lovetodream/swift-log-loki

Grafana Loki Logging for Swift based on swift-log

swift-log-loki's Issues

Unsupported characters in the label

I got an error in Grafana when trying to make a query:
could not write JSON response: 1:108: parse error: unexpected character inside braces: '-'

Loki's documentation says:

Unsupported characters in the label should be converted to an underscore. For example, the label app.kubernetes.io/name should be written as app_kubernetes_io_name.

https://grafana.com/docs/loki/latest/get-started/labels/#format

Tag for SPM

main brunch must have tag 0.1.0 for spm

LokiStream.swift: Reuse NumberFormatter

Hi, I stumbled across this Swift package because I am looking for a similar solution.

I noticed that at one point you create a new NumberFormatter() for each log entry and I would like to kindly suggest that you either pull this out of the compactMap or - better - use a factory for it.

NumberFormatter() are quite expensive to create and it is recommended to reuse them as often as possible.
(see https://sarunw.com/posts/how-expensive-is-dateformatter/)

swift-log-loki/Sources/LoggingLoki/LokiStream.swift

Lines 10 to 16 in fb800a4

	self.values = logs.compactMap { log in
	let formatter = NumberFormatter()
	formatter.numberStyle = .decimal
	formatter.groupingSeparator = ""
	#if os(macOS) || !canImport(Darwin)
	formatter.thousandSeparator = ""
	#endif

One way could be

private class LokiFormatters {
    
    static let decimalFormatter = {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.groupingSeparator = ""
        #if os(macOS) || !canImport(Darwin)
        formatter.thousandSeparator = ""
        #endif
        
        return formatter
    }()
    
}


struct LokiStream: Encodable, Sendable {
    var stream: Dictionary<String, String>
    var values: Array<Array<String>>

    init(_ logs: [LokiLog], with labels: LokiLabels) {
        self.stream = labels
        self.values = logs.compactMap { log in
            let timestamp = Int64(log.timestamp.timeIntervalSince1970 * 1_000_000_000) as NSNumber
            guard let formattedTimestamp = LokiFormatters.decimalFormatter.string(from: timestamp) else {
                return nil
            }
            return [formattedTimestamp, log.message]
        }
    }
}