func Filter(query *parser.SelectQuery, series *protocol.Series) (*protocol.Series, error) {
if query.GetWhereCondition() == nil {
return series, nil
}
columns := map[string]struct{}{}
if query.GetFromClause().Type == parser.FromClauseInnerJoin {
outer:
for t, cs := range query.GetResultColumns() {
for _, c := range cs {
// if this is a wildcard select, then drop all columns and
// just use '*'
if c == "*" {
columns = make(map[string]struct{}, 1)
columns[c] = struct{}{}
break outer
}
columns[t.Name+"."+c] = struct{}{}
}
}
} else {
for _, cs := range query.GetResultColumns() {
for _, c := range cs {
columns[c] = struct{}{}
}
}
}
points := series.Points
series.Points = nil
for _, point := range points {
ok, err := matches(query.GetWhereCondition(), series.Fields, point)
if err != nil {
return nil, err
}
if ok {
filterColumns(columns, series.Fields, point)
series.Points = append(series.Points, point)
}
}
if _, ok := columns["*"]; !ok {
newFields := []string{}
for _, f := range series.Fields {
if _, ok := columns[f]; !ok {
continue
}
newFields = append(newFields, f)
}
series.Fields = newFields
}
return series, nil
}
func (s *RaftServer) runContinuousQuery(db string, query *parser.SelectQuery, start time.Time, end time.Time) {
adminName := s.clusterConfig.GetClusterAdmins()[0]
clusterAdmin := s.clusterConfig.GetClusterAdmin(adminName)
intoClause := query.GetIntoClause()
targetName := intoClause.Target.Name
queryString := query.GetQueryStringWithTimesAndNoIntoClause(start, end)
writer := NewContinuousQueryWriter(s.coordinator, db, targetName, query)
s.coordinator.RunQuery(clusterAdmin, db, queryString, writer)
}
func NewQueryEngine(next Processor, query *parser.SelectQuery, shards []uint32) (Processor, error) {
limit := query.Limit
var engine Processor = NewPassthroughEngineWithLimit(next, 1, limit)
var err error
if query.HasAggregates() {
engine, err = NewAggregatorEngine(query, engine)
} else if query.ContainsArithmeticOperators() {
engine, err = NewArithmeticEngine(query, engine)
}
fromClause := query.GetFromClause()
switch fromClause.Type {
case parser.FromClauseInnerJoin:
engine = NewJoinEngine(shards, query, engine)
case parser.FromClauseMerge:
tables := make([]string, len(fromClause.Names))
for i, name := range fromClause.Names {
tables[i] = name.Name.Name
}
engine = NewMergeEngine(shards, query.Ascending, engine)
case parser.FromClauseMergeRegex:
// At this point the regex should be expanded to the list of
// tables that will be queries
panic("QueryEngine cannot be called with merge function")
}
if err != nil {
return nil, err
}
return engine, nil
}
func NewArithmeticEngine(query *parser.SelectQuery, next Processor) (*ArithmeticEngine, error) {
names := map[string]*parser.Value{}
for idx, v := range query.GetColumnNames() {
switch v.Type {
case parser.ValueSimpleName:
names[v.Name] = v
case parser.ValueFunctionCall:
names[v.Name] = v
case parser.ValueExpression:
if v.Alias != "" {
names[v.Alias] = v
} else {
names["expr"+strconv.Itoa(idx)] = v
}
}
}
return &ArithmeticEngine{
next: next,
names: names,
}, nil
}
// Create and return a new JoinEngine given the shards that will be
// processed and the query
func NewJoinEngine(shards []uint32, query *parser.SelectQuery, next Processor) Processor {
tableNames := query.GetFromClause().Names
name := query.GetFromClause().GetString()
log4go.Debug("NewJoinEngine: shards=%v, query=%s, next=%s, tableNames=%v, name=%s",
shards, query.GetQueryString(), next.Name(), tableNames, name)
joinEngine := &JoinEngine{
next: next,
name: name,
tablesState: make([]joinEngineState, len(tableNames)),
tableIdx: make(map[string]int, len(tableNames)),
query: query,
pts: 0,
}
for i, tn := range tableNames {
alias := tn.GetAlias()
joinEngine.tablesState[i] = joinEngineState{}
joinEngine.tableIdx[alias] = i
}
mergeEngine := NewCommonMergeEngine(shards, false, query.Ascending, joinEngine)
return mergeEngine
}
func NewFilteringEngine(query *parser.SelectQuery, processor Processor) *FilteringEngine {
shouldFilter := query.GetWhereCondition() != nil
return &FilteringEngine{query, processor, shouldFilter}
}
func NewAggregatorEngine(query *parser.SelectQuery, next Processor) (*AggregatorEngine, error) {
ae := &AggregatorEngine{
next: next,
seriesStates: make(map[string]*SeriesState),
ascending: query.Ascending,
}
var err error
ae.duration, ae.irregularInterval, err = query.GetGroupByClause().GetGroupByTime()
if err != nil {
return nil, err
}
ae.aggregators = []Aggregator{}
for _, value := range query.GetColumnNames() {
if !value.IsFunctionCall() {
continue
}
lowerCaseName := strings.ToLower(value.Name)
initializer := registeredAggregators[lowerCaseName]
if initializer == nil {
return nil, common.NewQueryError(common.InvalidArgument, fmt.Sprintf("Unknown function %s", value.Name))
}
aggregator, err := initializer(query, value, query.GetGroupByClause().FillValue)
if err != nil {
return nil, common.NewQueryError(common.InvalidArgument, fmt.Sprintf("%s", err))
}
ae.aggregators = append(ae.aggregators, aggregator)
}
for _, elem := range query.GetGroupByClause().Elems {
if elem.IsFunctionCall() {
continue
}
ae.elems = append(ae.elems, elem)
}
ae.isFillQuery = query.GetGroupByClause().FillWithZero
// This is a special case for issue #426. If the start time is
// specified and there's a group by clause and fill with zero, then
// we need to fill the entire range from start time to end time
if query.IsStartTimeSpecified() && ae.duration != nil && ae.isFillQuery {
ae.startTimeSpecified = true
ae.startTime = query.GetStartTime().Truncate(*ae.duration).UnixNano() / 1000
ae.endTime = query.GetEndTime().Truncate(*ae.duration).UnixNano() / 1000
}
ae.initializeFields()
return ae, nil
}