Only compile library.properties schemas once

While it's necessary to do the validation against the schemas for each library, the schemas themselves don't change so
there's no need to recompile them for each library checked.

Author: per1234

project/library/libraryproperties/libraryproperties.go

@@ -33,6 +33,8 @@ func Properties(libraryPath *paths.Path) (*properties.Map, error) {
 	return libraryProperties, nil
 }
 
+var schemaObject = make(map[compliancelevel.Type]*jsonschema.Schema)
+
 // Validate validates library.properties data against the JSON schema and returns a map of the result for each compliance level.
 func Validate(libraryProperties *properties.Map, schemasPath *paths.Path) map[compliancelevel.Type]*jsonschema.ValidationError {
 	referencedSchemaFilenames := []string{
@@ -42,14 +44,15 @@ func Validate(libraryProperties *properties.Map, schemasPath *paths.Path) map[co
 
 	var validationResults = make(map[compliancelevel.Type]*jsonschema.ValidationError)
 
-	schemaObject := schema.Compile("arduino-library-properties-permissive-schema.json", referencedSchemaFilenames, schemasPath)
-	validationResults[compliancelevel.Permissive] = schema.Validate(libraryProperties, schemaObject, schemasPath)
-
-	schemaObject = schema.Compile("arduino-library-properties-schema.json", referencedSchemaFilenames, schemasPath)
-	validationResults[compliancelevel.Specification] = schema.Validate(libraryProperties, schemaObject, schemasPath)
+	if schemaObject[compliancelevel.Permissive] == nil { // Only compile the schemas once.
+		schemaObject[compliancelevel.Permissive] = schema.Compile("arduino-library-properties-permissive-schema.json", referencedSchemaFilenames, schemasPath)
+		schemaObject[compliancelevel.Specification] = schema.Compile("arduino-library-properties-schema.json", referencedSchemaFilenames, schemasPath)
+		schemaObject[compliancelevel.Strict] = schema.Compile("arduino-library-properties-strict-schema.json", referencedSchemaFilenames, schemasPath)
+	}
 
-	schemaObject = schema.Compile("arduino-library-properties-strict-schema.json", referencedSchemaFilenames, schemasPath)
-	validationResults[compliancelevel.Strict] = schema.Validate(libraryProperties, schemaObject, schemasPath)
+	validationResults[compliancelevel.Permissive] = schema.Validate(libraryProperties, schemaObject[compliancelevel.Permissive], schemasPath)
+	validationResults[compliancelevel.Specification] = schema.Validate(libraryProperties, schemaObject[compliancelevel.Specification], schemasPath)
+	validationResults[compliancelevel.Strict] = schema.Validate(libraryProperties, schemaObject[compliancelevel.Strict], schemasPath)
 
 	return validationResults
 }