improve package gerror, add HasCode/HasError function for package gerror (#2006)

errors/gerror/gerror_api_stack.go

@@ -0,0 +1,118 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gerror
+
+import (
+	"runtime"
+)
+
+// stack represents a stack of program counters.
+type stack []uintptr
+
+const (
+	// maxStackDepth marks the max stack depth for error back traces.
+	maxStackDepth = 32
+)
+
+// Cause returns the root cause error of `err`.
+func Cause(err error) error {
+	if err == nil {
+		return nil
+	}
+	if e, ok := err.(ICause); ok {
+		return e.Cause()
+	}
+	if e, ok := err.(IUnwrap); ok {
+		return Cause(e.Unwrap())
+	}
+	return err
+}
+
+// Stack returns the stack callers as string.
+// It returns the error string directly if the `err` does not support stacks.
+func Stack(err error) string {
+	if err == nil {
+		return ""
+	}
+	if e, ok := err.(IStack); ok {
+		return e.Stack()
+	}
+	return err.Error()
+}
+
+// Current creates and returns the current level error.
+// It returns nil if current level error is nil.
+func Current(err error) error {
+	if err == nil {
+		return nil
+	}
+	if e, ok := err.(ICurrent); ok {
+		return e.Current()
+	}
+	return err
+}
+
+// Unwrap returns the next level error.
+// It returns nil if current level error or the next level error is nil.
+func Unwrap(err error) error {
+	if err == nil {
+		return nil
+	}
+	if e, ok := err.(IUnwrap); ok {
+		return e.Unwrap()
+	}
+	return nil
+}
+
+// HasStack checks and reports whether `err` implemented interface `gerror.IStack`.
+func HasStack(err error) bool {
+	_, ok := err.(IStack)
+	return ok
+}
+
+// Equal reports whether current error `err` equals to error `target`.
+// Please note that, in default comparison logic for `Error`,
+// the errors are considered the same if both the `code` and `text` of them are the same.
+func Equal(err, target error) bool {
+	if err == target {
+		return true
+	}
+	if e, ok := err.(IEqual); ok {
+		return e.Equal(target)
+	}
+	if e, ok := target.(IEqual); ok {
+		return e.Equal(err)
+	}
+	return false
+}
+
+// Is reports whether current error `err` has error `target` in its chaining errors.
+// It is just for implements for stdlib errors.Is from Go version 1.17.
+func Is(err, target error) bool {
+	if e, ok := err.(IIs); ok {
+		return e.Is(target)
+	}
+	return false
+}
+
+// HasError is alias of Is, which more easily understanding semantics.
+func HasError(err, target error) bool {
+	return Is(err, target)
+}
+
+// callers returns the stack callers.
+// Note that it here just retrieves the caller memory address array not the caller information.
+func callers(skip ...int) stack {
+	var (
+		pcs [maxStackDepth]uintptr
+		n   = 3
+	)
+	if len(skip) > 0 {
+		n += skip[0]
+	}
+	return pcs[:runtime.Callers(n, pcs[:])]
+}