From 4dd382aaf25132b31eb269749a2cd36daf0cb792 Mon Sep 17 00:00:00 2001
From: Eugene Burkov <e.burkov@adguard.com>
Date: Mon, 23 Nov 2020 13:59:10 +0300
Subject: [PATCH] all: improve code quality

---
 internal/aghio/limitedreadcloser.go      | 4 ++--
 internal/aghio/limitedreadcloser_test.go | 2 +-
 internal/home/auth_glinet.go             | 3 ++-
 internal/home/middlewares.go             | 4 ++++
 internal/home/whois.go                   | 3 ++-
 internal/update/check.go                 | 3 ++-
 internal/update/updater.go               | 5 +++--
 7 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/internal/aghio/limitedreadcloser.go b/internal/aghio/limitedreadcloser.go
index 4f53a2fbdc5..055ee60864b 100644
--- a/internal/aghio/limitedreadcloser.go
+++ b/internal/aghio/limitedreadcloser.go
@@ -47,9 +47,9 @@ func (lrc *limitedReadCloser) Close() error {
 
 // LimitReadCloser wraps ReadCloser to make it's Reader stop with
 // ErrLimitReached after n bytes read.
-func LimitReadCloser(rc io.ReadCloser, n int64) (new io.ReadCloser, err error) {
+func LimitReadCloser(rc io.ReadCloser, n int64) (newRC io.ReadCloser, err error) {
 	if n < 0 {
-		return nil, fmt.Errorf("invalid n: %d", n)
+		return nil, fmt.Errorf("aghio: invalid n in LimitReadCloser: %d", n)
 	}
 	return &limitedReadCloser{
 		limit: n,
diff --git a/internal/aghio/limitedreadcloser_test.go b/internal/aghio/limitedreadcloser_test.go
index e6cb084f452..1f10e32bf7e 100644
--- a/internal/aghio/limitedreadcloser_test.go
+++ b/internal/aghio/limitedreadcloser_test.go
@@ -26,7 +26,7 @@ func TestLimitReadCloser(t *testing.T) {
 	}, {
 		name: "negative",
 		n:    -1,
-		want: fmt.Errorf("invalid n: -1"),
+		want: fmt.Errorf("aghio: invalid n in LimitReadCloser: -1"),
 	}}
 
 	for _, tc := range testCases {
diff --git a/internal/home/auth_glinet.go b/internal/home/auth_glinet.go
index a99118b119b..228843fa167 100644
--- a/internal/home/auth_glinet.go
+++ b/internal/home/auth_glinet.go
@@ -83,10 +83,11 @@ func glGetTokenDate(file string) uint32 {
 		log.Error("os.Open: %s", err)
 		return 0
 	}
+	defer f.Close()
+
 	fileReadCloser, err := aghio.LimitReadCloser(f, MaxFileSize)
 	if err != nil {
 		log.Error("LimitReadCloser: %s", err)
-		f.Close()
 		return 0
 	}
 	defer fileReadCloser.Close()
diff --git a/internal/home/middlewares.go b/internal/home/middlewares.go
index 9dce404017c..4a38160dc00 100644
--- a/internal/home/middlewares.go
+++ b/internal/home/middlewares.go
@@ -5,6 +5,8 @@ import (
 	"strings"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghio"
+
+	"github.com/AdguardTeam/golibs/log"
 )
 
 // middlerware is a wrapper function signature.
@@ -31,6 +33,8 @@ func limitRequestBody(h http.Handler) (limited http.Handler) {
 		var err error
 		r.Body, err = aghio.LimitReadCloser(r.Body, RequestBodySizeLimit)
 		if err != nil {
+			log.Error("limitRequestBody: %s", err)
+
 			return
 		}
 
diff --git a/internal/home/whois.go b/internal/home/whois.go
index 0d6fbd10e78..4884d776dc0 100644
--- a/internal/home/whois.go
+++ b/internal/home/whois.go
@@ -129,9 +129,10 @@ func (w *Whois) query(target, serverAddr string) (string, error) {
 	if err != nil {
 		return "", err
 	}
+	defer conn.Close()
+
 	connReadCloser, err := aghio.LimitReadCloser(conn, MaxConnReadSize)
 	if err != nil {
-		conn.Close()
 		return "", err
 	}
 	defer connReadCloser.Close()
diff --git a/internal/update/check.go b/internal/update/check.go
index aa2fa675e1a..e83ab5c20f2 100644
--- a/internal/update/check.go
+++ b/internal/update/check.go
@@ -35,9 +35,10 @@ func (u *Updater) GetVersionResponse(forceRecheck bool) (VersionInfo, error) {
 	if err != nil {
 		return VersionInfo{}, fmt.Errorf("updater: HTTP GET %s: %w", u.VersionURL, err)
 	}
+	defer resp.Body.Close()
+
 	resp.Body, err = aghio.LimitReadCloser(resp.Body, MaxResponseSize)
 	if err != nil {
-		resp.Body.Close()
 		return VersionInfo{}, fmt.Errorf("updater: LimitReadCloser: %w", err)
 	}
 	defer resp.Body.Close()
diff --git a/internal/update/updater.go b/internal/update/updater.go
index 032c5a4e04b..34d6681949e 100644
--- a/internal/update/updater.go
+++ b/internal/update/updater.go
@@ -219,7 +219,8 @@ func (u *Updater) clean() {
 }
 
 // MaxPackageFileSize is a maximum package file length in bytes. The largest
-// package whose size is limited by this constant has size of 9MiB for now.
+// package whose size is limited by this constant currently has the size of
+// approximately 9 MiB.
 const MaxPackageFileSize = 32 * 1024 * 1024
 
 // Download package file and save it to disk
@@ -228,10 +229,10 @@ func (u *Updater) downloadPackageFile(url string, filename string) error {
 	if err != nil {
 		return fmt.Errorf("http request failed: %w", err)
 	}
+	defer resp.Body.Close()
 
 	resp.Body, err = aghio.LimitReadCloser(resp.Body, MaxPackageFileSize)
 	if err != nil {
-		resp.Body.Close()
 		return fmt.Errorf("http request failed: %w", err)
 	}
 	defer resp.Body.Close()