public List<RowLogMessage> next(String subscription, Long minimalTimestamp, boolean problematic)
throws RowLogException {
byte[] rowPrefix;
byte[] subscriptionBytes = Bytes.toBytes(subscription);
if (problematic) {
rowPrefix = PROBLEMATIC_MARKER;
rowPrefix = Bytes.add(rowPrefix, subscriptionBytes);
} else {
rowPrefix = subscriptionBytes;
}
byte[] startRow = rowPrefix;
if (minimalTimestamp != null) startRow = Bytes.add(startRow, Bytes.toBytes(minimalTimestamp));
try {
List<RowLogMessage> rowLogMessages = new ArrayList<RowLogMessage>();
Scan scan = new Scan(startRow);
if (minimalTimestamp != null) scan.setTimeRange(minimalTimestamp, Long.MAX_VALUE);
scan.addColumn(MESSAGES_CF, MESSAGE_COLUMN);
ResultScanner scanner = table.getScanner(scan);
boolean keepScanning = problematic;
do {
Result[] results = scanner.next(batchSize);
if (results.length == 0) {
keepScanning = false;
}
for (Result next : results) {
byte[] rowKey = next.getRow();
if (!Bytes.startsWith(rowKey, rowPrefix)) {
keepScanning = false;
break; // There were no messages for this subscription
}
if (problematic) {
rowKey = Bytes.tail(rowKey, rowKey.length - PROBLEMATIC_MARKER.length);
}
byte[] value = next.getValue(MESSAGES_CF, MESSAGE_COLUMN);
byte[] messageId = Bytes.tail(rowKey, rowKey.length - subscriptionBytes.length);
rowLogMessages.add(decodeMessage(messageId, value));
}
} while (keepScanning);
// The scanner is not closed in a finally block, since when we get an IOException from
// HBase, it is likely that closing the scanner will give problems too. Not closing
// the scanner is not fatal since HBase will expire it after a while.
Closer.close(scanner);
return rowLogMessages;
} catch (IOException e) {
throw new RowLogException("Failed to fetch next message from RowLogShard", e);
}
}
public ReturnCode filterColumn(Cell cell) {
byte[] qualifier = CellUtil.cloneQualifier(cell);
TreeSet<byte[]> lesserOrEqualPrefixes =
(TreeSet<byte[]>) sortedPrefixes.headSet(qualifier, true);
if (lesserOrEqualPrefixes.size() != 0) {
byte[] largestPrefixSmallerThanQualifier = lesserOrEqualPrefixes.last();
if (Bytes.startsWith(qualifier, largestPrefixSmallerThanQualifier)) {
return ReturnCode.INCLUDE;
}
if (lesserOrEqualPrefixes.size() == sortedPrefixes.size()) {
return ReturnCode.NEXT_ROW;
} else {
hint = sortedPrefixes.higher(largestPrefixSmallerThanQualifier);
return ReturnCode.SEEK_NEXT_USING_HINT;
}
} else {
hint = sortedPrefixes.first();
return ReturnCode.SEEK_NEXT_USING_HINT;
}
}
public ReturnCode filterColumn(byte[] buffer, int qualifierOffset, int qualifierLength) {
byte[] qualifier =
Arrays.copyOfRange(buffer, qualifierOffset, qualifierLength + qualifierOffset);
TreeSet<byte[]> lesserOrEqualPrefixes =
(TreeSet<byte[]>) sortedPrefixes.headSet(qualifier, true);
if (lesserOrEqualPrefixes.size() != 0) {
byte[] largestPrefixSmallerThanQualifier = lesserOrEqualPrefixes.last();
if (Bytes.startsWith(qualifier, largestPrefixSmallerThanQualifier)) {
return ReturnCode.INCLUDE;
}
if (lesserOrEqualPrefixes.size() == sortedPrefixes.size()) {
return ReturnCode.NEXT_ROW;
} else {
hint = sortedPrefixes.higher(largestPrefixSmallerThanQualifier);
return ReturnCode.SEEK_NEXT_USING_HINT;
}
} else {
hint = sortedPrefixes.first();
return ReturnCode.SEEK_NEXT_USING_HINT;
}
}
/** Return true if the given file info key is reserved for internal use. */
public static boolean isReservedFileInfoKey(byte[] key) {
return Bytes.startsWith(key, FileInfo.RESERVED_PREFIX_BYTES);
}
