67 lines
1.9 KiB
Go
67 lines
1.9 KiB
Go
package engine
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import "github.com/influxdb/influxdb/protocol"
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// Traverses the buckets in either ascending or descending order. Each
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// bucket have the form (C1, C2, time) where C1 and C2 are column
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// values and time is the timestamp. The traverser applies the given
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// function on all nodes with the timestamp in either ascending or
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// descending order
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type bucketTraverser struct {
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trie *Trie // the trie we're going to traverse
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last int64 // the last bucket's timestamp that we will visit
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current int64 // the current timestamp
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step int64 // the step (could be negative if the query is descending)
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levels int // the number of levels in the trie
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aggregators int // the number of aggregators that we have to run
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asc bool // ascending or descending query
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}
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func newBucketTraverser(trie *Trie, levels, aggregators int, startBucket, endBucket, durationMicro int64, asc bool) *bucketTraverser {
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bt := &bucketTraverser{
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trie: trie,
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levels: levels,
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aggregators: aggregators,
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last: startBucket,
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current: endBucket,
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step: -durationMicro,
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asc: asc,
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}
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if !asc {
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return bt
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}
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bt.last = endBucket
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bt.current = startBucket
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bt.step = durationMicro
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return bt
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}
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func (bt *bucketTraverser) reachedEnd() bool {
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if bt.asc {
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return bt.current > bt.last
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}
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return bt.current < bt.last
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}
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func (bt *bucketTraverser) apply(f func(fv []*protocol.FieldValue, node *Node) error) error {
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for !bt.reachedEnd() {
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timestamp := &protocol.FieldValue{Int64Value: protocol.Int64(bt.current)}
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defaultChildNode := &Node{states: make([]interface{}, bt.aggregators)}
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err := bt.trie.TraverseLevel(bt.levels, func(v []*protocol.FieldValue, node *Node) error {
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childNode := node.GetChildNode(timestamp)
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if childNode == nil {
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childNode = defaultChildNode
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}
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return f(append(v, timestamp), childNode)
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})
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if err != nil {
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return err
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}
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bt.current += bt.step
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}
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return nil
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}
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