remove helpers

Author: Murat Kabilov

pkg/config/config.go

@@ -4,10 +4,34 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"regexp"
+	"strconv"
+	"strings"
 
 	"gopkg.in/yaml.v2"
 )
 
+// Column usage types
+const (
+	Discard ColumnUsage = iota // Ignore this column
+	Label                      // Use this column as a label
+	Counter                    // Use this column as a counter
+	Gauge                      // Use this column as a gauge
+
+	NoVersion PgVersion = -1
+)
+
+var (
+	pgVerRegex = regexp.MustCompile(`^(\d+)(?:\.(\d+))?(?:\.(\d+))?$`)
+
+	columnUsageMapping = map[string]ColumnUsage{
+		"DISCARD": Discard,
+		"LABEL":   Label,
+		"COUNTER": Counter,
+		"GAUGE":   Gauge,
+	}
+)
+
 // ConfigInterface describes Config methods
 type ConfigInterface interface {
 	Load() error
@@ -21,6 +45,189 @@ type Config struct {
 	dbs        map[string]DbConfig
 }
 
+// ColumnUsage describes column usage
+type ColumnUsage int
+
+// PgVersion describes version in server_version_num format
+type PgVersion int
+
+// Metrics describe metrics
+type Metrics map[string]Metric
+
+// VerSQLs contain version specific SQLs
+type VerSQLs []VerSQL
+
+// Metric describes metric
+type Metric struct {
+	Usage       ColumnUsage `yaml:"usage"`
+	Description string      `yaml:"description"`
+}
+
+// VerSQL describes PostgreSQL version specific SQL
+type VerSQL struct {
+	SQL    string
+	MinVer PgVersion
+	MaxVer PgVersion
+}
+
+// Query describes query
+type Query struct {
+	Name        string
+	Metrics     Metrics `yaml:"metrics"`
+	VerSQL      VerSQLs `yaml:"query"`
+	NameColumn  string  `yaml:"nameColumn"`
+	ValueColumn string  `yaml:"valueColumn"`
+}
+
+// UnmarshalYAML unmarshals the yaml
+func (v *VerSQLs) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	res := make(VerSQLs, 0)
+	var val interface{}
+
+	err := unmarshal(&val)
+	if err != nil {
+		return fmt.Errorf("could not unmarshal: %v", err)
+	}
+
+	switch val := val.(type) {
+	case map[interface{}]interface{}:
+		for k, v := range val {
+			minPg, maxPg := parseVersionRange(fmt.Sprintf("%v", k))
+			res = append(res, VerSQL{
+				MinVer: minPg,
+				MaxVer: maxPg,
+				SQL:    v.(string),
+			})
+		}
+	case interface{}:
+		res = append(res, VerSQL{
+			SQL: val.(string),
+		})
+	}
+
+	*v = res
+
+	return nil
+}
+
+// UnmarshalYAML unmarshals the yaml
+func (c *ColumnUsage) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var value string
+	unmarshal(&value)
+	cu, ok := columnUsageMapping[value]
+	if !ok {
+		return fmt.Errorf("unknown usage: %v", value)
+	}
+
+	*c = cu
+
+	return nil
+}
+
+// UnmarshalYAML unmarshals the yaml
+func (m *Metrics) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	value := make(map[string]Metric, 0)
+	queryMetrics := make([]map[string]Metric, 0)
+
+	if err := unmarshal(&queryMetrics); err != nil {
+		return err
+	}
+
+	for _, metrics := range queryMetrics {
+		for name, descr := range metrics {
+			value[name] = descr
+		}
+	}
+
+	*m = value
+
+	return nil
+}
+
+// UnmarshalYAML unmarshals the yaml
+func (v *PgVersion) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var str string
+	if err := unmarshal(&str); err != nil {
+		return err
+	}
+
+	val := strings.Replace(str, ".", "", -1)
+	intVal, err := strconv.Atoi(val)
+	if err != nil {
+		return fmt.Errorf("could not convert string: %v", err)
+	}
+	*v = PgVersion(intVal)
+	return nil
+}
+
+// PgVersion returns string representation of the version
+func (v PgVersion) String() string {
+	return fmt.Sprintf("%d.%d.%d", v/10000, (v/100)%100, v%100)
+}
+
+// Query returns query for the requested postgresql version
+func (v VerSQLs) Query(version PgVersion) string {
+	if version == NoVersion ||
+		(len(v) == 1 && v[0].MaxVer == PgVersion(0) && v[0].MinVer == PgVersion(0)) {
+		return v[0].SQL
+	}
+
+	for _, query := range v {
+		if (version >= query.MinVer || query.MinVer == 0) && (version < query.MaxVer || query.MaxVer == 0) {
+			return query.SQL
+		}
+	}
+
+	return ""
+}
+
+func parseVersion(str string) PgVersion {
+	var res int
+	matches := pgVerRegex.FindStringSubmatch(str)
+	if matches == nil {
+		return PgVersion(res)
+	}
+	if matches[1] != "" {
+		val, _ := strconv.Atoi(matches[1])
+		res = val * 10000
+		if val > 9 && matches[2] != "" {
+			val, _ := strconv.Atoi(matches[2])
+			res += val
+		} else if matches[2] != "" {
+			val, _ := strconv.Atoi(matches[2])
+			res += val * 100
+			if matches[3] != "" {
+				val, _ := strconv.Atoi(matches[3])
+				res += val
+			}
+		}
+	}
+
+	return PgVersion(res)
+}
+
+func parseVersionRange(str string) (PgVersion, PgVersion) {
+	var min, max PgVersion
+	if str == "" {
+		return min, max
+	}
+
+	parts := strings.Split(str, "-")
+	if len(parts) == 1 {
+		min = parseVersion(parts[0])
+		max = min
+	} else {
+		if parts[0] != "" {
+			min = parseVersion(parts[0])
+		}
+		if parts[1] != "" {
+			max = parseVersion(parts[1])
+		}
+	}
+
+	return min, max
+}
+
 // New creates new config
 func New(filename string) *Config {
 	cfg := Config{