feat: Add basic support for bindings/go using CGO (#3204)

Demo for bindings/go using CGO

bindings/go/build_dynamic.go

@@ -0,0 +1,30 @@
+//go:build dynamic
+// +build dynamic
+
+/*
+ * 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 opendal
+
+/*
+#cgo pkg-config: opendal_c
+*/
+import "C"
+
+const LibopendalLinkInfo = "dynamically linked to libopendal_c"

bindings/go/go.mod

@@ -0,0 +1,11 @@
+module opendal.apache.org/go
+
+go 1.20
+
+require github.com/stretchr/testify v1.8.4
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

bindings/go/go.sum

@@ -0,0 +1,9 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

bindings/go/opendal.go

@@ -0,0 +1,83 @@
+/*
+ * 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 opendal
+
+/*
+#include "opendal.h"
+*/
+import "C"
+import (
+	"errors"
+	"fmt"
+	"unsafe"
+)
+
+var (
+	errInvalidScheme = errors.New("invalid scheme")
+	errValueEmpty    = errors.New("value is empty")
+)
+
+type Options map[string]string
+
+type Operator struct {
+	inner *C.opendal_operator_ptr
+}
+
+func NewOperator(scheme string, opt Options) (*Operator, error) {
+	fmt.Println("libopendal_c info: ", LibopendalLinkInfo)
+	if len(scheme) == 0 {
+		return nil, errInvalidScheme
+	}
+	opts := C.opendal_operator_options_new()
+	defer C.opendal_operator_options_free(opts)
+	for k, v := range opt {
+		C.opendal_operator_options_set(opts, C.CString(k), C.CString(v))
+	}
+	op := C.opendal_operator_new(C.CString(scheme), opts)
+	return &Operator{
+		inner: op,
+	}, nil
+}
+
+func (o *Operator) Write(key string, value []byte) error {
+	if len(value) == 0 {
+		return errValueEmpty
+	}
+	bytes := C.opendal_bytes{data: (*C.uchar)(unsafe.Pointer(&value[0])), len: C.ulong(len(value))}
+	ret := C.opendal_operator_blocking_write(o.inner, C.CString(key), bytes)
+	if ret != 0 {
+		return errors.New(fmt.Sprintf("write failed, error code: %d", ret))
+	}
+	return nil
+}
+
+func (o *Operator) Read(key string) ([]byte, error) {
+	result := C.opendal_operator_blocking_read(o.inner, C.CString(key))
+	ret := int(result.code)
+	if ret != 0 {
+		return nil, errors.New(fmt.Sprintf("write failed, error code: %d", ret))
+	}
+	return C.GoBytes(unsafe.Pointer(result.data.data), C.int(result.data.len)), nil
+}
+
+func (o *Operator) Close() error {
+	C.opendal_operator_free(o.inner)
+	return nil
+}

bindings/go/opendal_test.go

@@ -0,0 +1,39 @@
+/*
+ * 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 opendal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestOperations(t *testing.T) {
+	opts := make(Options)
+	opts["root"] = "/myroot"
+	operator, err := NewOperator("memory", opts)
+	assert.NoError(t, err)
+	defer operator.Close()
+	err = operator.Write("test", []byte("Hello World"))
+	assert.NoError(t, err)
+	value, err := operator.Read("test")
+	assert.NoError(t, err)
+	assert.Equal(t, "Hello World", string(value))
+}