iterfunc experiment

This commit is contained in:
jdl 2023-12-24 20:41:43 +01:00
parent 5ffd50bdea
commit 6b0b7408bc
5 changed files with 45 additions and 47 deletions

2
go.mod
View File

@ -1,6 +1,6 @@
module git.crumpington.com/public/jldb module git.crumpington.com/public/jldb
go 1.21.1 go 1.22
require ( require (
github.com/google/btree v1.1.2 github.com/google/btree v1.1.2

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@ -743,29 +743,25 @@ var testDBTestCases = []DBTestCase{{
first := true first := true
pivot := User{Name: "User1"} pivot := User{Name: "User1"}
db.Users.ByName.AscendAfter(tx, &pivot, func(u *User) bool { for u := range db.Users.ByName.AscendAfter(tx, &pivot) {
u.Name += "Mod" u.Name += "Mod"
if err = db.Users.Update(tx, u); err != nil { if err = db.Users.Update(tx, u); err != nil {
return false return err
} }
if first { if first {
first = false first = false
return true continue
} }
prev := db.Users.ByID.Get(tx, &User{ID: u.ID - 1}) prev := db.Users.ByID.Get(tx, &User{ID: u.ID - 1})
if prev == nil { if prev == nil {
err = errors.New("Previous user not found") return errors.New("Previous user not found")
return false
} }
if !strings.HasSuffix(prev.Name, "Mod") { if !strings.HasSuffix(prev.Name, "Mod") {
err = errors.New("Incorrect user name: " + prev.Name) return errors.New("Incorrect user name: " + prev.Name)
return false }
} }
return true
})
return nil return nil
}, },
@ -801,29 +797,26 @@ var testDBTestCases = []DBTestCase{{
} }
first := true first := true
db.Users.ByName.DescendAfter(tx, &User{Name: "User5Mod"}, func(u *User) bool { for u := range db.Users.ByName.DescendAfter(tx, &User{Name: "User5Mod"}) {
u.Name = strings.TrimSuffix(u.Name, "Mod") u.Name = strings.TrimSuffix(u.Name, "Mod")
if err = db.Users.Update(tx, u); err != nil { if err = db.Users.Update(tx, u); err != nil {
return false return err
} }
if first { if first {
first = false first = false
return true continue
} }
prev := db.Users.ByID.Get(tx, &User{ID: u.ID + 1}) prev := db.Users.ByID.Get(tx, &User{ID: u.ID + 1})
if prev == nil { if prev == nil {
err = errors.New("Previous user not found") return errors.New("Previous user not found")
return false
} }
if strings.HasSuffix(prev.Name, "Mod") { if strings.HasSuffix(prev.Name, "Mod") {
err = errors.New("Incorrect user name: " + prev.Name) return errors.New("Incorrect user name: " + prev.Name)
return false }
} }
return true
})
return nil return nil
}, },

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@ -1,7 +1,6 @@
package mdb package mdb
import ( import (
"fmt"
"reflect" "reflect"
"testing" "testing"
) )
@ -20,18 +19,16 @@ func (i Index[T]) AssertEqual(t *testing.T, tx1, tx2 *Snapshot) {
} }
errStr := "" errStr := ""
i.Ascend(tx1, func(item1 *T) bool { iter := i.Ascend(tx1)
for item1 := range iter {
item2 := i.Get(tx2, item1) item2 := i.Get(tx2, item1)
if item2 == nil { if item2 == nil {
errStr = fmt.Sprintf("Indices don't match. %v not found.", item1) t.Fatalf("Indices don't match. %v not found.", item1)
return false
} }
if !reflect.DeepEqual(item1, item2) { if !reflect.DeepEqual(item1, item2) {
errStr = fmt.Sprintf("%v != %v", item1, item2) t.Fatalf("%v != %v", item1, item2)
return false }
} }
return true
})
if errStr != "" { if errStr != "" {
t.Fatal(errStr) t.Fatal(errStr)

View File

@ -1,6 +1,7 @@
package mdb package mdb
import ( import (
"iter"
"unsafe" "unsafe"
"github.com/google/btree" "github.com/google/btree"
@ -111,33 +112,41 @@ func (i *Index[T]) Max(tx *Snapshot) *T {
return nil return nil
} }
func (i *Index[T]) Ascend(tx *Snapshot, each func(*T) bool) { func (i *Index[T]) Ascend(tx *Snapshot) iter.Seq[*T] {
tx = i.ensureSnapshot(tx) tx = i.ensureSnapshot(tx)
return func(yield func(*T) bool) {
i.btreeForIter(tx).Ascend(func(t *T) bool { i.btreeForIter(tx).Ascend(func(t *T) bool {
return each(i.copy(t)) return yield(i.copy(t))
}) })
} }
}
func (i *Index[T]) AscendAfter(tx *Snapshot, after *T, each func(*T) bool) { func (i *Index[T]) AscendAfter(tx *Snapshot, after *T) iter.Seq[*T] {
tx = i.ensureSnapshot(tx) tx = i.ensureSnapshot(tx)
return func(yield func(*T) bool) {
i.btreeForIter(tx).AscendGreaterOrEqual(after, func(t *T) bool { i.btreeForIter(tx).AscendGreaterOrEqual(after, func(t *T) bool {
return each(i.copy(t)) return yield(i.copy(t))
}) })
} }
}
func (i *Index[T]) Descend(tx *Snapshot, each func(*T) bool) { func (i *Index[T]) Descend(tx *Snapshot) iter.Seq[*T] {
tx = i.ensureSnapshot(tx) tx = i.ensureSnapshot(tx)
return func(yield func(*T) bool) {
i.btreeForIter(tx).Descend(func(t *T) bool { i.btreeForIter(tx).Descend(func(t *T) bool {
return each(i.copy(t)) return yield(i.copy(t))
}) })
} }
}
func (i *Index[T]) DescendAfter(tx *Snapshot, after *T, each func(*T) bool) { func (i *Index[T]) DescendAfter(tx *Snapshot, after *T) iter.Seq[*T] {
tx = i.ensureSnapshot(tx) tx = i.ensureSnapshot(tx)
return func(yield func(*T) bool) {
i.btreeForIter(tx).DescendLessOrEqual(after, func(t *T) bool { i.btreeForIter(tx).DescendLessOrEqual(after, func(t *T) bool {
return each(i.copy(t)) return yield(i.copy(t))
}) })
} }
}
func (i *Index[T]) Count(tx *Snapshot) int { func (i *Index[T]) Count(tx *Snapshot) int {
tx = i.ensureSnapshot(tx) tx = i.ensureSnapshot(tx)

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@ -1,9 +1,8 @@
package mdb package mdb
func (i Index[T]) Dump(tx *Snapshot) (l []T) { func (i Index[T]) Dump(tx *Snapshot) (l []T) {
i.Ascend(tx, func(t *T) bool { for t := range i.Ascend(tx) {
l = append(l, *t) l = append(l, *t)
return true }
})
return l return l
} }