move recorder to interface

pkg/weather/recorder/recorders/memory/get.go

@@ -0,0 +1,75 @@
+package memory
+
+import (
+	"context"
+	"errors"
+	"slices"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+
+	pb "gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/api/v1alpha1/weather"
+	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather"
+)
+
+func (r *MemoryRecorder) Get(ctx context.Context, req *pb.GetWeatherRequest) (
+	[]*weather.WeatherUpdate, error,
+) {
+	ctx, span := r.tracer.Start(ctx, "memoryRecorder.Get")
+	defer span.End()
+
+	r.RLock()
+	defer r.RUnlock()
+
+	span.AddEvent("acquired lock on recorder cache")
+
+	updates := r.updates
+
+	if r.count() == 0 {
+		err := errors.New("no recorded updates to get")
+		span.RecordError(err)
+		return nil, err
+	} else if r.count() <= int(*req.Limit) {
+		span.RecordError(errors.New("requested more updates than recorded"))
+	}
+
+	// Filter by Station Name if requested
+	if req.Opts.StationName != nil && *req.Opts.StationName != "" {
+		updates = slices.DeleteFunc(updates, func(u *weather.WeatherUpdate) bool {
+			return u.StationConfig == nil || u.StationConfig.Name != *req.Opts.StationName
+		})
+	}
+
+	// Filter by Station Type if requested
+	if req.Opts.StationType != nil && *req.Opts.StationType != "" {
+		updates = slices.DeleteFunc(updates, func(u *weather.WeatherUpdate) bool {
+			return u.StationType == nil || *u.StationType != *req.Opts.StationType
+		})
+	}
+
+	// Limit results
+	if len(updates) > int(*req.Limit) {
+		updates = updates[len(updates)-int(*req.Limit):]
+	}
+
+	span.SetAttributes(attribute.Int("retrieved", len(updates)))
+	span.SetStatus(codes.Ok, "")
+
+	return updates, nil
+}
+
+func (r *MemoryRecorder) Count(ctx context.Context) int {
+	_, span := r.tracer.Start(ctx, "countWeatherRecorder")
+	defer span.End()
+
+	count := r.count()
+
+	span.SetAttributes(attribute.Int("count", count))
+	span.SetStatus(codes.Ok, "")
+
+	return count
+}
+
+func (r *MemoryRecorder) count() int {
+	return len(r.updates)
+}

pkg/weather/recorder/recorders/memory/memory.go

@@ -0,0 +1,35 @@
+package memory
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel/trace"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/otel"
+
+	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather"
+	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather/recorder/recorders"
+)
+
+const defRetainLast = 120
+
+type MemoryRecorder struct {
+	baseCtx context.Context
+	updates []*weather.WeatherUpdate
+	tracer  trace.Tracer
+	keep    int
+	*sync.RWMutex
+}
+
+func (r *MemoryRecorder) Init(ctx context.Context, opts *recorders.RecorderOpts) {
+	if opts.RetainLast < 1 {
+		opts.RetainLast = defRetainLast
+	}
+
+	r.updates = make([]*weather.WeatherUpdate, 0, opts.RetainLast)
+	r.keep = opts.RetainLast
+	r.baseCtx = opts.BaseCtx
+	r.RWMutex = &sync.RWMutex{}
+	r.tracer = otel.GetTracer(r.baseCtx, "memoryRecorder")
+}

pkg/weather/recorder/recorders/memory/set.go

@@ -0,0 +1,38 @@
+package memory
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+
+	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather"
+)
+
+func (r *MemoryRecorder) Set(ctx context.Context, u *weather.WeatherUpdate) error {
+	r.Lock()
+	defer r.Unlock()
+
+	ctx, span := r.tracer.Start(ctx, "memoryRecorder.Set")
+	span.SetAttributes(
+		attribute.Int("countWeatherUpdates", r.Count(ctx)),
+		attribute.Int("keepUpdates", r.keep),
+	)
+	defer span.End()
+
+	return r.set(ctx, u)
+}
+
+func (r *MemoryRecorder) set(ctx context.Context, u *weather.WeatherUpdate) error {
+	span := trace.SpanFromContext(ctx)
+
+	if len(r.updates) > r.keep {
+		r.updates = r.updates[1:]
+		span.AddEvent("trimmed recorded updates by 1")
+	}
+
+	r.updates = append(r.updates, u)
+	span.AddEvent("recorded weather update")
+
+	return nil
+}

pkg/weather/recorder/recorders/recorders.go

@@ -0,0 +1,20 @@
+package recorders
+
+import (
+	"context"
+
+	pb "gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/api/v1alpha1/weather"
+	"gitea.libretechconsulting.com/rmcguire/ambient-local-exporter/pkg/weather"
+)
+
+type RecorderOpts struct {
+	RetainLast int
+	BaseCtx    context.Context
+}
+
+type Recorder interface {
+	Init(context.Context, *RecorderOpts)
+	Set(context.Context, *weather.WeatherUpdate) error
+	Get(context.Context, *pb.GetWeatherRequest) ([]*weather.WeatherUpdate, error)
+	Count(context.Context) int // Best Effort
+}