BTree

B-Tree key/value database file access class.

This class provides a high performance key/value storage mechanism that stores data to file. A B-tree is a self-balancing tree data structure that keeps data sorted and allows searches, sequential access, insertions, and deletions in logarithmic time.

Constants

SIZEOF_HEADER

 const SIZEOF_HEADER = 6

HEADER

 const HEADER = "\xffbtree"

NODE_SLOTS

 const NODE_SLOTS = 16

SIZEOF_INT

 const SIZEOF_INT = 4

KVNODE

 const KVNODE = kv

KPNODE

 const KPNODE = kp

NODECHACHE_SIZE

 const NODECHACHE_SIZE = 64

Properties

file

public File $file

nodecache

private array $nodecache

readOnly

private bool $readOnly

Methods

__construct

Use static method open() to get instance.

public  __construct({Array})

Parameters

Parameter	Type	Description
$file	string
$readOnly	bool

open

Open the file for access.

public  open({Array})

Parameters

Parameter	Type	Description
$file	string
$readOnly	bool

close

Close the file.

public  close({Array})

resetBTreeFile

The the B-Tree source file.

public  resetBTreeFile({Array})

get

Get value by key.

public  get({Array})

Parameters

Parameter	Type	Description
$key	string	The key to return data for

range

Get all values where startkey <= key < endkey.

public  range({Array})

To get all data, use:

$values = $btree->range("\x00", "\xff");

Parameters

Parameter	Type	Description
$startkey	string
$endkey	string

set

Set value under given key.

public  set({Array})

Parameters

Parameter	Type	Description
$key	string	the key to store the value under
$value	mixed	The value to store. A NULL value deletes given key.

remove

public  remove({Array})

Parameters

Parameter	Type	Description
$key	string

has

Check if a given key exists in the database.

public  has({Array})

Parameters

Parameter	Type	Description
$key	string

keys

Get a list of all available keys in the database.

public  keys({Array})

Warning: Unlike a search this will hit almost every part of the database file and can be a bit slow.

leaves

Get positions of all leaves.

public  leaves({Array})

compact

Remove old nodes from BTree file.

public  compact({Array})

dropCache

public  dropCache({Array})

toArray

public  toArray({Array})

lookup

Look up a key.

private  lookup({Array})

Parameters

Parameter	Type	Description
$key	string
$nodeType	string
$node	array
$	bool

leafHunt

Find positions of all leaves.

private  leafHunt({Array})

Parameters

Parameter	Type	Description
$p	int	pointer to node

copyTo

Copy node from opened file to another.

private  copyTo({Array})

Parameters

Parameter	Type	Description
$to	File	The file to copy everything to
$nodeType	string
$node	array

root

Get root node.

private  root({Array})

rootHunt

Try to get position of root.

private  rootHunt({Array})

node

Get node.

private  node({Array})

Parameters

Parameter	Type	Description
$p	int	Pointer to node (offset in file)

serialize

private  serialize({Array})

Parameters

Parameter	Type	Description
$type	string
$node	array

unserialize

private  unserialize({Array})

Parameters

Parameter	Type	Description
$str	string

header

private  header({Array})

Parameters

Parameter	Type	Description
$file	File
$root	``````

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