// idsForExpr will return a collection of series ids and a filter expression that should
// be used to filter points from those series.
func (m *Measurement) idsForExpr(n *influxql.BinaryExpr) (SeriesIDs, influxql.Expr, error) {
// If this binary expression has another binary expression, then this
// is some expression math and we should just pass it to the underlying query.
if _, ok := n.LHS.(*influxql.BinaryExpr); ok {
return m.seriesIDs, n, nil
} else if _, ok := n.RHS.(*influxql.BinaryExpr); ok {
return m.seriesIDs, n, nil
}
// Retrieve the variable reference from the correct side of the expression.
name, ok := n.LHS.(*influxql.VarRef)
value := n.RHS
if !ok {
name, ok = n.RHS.(*influxql.VarRef)
if !ok {
return nil, nil, fmt.Errorf("invalid expression: %s", n.String())
}
value = n.LHS
}
// For time literals, return all series IDs and "true" as the filter.
if _, ok := value.(*influxql.TimeLiteral); ok || name.Val == "time" {
return m.seriesIDs, &influxql.BooleanLiteral{Val: true}, nil
}
// For fields, return all series IDs from this measurement and return
// the expression passed in, as the filter.
if name.Val != "_name" && ((name.Type == influxql.Unknown && m.hasField(name.Val)) || name.Type == influxql.AnyField || (name.Type != influxql.Tag && name.Type != influxql.Unknown)) {
return m.seriesIDs, n, nil
} else if value, ok := value.(*influxql.VarRef); ok {
// Check if the RHS is a variable and if it is a field.
if value.Val != "_name" && ((value.Type == influxql.Unknown && m.hasField(value.Val)) || name.Type == influxql.AnyField || (value.Type != influxql.Tag && value.Type != influxql.Unknown)) {
return m.seriesIDs, n, nil
}
}
// Retrieve list of series with this tag key.
tagVals := m.seriesByTagKeyValue[name.Val]
// if we're looking for series with a specific tag value
if str, ok := value.(*influxql.StringLiteral); ok {
var ids SeriesIDs
// Special handling for "_name" to match measurement name.
if name.Val == "_name" {
if (n.Op == influxql.EQ && str.Val == m.Name) || (n.Op == influxql.NEQ && str.Val != m.Name) {
return m.seriesIDs, &influxql.BooleanLiteral{Val: true}, nil
}
return nil, &influxql.BooleanLiteral{Val: true}, nil
}
if n.Op == influxql.EQ {
if str.Val != "" {
// return series that have a tag of specific value.
ids = tagVals[str.Val]
} else {
ids = m.seriesIDs
for k := range tagVals {
ids = ids.Reject(tagVals[k])
}
}
} else if n.Op == influxql.NEQ {
if str.Val != "" {
ids = m.seriesIDs.Reject(tagVals[str.Val])
} else {
for k := range tagVals {
ids = ids.Union(tagVals[k])
}
}
}
return ids, &influxql.BooleanLiteral{Val: true}, nil
}
// if we're looking for series with a tag value that matches a regex
if re, ok := value.(*influxql.RegexLiteral); ok {
var ids SeriesIDs
// Special handling for "_name" to match measurement name.
if name.Val == "_name" {
match := re.Val.MatchString(m.Name)
if (n.Op == influxql.EQREGEX && match) || (n.Op == influxql.NEQREGEX && !match) {
return m.seriesIDs, &influxql.BooleanLiteral{Val: true}, nil
}
return nil, &influxql.BooleanLiteral{Val: true}, nil
}
// Check if we match the empty string to see if we should include series
// that are missing the tag.
empty := re.Val.MatchString("")
// Gather the series that match the regex. If we should include the empty string,
// start with the list of all series and reject series that don't match our condition.
// If we should not include the empty string, include series that match our condition.
if empty && n.Op == influxql.EQREGEX {
ids = m.seriesIDs
for k := range tagVals {
if !re.Val.MatchString(k) {
ids = ids.Reject(tagVals[k])
}
}
} else if empty && n.Op == influxql.NEQREGEX {
for k := range tagVals {
if !re.Val.MatchString(k) {
ids = ids.Union(tagVals[k])
}
}
} else if !empty && n.Op == influxql.EQREGEX {
for k := range tagVals {
if re.Val.MatchString(k) {
ids = ids.Union(tagVals[k])
}
}
} else if !empty && n.Op == influxql.NEQREGEX {
ids = m.seriesIDs
for k := range tagVals {
if re.Val.MatchString(k) {
ids = ids.Reject(tagVals[k])
}
}
}
return ids, &influxql.BooleanLiteral{Val: true}, nil
}
// compare tag values
if ref, ok := value.(*influxql.VarRef); ok {
var ids SeriesIDs
if n.Op == influxql.NEQ {
ids = m.seriesIDs
}
rhsTagVals := m.seriesByTagKeyValue[ref.Val]
for k := range tagVals {
tags := tagVals[k].Intersect(rhsTagVals[k])
if n.Op == influxql.EQ {
ids = ids.Union(tags)
} else if n.Op == influxql.NEQ {
ids = ids.Reject(tags)
}
}
return ids, &influxql.BooleanLiteral{Val: true}, nil
}
if n.Op == influxql.NEQ || n.Op == influxql.NEQREGEX {
return m.seriesIDs, &influxql.BooleanLiteral{Val: true}, nil
}
return nil, nil, nil
}
// idsForExpr will return a collection of series ids and a filter expression that should
// be used to filter points from those series.
func (m *Measurement) idsForExpr(n *influxql.BinaryExpr) (SeriesIDs, influxql.Expr, error) {
name, ok := n.LHS.(*influxql.VarRef)
value := n.RHS
if !ok {
name, ok = n.RHS.(*influxql.VarRef)
if !ok {
return nil, nil, fmt.Errorf("invalid expression: %s", n.String())
}
value = n.LHS
}
// For time literals, return all series IDs and "true" as the filter.
if _, ok := value.(*influxql.TimeLiteral); ok || name.Val == "time" {
return m.seriesIDs, &influxql.BooleanLiteral{Val: true}, nil
}
// For fields, return all series IDs from this measurement and return
// the expression passed in, as the filter.
if m.HasField(name.Val) {
return m.seriesIDs, n, nil
}
tagVals, ok := m.seriesByTagKeyValue[name.Val]
if !ok {
return nil, nil, nil
}
// if we're looking for series with a specific tag value
if str, ok := value.(*influxql.StringLiteral); ok {
var ids SeriesIDs
if n.Op == influxql.EQ {
// return series that have a tag of specific value.
ids = tagVals[str.Val]
} else if n.Op == influxql.NEQ {
ids = m.seriesIDs.Reject(tagVals[str.Val])
}
return ids, &influxql.BooleanLiteral{Val: true}, nil
}
// if we're looking for series with a tag value that matches a regex
if re, ok := value.(*influxql.RegexLiteral); ok {
var ids SeriesIDs
// The operation is a NEQREGEX, code must start by assuming all match, even
// series without any tags.
if n.Op == influxql.NEQREGEX {
ids = m.seriesIDs
}
for k := range tagVals {
match := re.Val.MatchString(k)
if match && n.Op == influxql.EQREGEX {
ids = ids.Union(tagVals[k])
} else if match && n.Op == influxql.NEQREGEX {
ids = ids.Reject(tagVals[k])
}
}
return ids, &influxql.BooleanLiteral{Val: true}, nil
}
return nil, nil, nil
}