Dubbo2.7.5: Add Page and Prioritized interface (#26)

* Add Page Support

* add comment

* Add Comment

* README.md

* Fix review comment

* fix review

* Fix review

* Add priority definition

* Add comments

* Fix review

README.md

@@ -24,13 +24,13 @@ A go sdk for [Apache Dubbo-go](github.com/apache/dubbo-go).
 ## math
 
 * Decimal
-
-## runtime
-
-* GoSafely 
-> Using `go` in a safe way.
-* GoUnterminated
-> Run a goroutine in a safe way whose task is long live as the whole process life time.
+
+## runtime
+
+* GoSafely 
+> Using `go` in a safe way.
+* GoUnterminated
+> Run a goroutine in a safe way whose task is long live as the whole process life time.
 
 ## sync
 
@@ -45,3 +45,7 @@ A go sdk for [Apache Dubbo-go](github.com/apache/dubbo-go).
 
 Timer optimization through time-wheel.
 
+## page
+
+Page for pagination. It contains the most common functions like offset, pagesize.
+

page/page.go

+/*
+ * 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 gxpage
+
+// Page is the default implementation of Page interface
+type Page struct {
+	requestOffset int
+	pageSize      int
+	totalSize     int
+	data          []interface{}
+	totalPages    int
+	hasNext       bool
+}
+
+// GetOffSet will return the offset
+func (d *Page) GetOffset() int {
+	return d.requestOffset
+}
+
+// GetPageSize will return the page size
+func (d *Page) GetPageSize() int {
+	return d.pageSize
+}
+
+// GetTotalPages will return the number of total pages
+func (d *Page) GetTotalPages() int {
+	return d.totalPages
+}
+
+// GetData will return the data
+func (d *Page) GetData() []interface{} {
+	return d.data
+}
+
+// GetDataSize will return the size of data.
+// it's len(GetData())
+func (d *Page) GetDataSize() int {
+	return len(d.GetData())
+}
+
+// HasNext will return whether has next page
+func (d *Page) HasNext() bool {
+	return d.hasNext
+}
+
+// HasData will return whether this page has data.
+func (d *Page) HasData() bool {
+	return d.GetDataSize() > 0
+}
+
+// New will create an instance
+func New(requestOffset int, pageSize int,
+	data []interface{}, totalSize int) *Page {
+
+	remain := totalSize % pageSize
+	totalPages := totalSize / pageSize
+	if remain > 0 {
+		totalPages++
+	}
+
+	hasNext := totalSize-requestOffset-pageSize > 0
+
+	return &Page{
+		requestOffset: requestOffset,
+		pageSize:      pageSize,
+		data:          data,
+		totalSize:     totalSize,
+		totalPages:    totalPages,
+		hasNext:       hasNext,
+	}
+}

page/page_test.go

+/*
+ * 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 gxpage
+
+import (
+	"testing"
+)
+
+import (
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewDefaultPage(t *testing.T) {
+	data := make([]interface{}, 10)
+	page := New(121, 10, data, 499)
+
+	assert.Equal(t, 10, page.GetDataSize())
+	assert.Equal(t, 121, page.GetOffset())
+	assert.Equal(t, 10, page.GetPageSize())
+	assert.Equal(t, 50, page.GetTotalPages())
+	assert.Equal(t, data, page.GetData())
+	assert.True(t, page.HasNext())
+	assert.True(t, page.HasData())
+
+	page = New(492, 10, data, 499)
+	assert.False(t, page.HasNext())
+}

page/pager.go

+/*
+ * 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 gxpage
+
+// Pager is the abstraction for pagination usage.
+type Pager interface {
+
+	// GetOffset will return the offset
+	GetOffset() int
+
+	// GetPageSize will return the page size
+	GetPageSize() int
+
+	// GetTotalPages will return the number of total pages
+	GetTotalPages() int
+
+	// GetData will return the data
+	GetData() []interface{}
+
+	// GetDataSize will return the size of data.
+	// Usually it's len(GetData())
+	GetDataSize() int
+
+	// HasNext will return whether has next page
+	HasNext() bool
+
+	// HasData will return whether this page has data.
+	HasData() bool
+}

sort/prioritized.go

+/*
+ * 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 gxsort
+
+// Prioritizer is the abstraction of priority.
+type Prioritizer interface {
+	// GetPriority will return the priority
+	GetPriority() int
+}