feat: image variants engine

internal/infrastructure/config/imageVariantSettings.go

@@ -0,0 +1,44 @@
+package config
+
+import (
+	"fmt"
+	"strconv"
+)
+
+const (
+	EnvImageVariantMaxSourceBytes     = "IMAGE_VARIANT_MAX_SOURCE_BYTES"
+	DefaultImageVariantMaxSourceBytes = "10485760"
+
+	EnvImageVariantMaxSourcePixels     = "IMAGE_VARIANT_MAX_SOURCE_PIXELS"
+	DefaultImageVariantMaxSourcePixels = "50000000"
+
+	EnvImageVariantMaxConcurrentRenders     = "IMAGE_VARIANT_MAX_CONCURRENT_RENDERS"
+	DefaultImageVariantMaxConcurrentRenders = "4"
+)
+
+func imageVariantMaxSourceBytesFromEnv() (int64, error) {
+	raw := envOrDefault(EnvImageVariantMaxSourceBytes, DefaultImageVariantMaxSourceBytes)
+	value, err := strconv.ParseInt(raw, 10, 64)
+	if err != nil || value < 1 {
+		return 0, fmt.Errorf("%s must be a whole number of bytes greater than zero, got %q", EnvImageVariantMaxSourceBytes, raw)
+	}
+	return value, nil
+}
+
+func imageVariantMaxSourcePixelsFromEnv() (int64, error) {
+	raw := envOrDefault(EnvImageVariantMaxSourcePixels, DefaultImageVariantMaxSourcePixels)
+	value, err := strconv.ParseInt(raw, 10, 64)
+	if err != nil || value < 1 {
+		return 0, fmt.Errorf("%s must be a whole number of pixels greater than zero, got %q", EnvImageVariantMaxSourcePixels, raw)
+	}
+	return value, nil
+}
+
+func imageVariantMaxConcurrentRendersFromEnv() (int, error) {
+	raw := envOrDefault(EnvImageVariantMaxConcurrentRenders, DefaultImageVariantMaxConcurrentRenders)
+	value, err := strconv.Atoi(raw)
+	if err != nil || value < 1 {
+		return 0, fmt.Errorf("%s must be a whole number of renders greater than zero, got %q", EnvImageVariantMaxConcurrentRenders, raw)
+	}
+	return value, nil
+}