go/zodb/btree: Rearrange data structure definitions

In the next patch we are going to expose access to BTree/Bucket entries
as public API. This will turn _BTreeItem into Entry and will also add
BucketEntry data type. Before doing that rearrange the order in which
the data structure go:

	- BTree,
	- Entry (_BTreeItem for now),
	- Bucket
	- BucketEntry (not present for now).

Only code movement - no other change.

go/zodb/btree/btree.go.in

@@ -29,33 +29,6 @@ import (
 	"lab.nexedi.com/kirr/neo/go/zodb/internal/pickletools"
 )
 
-// Bucket is a leaf node of a B⁺ tree.
-//
-// It mimics Bucket from btree/py.
-type Bucket struct {
-	zodb.Persistent
-
-	// https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BTreeModuleTemplate.c#L179:
-	//
-	// A Bucket wraps contiguous vectors of keys and values.  Keys are unique,
-	// and stored in sorted order.  The 'values' pointer may be NULL if the
-	// Bucket is used to implement a set.  Buckets serving as leafs of BTrees
-	// are chained together via 'next', so that the entire BTree contents
-	// can be traversed in sorted order quickly and easily.
-
-	next   *Bucket       // the bucket with the next-larger keys
-	keys   []KEY         // 'len' keys, in increasing order
-	values []interface{} // 'len' corresponding values
-}
-
-// _BTreeItem mimics BTreeItem from btree/py.
-//
-// XXX export for BTree.Children?
-type _BTreeItem struct {
-	key   KEY
-	child interface{} // BTree or Bucket
-}
-
 // BTree is a non-leaf node of a B⁺ tree.
 //
 // It mimics BTree from btree/py.
@@ -79,6 +52,33 @@ type BTree struct {
 	data []_BTreeItem
 }
 
+// _BTreeItem mimics BTreeItem from btree/py.
+//
+// XXX export for BTree.Children?
+type _BTreeItem struct {
+	key   KEY
+	child interface{} // BTree or Bucket
+}
+
+// Bucket is a leaf node of a B⁺ tree.
+//
+// It mimics Bucket from btree/py.
+type Bucket struct {
+	zodb.Persistent
+
+	// https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BTreeModuleTemplate.c#L179:
+	//
+	// A Bucket wraps contiguous vectors of keys and values.  Keys are unique,
+	// and stored in sorted order.  The 'values' pointer may be NULL if the
+	// Bucket is used to implement a set.  Buckets serving as leafs of BTrees
+	// are chained together via 'next', so that the entire BTree contents
+	// can be traversed in sorted order quickly and easily.
+
+	next   *Bucket       // the bucket with the next-larger keys
+	keys   []KEY         // 'len' keys, in increasing order
+	values []interface{} // 'len' corresponding values
+}
+
 // Get searches BTree by key.
 //
 // It loads intermediate BTree nodes from database on demand as needed.

go/zodb/btree/ziobtree.go

@@ -31,33 +31,6 @@ import (
 	"lab.nexedi.com/kirr/neo/go/zodb/internal/pickletools"
 )
 
-// IOBucket is a leaf node of a B⁺ tree.
-//
-// It mimics IOBucket from btree/py.
-type IOBucket struct {
-	zodb.Persistent
-
-	// https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BTreeModuleTemplate.c#L179:
-	//
-	// A IOBucket wraps contiguous vectors of keys and values.  Keys are unique,
-	// and stored in sorted order.  The 'values' pointer may be NULL if the
-	// IOBucket is used to implement a set.  Buckets serving as leafs of BTrees
-	// are chained together via 'next', so that the entire IOBTree contents
-	// can be traversed in sorted order quickly and easily.
-
-	next   *IOBucket       // the bucket with the next-larger keys
-	keys   []int32         // 'len' keys, in increasing order
-	values []interface{} // 'len' corresponding values
-}
-
-// _IOBTreeItem mimics BTreeItem from btree/py.
-//
-// XXX export for IOBTree.Children?
-type _IOBTreeItem struct {
-	key   int32
-	child interface{} // IOBTree or IOBucket
-}
-
 // IOBTree is a non-leaf node of a B⁺ tree.
 //
 // It mimics IOBTree from btree/py.
@@ -81,6 +54,33 @@ type IOBTree struct {
 	data []_IOBTreeItem
 }
 
+// _IOBTreeItem mimics BTreeItem from btree/py.
+//
+// XXX export for IOBTree.Children?
+type _IOBTreeItem struct {
+	key   int32
+	child interface{} // IOBTree or IOBucket
+}
+
+// IOBucket is a leaf node of a B⁺ tree.
+//
+// It mimics IOBucket from btree/py.
+type IOBucket struct {
+	zodb.Persistent
+
+	// https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BTreeModuleTemplate.c#L179:
+	//
+	// A IOBucket wraps contiguous vectors of keys and values.  Keys are unique,
+	// and stored in sorted order.  The 'values' pointer may be NULL if the
+	// IOBucket is used to implement a set.  Buckets serving as leafs of BTrees
+	// are chained together via 'next', so that the entire IOBTree contents
+	// can be traversed in sorted order quickly and easily.
+
+	next   *IOBucket       // the bucket with the next-larger keys
+	keys   []int32         // 'len' keys, in increasing order
+	values []interface{} // 'len' corresponding values
+}
+
 // Get searches IOBTree by key.
 //
 // It loads intermediate IOBTree nodes from database on demand as needed.

go/zodb/btree/zlobtree.go

@@ -31,33 +31,6 @@ import (
 	"lab.nexedi.com/kirr/neo/go/zodb/internal/pickletools"
 )
 
-// LOBucket is a leaf node of a B⁺ tree.
-//
-// It mimics LOBucket from btree/py.
-type LOBucket struct {
-	zodb.Persistent
-
-	// https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BTreeModuleTemplate.c#L179:
-	//
-	// A LOBucket wraps contiguous vectors of keys and values.  Keys are unique,
-	// and stored in sorted order.  The 'values' pointer may be NULL if the
-	// LOBucket is used to implement a set.  Buckets serving as leafs of BTrees
-	// are chained together via 'next', so that the entire LOBTree contents
-	// can be traversed in sorted order quickly and easily.
-
-	next   *LOBucket       // the bucket with the next-larger keys
-	keys   []int64         // 'len' keys, in increasing order
-	values []interface{} // 'len' corresponding values
-}
-
-// _LOBTreeItem mimics BTreeItem from btree/py.
-//
-// XXX export for LOBTree.Children?
-type _LOBTreeItem struct {
-	key   int64
-	child interface{} // LOBTree or LOBucket
-}
-
 // LOBTree is a non-leaf node of a B⁺ tree.
 //
 // It mimics LOBTree from btree/py.
@@ -81,6 +54,33 @@ type LOBTree struct {
 	data []_LOBTreeItem
 }
 
+// _LOBTreeItem mimics BTreeItem from btree/py.
+//
+// XXX export for LOBTree.Children?
+type _LOBTreeItem struct {
+	key   int64
+	child interface{} // LOBTree or LOBucket
+}
+
+// LOBucket is a leaf node of a B⁺ tree.
+//
+// It mimics LOBucket from btree/py.
+type LOBucket struct {
+	zodb.Persistent
+
+	// https://github.com/zopefoundation/BTrees/blob/4.5.0-1-gc8bf24e/BTrees/BTreeModuleTemplate.c#L179:
+	//
+	// A LOBucket wraps contiguous vectors of keys and values.  Keys are unique,
+	// and stored in sorted order.  The 'values' pointer may be NULL if the
+	// LOBucket is used to implement a set.  Buckets serving as leafs of BTrees
+	// are chained together via 'next', so that the entire LOBTree contents
+	// can be traversed in sorted order quickly and easily.
+
+	next   *LOBucket       // the bucket with the next-larger keys
+	keys   []int64         // 'len' keys, in increasing order
+	values []interface{} // 'len' corresponding values
+}
+
 // Get searches LOBTree by key.
 //
 // It loads intermediate LOBTree nodes from database on demand as needed.