Examples with Expression net.opentsdb.query.pojo.Expression used on opensource projects

Example 1 with Expression

use of net.opentsdb.query.pojo.Expression in project opentsdb by OpenTSDB.

the class QueryExecutor method serialize.

/**
   * Writes the results to a ChannelBuffer to return to the caller. This will
   * iterate over all of the outputs and drop in meta data where appropriate.
   * @throws Exception if something went pear shaped
   */
private Deferred<ChannelBuffer> serialize() throws Exception {
    final long start = System.currentTimeMillis();
    // buffers and an array list to stored the deferreds
    final ChannelBuffer response = ChannelBuffers.dynamicBuffer();
    final OutputStream output_stream = new ChannelBufferOutputStream(response);
    final JsonGenerator json = JSON.getFactory().createGenerator(output_stream);
    json.writeStartObject();
    json.writeFieldName("outputs");
    json.writeStartArray();
    // We want the serializer to execute serially so we need to create a callback
    // chain so that when one DPsResolver is finished, it triggers the next to
    // start serializing.
    final Deferred<Object> cb_chain = new Deferred<Object>();
    // default to the expressions if there, or fall back to the metrics
    final List<Output> outputs;
    if (query.getOutputs() == null || query.getOutputs().isEmpty()) {
        if (query.getExpressions() != null && !query.getExpressions().isEmpty()) {
            outputs = new ArrayList<Output>(query.getExpressions().size());
            for (final Expression exp : query.getExpressions()) {
                outputs.add(Output.Builder().setId(exp.getId()).build());
            }
        } else if (query.getMetrics() != null && !query.getMetrics().isEmpty()) {
            outputs = new ArrayList<Output>(query.getMetrics().size());
            for (final Metric metric : query.getMetrics()) {
                outputs.add(Output.Builder().setId(metric.getId()).build());
            }
        } else {
            throw new IllegalArgumentException("How did we get here?? No metrics or expressions??");
        }
    } else {
        outputs = query.getOutputs();
    }
    for (final Output output : outputs) {
        if (expressions != null) {
            final ExpressionIterator it = expressions.get(output.getId());
            if (it != null) {
                cb_chain.addCallback(new SerializeExpressionIterator(tsdb, json, output, it, ts_query));
                continue;
            }
        }
        if (query.getMetrics() != null && !query.getMetrics().isEmpty()) {
            final TSSubQuery sub = sub_queries.get(output.getId());
            if (sub != null) {
                final TimeSyncedIterator it = new TimeSyncedIterator(output.getId(), sub.getFilterTagKs(), sub_query_results.get(output.getId()));
                cb_chain.addCallback(new SerializeSubIterator(tsdb, json, output, it));
                continue;
            }
        } else {
            LOG.warn("Couldn't find a variable matching: " + output.getId() + " in query " + query);
        }
    }
    /** Final callback to close out the JSON array and return our results */
    class FinalCB implements Callback<ChannelBuffer, Object> {

        public ChannelBuffer call(final Object obj) throws Exception {
            json.writeEndArray();
            //        ts_query.getQueryStats().setTimeSerialization(
            //            DateTime.currentTimeMillis() - start);
            ts_query.getQueryStats().markSerializationSuccessful();
            // dump the original query
            if (true) {
                json.writeFieldName("query");
                json.writeObject(QueryExecutor.this.query);
            }
            // IMPORTANT Make sure the close the JSON array and the generator
            json.writeEndObject();
            json.close();
            return response;
        }
    }
    // trigger the callback chain here
    cb_chain.callback(null);
    return cb_chain.addCallback(new FinalCB());
}