grafana/pkg/tsdb/postgres/macros.go

106 lines
3.2 KiB
Go

package postgres
import (
"fmt"
"regexp"
"strings"
"time"
"github.com/grafana/grafana/pkg/tsdb"
)
//const rsString = `(?:"([^"]*)")`;
const rsIdentifier = `([_a-zA-Z0-9]+)`
const sExpr = `\$` + rsIdentifier + `\(([^\)]*)\)`
type PostgresMacroEngine struct {
TimeRange *tsdb.TimeRange
}
func NewPostgresMacroEngine() tsdb.SqlMacroEngine {
return &PostgresMacroEngine{}
}
func (m *PostgresMacroEngine) Interpolate(timeRange *tsdb.TimeRange, sql string) (string, error) {
m.TimeRange = timeRange
rExp, _ := regexp.Compile(sExpr)
var macroError error
sql = replaceAllStringSubmatchFunc(rExp, sql, func(groups []string) string {
res, err := m.evaluateMacro(groups[1], strings.Split(groups[2], ","))
if err != nil && macroError == nil {
macroError = err
return "macro_error()"
}
return res
})
if macroError != nil {
return "", macroError
}
return sql, nil
}
func replaceAllStringSubmatchFunc(re *regexp.Regexp, str string, repl func([]string) string) string {
result := ""
lastIndex := 0
for _, v := range re.FindAllSubmatchIndex([]byte(str), -1) {
groups := []string{}
for i := 0; i < len(v); i += 2 {
groups = append(groups, str[v[i]:v[i+1]])
}
result += str[lastIndex:v[0]] + repl(groups)
lastIndex = v[1]
}
return result + str[lastIndex:]
}
func (m *PostgresMacroEngine) evaluateMacro(name string, args []string) (string, error) {
switch name {
case "__time":
if len(args) == 0 {
return "", fmt.Errorf("missing time column argument for macro %v", name)
}
return fmt.Sprintf("%s AS \"time\"", args[0]), nil
case "__timeEpoch":
if len(args) == 0 {
return "", fmt.Errorf("missing time column argument for macro %v", name)
}
return fmt.Sprintf("extract(epoch from %s) as \"time\"", args[0]), nil
case "__timeFilter":
// dont use to_timestamp in this macro for redshift compatibility #9566
if len(args) == 0 {
return "", fmt.Errorf("missing time column argument for macro %v", name)
}
return fmt.Sprintf("extract(epoch from %s) BETWEEN %d AND %d", args[0], uint64(m.TimeRange.GetFromAsMsEpoch()/1000), uint64(m.TimeRange.GetToAsMsEpoch()/1000)), nil
case "__timeFrom":
return fmt.Sprintf("to_timestamp(%d)", uint64(m.TimeRange.GetFromAsMsEpoch()/1000)), nil
case "__timeTo":
return fmt.Sprintf("to_timestamp(%d)", uint64(m.TimeRange.GetToAsMsEpoch()/1000)), nil
case "__timeGroup":
if len(args) != 2 {
return "", fmt.Errorf("macro %v needs time column and interval", name)
}
interval, err := time.ParseDuration(strings.Trim(args[1], `' `))
if err != nil {
return "", fmt.Errorf("error parsing interval %v", args[1])
}
return fmt.Sprintf("(extract(epoch from \"%s\")/%v)::bigint*%v", args[0], interval.Seconds(), interval.Seconds()), nil
case "__unixEpochFilter":
if len(args) == 0 {
return "", fmt.Errorf("missing time column argument for macro %v", name)
}
return fmt.Sprintf("%s >= %d AND %s <= %d", args[0], uint64(m.TimeRange.GetFromAsMsEpoch()/1000), args[0], uint64(m.TimeRange.GetToAsMsEpoch()/1000)), nil
case "__unixEpochFrom":
return fmt.Sprintf("%d", uint64(m.TimeRange.GetFromAsMsEpoch()/1000)), nil
case "__unixEpochTo":
return fmt.Sprintf("%d", uint64(m.TimeRange.GetToAsMsEpoch()/1000)), nil
default:
return "", fmt.Errorf("Unknown macro %v", name)
}
}