refactor: move accesslog to logging/accesslog

internal/logging/accesslog/retention.go

@@ -0,0 +1,94 @@
+package accesslog
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/yusing/go-proxy/internal/gperr"
+	"github.com/yusing/go-proxy/internal/utils/strutils"
+)
+
+type Retention struct {
+	Days     uint64 `json:"days"`
+	Last     uint64 `json:"last"`
+	KeepSize uint64 `json:"keep_size"`
+}
+
+var (
+	ErrInvalidSyntax = gperr.New("invalid syntax")
+	ErrZeroValue     = gperr.New("zero value")
+)
+
+// see back_scanner_test.go#L210 for benchmarks
+var defaultChunkSize = 256 * kilobyte
+
+// Syntax:
+//
+// <N> days|weeks|months
+//
+// last <N>
+//
+// <N> KB|MB|GB|kb|mb|gb
+//
+// Parse implements strutils.Parser.
+func (r *Retention) Parse(v string) (err error) {
+	split := strutils.SplitSpace(v)
+	if len(split) != 2 {
+		return ErrInvalidSyntax.Subject(v)
+	}
+	switch split[0] {
+	case "last":
+		r.Last, err = strconv.ParseUint(split[1], 10, 64)
+	default: // <N> days|weeks|months
+		n, err := strconv.ParseUint(split[0], 10, 64)
+		if err != nil {
+			return err
+		}
+		switch split[1] {
+		case "day", "days":
+			r.Days = n
+		case "week", "weeks":
+			r.Days = n * 7
+		case "month", "months":
+			r.Days = n * 30
+		case "kb", "Kb":
+			r.KeepSize = n * kilobits
+		case "KB":
+			r.KeepSize = n * kilobyte
+		case "mb", "Mb":
+			r.KeepSize = n * megabits
+		case "MB":
+			r.KeepSize = n * megabyte
+		case "gb", "Gb":
+			r.KeepSize = n * gigabits
+		case "GB":
+			r.KeepSize = n * gigabyte
+		default:
+			return ErrInvalidSyntax.Subject("unit " + split[1])
+		}
+	}
+	if !r.IsValid() {
+		return ErrZeroValue
+	}
+	return
+}
+
+func (r *Retention) String() string {
+	if r.Days > 0 {
+		return fmt.Sprintf("%d days", r.Days)
+	}
+	if r.Last > 0 {
+		return fmt.Sprintf("last %d", r.Last)
+	}
+	if r.KeepSize > 0 {
+		return strutils.FormatByteSize(r.KeepSize)
+	}
+	return "<invalid>"
+}
+
+func (r *Retention) IsValid() bool {
+	if r == nil {
+		return false
+	}
+	return r.Days > 0 || r.Last > 0 || r.KeepSize > 0
+}