refactor: call function

plugin.go

@@ -0,0 +1,132 @@
+package hrp
+
+import (
+	"fmt"
+	"plugin"
+	"reflect"
+	"runtime"
+
+	"github.com/rs/zerolog/log"
+
+	"github.com/httprunner/hrp/internal/builtin"
+)
+
+func (p *parser) loadPlugin(path string) error {
+	if runtime.GOOS == "windows" {
+		log.Warn().Msg("go plugin does not support windows")
+		return nil
+	}
+
+	if path == "" {
+		return nil
+	}
+
+	// check if loaded before
+	if p.pluginLoader != nil {
+		return nil
+	}
+
+	// locate plugin file
+	pluginPath, err := locatePlugin(path)
+	if err != nil {
+		// plugin not found
+		return nil
+	}
+
+	// load plugin
+	plugins, err := plugin.Open(pluginPath)
+	if err != nil {
+		log.Error().Err(err).Str("path", path).Msg("load go plugin failed")
+		return err
+	}
+	p.pluginLoader = plugins
+
+	log.Info().Str("path", path).Msg("load go plugin success")
+	return nil
+}
+
+func getMappingFunction(funcName string, pluginLoader *plugin.Plugin) (reflect.Value, error) {
+	var fn reflect.Value
+	var err error
+
+	defer func() {
+		// check function type
+		if err == nil && fn.Kind() != reflect.Func {
+			// function not valid
+			err = fmt.Errorf("function %s is invalid", funcName)
+			return
+		}
+	}()
+
+	// get function from plugin loader
+	if pluginLoader != nil {
+		sym, err := pluginLoader.Lookup(funcName)
+		if err == nil {
+			fn = reflect.ValueOf(sym)
+			return fn, nil
+		}
+	}
+
+	// get builtin function
+	if function, ok := builtin.Functions[funcName]; ok {
+		fn = reflect.ValueOf(function)
+		return fn, nil
+	}
+
+	// function not found
+	return reflect.Value{}, fmt.Errorf("function %s is not found", funcName)
+}
+
+// callFunc calls function with arguments
+// only support return at most one result value
+func (p *parser) callFunc(funcName string, arguments ...interface{}) (interface{}, error) {
+	fn, err := getMappingFunction(funcName, p.pluginLoader)
+	if err != nil {
+		return nil, err
+	}
+
+	if fn.Type().NumIn() != len(arguments) {
+		// function arguments not match
+		return nil, fmt.Errorf("function arguments number not match")
+	}
+
+	argumentsValue := make([]reflect.Value, len(arguments))
+	for index, argument := range arguments {
+		argumentValue := reflect.ValueOf(argument)
+		expectArgumentType := fn.Type().In(index)
+		actualArgumentType := reflect.TypeOf(argument)
+
+		// type match
+		if expectArgumentType == actualArgumentType {
+			argumentsValue[index] = argumentValue
+			continue
+		}
+
+		// type not match, check if convertible
+		if !actualArgumentType.ConvertibleTo(expectArgumentType) {
+			// function argument type not match and not convertible
+			err := fmt.Errorf("function argument %d's type is neither match nor convertible, expect %v, actual %v",
+				index, expectArgumentType, actualArgumentType)
+			return nil, err
+		}
+		// convert argument to expect type
+		argumentsValue[index] = argumentValue.Convert(expectArgumentType)
+	}
+
+	resultValues := fn.Call(argumentsValue)
+	if len(resultValues) > 1 {
+		// function should return at most one value
+		err := fmt.Errorf("function should return at most one value")
+		return nil, err
+	}
+
+	// no return value
+	if len(resultValues) == 0 {
+		return nil, nil
+	}
+
+	// return one value
+	// convert reflect.Value to interface{}
+	result := resultValues[0].Interface()
+	return result, nil
+}