/*
 * Copyright 2004-2019 H2 Group. Multiple-Licensed under the MPL 2.0,
 * and the EPL 1.0 (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.store;

import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import org.h2.value.Value;
import org.h2.value.ValueLobDb;

A mechanism to store and retrieve lob data.
/**
 * A mechanism to store and retrieve lob data.
 */
public interface LobStorageInterface {

    
Create a CLOB object.
Params:
reader – the reader
maxLength – the maximum length (-1 if not known)
Returns:
the LOB/**
     * Create a CLOB object.
     *
     * @param reader the reader
     * @param maxLength the maximum length (-1 if not known)
     * @return the LOB
     */
    Value createClob(Reader reader, long maxLength);

    
Create a BLOB object.
Params:
in – the input stream
maxLength – the maximum length (-1 if not known)
Returns:
the LOB/**
     * Create a BLOB object.
     *
     * @param in the input stream
     * @param maxLength the maximum length (-1 if not known)
     * @return the LOB
     */
    Value createBlob(InputStream in, long maxLength);

    
Copy a lob.
Params:
old – the old lob
tableId – the new table id
length – the length
Returns:
the new lob/**
     * Copy a lob.
     *
     * @param old the old lob
     * @param tableId the new table id
     * @param length the length
     * @return the new lob
     */
    ValueLobDb copyLob(ValueLobDb old, int tableId, long length);

    
Get the input stream for the given lob.
Params:
lob – the lob id
hmac – the message authentication code (for remote input streams)
byteCount – the number of bytes to read, or -1 if not known
Returns:
the stream/**
     * Get the input stream for the given lob.
     *
     * @param lob the lob id
     * @param hmac the message authentication code (for remote input streams)
     * @param byteCount the number of bytes to read, or -1 if not known
     * @return the stream
     */
    InputStream getInputStream(ValueLobDb lob, byte[] hmac, long byteCount)
            throws IOException;

    
Delete a LOB (from the database, if it is stored there).
Params:
lob – the lob/**
     * Delete a LOB (from the database, if it is stored there).
     *
     * @param lob the lob
     */
    void removeLob(ValueLobDb lob);

    
Remove all LOBs for this table.
Params:
tableId – the table id/**
     * Remove all LOBs for this table.
     *
     * @param tableId the table id
     */
    void removeAllForTable(int tableId);

    
Initialize the lob storage.
/**
     * Initialize the lob storage.
     */
    void init();

    
Whether the storage is read-only
Returns:
true if yes/**
     * Whether the storage is read-only
     *
     * @return true if yes
     */
    boolean isReadOnly();

}