| javax.media.jai.TileCache
All known Subclasses: com.sun.media.jai.util.SunTileCache,
| TileCache | | public interface TileCache (Code) | | A class implementing a caching mechanism for image tiles.
TileCache provides a mechanism by which an
OpImage may cache its computed tiles. There may be
multiple TileCaches used in an application up to the
point of having a different TileCache for each
OpImage.
The TileCache used for a particular OpImage
is derived from the RenderingHints assigned to the
associated imaging chain node. If the node is constructed using
JAI.create() and no TileCache is specified
in the RenderingHints parameter, then one is derived
from the RenderingHints associated with the instance of the
JAI class being used.
In the Sun reference implementation, the cache size is limited by
the memory capacity, which is set to a default value at construction
or subsequently using the setMemoryCapacity() method.
The initial value may be obtained using getMemoryCapacity().
The tile capacity is not used as different images may have very different
tile sizes so that this metric is not a particularly meaningful control
of memory resource consumption in general.
See Also: JAI
See Also: RenderedOp
See Also: java.awt.RenderingHints |
| Method Summary | |
| void | add(RenderedImage owner, int tileX, int tileY, Raster data)
Adds a tile to the cache. | | void | add(RenderedImage owner, int tileX, int tileY, Raster data, Object tileCacheMetric)
| | void | addTiles(RenderedImage owner, Point[] tileIndices, Raster[] tiles, Object tileCacheMetric)
Adds an array of tiles to the tile cache. | | void | flush()
Advises the cache that all of its tiles may be discarded. | | long | getMemoryCapacity()
Returns the memory capacity in bytes. | | float | getMemoryThreshold()
Returns the memory threshold, which is the fractional
amount of cache memory to retain during tile removal. | | Raster | getTile(RenderedImage owner, int tileX, int tileY)
Retrieves a tile. | | int | getTileCapacity()
Returns the tile capacity in tiles. | | Comparator | getTileComparator()
Returns the Comparator currently set for use in ordering
the CachedTiles stored by the TileCache. | | Raster[] | getTiles(RenderedImage owner)
Retrieves an array of all tiles in the cache which are owned by the
specified image.
Parameters:
owner - The RenderedImage to which the tiles belong. | | Raster[] | getTiles(RenderedImage owner, Point[] tileIndices)
Returns an array of tile Rasters from the cache. | | void | memoryControl()
Advises the cache that some of its tiles may be discarded. | | void | remove(RenderedImage owner, int tileX, int tileY)
Advises the cache that a tile is no longer needed. | | void | removeTiles(RenderedImage owner)
Advises the cache that all tiles associated with a given image
are no longer needed. | | void | setMemoryCapacity(long memoryCapacity)
Sets the memory capacity to a desired number of bytes. | | void | setMemoryThreshold(float memoryThreshold)
Sets the memoryThreshold value to a floating
point number that ranges from 0.0 to 1.0.
When the cache memory is full, the memory
usage will be reduced to this fraction of
the total cache memory capacity. | | void | setTileCapacity(int tileCapacity)
Sets the tile capacity to a desired number of tiles.
If the capacity is smaller than the current capacity,
tiles are flushed from the cache. | | void | setTileComparator(Comparator comparator)
Sets a Comparator which imposes an order on the
CachedTiles stored in the TileCache.
This ordering is used in memoryControl() to determine
the sequence in which tiles will be removed from the
TileCache so as to reduce the memory to the level given
by the memory threshold. |
| add | | void add(RenderedImage owner, int tileX, int tileY, Raster data)(Code) | | Adds a tile to the cache.
Parameters:
owner - The RenderedImage that the tile belongs to.
Parameters:
tileX - The X index of the tile in the owner's tile grid.
Parameters:
tileY - The Y index of the tile in the owner's tile grid.
Parameters:
data - A Raster containing the tile data. |
| add | | void add(RenderedImage owner, int tileX, int tileY, Raster data, Object tileCacheMetric)(Code) | | Adds a tile to the cache with an associated compute cost
Parameters:
owner - The RenderedImage that the tile belongs to.
Parameters:
tileX - The X index of the tile in the owner's tile grid.
Parameters:
tileY - The Y index of the tile in the owner's tile grid.
Parameters:
data - A Raster containing the tile data.
Parameters:
tileCacheMetric - An Object as a tile metric.
since:
JAI 1.1 |
| addTiles | | void addTiles(RenderedImage owner, Point[] tileIndices, Raster[] tiles, Object tileCacheMetric)(Code) | | Adds an array of tiles to the tile cache.
Parameters:
owner - The RenderedImage that the tile belongs to.
Parameters:
tileIndices - An array of Points containing thetileX and tileY indices for each tile.
Parameters:
tiles - The array of tile Rasters containing tile data.
Parameters:
tileCacheMetric - Object which provides an ordering metricassociated with the RenderedImage owner.
since:
JAI 1.1 |
| flush | | void flush()(Code) | | Advises the cache that all of its tiles may be discarded. It
is legal to implement this method as a no-op.
|
| getMemoryCapacity | | long getMemoryCapacity()(Code) | | Returns the memory capacity in bytes.
|
| getMemoryThreshold | | float getMemoryThreshold()(Code) | | Returns the memory threshold, which is the fractional
amount of cache memory to retain during tile removal.
since:
JAI 1.1 |
| getTile | | Raster getTile(RenderedImage owner, int tileX, int tileY)(Code) | | Retrieves a tile. Returns null if the tile is not
present in the cache.
Parameters:
owner - The RenderedImage that the tile belongs to.
Parameters:
tileX - The X index of the tile in the owner's tile grid.
Parameters:
tileY - The Y index of the tile in the owner's tile grid. |
| getTileCapacity | | int getTileCapacity()(Code) | | Returns the tile capacity in tiles. It is legal to
implement this method as a no-op which should be
signaled by returning zero.
|
| getTileComparator | | Comparator getTileComparator()(Code) | | Returns the Comparator currently set for use in ordering
the CachedTiles stored by the TileCache.
The tile Comparator or null if theimplementation-dependent ordering algorithm is being used.
since:
JAI 1.1 |
| getTiles | | Raster[] getTiles(RenderedImage owner)(Code) | | Retrieves an array of all tiles in the cache which are owned by the
specified image.
Parameters:
owner - The RenderedImage to which the tiles belong. An array of all tiles owned by the specified image ornull if there are none currently in the cache.
since:
JAI 1.1 |
| getTiles | | Raster[] getTiles(RenderedImage owner, Point[] tileIndices)(Code) | | Returns an array of tile Rasters from the cache.
Any or all of the elements of the returned array may be
null if the corresponding tile is not in the cache.
The length of the returned array must be the same as that of the
parameter array and the ith Raster in the
returned array must correspond to the ith tile index in
the parameter array.
Parameters:
owner - The RenderedImage that the tile belongs to.
Parameters:
tileIndices - An array of Points containing thetileX and tileY indices for each tile.
since:
JAI 1.1 |
| memoryControl | | void memoryControl()(Code) | | Advises the cache that some of its tiles may be discarded. It
is legal to implement this method as a no-op.
since:
JAI 1.1 |
| remove | | void remove(RenderedImage owner, int tileX, int tileY)(Code) | | Advises the cache that a tile is no longer needed. It is legal
to implement this method as a no-op.
Parameters:
owner - The RenderedImage that the tile belongs to.
Parameters:
tileX - The X index of the tile in the owner's tile grid.
Parameters:
tileY - The Y index of the tile in the owner's tile grid. |
| removeTiles | | void removeTiles(RenderedImage owner)(Code) | | Advises the cache that all tiles associated with a given image
are no longer needed. It is legal to implement this method as
a no-op.
Parameters:
owner - The RenderedImage owner of the tilesto be removed. |
| setMemoryCapacity | | void setMemoryCapacity(long memoryCapacity)(Code) | | Sets the memory capacity to a desired number of bytes.
If the memory capacity is smaller than the amount of
memory currently used by the cache, tiles are flushed
until the TileCache's memory usage is less than
memoryCapacity.
Parameters:
memoryCapacity - The new capacity, in bytes. |
| setMemoryThreshold | | void setMemoryThreshold(float memoryThreshold)(Code) | | Sets the memoryThreshold value to a floating
point number that ranges from 0.0 to 1.0.
When the cache memory is full, the memory
usage will be reduced to this fraction of
the total cache memory capacity. For example,
a value of .75 will cause 25% of the memory
to be cleared, while retaining 75%.
memoryThreshold. Retained fraction of memory
throws:
IllegalArgumentException - if the memoryThresholdis less than 0.0 or greater than 1.0
since:
JAI 1.1 |
| setTileCapacity | | void setTileCapacity(int tileCapacity)(Code) | | Sets the tile capacity to a desired number of tiles.
If the capacity is smaller than the current capacity,
tiles are flushed from the cache. It is legal to
implement this method as a no-op.
Parameters:
tileCapacity - The new capacity, in tiles. |
| setTileComparator | | void setTileComparator(Comparator comparator)(Code) | | Sets a Comparator which imposes an order on the
CachedTiles stored in the TileCache.
This ordering is used in memoryControl() to determine
the sequence in which tiles will be removed from the
TileCache so as to reduce the memory to the level given
by the memory threshold. The Objects passed to the
compare() method of the Comparator will
be instances of CachedTile. CachedTiles
will be removed from the TileCache in the ascending
order imposed by this Comparator. If no
Comparator is currently set, the TileCache
should use an implementation-dependent default ordering. In the
Sun Microsystems, Inc., implementation of TileCache,
this ordering is the least recently used
ordering, i.e., the tiles least recently used will be removed first
by memoryControl().
Parameters:
comparator - A Comparator which orders theCachedTiles stored by the TileCache;if null an implementation-dependent algorithmwill be used.
since:
JAI 1.1 |
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