diffusion/src/node_modules/features/time-series/query-result.js

Diffusion JavaScript client

var RangeQueryParameters = require('features/time-series/range-query-parameters');
var Long = require('long');

function nonNull(e) {
    return !!e;
}

function comparingSequenceNumbers(e1, e2) {
    return e1.originalEvent.sequence !== e2.originalEvent.sequence
        ? e1.originalEvent.sequence - e2.originalEvent.sequence
        : e1.sequence - e2.sequence;
}

function replaceWithLatest(allEvents) {
    var latestByOriginalSequence = {};

    allEvents.forEach(function(e) {
        var k = e.originalEvent.sequence;

        if (!latestByOriginalSequence[k] || latestByOriginalSequence[k].sequence.toNumber() < e.sequence.toNumber()) {
            latestByOriginalSequence[k] = e;
        }
    });

    return function(e) {
        var originalSequence = e.originalEvent.sequence;
        var latest = latestByOriginalSequence[originalSequence];

        if (!latest) {
            return null;
        }

        if (!e.isEditEvent) {
            delete latestByOriginalSequence[originalSequence];
            return latest;
        } else if (e.sequence.equals(latest.sequence)) {
            delete latestByOriginalSequence[originalSequence];
            return e;
        } else {
            return null;
        }
    };
}

function QueryResult(selectedCount, eventCount, streamStructure, events) {
    this.events = events;

    this.selectedCount = selectedCount.toNumber();

    this.isComplete = (selectedCount.equals(eventCount));

    this.streamStructure = streamStructure;

    this.merge = function(other) {
        var merged = events.concat(other.events)
                           .sort(comparingSequenceNumbers)
                           .map(replaceWithLatest(events.concat(other.events)))
                           .filter(nonNull);

        var count = Long.fromNumber(merged.length);

        return new QueryResult(count, count, RangeQueryParameters.StreamStructure.VALUE_EVENT_STREAM, merged);
    };
}

module.exports = QueryResult;