package tools
import (
"encoding/json"
"fmt"
)
const profileDurationPruneRatio = 0.01
type flameGraphNode struct {
Name string `json:"name"`
Start int64 `json:"start"`
Duration int64 `json:"duration"`
Children []*flameGraphNode `json:"children"`
Color *string `json:"color,omitempty"`
Data map[string]string `json:"data,omitempty"`
}
func trimProfilesResponse(response []byte) ([]byte, error) {
var root flameGraphNode
if err := json.Unmarshal(response, &root); err != nil {
return nil, fmt.Errorf("error unmarshaling profiles response: %v", err)
}
changed := pruneFlameGraphNodesBelowDurationThreshold(&root)
if !changed {
return response, nil
}
trimmed, err := json.Marshal(root)
if err != nil {
return nil, fmt.Errorf("error marshaling trimmed profiles response: %v", err)
}
return trimmed, nil
}
func pruneFlameGraphNodesBelowDurationThreshold(root *flameGraphNode) bool {
if root == nil || root.Duration <= 0 {
return false
}
minDuration := float64(root.Duration) * profileDurationPruneRatio
return pruneFlameGraphChildren(root, minDuration)
}
func pruneFlameGraphChildren(node *flameGraphNode, minDuration float64) bool {
if node == nil || len(node.Children) == 0 {
return false
}
changed := false
filteredChildren := node.Children[:0]
for _, child := range node.Children {
if child == nil || float64(child.Duration) < minDuration {
changed = true
continue
}
if pruneFlameGraphChildren(child, minDuration) {
changed = true
}
filteredChildren = append(filteredChildren, child)
}
node.Children = filteredChildren
return changed
}
