Package com.graphhopper.storage

Class RAMDataAccess

java.lang.Object

com.graphhopper.storage.AbstractDataAccess

com.graphhopper.storage.RAMDataAccess

All Implemented Interfaces:

DataAccess, Closeable, AutoCloseable

public class RAMDataAccess
extends AbstractDataAccess

This is an in-memory byte-based data structure with the possibility to be stored on flush(). Read thread-safe.

Author:

Peter Karich

Field Summary

Fields inherited from class com.graphhopper.storage.AbstractDataAccess

bitUtil, byteOrder, closed, EMPTY, header, HEADER_OFFSET, indexDivisor, name, SEGMENT_SIZE_MIN, segmentSizeInBytes, segmentSizePower

Method Summary

Modifier and Type	Method	Description
void	close()	This method makes sure that the underlying used resources are released.
RAMDataAccess	create(long bytes)	The first time you use a DataAccess object after configuring it you need to call this method.
boolean	ensureCapacity(long bytes)	Ensures that the capacity of this object is at least the specified bytes.
void	flush()	This method makes sure that the underlying data is written to the storage.
final byte	getByte(long bytePos)
void	getBytes(long bytePos, byte[] values, int length)	Get bytes from position 'index'
long	getCapacity()
final int	getInt(long bytePos)	Get 4 bytes from position 'bytePos'
int	getSegments()
final short	getShort(long bytePos)	Get 2 bytes from position 'index'
DAType	getType()
boolean	isStoring()
boolean	loadExisting()
final void	setByte(long bytePos, byte value)
void	setBytes(long bytePos, byte[] values, int length)	Set bytes from position 'index' to the specified values
final void	setInt(long bytePos, int value)	Set 4 bytes at position 'bytePos' to the specified value
final void	setShort(long bytePos, short value)	Set 2 bytes at position 'index' to the specified value
RAMDataAccess	store(boolean store)

Methods inherited from class com.graphhopper.storage.AbstractDataAccess

copyHeader, getFullName, getHeader, getName, getSegmentSize, isClosed, isIntBased, readHeader, setHeader, toString, writeHeader

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Details

store

public RAMDataAccess store(boolean store)

Parameters:

store - true if in-memory data should be saved when calling flush

isStoring

public boolean isStoring()

Overrides:

isStoring in class AbstractDataAccess

create

public RAMDataAccess create(long bytes)

Description copied from interface: DataAccess

The first time you use a DataAccess object after configuring it you need to call this method. After that first call you have to use ensureCapacity to ensure that enough space is reserved.

ensureCapacity

public boolean ensureCapacity(long bytes)

Description copied from interface: DataAccess

Ensures that the capacity of this object is at least the specified bytes. The first time you have to call 'create' instead.

Returns:

true if size was increased

See Also:

• DataAccess.create(long)

loadExisting

public boolean loadExisting()

Returns:

true if successfully loaded from persistent storage.

flush

public void flush()

Description copied from interface: DataAccess

This method makes sure that the underlying data is written to the storage. Keep in mind that a disc normally has an IO cache so that flush() is (less) probably not save against power loses.

setInt

public final void setInt(long bytePos,
 int value)

Description copied from interface: DataAccess

Set 4 bytes at position 'bytePos' to the specified value

getInt

public final int getInt(long bytePos)

Description copied from interface: DataAccess

Get 4 bytes from position 'bytePos'

setShort

public final void setShort(long bytePos,
 short value)

Description copied from interface: DataAccess

Set 2 bytes at position 'index' to the specified value

getShort

public final short getShort(long bytePos)

Description copied from interface: DataAccess

Get 2 bytes from position 'index'

setBytes

public void setBytes(long bytePos,
 byte[] values,
 int length)

Description copied from interface: DataAccess

Set bytes from position 'index' to the specified values

getBytes

public void getBytes(long bytePos,
 byte[] values,
 int length)

Description copied from interface: DataAccess

Get bytes from position 'index'

values - acts as output

setByte

public final void setByte(long bytePos,
 byte value)

getByte

public final byte getByte(long bytePos)

close

public void close()

Description copied from interface: DataAccess

This method makes sure that the underlying used resources are released. WARNING: it does NOT flush on close!

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface DataAccess

Overrides:

close in class AbstractDataAccess

getCapacity

public long getCapacity()

Returns:

the allocated storage size in bytes

getSegments

public int getSegments()

Returns:

the number of segments.

getType

public DAType getType()

Returns:

the data access type of this object.