org.deegree.coverage.raster.io.grid
Class GridReader

java.lang.Object
  org.deegree.coverage.raster.io.grid.GridReader

All Implemented Interfaces:

RasterReader

Direct Known Subclasses:

GridFileReader

public abstract class GridReader
extends Object
implements RasterReader

The GridReader class TODO add class documentation here.

Version:

$Revision: 31644 $, $Date: 2011-08-24 22:27:43 +0200 (Wed, 24 Aug 2011) $

Author:

Rutger Bezema, last edited by: $Author: mschneider $

Field Summary

protected GridMetaInfoFile	infoFile Holds information on the grid.
protected int	sampleSize The size of one sample

Constructor Summary

GridReader()

Method Summary

protected ByteBuffer	allocateTileBuffer(boolean direct, boolean forCache) Allocate a buffer which can hold a tile.
boolean	canReadTiles() should return true if the given reader can easily read tiles,without consuming much more memory than needed.
long	getBytesPerTile()
Envelope	getEnvelope()
RasterGeoReference	getGeoReference()
int	getHeight()
protected int[]	getIntersectingTiles(RasterRect rect) Returns the min column, row and max column row of the given rect.
int	getNumberOfTiles()
RasterDataInfo	getRasterDataInfo()
AbstractRaster	getTile(int columnId, int rowId) Read a raster from the grid file at location (row,column).
int	getTileColumns()
ByteBuffer	getTileData(int column, int row, ByteBuffer buffer)
protected Envelope	getTileEnvelope(int column, int row) Calculates the envelope for a tile at a given position in the grid.
protected int	getTileId(int columnId, int rowId) Calculates the id for a tile at a given position in the grid.
int	getTileRasterHeight()
int	getTileRasterWidth()
int	getTileRows()
int	getTilesPerBlob()
int	getWidth()
protected void	instantiate(GridMetaInfoFile infoFile) Instantiates this grid reader with the given information.
AbstractRaster	load(InputStream stream, RasterIOOptions options) Read the given input stream into an abstract raster.
protected abstract void	read(int columnId, int rowId, ByteBuffer buffer) Reads the data from the grid.
void	setTilesPerBlob(int tilesPerBlob)
boolean	shouldCreateCacheFile()
protected RasterRect	snapToGrid(RasterRect original) Get intersection of the requested rectangle with the rectangle of the grid file.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.deegree.coverage.raster.io.RasterReader

canLoad, dispose, file, getDataLocationId, getSupportedFormats, load, read

Field Detail

infoFile

protected GridMetaInfoFile infoFile

Holds information on the grid.

sampleSize

protected int sampleSize

The size of one sample

Constructor Detail

GridReader

public GridReader()

Method Detail

instantiate

protected void instantiate(GridMetaInfoFile infoFile)

Instantiates this grid reader with the given information.

Parameters:

infoFile -

snapToGrid

protected RasterRect snapToGrid(RasterRect original)

Get intersection of the requested rectangle with the rectangle of the grid file.

Parameters:

original -

Returns:

the intersection with the grids raster rectangle and the given.

getTileId

protected int getTileId(int columnId,
                        int rowId)

Calculates the id for a tile at a given position in the grid.

Parameters:

columnId - column id, must be in the range [0 ... #columns - 1]

rowId - row id, must be in the range [0 ... #rows - 1]

Returns:

the tile's id

getTileEnvelope

protected Envelope getTileEnvelope(int column,
                                   int row)

Calculates the envelope for a tile at a given position in the grid.

Parameters:

column - column id, must be in the range [0 ... #columns - 1]

row - row id, must be in the range [0 ... #rows - 1]

Returns:

the tile's envelope

getTile

public AbstractRaster getTile(int columnId,
                              int rowId)
                       throws IOException

Read a raster from the grid file at location (row,column).

Parameters:

columnId -

rowId -

Returns:

the read raster or null if it could not be read.

Throws:

IOException

read

protected abstract void read(int columnId,
                             int rowId,
                             ByteBuffer buffer)
                      throws IOException

Reads the data from the grid.

Parameters:

columnId -

rowId -

buffer -

Throws:

IOException

load

public AbstractRaster load(InputStream stream,
                           RasterIOOptions options)
                    throws IOException

Description copied from interface: RasterReader

Read the given input stream into an abstract raster.

Specified by:

load in interface RasterReader

Returns:

the loaded raster

Throws:

IOException - may be thrown when there is a problem with reading the raster.

getNumberOfTiles

public int getNumberOfTiles()

Returns:

the number of tiles in this blob.

getBytesPerTile

public long getBytesPerTile()

Returns:

the number of bytes one tile in the given grid has.

getGeoReference

public RasterGeoReference getGeoReference()

Specified by:

getGeoReference in interface RasterReader

Returns:

the geo reference of the read raster

getHeight

public int getHeight()

Specified by:

getHeight in interface RasterReader

Returns:

the height (in pixels) of the read raster

getWidth

public int getWidth()

Specified by:

getWidth in interface RasterReader

Returns:

the width (in pixels) of the read raster

getTileRasterWidth

public int getTileRasterWidth()

Returns:

the width of a tile in raster coordinates.

getTileRasterHeight

public int getTileRasterHeight()

Returns:

the height of a tile in raster coordinates.

canReadTiles

public boolean canReadTiles()

Description copied from interface: RasterReader

should return true if the given reader can easily read tiles,without consuming much more memory than needed.

Specified by:

canReadTiles in interface RasterReader

Returns:

true if the reader can easily read tiles.

getIntersectingTiles

protected int[] getIntersectingTiles(RasterRect rect)

Returns the min column, row and max column row of the given rect. The rectangle will be cut off to fit the data. If the rect does not intersect the data, null will be returned.

Parameters:

rect -

Returns:

{min column, min row, max column, max row} or null if the given rect does not intersect the data.

shouldCreateCacheFile

public boolean shouldCreateCacheFile()

Specified by:

shouldCreateCacheFile in interface RasterReader

Returns:

true if a cache file should be created for the read raster.

getTileData

public ByteBuffer getTileData(int column,
                              int row,
                              ByteBuffer buffer)
                       throws IOException

Parameters:

column -

row -

buffer -

Returns:

a newly allocated buffer if the given one was null

Throws:

IOException

allocateTileBuffer

protected ByteBuffer allocateTileBuffer(boolean direct,
                                        boolean forCache)

Allocate a buffer which can hold a tile.

Parameters:

direct - if the buffer should be direct

forCache - if the buffer is used for caching mechanisms.

Returns:

a ByteBuffer which can hold a tile.

getTileRows

public int getTileRows()

Returns:

the number of grid rows

getTileColumns

public int getTileColumns()

Returns:

the number of grid columns

getTilesPerBlob

public int getTilesPerBlob()

Returns:

the tilesPerBlob

setTilesPerBlob

public void setTilesPerBlob(int tilesPerBlob)

Parameters:

tilesPerBlob -

getRasterDataInfo

public RasterDataInfo getRasterDataInfo()

Specified by:

getRasterDataInfo in interface RasterReader

Returns:

the raster data info

getEnvelope

public final Envelope getEnvelope()

Returns:

the envelope