Method Query

database/sqlite/sharded.go:48–143

(params database.Params)

}

func (driver *Sharded) Query(params database.Params) (*database.Analytics, error) {
	// Construct DBPath
	dbPath := manager.DBPath{
		Name:      params.DBName,
		Directory: driver.directory,
	}

	// Check if DB file exists
	dbExists, err := driver.DBManager.DBExists(dbPath)
	if err != nil {
		driver.DBManager.Logger.Error("Error executing Query/DBExists on DB %s: %v\n", dbPath, err)
		return nil, &errors.InternalError
	}

	// DB doesn't exist
	if !dbExists {
		return nil, &errors.InvalidDatabaseName
	}

	// At this point, there should be shards to query
	// Get list of shards by reading directory
	shards := listShards(dbPath)
	analytics := database.Analytics{}
	cachedRequest := cachedRequest(params.URL)

	// Read from each shard
	for _, shardName := range shards {

		// Don't include shard if not in timerange
		shardInt, err := shardNameToInt(shardName)
		if err != nil {
			return nil, err
		}

		startInt, endInt := timeRangeToInt(params.TimeRange)
		if shardInt < startInt || shardInt > endInt {
			continue
		}

		// Get result if is cached
		var shardAnalytics *database.Analytics

		cacheURL, err := formatURLForCache(params.URL, shardInt, startInt, endInt, params.TimeRange)
		if err != nil {
			return nil, err
		}

		cached, inCache := driver.cache.Get(cacheURL)
		if inCache {
			err = json.Unmarshal(cached, &shardAnalytics)
			if err != nil {
				driver.DBManager.Logger.Error("Error unmarshaling from cache: %v\n", err)
				return nil, err
			}
		} else {
			// Else query shard
			// Construct each shard DBPath
			shardPath := manager.DBPath{