change signature of Plan#BlocksAccessed

Author: uchijo

plan/group_by_plan.go

@@ -47,7 +47,7 @@ func (g *GroupByPlan) Open() (scan.Scan, error) {
 	return query.NewGroupByScan(s, g.groupFields, g.aggregationFunc), nil
 }
 
-func (g *GroupByPlan) BlocksAccessed() int {
+func (g *GroupByPlan) BlocksAccessed() (int, error) {
 	return g.plan.BlocksAccessed()
 }
 

plan/index_join_plan.go

@@ -51,8 +51,12 @@ func (ijp *IndexJoinPlan) Open() (*query.IndexJoinScan, error) {
 	return query.NewIndexJoinScan(scan1, idx, ijp.joinField, ts)
 }
 
-func (ijp *IndexJoinPlan) BlocksAccessed() int {
-	return ijp.plan1.BlocksAccessed() + (ijp.plan1.RecordsOutput() * ijp.ii.BlocksAccessed()) + ijp.RecordsOutput()
+func (ijp *IndexJoinPlan) BlocksAccessed() (int, error) {
+	plan1BlockAccesses, err := ijp.plan1.BlocksAccessed()
+	if err != nil {
+		return 0, err
+	}
+	return plan1BlockAccesses + (ijp.plan1.RecordsOutput() * ijp.ii.BlocksAccessed()) + ijp.RecordsOutput(), nil
 }
 
 func (ijp *IndexJoinPlan) RecordsOutput() int {

plan/materialize_plan.go

@@ -1,7 +1,6 @@
 package plan
 
 import (
-	"log"
 	"math"
 
 	"github.com/team-gonyo/gonyo-db/query"
@@ -76,23 +75,19 @@ func (m *MaterializePlan) Open() (scan.Scan, error) {
 	return dest, nil
 }
 
-func (m *MaterializePlan) BlocksAccessed() int {
+func (m *MaterializePlan) BlocksAccessed() (int, error) {
 	// create a dummy layout object to calculate slot size
 	// FIXME: エラー握りつぶし！！
 	// Plan#BlocksAccessed()のシグネチャを変えないとエラーをエスカレーションできない
 	// だが、12章のIndexPlanもPlanを実装していて、そっちがマージされてからじゃないとコンフリクトしそう
 	// 溜まったPRが落ち着いて、直せるようになった時点で対処すること
 	layout, err := record.NewLayoutFromSchema(m.Schema())
 	if err != nil {
-		// 一旦エラーログ出す
-		log.Printf("failed to invoke MaterializePlan#BlocksAccessed: %v", err)
-
-		// 特に理由のない1000000
-		return 1000000
+		return 0, err
 	}
 
 	recordPerBlock := (float64(m.tx.BlockSize())) / float64(layout.SlotSize())
-	return int(math.Ceil(float64(m.srcPlan.RecordsOutput()) / recordPerBlock))
+	return int(math.Ceil(float64(m.srcPlan.RecordsOutput()) / recordPerBlock)), nil
 }
 
 func (m *MaterializePlan) RecordsOutput() int {

plan/merge_join_plan.go

@@ -56,8 +56,16 @@ func (m *MergeJoinPlan) Open() (scan.Scan, error) {
 	return query.NewMergeJoinScan(s1, s2, m.fieldName1, m.fieldName2), nil
 }
 
-func (m *MergeJoinPlan) BlocksAccessed() int {
-	return m.p1.BlocksAccessed() + m.p2.BlocksAccessed()
+func (m *MergeJoinPlan) BlocksAccessed() (int, error) {
+	p1BlockAccesses, err := m.p1.BlocksAccessed()
+	if err != nil {
+		return 0, err
+	}
+	p2BlockAccesses, err := m.p2.BlocksAccessed()
+	if err != nil {
+		return 0, err
+	}
+	return p1BlockAccesses + p2BlockAccesses, nil
 }
 
 func (m *MergeJoinPlan) RecordsOutput() int {

plan/plan.go

@@ -10,7 +10,7 @@ type Plan interface {
 	Open() (scan.Scan, error)
 
 	// Plan実行によるブロックアクセス数を推定
-	BlocksAccessed() int
+	BlocksAccessed() (int, error)
 
 	// Plan実行による出力レコード数を推定
 	RecordsOutput() int

plan/product_plan.go

@@ -75,8 +75,16 @@ func (pp *ProductPlan) Open() (scan.Scan, error) {
 	return query.NewProductScan(s1, s2)
 }
 
-func (pp *ProductPlan) BlocksAccessed() int {
-	return pp.p1.BlocksAccessed() + (pp.p1.RecordsOutput() * pp.p2.BlocksAccessed())
+func (pp *ProductPlan) BlocksAccessed() (int, error) {
+	p1BlockAccesses, err := pp.p1.BlocksAccessed()
+	if err != nil {
+		return 0, err
+	}
+	p2BlockAccesses, err := pp.p2.BlocksAccessed()
+	if err != nil {
+		return 0, err
+	}
+	return p1BlockAccesses + (pp.p1.RecordsOutput() * p2BlockAccesses), nil
 }
 
 func (pp *ProductPlan) RecordsOutput() int {

plan/project_plan.go

@@ -49,7 +49,7 @@ func (pp *ProjectPlan) Open() (scan.Scan, error) {
 	return query.NewProjectScan(s, pp.schema.Fields()), nil
 }
 
-func (pp *ProjectPlan) BlocksAccessed() int {
+func (pp *ProjectPlan) BlocksAccessed() (int, error) {
 	return pp.p.BlocksAccessed()
 }
 

plan/select_plan.go

@@ -28,7 +28,7 @@ func (sp *SelectPlan) Open() (scan.Scan, error) {
 	return query.NewSelectScan(s, sp.pred), nil
 }
 
-func (sp *SelectPlan) BlocksAccessed() int {
+func (sp *SelectPlan) BlocksAccessed() (int, error) {
 	return sp.p.BlocksAccessed()
 }
 

plan/sort_plan.go

@@ -210,7 +210,7 @@ func (s *SortPlan) mergeTwoRuns(p1, p2 query.TempTable) (query.TempTable, error)
 	return *result, nil
 }
 
-func (s *SortPlan) BlocksAccessed() int {
+func (s *SortPlan) BlocksAccessed() (int, error) {
 	// ソート時のコストは考慮しない
 	mp := NewMaterializePlan(s.tx, s.plan)
 	return mp.BlocksAccessed()

plan/table_plan.go

@@ -39,8 +39,8 @@ func (tp *TablePlan) Open() (scan.Scan, error) {
 	return scan.NewTableScan(tp.tx, tp.tblName, tp.layout)
 }
 
-func (tp *TablePlan) BlocksAccessed() int {
-	return tp.si.BlocksAccessed()
+func (tp *TablePlan) BlocksAccessed() (int, error) {
+	return tp.si.BlocksAccessed(), nil
 }
 
 func (tp *TablePlan) RecordsOutput() int {