feat: geo ip.

geoip/qqwry/utils.go

@@ -0,0 +1,28 @@
+package qqwry
+
+import (
+	"bytes"
+	"io"
+
+	"golang.org/x/text/encoding/simplifiedchinese"
+	"golang.org/x/text/transform"
+)
+
+func gb18030Decode(src []byte) string {
+	in := bytes.NewReader(src)
+	out := transform.NewReader(in, simplifiedchinese.GB18030.NewDecoder())
+	d, _ := io.ReadAll(out)
+	return string(d)
+}
+
+// getMiddleOffset 取得begin和end之间的偏移量，用于二分搜索
+func getMiddleOffset(start uint32, end uint32) uint32 {
+	return start + (((end-start)/ipRecordLength)>>1)*ipRecordLength
+}
+
+func byte3ToUInt32(data []byte) uint32 {
+	i := uint32(data[0]) & 0xff
+	i |= (uint32(data[1]) << 8) & 0xff00
+	i |= (uint32(data[2]) << 16) & 0xff0000
+	return i
+}