manifest: add btree.All

Add an All method that returns a Go iterator over the B-Tree's items.

Author: jbowens

internal/manifest/btree.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	stdcmp "cmp"
 	"fmt"
+	"iter"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -773,6 +774,20 @@ func (t *btree[M]) Insert(item M) error {
 	return err
 }
 
+// All returns an iterator over all the items in the tree.
+func (t *btree[M]) All() iter.Seq[M] {
+	iter := iterator[M]{r: t.root, pos: -1, cmp: t.bcmp}
+	iter.first()
+	return func(yield func(M) bool) {
+		for iter.valid() {
+			if !yield(iter.cur()) {
+				return
+			}
+			iter.next()
+		}
+	}
+}
+
 // tableMetadataIter returns a new iterator over a B-Tree of *TableMetadata. It
 // is not safe to continue using an iterator after modifications are made to the
 // tree. If modifications are made, create a new iterator.

internal/manifest/btree_test.go

@@ -462,7 +462,8 @@ func TestBTreeCloneConcurrentOperations(t *testing.T) {
 	t.Logf("Starting equality checks on %d trees", len(trees))
 	want := rang(0, cloneTestSize-1)
 	for i, tree := range trees {
-		if got := all(tree); !reflect.DeepEqual(strReprs(got), strReprs(want)) {
+		got := slices.Collect(tree.All())
+		if !reflect.DeepEqual(strReprs(got), strReprs(want)) {
 			t.Errorf("tree %v mismatch", i)
 		}
 	}
@@ -489,7 +490,8 @@ func TestBTreeCloneConcurrentOperations(t *testing.T) {
 		} else {
 			wantpart = want
 		}
-		if got := all(tree); !reflect.DeepEqual(strReprs(got), strReprs(wantpart)) {
+		got := slices.Collect(tree.All())
+		if !reflect.DeepEqual(strReprs(got), strReprs(wantpart)) {
 			t.Errorf("tree %v mismatch, want %#v got %#v", i, strReprs(wantpart), strReprs(got))
 		}
 	}
@@ -666,17 +668,6 @@ func strReprs(items []*TableMetadata) []string {
 	return s
 }
 
-// all extracts all items from a tree in order as a slice.
-func all(tr *btree[*TableMetadata]) (out []*TableMetadata) {
-	it := tableMetadataIter(tr)
-	it.first()
-	for it.valid() {
-		out = append(out, it.cur())
-		it.next()
-	}
-	return out
-}
-
 func forBenchmarkSizes(b *testing.B, f func(b *testing.B, count int)) {
 	for _, count := range []int{16, 128, 1024, 8192, 65536} {
 		b.Run(fmt.Sprintf("count=%d", count), func(b *testing.B) {