		path = os.Args[1]
+	}
+	input, err := arrow.NewMemoryMappedInputStream(path);
+	if err != nil {
+		log.Fatalf("Failed to open path: <%s>: %v", path, err)
+	}
+	reader, err := arrow.NewFileReader(input)
+	if err != nil {
+		log.Fatalf("Failed to parse data: %v", err)
+	}
+	var i uint32
+	nRecordBatches := reader.GetNRecordBatches()
+	for i = 0; i < nRecordBatches; i++ {
+		recordBatch, err := reader.GetRecordBatch(i)
+		if err != nil {
+			log.Fatalf("Failed to get record batch[%d]: %v", i, err)
+		}
+		fmt.Println(strings.Repeat("=", 40))
+		fmt.Printf("record-batch[%d]:\n", i)
+		PrintRecordBatch(recordBatch)
+	}
+}

c_glib/example/go/read-stream.go

@@ -0,0 +1,101 @@
+// 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.
+
+package main
+
+import (
+	"os"
+	"log"
+	"fmt"
+	"strings"
+)
+
+import "gir/arrow-1.0"
+
+func PrintColumnValue(column *arrow.Array, i int64) {
+	valueType := column.GetValueType()
+	switch valueType {
+	case arrow.TypeUint8:
+		fmt.Print(arrow.ToUInt8Array(column).GetValue(i))
+	case arrow.TypeUint16:
+		fmt.Print(arrow.ToUInt16Array(column).GetValue(i))
+	case arrow.TypeUint32:
+		fmt.Print(arrow.ToUInt32Array(column).GetValue(i))
+	case arrow.TypeUint64:
+		fmt.Print(arrow.ToUInt64Array(column).GetValue(i))
+	case arrow.TypeInt8:
+		fmt.Print(arrow.ToInt8Array(column).GetValue(i))
+	case arrow.TypeInt16:
+		fmt.Print(arrow.ToInt16Array(column).GetValue(i))
+	case arrow.TypeInt32:
+		fmt.Print(arrow.ToInt32Array(column).GetValue(i))
+	case arrow.TypeInt64:
+		fmt.Print(arrow.ToInt64Array(column).GetValue(i))
+	case arrow.TypeFloat:
+		fmt.Print(arrow.ToFloatArray(column).GetValue(i))
+	case arrow.TypeDouble:
+		fmt.Print(arrow.ToDoubleArray(column).GetValue(i))
+	default:
+		fmt.Printf("unknown(%s)", valueType)
+	}
+}
+
+func PrintRecordBatch(recordBatch *arrow.RecordBatch) {
+	nColumns := recordBatch.GetNColumns()
+	for i := uint32(0); i < nColumns; i++ {
+		column := recordBatch.GetColumn(i)
+		columnName := recordBatch.GetColumnName(i)
+		fmt.Printf("  %s: [", columnName)
+		nRows := recordBatch.GetNRows()
+		for j := int64(0); j < nRows; j++ {
+			if j > 0 {
+				fmt.Print(", ")
+			}
+			PrintColumnValue(column, j)
+		}
+		fmt.Println("]")
+	}
+}
+
+func main() {
+	var path string
+	if len(os.Args) < 2 {
+		path = "/tmp/stream.arrow"
+	} else {
+		path = os.Args[1]
+	}
+	input, err := arrow.NewMemoryMappedInputStream(path);
+	if err != nil {
+		log.Fatalf("Failed to open path: <%s>: %v", path, err)
+	}
+	reader, err := arrow.NewStreamReader(input)
+	if err != nil {
+		log.Fatalf("Failed to parse data: %v", err)
+	}
+	for i := 0; true; i++ {
+		recordBatch, err := reader.GetNextRecordBatch()
+		if err != nil {
+			log.Fatalf("Failed to get next record batch: %v", err)
+		}
+		if recordBatch == nil {
+			break
+		}
+		fmt.Println(strings.Repeat("=", 40))
+		fmt.Printf("record-batch[%d]:\n", i)
+		PrintRecordBatch(recordBatch)
+	}
+}