Files
grafana/pkg/tsdb/influxdb/query_builder.go
2016-11-10 11:21:38 +01:00

145 lines
3.2 KiB
Go

package influxdb
import (
"fmt"
"strconv"
"strings"
"regexp"
"github.com/grafana/grafana/pkg/tsdb"
)
var (
regexpOperatorPattern *regexp.Regexp = regexp.MustCompile(`^\/.*\/$`)
)
type QueryBuilder struct{}
func (qb *QueryBuilder) Build(query *Query, queryContext *tsdb.QueryContext) (string, error) {
if query.RawQuery != "" {
q := query.RawQuery
q = strings.Replace(q, "$timeFilter", qb.renderTimeFilter(query, queryContext), 1)
q = strings.Replace(q, "$interval", tsdb.CalculateInterval(queryContext.TimeRange), 1)
return q, nil
}
res := qb.renderSelectors(query, queryContext)
res += qb.renderMeasurement(query)
res += qb.renderWhereClause(query)
res += qb.renderTimeFilter(query, queryContext)
res += qb.renderGroupBy(query, queryContext)
return res, nil
}
func (qb *QueryBuilder) renderTags(query *Query) []string {
var res []string
for i, tag := range query.Tags {
str := ""
if i > 0 {
if tag.Condition == "" {
str += "AND"
} else {
str += tag.Condition
}
str += " "
}
//If the operator is missing we fall back to sensible defaults
if tag.Operator == "" {
if regexpOperatorPattern.Match([]byte(tag.Value)) {
tag.Operator = "=~"
} else {
tag.Operator = "="
}
}
textValue := ""
numericValue, err := strconv.ParseFloat(tag.Value, 64)
// quote value unless regex or number
if tag.Operator == "=~" || tag.Operator == "!~" {
textValue = tag.Value
} else if err == nil {
textValue = fmt.Sprintf("%v", numericValue)
} else {
textValue = fmt.Sprintf("'%s'", tag.Value)
}
res = append(res, fmt.Sprintf(`%s"%s" %s %s`, str, tag.Key, tag.Operator, textValue))
}
return res
}
func (qb *QueryBuilder) renderTimeFilter(query *Query, queryContext *tsdb.QueryContext) string {
from := "now() - " + queryContext.TimeRange.From
to := ""
if queryContext.TimeRange.To != "now" && queryContext.TimeRange.To != "" {
to = " and time < now() - " + strings.Replace(queryContext.TimeRange.To, "now-", "", 1)
}
return fmt.Sprintf("time > %s%s", from, to)
}
func (qb *QueryBuilder) renderSelectors(query *Query, queryContext *tsdb.QueryContext) string {
res := "SELECT "
var selectors []string
for _, sel := range query.Selects {
stk := ""
for _, s := range *sel {
stk = s.Render(query, queryContext, stk)
}
selectors = append(selectors, stk)
}
return res + strings.Join(selectors, ", ")
}
func (qb *QueryBuilder) renderMeasurement(query *Query) string {
policy := ""
if query.Policy == "" || query.Policy == "default" {
policy = ""
} else {
policy = `"` + query.Policy + `".`
}
return fmt.Sprintf(` FROM %s"%s"`, policy, query.Measurement)
}
func (qb *QueryBuilder) renderWhereClause(query *Query) string {
res := " WHERE "
conditions := qb.renderTags(query)
res += strings.Join(conditions, " ")
if len(conditions) > 0 {
res += " AND "
}
return res
}
func (qb *QueryBuilder) renderGroupBy(query *Query, queryContext *tsdb.QueryContext) string {
groupBy := ""
for i, group := range query.GroupBy {
if i == 0 {
groupBy += " GROUP BY"
}
if i > 0 && group.Type != "fill" {
groupBy += ", " //fill is so very special. fill is a creep, fill is a weirdo
} else {
groupBy += " "
}
groupBy += group.Render(query, queryContext, "")
}
return groupBy
}