[performance] minimise log field allocations (#3529)

* when appending log field only do so by minimal amount

* move slice utils to separate package to fix import cycle, add GrowJust() and AppendJust() functions

* fix GrowJust() not returning slice of same length

* improved xslices tests

* make AppendJust() test check for slice contents, fix AppendJust() final copying behaviour

* add a +1 with field growth to try minimise allocation for log 'msg' field

1 files changed, 0 insertions, 94 deletions

diff --git a/internal/util/slices_test.go b/internal/util/slices_test.go
deleted file mode 100644
index c93e489f5..000000000
--- a/internal/util/slices_test.go
+++ /dev/null
@@ -1,94 +0,0 @@
-// GoToSocial
-// Copyright (C) GoToSocial Authors admin@gotosocial.org
-// SPDX-License-Identifier: AGPL-3.0-or-later
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-package util_test
-
-import (
-	"net/url"
-	"slices"
-	"testing"
-
-	"github.com/superseriousbusiness/gotosocial/internal/util"
-)
-
-var (
-	testURLSlice = []*url.URL{}
-)
-
-func TestGather(t *testing.T) {
-	out := util.Gather(nil, []*url.URL{
-		{Scheme: "https", Host: "google.com", Path: "/some-search"},
-		{Scheme: "http", Host: "example.com", Path: "/robots.txt"},
-	}, (*url.URL).String)
-	if !slices.Equal(out, []string{
-		"https://google.com/some-search",
-		"http://example.com/robots.txt",
-	}) {
-		t.Fatal("unexpected gather output")
-	}
-
-	out = util.Gather([]string{
-		"starting input string",
-		"another starting input",
-	}, []*url.URL{
-		{Scheme: "https", Host: "google.com", Path: "/some-search"},
-		{Scheme: "http", Host: "example.com", Path: "/robots.txt"},
-	}, (*url.URL).String)
-	if !slices.Equal(out, []string{
-		"starting input string",
-		"another starting input",
-		"https://google.com/some-search",
-		"http://example.com/robots.txt",
-	}) {
-		t.Fatal("unexpected gather output")
-	}
-}
-
-func TestGatherIf(t *testing.T) {
-	out := util.GatherIf(nil, []string{
-		"hello world",
-		"not hello world",
-		"hello world",
-	}, func(s string) (string, bool) {
-		return s, s == "hello world"
-	})
-	if !slices.Equal(out, []string{
-		"hello world",
-		"hello world",
-	}) {
-		t.Fatal("unexpected gatherif output")
-	}
-
-	out = util.GatherIf([]string{
-		"starting input string",
-		"another starting input",
-	}, []string{
-		"hello world",
-		"not hello world",
-		"hello world",
-	}, func(s string) (string, bool) {
-		return s, s == "hello world"
-	})
-	if !slices.Equal(out, []string{
-		"starting input string",
-		"another starting input",
-		"hello world",
-		"hello world",
-	}) {
-		t.Fatal("unexpected gatherif output")
-	}
-}