From c099fd298646caca10ab8f38294db5b85b170cfe Mon Sep 17 00:00:00 2001
From: Mike Zak <feanorr@gmail.com>
Date: Mon, 7 Jun 2021 11:46:31 +0300
Subject: [PATCH] Add error.go to mempool

---
 domain/miningmanager/mempool/error.go | 124 ++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 domain/miningmanager/mempool/error.go

diff --git a/domain/miningmanager/mempool/error.go b/domain/miningmanager/mempool/error.go
new file mode 100644
index 000000000..bc51bb3a0
--- /dev/null
+++ b/domain/miningmanager/mempool/error.go
@@ -0,0 +1,124 @@
+// Copyright (c) 2014-2016 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package mempool
+
+import (
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+// RuleError identifies a rule violation. It is used to indicate that
+// processing of a transaction failed due to one of the many validation
+// rules. The caller can use type assertions to determine if a failure was
+// specifically due to a rule violation and use the Err field to access the
+// underlying error, which will be either a TxRuleError or a
+// ruleerrors.RuleError.
+type RuleError struct {
+	Err error
+}
+
+// Error satisfies the error interface and prints human-readable errors.
+func (e RuleError) Error() string {
+	if e.Err == nil {
+		return "<nil>"
+	}
+	return e.Err.Error()
+}
+
+// Unwrap unwraps the wrapped error
+func (e RuleError) Unwrap() error {
+	return e.Err
+}
+
+// RejectCode represents a numeric value by which a remote peer indicates
+// why a message was rejected.
+type RejectCode uint8
+
+// These constants define the various supported reject codes.
+const (
+	RejectMalformed       RejectCode = 0x01
+	RejectInvalid         RejectCode = 0x10
+	RejectObsolete        RejectCode = 0x11
+	RejectDuplicate       RejectCode = 0x12
+	RejectNotRequested    RejectCode = 0x13
+	RejectNonstandard     RejectCode = 0x40
+	RejectDust            RejectCode = 0x41
+	RejectInsufficientFee RejectCode = 0x42
+	RejectFinality        RejectCode = 0x43
+	RejectDifficulty      RejectCode = 0x44
+	RejectImmatureSpend   RejectCode = 0x45
+)
+
+// Map of reject codes back strings for pretty printing.
+var rejectCodeStrings = map[RejectCode]string{
+	RejectMalformed:       "REJECT_MALFORMED",
+	RejectInvalid:         "REJECT_INVALID",
+	RejectObsolete:        "REJECT_OBSOLETE",
+	RejectDuplicate:       "REJECT_DUPLICATE",
+	RejectNonstandard:     "REJECT_NONSTANDARD",
+	RejectDust:            "REJECT_DUST",
+	RejectInsufficientFee: "REJECT_INSUFFICIENTFEE",
+	RejectFinality:        "REJECT_FINALITY",
+	RejectDifficulty:      "REJECT_DIFFICULTY",
+	RejectNotRequested:    "REJECT_NOTREQUESTED",
+	RejectImmatureSpend:   "REJECT_IMMATURESPEND",
+}
+
+// String returns the RejectCode in human-readable form.
+func (code RejectCode) String() string {
+	if s, ok := rejectCodeStrings[code]; ok {
+		return s
+	}
+
+	return fmt.Sprintf("Unknown RejectCode (%d)", uint8(code))
+}
+
+// TxRuleError identifies a rule violation. It is used to indicate that
+// processing of a transaction failed due to one of the many validation
+// rules. The caller can use type assertions to determine if a failure was
+// specifically due to a rule violation and access the ErrorCode field to
+// ascertain the specific reason for the rule violation.
+type TxRuleError struct {
+	RejectCode  RejectCode // The code to send with reject messages
+	Description string     // Human readable description of the issue
+}
+
+// Error satisfies the error interface and prints human-readable errors.
+func (e TxRuleError) Error() string {
+	return e.Description
+}
+
+// txRuleError creates an underlying TxRuleError with the given a set of
+// arguments and returns a RuleError that encapsulates it.
+func txRuleError(c RejectCode, desc string) RuleError {
+	return RuleError{
+		Err: TxRuleError{RejectCode: c, Description: desc},
+	}
+}
+
+func newRuleError(err error) RuleError {
+	return RuleError{
+		Err: err,
+	}
+}
+
+// extractRejectCode attempts to return a relevant reject code for a given error
+// by examining the error for known types. It will return true if a code
+// was successfully extracted.
+func extractRejectCode(err error) (RejectCode, bool) {
+	// Pull the underlying error out of a RuleError.
+	var ruleErr RuleError
+	if ok := errors.As(err, &ruleErr); ok {
+		err = ruleErr.Err
+	}
+
+	var trErr TxRuleError
+	if errors.As(err, &trErr) {
+		return trErr.RejectCode, true
+	}
+
+	return RejectInvalid, false
+}