|Modifier and Type||Class and Description|
Interface definition for a callback to be notified of
|Constructor and Description|
|Modifier and Type||Method and Description|
Reads up to
public CacheDataSource(Cache cache, DataSource upstream, boolean blockOnCache, boolean ignoreCacheOnError)
public CacheDataSource(Cache cache, DataSource upstream, boolean blockOnCache, boolean ignoreCacheOnError, long maxCacheFileSize)
public CacheDataSource(Cache cache, DataSource upstream, DataSource cacheReadDataSource, DataSink cacheWriteDataSink, boolean blockOnCache, boolean ignoreCacheOnError, CacheDataSource.EventListener eventListener)
DataSinkinstances for reading and writing the cache. One use of this constructor is to allow data to be transformed before it is written to disk.
cache- The cache.
DataSourcefor reading data not in the cache.
DataSourcefor reading data from the cache.
DataSinkfor writing data to the cache.
blockOnCache- A flag indicating whether we will block reads if the cache key is locked. If this flag is false, then we will read from upstream if the cache key is locked.
ignoreCacheOnError- Whether the cache is bypassed following any cache related error. If true, then cache related exceptions may be thrown for one cycle of open, read and close calls. Subsequent cycles of these calls will then bypass the cache.
eventListener- An optional
CacheDataSource.EventListenerto receive events.
public long open(DataSpec dataSpec) throws IOException
DataSourceto read the specified data. Calls to
DataSource.close()must be balanced.
DataSource.open(DataSpec) throws an
IOException, callers must still call
DataSource.close() to ensure that any partial effects of the
are cleaned up. Implementations of this class can assume that callers will call
DataSource.close() in this case.
dataSpec- Defines the data to be read.
C.LENGTH_UNBOUNDED) this value is the resolved length of the request, or
C.LENGTH_UNBOUNDEDif the length is still unresolved. For all other requests, the value returned will be equal to the request's
IOException- If an error occurs opening the source.
public int read(byte buffer, int offset, int max) throws IOException
lengthbytes of data and stores them into
buffer, starting at index
This method blocks until at least one byte of data can be read, the end of the opened range is detected, or an exception is thrown.
buffer- The buffer into which the read data should be stored.
offset- The start offset into
bufferat which data should be written.
max- The maximum number of bytes to read.
C.RESULT_END_OF_INPUTif the end of the opened range is reached.
IOException- If an error occurs reading from the source.
public void close() throws IOException