move implementation to internal/ directory (#828)

internal/config/retentiongrid.go

@@ -0,0 +1,119 @@
+package config
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type RetentionIntervalList []RetentionInterval
+
+type PruneGrid struct {
+	Type  string                `yaml:"type"`
+	Grid  RetentionIntervalList `yaml:"grid"`
+	Regex string                `yaml:"regex"`
+}
+
+type RetentionInterval struct {
+	length    time.Duration
+	keepCount int
+}
+
+func (i *RetentionInterval) Length() time.Duration {
+	return i.length
+}
+
+func (i *RetentionInterval) KeepCount() int {
+	return i.keepCount
+}
+
+const RetentionGridKeepCountAll int = -1
+
+func (t *RetentionIntervalList) UnmarshalYAML(u func(interface{}, bool) error) (err error) {
+	var in string
+	if err := u(&in, true); err != nil {
+		return err
+	}
+
+	intervals, err := ParseRetentionIntervalSpec(in)
+	if err != nil {
+		return err
+	}
+
+	*t = intervals
+
+	return nil
+}
+
+var retentionStringIntervalRegex *regexp.Regexp = regexp.MustCompile(`^\s*(\d+)\s*x\s*([^\(]+)\s*(\((.*)\))?\s*$`)
+
+func parseRetentionGridIntervalString(e string) (intervals []RetentionInterval, err error) {
+
+	comps := retentionStringIntervalRegex.FindStringSubmatch(e)
+	if comps == nil {
+		err = fmt.Errorf("retention string does not match expected format")
+		return
+	}
+
+	times, err := strconv.Atoi(comps[1])
+	if err != nil {
+		return nil, err
+	} else if times <= 0 {
+		return nil, fmt.Errorf("contains factor <= 0")
+	}
+
+	duration, err := parsePositiveDuration(comps[2])
+	if err != nil {
+		return nil, err
+	}
+
+	keepCount := 1
+	if comps[3] != "" {
+		// Decompose key=value, comma separated
+		// For now, only keep_count is supported
+		re := regexp.MustCompile(`^\s*keep=(.+)\s*$`)
+		res := re.FindStringSubmatch(comps[4])
+		if res == nil || len(res) != 2 {
+			err = fmt.Errorf("interval parameter contains unknown parameters")
+			return
+		}
+		if res[1] == "all" {
+			keepCount = RetentionGridKeepCountAll
+		} else {
+			keepCount, err = strconv.Atoi(res[1])
+			if err != nil {
+				err = fmt.Errorf("cannot parse keep_count value")
+				return
+			}
+		}
+	}
+
+	intervals = make([]RetentionInterval, times)
+	for i := range intervals {
+		intervals[i] = RetentionInterval{
+			length:    duration,
+			keepCount: keepCount,
+		}
+	}
+
+	return
+
+}
+
+func ParseRetentionIntervalSpec(s string) (intervals []RetentionInterval, err error) {
+
+	ges := strings.Split(s, "|")
+	intervals = make([]RetentionInterval, 0, 7*len(ges))
+
+	for intervalIdx, e := range ges {
+		parsed, err := parseRetentionGridIntervalString(e)
+		if err != nil {
+			return nil, fmt.Errorf("cannot parse interval %d of %d: %s: %s", intervalIdx+1, len(ges), err, strings.TrimSpace(e))
+		}
+		intervals = append(intervals, parsed...)
+	}
+
+	return
+}