StreamStore

A facility to store streams in a map. Streams are split into blocks, which are stored in a map. Very small streams are inlined in the stream id.

The key of the map is a long (incremented for each stored block). The default initial value is 0. Before storing blocks into the map, the stream store checks if there is already a block with the next key, and if necessary searches the next free entry using a binary search (0 to Long.MAX_VALUE).

Before storing

The format of the binary id is: An empty id represents 0 bytes of data. In-place data is encoded as 0, the size (a variable size int), then the data. A stored block is encoded as 1, the length of the block (a variable size int), then the key (a variable size long). Multiple ids can be concatenated to concatenate the data. If the id is large, it is stored itself, which is encoded as 2, the total length (a variable size long), and the key of the block that contains the id (a variable size long).

Methods
static String	toString(byte[] id) Convert the id to a human readable string.
static String	toString(byte[] id) Convert the id to a human readable string. Parameters: id - the stream id Returns: the string
	StreamStore(Map map) Create a stream store instance.
	StreamStore(Map map) Create a stream store instance. Parameters: map - the map to store blocks of data
InputStream	get(byte[] id) Open an input stream to read data.
InputStream	get(byte[] id) Open an input stream to read data. Parameters: id - the id Returns: the stream
byte[]	getBlock(long key) Get the block.
byte[]	getBlock(long key) Get the block. Parameters: key - the key Returns: the block
Map	getMap()
Map	getMap()
long	getMaxBlockKey(byte[] id) Get the key of the biggest block, of -1 for inline data.
long	getMaxBlockKey(byte[] id) Get the key of the biggest block, of -1 for inline data. This method is used to garbage collect orphaned blocks. Parameters: id - the id Returns: the key, or -1
long	getMaxBlockSize()
long	getMaxBlockSize()
int	getMinBlockSize()
int	getMinBlockSize()
long	getNextKey()
long	getNextKey()
boolean	isInPlace(byte[] id) Check whether the id itself contains all the data.
boolean	isInPlace(byte[] id) Check whether the id itself contains all the data. This operation does not cause any reads in the map. Parameters: id - the id Returns: if the id contains the data
long	length(byte[] id) Calculate the number of data bytes for the given id.
long	length(byte[] id) Calculate the number of data bytes for the given id. As the length is encoded in the id, this operation does not cause any reads in the map. Parameters: id - the id Returns: the length
void	onStore(int len) This method is called after a block of data is stored.
void	onStore(int len) This method is called after a block of data is stored. Override this method to persist data if necessary. Parameters: len - the length of the stored block.
byte[]	put(InputStream in) Store the stream, and return the id.
byte[]	put(InputStream in) throws IOException Store the stream, and return the id. The stream is not closed. Parameters: in - the stream Returns: the id (potentially an empty array)
void	remove(byte[] id) Remove all stored blocks for the given id.
void	remove(byte[] id) Remove all stored blocks for the given id. Parameters: id - the id
void	setMaxBlockSize(int maxBlockSize) Set the maximum block size.
void	setMaxBlockSize(int maxBlockSize) Set the maximum block size. The default is 256 KB. Parameters: maxBlockSize - the new value
void	setMinBlockSize(int minBlockSize) Set the minimum block size.
void	setMinBlockSize(int minBlockSize) Set the minimum block size. The default is 256 bytes. Parameters: minBlockSize - the new value
void	setNextKey(long nextKey)
void	setNextKey(long nextKey)