/** Redis SETRANGE command handler. */
public class GridRedisGetRangeCommandHandler extends GridRedisRestCommandHandler {
/** Supported commands. */
private static final Collection<GridRedisCommand> SUPPORTED_COMMANDS = U.sealList(GETRANGE);
/** Start offset position in Redis message parameters. */
private static final int START_OFFSET_POS = 1;
/** End offset position in Redis message parameters. */
private static final int END_OFFSET_POS = 2;
/**
* Handler constructor.
*
* @param log Logger to use.
* @param hnd Rest handler.
*/
public GridRedisGetRangeCommandHandler(
final IgniteLogger log, final GridRestProtocolHandler hnd) {
super(log, hnd);
}
/** {@inheritDoc} */
@Override
public Collection<GridRedisCommand> supportedCommands() {
return SUPPORTED_COMMANDS;
}
/** {@inheritDoc} */
@Override
public GridRestRequest asRestRequest(GridRedisMessage msg) throws IgniteCheckedException {
assert msg != null;
if (msg.messageSize() < 4) throw new GridRedisGenericException("Wrong number of arguments");
GridRestCacheRequest getReq = new GridRestCacheRequest();
getReq.clientId(msg.clientId());
getReq.key(msg.key());
getReq.command(CACHE_GET);
return getReq;
}
/** {@inheritDoc} */
@Override
public ByteBuffer makeResponse(final GridRestResponse restRes, List<String> params) {
if (restRes.getResponse() == null) return GridRedisProtocolParser.toBulkString("");
if (restRes.getResponse() instanceof String) {
String res = String.valueOf(restRes.getResponse());
int startOff;
int endOff;
try {
startOff = boundedStartOffset(Integer.parseInt(params.get(START_OFFSET_POS)), res.length());
endOff = boundedEndOffset(Integer.parseInt(params.get(END_OFFSET_POS)), res.length());
} catch (NumberFormatException e) {
U.error(log, "Erroneous offset", e);
return GridRedisProtocolParser.toGenericError("Offset is not an integer");
}
return GridRedisProtocolParser.toBulkString(res.substring(startOff, endOff));
} else
return GridRedisProtocolParser.toTypeError(
"Operation against a key holding the wrong kind of value");
}
/**
* @param idx Index.
* @param size Bounds.
* @return Offset within the bounds.
*/
private int boundedStartOffset(int idx, int size) {
return idx >= 0 ? Math.min(idx, size) : size + idx;
}
/**
* @param idx Index.
* @param size Bounds.
* @return Offset within the bounds.
*/
private int boundedEndOffset(int idx, int size) {
return idx >= 0 ? Math.min(idx + 1, size) : size + idx + 1;
}
}
