实现基础的206 partial content缓存

internal/utils/ranges/range.go

@@ -0,0 +1,53 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package rangeutils
+
+import "strconv"
+
+type Range [2]int64
+
+func NewRange(start int64, end int64) Range {
+	return [2]int64{start, end}
+}
+
+func (this Range) Start() int64 {
+	return this[0]
+}
+
+func (this Range) End() int64 {
+	return this[1]
+}
+
+func (this Range) Length() int64 {
+	return this[1] - this[0] + 1
+}
+
+func (this Range) Convert(total int64) (newRange Range, ok bool) {
+	if total <= 0 {
+		return this, false
+	}
+	if this[0] < 0 {
+		this[0] += total
+		if this[0] < 0 {
+			return this, false
+		}
+		this[1] = total - 1
+	}
+	if this[1] < 0 {
+		this[1] = total - 1
+	}
+	if this[1] > total-1 {
+		this[1] = total - 1
+	}
+	if this[0] > this[1] {
+		return this, false
+	}
+
+	return this, true
+}
+
+// ComposeContentRangeHeader 组合Content-Range Header
+// totalSize 可能是一个数字，也可能是一个星号（*）
+func (this Range) ComposeContentRangeHeader(totalSize string) string {
+	return "bytes " + strconv.FormatInt(this[0], 10) + "-" + strconv.FormatInt(this[1], 10) + "/" + totalSize
+}

internal/utils/ranges/range_test.go

@@ -0,0 +1,69 @@
+// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package rangeutils_test
+
+import (
+	rangeutils "github.com/TeaOSLab/EdgeNode/internal/utils/ranges"
+	"github.com/iwind/TeaGo/assert"
+	"testing"
+)
+
+func TestRange(t *testing.T) {
+	var a = assert.NewAssertion(t)
+
+	var r = rangeutils.NewRange(1, 100)
+	a.IsTrue(r.Start() == 1)
+	a.IsTrue(r.End() == 100)
+	t.Log("start:", r.Start(), "end:", r.End())
+}
+
+func TestRange_Convert(t *testing.T) {
+	var a = assert.NewAssertion(t)
+
+	{
+		var r = rangeutils.NewRange(1, 100)
+		newR, ok := r.Convert(200)
+		a.IsTrue(ok)
+		a.IsTrue(newR.Start() == 1)
+		a.IsTrue(newR.End() == 100)
+	}
+
+	{
+		var r = rangeutils.NewRange(1, 100)
+		newR, ok := r.Convert(50)
+		a.IsTrue(ok)
+		a.IsTrue(newR.Start() == 1)
+		a.IsTrue(newR.End() == 49)
+	}
+
+	{
+		var r = rangeutils.NewRange(1, 100)
+		_, ok := r.Convert(0)
+		a.IsFalse(ok)
+	}
+
+	{
+		var r = rangeutils.NewRange(-30, -1)
+		newR, ok := r.Convert(50)
+		a.IsTrue(ok)
+		a.IsTrue(newR.Start() == 50-30)
+		a.IsTrue(newR.End() == 49)
+	}
+
+	{
+		var r = rangeutils.NewRange(1000, 100)
+		_, ok := r.Convert(0)
+		a.IsFalse(ok)
+	}
+
+	{
+		var r = rangeutils.NewRange(50, 100)
+		_, ok := r.Convert(49)
+		a.IsFalse(ok)
+	}
+}
+
+func TestRange_ComposeContentRangeHeader(t *testing.T) {
+	var r = rangeutils.NewRange(1, 100)
+	t.Log(r.ComposeContentRangeHeader("1000"))
+}