Package org.syncany.database.dao

Class ChunkSqlDao

java.lang.Object

org.syncany.database.dao.AbstractSqlDao

org.syncany.database.dao.ChunkSqlDao

public class ChunkSqlDao
extends AbstractSqlDao

The chunk data access object (DAO) writes and queries the SQL database for information on ChunkEntrys. It translates the relational data in the "chunk" table to Java objects.

Field Summary

Fields inherited from class org.syncany.database.dao.AbstractSqlDao

connection

Constructor Summary

Constructors

Constructor	Description
ChunkSqlDao(java.sql.Connection connection)

Method Summary

Modifier and Type	Method	Description
void	clearCache()	Clears the chunk cache loaded by getChunk() and resets the cache.
protected java.util.Map<ChunkEntry.ChunkChecksum,ChunkEntry>	createChunkEntries(java.sql.ResultSet resultSet)
protected ChunkEntry	createChunkEntryFromRow(java.sql.ResultSet resultSet)
ChunkEntry	getChunk(ChunkEntry.ChunkChecksum chunkChecksum)	Queries the database of a chunk with the given checksum.
java.util.Map<ChunkEntry.ChunkChecksum,ChunkEntry>	getChunks(VectorClock vectorClock)	Queries the SQL database for all chunks that originally appeared in the database version identified by the given vector clock.
protected void	loadChunkCache()
void	removeUnreferencedChunks()	Removes unreferenced chunks from the database.
void	updateDirtyChunksNewDatabaseId(long newDatabaseVersionId)	no commit
void	writeChunks(java.sql.Connection connection, long databaseVersionId, java.util.Collection<ChunkEntry> chunks)	Writes a list of ChunkEntrys to the database using INSERTs and the given connection.

Methods inherited from class org.syncany.database.dao.AbstractSqlDao

getConnection, getStatement, getStatement, runScript

Methods inherited from class java.lang.Object

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

Constructor Detail

ChunkSqlDao

public ChunkSqlDao(java.sql.Connection connection)

Method Detail

writeChunks

public void writeChunks(java.sql.Connection connection,
                        long databaseVersionId,
                        java.util.Collection<ChunkEntry> chunks)
                 throws java.sql.SQLException

Writes a list of ChunkEntrys to the database using INSERTs and the given connection.

Note: This method executes, but does not commit the query.

Parameters:

connection - The connection used to execute the statements

databaseVersionId -

chunks - List of ChunkEntrys to be inserted in the database

Throws:

java.sql.SQLException - If the SQL statement fails

removeUnreferencedChunks

public void removeUnreferencedChunks()

Removes unreferenced chunks from the database. Unreferenced chunks are chunks that are not referenced by any file content or multichunk.

During the cleanup process, when file versions are deleted, unused chunks are left over. This method removes these chunks from the database.

Note: This method executes, but does not commit the query.

getChunk

public ChunkEntry getChunk(ChunkEntry.ChunkChecksum chunkChecksum)

Queries the database of a chunk with the given checksum.

Note: When first called, this method loads the chunk cache and keeps this cache until it is cleared explicitly with clearCache().

Also note that this method will return null if the chunk has been added after the cache has been filled.

Parameters:

chunkChecksum - Chunk checksum of the chunk to be selected

Returns:

Returns the chunk entry, or null if the chunk does not exist.

clearCache

public void clearCache()

Clears the chunk cache loaded by getChunk() and resets the cache. If getChunk() is called after the cache is cleared, it is re-populated.

getChunks

public java.util.Map<ChunkEntry.ChunkChecksum,ChunkEntry> getChunks(VectorClock vectorClock)

Queries the SQL database for all chunks that originally appeared in the database version identified by the given vector clock.

Note: This method does not select all the chunks that are referenced in the database version. In particular, it does not return chunks that appeared in previous other database versions.

Parameters:

vectorClock - Vector clock that identifies the database version

Returns:

Returns all chunks that originally belong to a database version

createChunkEntries

protected java.util.Map<ChunkEntry.ChunkChecksum,ChunkEntry> createChunkEntries(java.sql.ResultSet resultSet)
                                                                               throws java.sql.SQLException

Throws:

java.sql.SQLException

createChunkEntryFromRow

protected ChunkEntry createChunkEntryFromRow(java.sql.ResultSet resultSet)
                                      throws java.sql.SQLException

Throws:

java.sql.SQLException

loadChunkCache

protected void loadChunkCache()

updateDirtyChunksNewDatabaseId

public void updateDirtyChunksNewDatabaseId(long newDatabaseVersionId)

no commit