private Optional getCommitTimestampWithRaces()

in hbase-coprocessor/src/main/java/org/apache/hadoop/hbase/regionserver/CompactorScanner.java [242:303]
47 lines of code
10 McCabe index (conditional complexity)

    private Optional<CommitTimestamp> getCommitTimestampWithRaces(Cell cell) throws IOException {
        try {
            byte[] family = CellUtil.cloneFamily(cell);
            byte[] qualifier = CellUtils.addShadowCellSuffixPrefix(cell.getQualifierArray(),
                    cell.getQualifierOffset(),
                    cell.getQualifierLength());
            // 2) Then check the commit table
            Optional<CommitTimestamp> ct = commitTableClient.getCommitTimestamp(cell.getTimestamp()).get();
            if (ct.isPresent()) {
                if (ct.get().isValid()) {
                    return Optional.of(ct.get());
                }
                // If invalid still should check sc because maybe we got falsely invalidated by another compaction or ll client
            }

            // 3) Read from shadow cell
            Result r = getShadowCell(CellUtil.cloneRow(cell), family, qualifier, cell.getTimestamp());
            if (r.containsColumn(CellUtil.cloneFamily(cell), qualifier)) {
                Optional<CommitTimestamp> retval = Optional.of(new CommitTimestamp(SHADOW_CELL,
                        Bytes.toLong(r.getValue(family, qualifier)), true));
                return retval;
            }

            // [OMID-146] - we have to invalidate a transaction if it hasn't reached the commit table
            // 4) invalidate the entry
            Boolean invalidated = commitTableClient.tryInvalidateTransaction(cell.getTimestamp()).get();
            if (invalidated) {
                // If we are running lowLatency Omid, we could have managed to invalidate a ct entry,
                // but the committing client already wrote to shadow cells:
                Result r2 = getShadowCell(CellUtil.cloneRow(cell), family, qualifier, cell.getTimestamp());
                if (r2.containsColumn(CellUtil.cloneFamily(cell), qualifier)) {
                    Optional<CommitTimestamp> retval = Optional.of(new CommitTimestamp(SHADOW_CELL,
                            Bytes.toLong(r2.getValue(family, qualifier)), true));
                    commitTableClient.deleteCommitEntry(cell.getTimestamp());
                    return retval;
                }
                return Optional.absent();
            }

            // 5) We did not manage to invalidate the transactions then check the commit table
            Optional<CommitTimestamp> ct2 = commitTableClient.getCommitTimestamp(cell.getTimestamp()).get();
            if (ct2.isPresent()) {
                return Optional.of(ct2.get());
            }

            // 6) Read from shadow cell
            Result r2 = getShadowCell(CellUtil.cloneRow(cell), family, qualifier, cell.getTimestamp());
            if (r2.containsColumn(CellUtil.cloneFamily(cell), qualifier)) {
                Optional<CommitTimestamp> retval = Optional.of(new CommitTimestamp(SHADOW_CELL,
                        Bytes.toLong(r2.getValue(family, qualifier)), true));
                return retval;
            }

        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new IOException("Interrupted while getting commit timestamp from commit table");
        } catch (ExecutionException e) {
            throw new IOException("Error getting commit timestamp from commit table", e);
        }

        return Optional.absent();
    }