func newBpTree(blocksize uint32, filename string, keysize uint32, fields []uint32) (*BpTree, bool) {
self := new(BpTree)
// 4 MB buffer with a block size of 4096 bytes
if bf, ok := NewBlockFile(filename, NewLFU(1000)); !ok {
fmt.Println("could not create block file")
return nil, false
} else {
self.bf = bf
}
self.blocksize = blocksize
if inter, ok := NewBlockDimensions(POINTERS|EQUAPTRS|NODUP, self.blocksize, keysize, 8, nil); !ok {
fmt.Println("Block Dimensions invalid")
return nil, false
} else {
self.internal = inter
}
if leaf, ok := NewBlockDimensions(RECORDS|EXTRAPTR, self.blocksize, keysize, 8, fields); !ok {
fmt.Println("Block Dimensions invalid")
return nil, false
} else {
self.external = leaf
}
if !self.bf.Open() {
fmt.Println("Couldn't open file")
return nil, false
}
if s, open := self.bf.Size(); open && s == 0 {
// This is a new file the size is zero
self.bf.Allocate(self.blocksize)
b, ok := NewKeyBlock(self.bf, self.external)
if !ok {
self.bf.Close()
fmt.Println("Could not create the root block")
return nil, false
}
if !b.SerializeToFile() {
self.bf.Close()
fmt.Println("Could not serialize root block to file")
return nil, false
}
self.info = treeinfo.New(self.bf, 1, b.Position())
} else {
self.info = treeinfo.Load(self.bf)
}
runtime.SetFinalizer(self, func(self *BpTree) { self.bf.Close() })
return self, true
}
func NewBTree(filename string, keysize uint32, fields []uint32) (*BTree, bool) {
self := new(BTree)
// 4 MB buffer with a block size of 4096 bytes
if bf, ok := NewBlockFile(filename, NewLFU(1000)); !ok {
fmt.Println("could not create block file")
return nil, false
} else {
self.bf = bf
}
if dim, ok := NewBlockDimensions(RECORDS|POINTERS, treeinfo.BLOCKSIZE, keysize, 8, fields); !ok {
fmt.Println("Block Dimensions invalid")
return nil, false
} else {
self.node = dim
}
if !self.bf.Open() {
fmt.Println("Couldn't open file")
return nil, false
}
if s, open := self.bf.Size(); open && s == 0 {
// This is a new file the size is zero
self.bf.Allocate(self.node.BlockSize)
b, ok := NewKeyBlock(self.bf, self.node)
if !ok {
self.bf.Close()
fmt.Println("Could not create the root block")
return nil, false
}
if !b.SerializeToFile() {
self.bf.Close()
fmt.Println("Could not serialize root block to file")
return nil, false
}
self.info = treeinfo.New(self.bf, 1, b.Position())
} else {
self.info = treeinfo.Load(self.bf)
}
runtime.SetFinalizer(self,
func(self *BTree) { self.bf.Close() })
return self, true
}