doc: add document for compare package

compare/compare_internal.go

@@ -0,0 +1,323 @@
+package compare
+
+import (
+	"bytes"
+	"encoding/json"
+	"reflect"
+	"time"
+
+	"github.com/duke-git/lancet/convertor"
+)
+
+func compareValue(operator string, left, right interface{}) bool {
+	leftType, rightType := reflect.TypeOf(left), reflect.TypeOf(right)
+
+	if leftType.Kind() != rightType.Kind() {
+		return false
+	}
+
+	switch leftType.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+		reflect.Float32, reflect.Float64, reflect.Bool, reflect.String:
+		return compareBasicValue(operator, left, right)
+
+	case reflect.Struct, reflect.Slice, reflect.Map:
+		return compareRefValue(operator, left, right, leftType.Kind())
+	}
+
+	return false
+}
+
+func compareRefValue(operator string, leftObj, rightObj interface{}, kind reflect.Kind) bool {
+	leftVal, rightVal := reflect.ValueOf(leftObj), reflect.ValueOf(rightObj)
+
+	switch kind {
+	case reflect.Struct:
+
+		// compare time
+		if leftVal.CanConvert(timeType) {
+			timeObj1, ok := leftObj.(time.Time)
+			if !ok {
+				timeObj1 = leftVal.Convert(timeType).Interface().(time.Time)
+			}
+
+			timeObj2, ok := rightObj.(time.Time)
+			if !ok {
+				timeObj2 = rightVal.Convert(timeType).Interface().(time.Time)
+			}
+
+			return compareBasicValue(operator, timeObj1.UnixNano(), timeObj2.UnixNano())
+		}
+
+		// for other struct type, only process equal operator
+		switch operator {
+		case equal:
+			return objectsAreEqualValues(leftObj, rightObj)
+		}
+
+	case reflect.Slice:
+		// compare []byte
+		if leftVal.CanConvert(bytesType) {
+			bytesObj1, ok := leftObj.([]byte)
+			if !ok {
+				bytesObj1 = leftVal.Convert(bytesType).Interface().([]byte)
+			}
+			bytesObj2, ok := rightObj.([]byte)
+			if !ok {
+				bytesObj2 = rightVal.Convert(bytesType).Interface().([]byte)
+			}
+
+			switch operator {
+			case equal:
+				if bytes.Compare(bytesObj1, bytesObj2) == 0 {
+					return true
+				}
+			case lessThan:
+				if bytes.Compare(bytesObj1, bytesObj2) == -1 {
+					return true
+				}
+			case greaterThan:
+				if bytes.Compare(bytesObj1, bytesObj2) == 1 {
+					return true
+				}
+			case lessOrEqual:
+				if bytes.Compare(bytesObj1, bytesObj2) <= 0 {
+					return true
+				}
+			case greaterOrEqual:
+				if bytes.Compare(bytesObj1, bytesObj2) >= 0 {
+					return true
+				}
+			}
+
+		}
+
+		// for other type slice, only process equal operator
+		switch operator {
+		case equal:
+			return reflect.DeepEqual(leftObj, rightObj)
+		}
+
+	case reflect.Map:
+		// only process equal operator
+		switch operator {
+		case equal:
+			return reflect.DeepEqual(leftObj, rightObj)
+		}
+	}
+
+	return false
+}
+
+func objectsAreEqualValues(expected, actual interface{}) bool {
+	if objectsAreEqual(expected, actual) {
+		return true
+	}
+
+	actualType := reflect.TypeOf(actual)
+	if actualType == nil {
+		return false
+	}
+	expectedValue := reflect.ValueOf(expected)
+	if expectedValue.IsValid() && expectedValue.Type().ConvertibleTo(actualType) {
+		// Attempt comparison after type conversion
+		return reflect.DeepEqual(expectedValue.Convert(actualType).Interface(), actual)
+	}
+
+	return false
+}
+
+func objectsAreEqual(expected, actual interface{}) bool {
+	if expected == nil || actual == nil {
+		return expected == actual
+	}
+
+	exp, ok := expected.([]byte)
+	if !ok {
+		return reflect.DeepEqual(expected, actual)
+	}
+
+	act, ok := actual.([]byte)
+	if !ok {
+		return false
+	}
+	if exp == nil || act == nil {
+		return exp == nil && act == nil
+	}
+	return bytes.Equal(exp, act)
+}
+
+// compareBasic compare basic value: integer, float, string, bool
+func compareBasicValue(operator string, leftValue, rightValue interface{}) bool {
+	if leftValue == nil && rightValue == nil && operator == equal {
+		return true
+	}
+
+	switch leftVal := leftValue.(type) {
+	case json.Number:
+		if left, err := leftVal.Float64(); err == nil {
+			switch rightVal := rightValue.(type) {
+			case json.Number:
+				if right, err := rightVal.Float64(); err == nil {
+					switch operator {
+					case equal:
+						if left == right {
+							return true
+						}
+					case lessThan:
+						if left < right {
+							return true
+						}
+					case greaterThan:
+						if left > right {
+							return true
+						}
+					case lessOrEqual:
+						if left <= right {
+							return true
+						}
+					case greaterOrEqual:
+						if left >= right {
+							return true
+						}
+					}
+
+				}
+
+			case float32, float64, int, uint, int8, uint8, int16, uint16, int32, uint32, int64, uint64:
+				right, err := convertor.ToFloat(rightValue)
+				if err != nil {
+					return false
+				}
+				switch operator {
+				case equal:
+					if left == right {
+						return true
+					}
+				case lessThan:
+					if left < right {
+						return true
+					}
+				case greaterThan:
+					if left > right {
+						return true
+					}
+				case lessOrEqual:
+					if left <= right {
+						return true
+					}
+				case greaterOrEqual:
+					if left >= right {
+						return true
+					}
+				}
+			}
+
+		}
+
+	case float32, float64, int, uint, int8, uint8, int16, uint16, int32, uint32, int64, uint64:
+		left, err := convertor.ToFloat(leftValue)
+		if err != nil {
+			return false
+		}
+		switch rightVal := rightValue.(type) {
+		case json.Number:
+			if right, err := rightVal.Float64(); err == nil {
+				switch operator {
+				case equal:
+					if left == right {
+						return true
+					}
+				case lessThan:
+					if left < right {
+						return true
+					}
+				case greaterThan:
+					if left > right {
+						return true
+					}
+				case lessOrEqual:
+					if left <= right {
+						return true
+					}
+				case greaterOrEqual:
+					if left >= right {
+						return true
+					}
+				}
+			}
+		case float32, float64, int, uint, int8, uint8, int16, uint16, int32, uint32, int64, uint64:
+			right, err := convertor.ToFloat(rightValue)
+			if err != nil {
+				return false
+			}
+
+			switch operator {
+			case equal:
+				if left == right {
+					return true
+				}
+			case lessThan:
+				if left < right {
+					return true
+				}
+			case greaterThan:
+				if left > right {
+					return true
+				}
+			case lessOrEqual:
+				if left <= right {
+					return true
+				}
+			case greaterOrEqual:
+				if left >= right {
+					return true
+				}
+			}
+		}
+
+	case string:
+		left := leftVal
+		switch right := rightValue.(type) {
+		case string:
+			switch operator {
+			case equal:
+				if left == right {
+					return true
+				}
+			case lessThan:
+				if left < right {
+					return true
+				}
+			case greaterThan:
+				if left > right {
+					return true
+				}
+			case lessOrEqual:
+				if left <= right {
+					return true
+				}
+			case greaterOrEqual:
+				if left >= right {
+					return true
+				}
+			}
+		}
+
+	case bool:
+		left := leftVal
+		switch right := rightValue.(type) {
+		case bool:
+			switch operator {
+			case equal:
+				if left == right {
+					return true
+				}
+			}
+		}
+
+	}
+
+	return false
+}