Xray-core/common/matcher/geosite/file.go

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2021-03-24 17:01:20 +02:00
package geosite
import (
"runtime"
"github.com/golang/protobuf/proto"
"github.com/xtls/xray-core/common/platform/filesystem"
)
var (
SiteCache = make(map[string]*GeoSite)
FileCache = make(map[string][]byte)
)
func loadFile(file string) ([]byte, error) {
if FileCache[file] == nil {
bs, err := filesystem.ReadAsset(file)
if err != nil {
return nil, newError("failed to open file: ", file).Base(err)
}
if len(bs) == 0 {
return nil, newError("empty file: ", file)
}
// Do not cache file, may save RAM when there
// are many files, but consume CPU each time.
return bs, nil
FileCache[file] = bs
}
return FileCache[file], nil
}
func loadSite(file, code string) ([]*Domain, error) {
index := file + ":" + code
if SiteCache[index] == nil {
bs, err := loadFile(file)
if err != nil {
return nil, newError("failed to load file: ", file).Base(err)
}
bs = find(bs, []byte(code))
if bs == nil {
return nil, newError("list not found in ", file, ": ", code)
}
var ges GeoSite
if err := proto.Unmarshal(bs, &ges); err != nil {
return nil, newError("error unmarshal Site in ", file, ": ", code).Base(err)
}
defer runtime.GC() // or debug.FreeOSMemory()
return ges.Domain, nil // do not cache geosite
SiteCache[index] = &ges
}
return SiteCache[index].Domain, nil
}
func find(data, code []byte) []byte {
codeL := len(code)
if codeL == 0 {
return nil
}
for {
dataL := len(data)
if dataL < 2 {
return nil
}
x, y := proto.DecodeVarint(data[1:])
if x == 0 && y == 0 {
return nil
}
headL, bodyL := 1+y, int(x)
dataL -= headL
if dataL < bodyL {
return nil
}
data = data[headL:]
if int(data[1]) == codeL {
for i := 0; i < codeL && data[2+i] == code[i]; i++ {
if i+1 == codeL {
return data[:bodyL]
}
}
}
if dataL == bodyL {
return nil
}
data = data[bodyL:]
}
}