📊 ssgodatabyip: new package

ssgodatabyip/.gitignore

@@ -0,0 +1 @@
+/ssgodatabyip

ssgodatabyip/ssgodatabyip.go

@@ -0,0 +1,84 @@
+// Package ssgodatabyip implements a simple command-line tool that reads shadowsocks-go
+// log entries from stdin, and prints peer data usage by IP address to stdout.
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"cmp"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/netip"
+	"os"
+	"slices"
+	"strconv"
+)
+
+func main() {
+	bytesByIP := make(map[netip.Addr]uint64)
+	r := bufio.NewReader(os.Stdin)
+
+	for {
+		line, err := r.ReadSlice('\n')
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			fmt.Fprintf(os.Stderr, "Failed to read line: %v\n", err)
+			os.Exit(1)
+		}
+
+		start := bytes.IndexByte(line, '{')
+		if start < 0 {
+			continue
+		}
+		data := line[start:]
+
+		var event Event
+		if err := json.Unmarshal(data, &event); err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to unmarshal event %q: %v\n", data, err)
+			continue
+		}
+
+		if event.ClientAddress.IsValid() {
+			bytesByIP[event.ClientAddress.Addr()] += event.NL2R + event.NR2L + event.PayloadBytesSent
+		}
+
+		if event.LastWriteDestAddress.IsValid() {
+			bytesByIP[event.LastWriteDestAddress.Addr()] += event.PayloadBytesSent
+		}
+	}
+
+	usage := make([]DataUsage, 0, len(bytesByIP))
+	for ip, bytes := range bytesByIP {
+		usage = append(usage, DataUsage{IP: ip, Bytes: bytes})
+	}
+	slices.SortFunc(usage, func(a, b DataUsage) int {
+		return -cmp.Compare(a.Bytes, b.Bytes)
+	})
+
+	const maxOutputLength = len("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff%enp5s0\t18446744073709551615\n")
+	output := make([]byte, 0, maxOutputLength)
+	for _, usage := range usage {
+		output = usage.IP.AppendTo(output)
+		output = append(output, '\t')
+		output = strconv.AppendUint(output, usage.Bytes, 10)
+		output = append(output, '\n')
+	}
+	_, _ = os.Stdout.Write(output)
+}
+
+type Event struct {
+	ClientAddress netip.AddrPort `json:"clientAddress"`
+	NL2R          uint64         `json:"nl2r"`
+	NR2L          uint64         `json:"nr2l"`
+
+	LastWriteDestAddress netip.AddrPort `json:"lastWriteDestAddress"`
+	PayloadBytesSent     uint64         `json:"payloadBytesSent"`
+}
+
+type DataUsage struct {
+	IP    netip.Addr `json:"ip"`
+	Bytes uint64     `json:"bytes"`
+}