moved the database-go project to this repository

models/b_tree.go

@@ -0,0 +1,69 @@
+package models
+
+import "encoding/binary"
+import "testify/assert"
+const HEADER = 4
+
+const BTREE_PAGE_SIZE = 4096
+const BTREE_MAX_KEY_SIZE = 1000
+const BTREE_MAX_VAL_SIZE = 1000
+
+type BNode []byte
+
+type BTree struct {
+	root uint64
+	get  func(uint64) []byte
+	new  func([]byte) uint64
+	del  func(uint64)
+}
+
+func init() {
+	noode1max := HEADER + 8 + 2 + 4 + BTREE_MAX_KEY_SIZE + BTREE_MAX_VAL_SIZE
+	assert(noode1max <= BTREE_PAGE_SIZE)
+}
+
+func (node BNode) btype() uint16 {
+	return binary.LittleEndian.Uint16(node[0:2])
+}
+
+func (node BNode) nkeys() uint16 {
+	return binary.LittleEndian.Uint16(node[2:4])
+}
+
+func (node BNode) setHeader(btype uint16, nkeys uint16) {
+	binary.LittleEndian.PutUint16(node[0:2], btype)
+	binary.LittleEndian.PutUint16(node[2:4], nkeys)
+}
+
+func (node BNode) getPtr(ids uint16) uint64 {
+	assert(ids < node.nkeys())
+	pos := HEADER + 8*ids
+	return binary.LittleEndian.Uint64(node[pos:])
+}
+
+func (node BNode) setPtr(idx uint16, val uint64) {
+	assert(idx <= node.nkeys())
+	pos := HEADER + 8*idx
+	binary.LittleEndian.PutUint64(node[pos:], val)
+}
+
+func (node BNode) getOffset(idx uint16) uint16 {
+	if (idx == 0) {
+		return 0
+	}
+	pos := HEADER + 8*node.nkeys() + 2*(idx - 1)
+	return binary.LittleEndian.Uint16(node[pos:])
+}
+
+func (node BNode) kvPos(idx uint16) (uint16) {
+	assert(idx < node.nkeys())
+	return 4 + 8*node.nkeys() + 2*node.nkeys() + node.getOffset(idx)
+}
+
+func(node BNode) getKey(idx uint16) []byte {
+	assert(idx < node.nkeys())
+	pos := node.kvPos(idx)
+	klen := binary.LittleEndian.Uint16(node[pos:])
+	vlen := binary.LittleEndian.Uint16(node[pos+2:])
+	return node[pos+4+klen:][:vlen]
+}

models/node.go

@@ -0,0 +1,30 @@
+package models
+
+import (
+	"github.com/stretchr/testify/assert"
+)
+const (
+	BNODE_NODE = 1
+	BNODE_LEAF = 2
+	BTREE_PAGE_SIZE = 4096
+	BTREE_MAX_KEY_SIZE = 1000
+	BTREE_MAX_VAL_SIZE = 3000
+)
+
+type Node struct {
+	keys [][]byte
+	vals [][]byte
+	kids []*Node
+}
+
+func init() {
+	node1max := HEADER + 8 + 2 + 4 + BTREE_MAX_KEY_SIZE + BTREE_MAX_VAL_SIZE
+	assert(node1max <= BTREE_PAGE_SIZE)
+}
+func Encode(node *Node) []byte	{
+	return nil
+}
+
+func Decode(page []byte) (*Node, error) {
+	return nil, nil
+}

models/utils.go

@@ -0,0 +1,32 @@
+package models
+
+import "encoding/binary"
+
+const (
+	BNODE_NODE = 1
+	BNODE_LEAF = 2
+)
+
+func (node BNode) btype() uint16 {
+	return binary.LittleEndian.Uint16(node[0:2])
+}
+
+
+func (node BNode) nkeys() uint16 {
+	return binary.LittleEndian.Uint16(node[2:4])
+}
+
+
+func (node BNode) setHeader(btype uint16, nkeys uint16) {
+	binary.LittleEndian.PutUint16(node[0:2], btype)
+	binary.LittleEndian.PutUint16(node[2:4], nkeys)
+}
+
+func (node BNode) getPrt(ids uint16) uint64{
+	assert(ids < node.nkeys())
+	pos := HEADER + 8*ids
+	return binary.LittleEndian.Uint64(node[pos:])
+}
+
+func (node BNode) setPtr(idx uint16, val uint64) {
+}