[chore] add a 'nos3' build tag to support compiling without S3 storage support (#4522)

on amd64 this reduces binary size from 75M (compiled with `'nootel'`) down to 73M (compiled with `'nootel nos3'`)

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4522
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

3 files changed, 202 insertions, 96 deletions

diff --git a/internal/storage/storage.go b/internal/storage/storage.go
index 12e2d8fec..2c47017b3 100644
--- a/internal/storage/storage.go
+++ b/internal/storage/storage.go
@@ -15,13 +15,13 @@
 // 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/>.
 
+//go:build !nos3
+
 package storage
 
 import (
 	"context"
-	"errors"
 	"fmt"
-	"io"
 	"mime"
 	"net/url"
 	"os"
@@ -31,10 +31,8 @@ import (
 	"code.superseriousbusiness.org/gotosocial/internal/config"
 	"code.superseriousbusiness.org/gotosocial/internal/gtserror"
 	"code.superseriousbusiness.org/gotosocial/internal/log"
-	"codeberg.org/gruf/go-bytesize"
 	"codeberg.org/gruf/go-cache/v3/ttl"
 	"codeberg.org/gruf/go-storage"
-	"codeberg.org/gruf/go-storage/disk"
 	"codeberg.org/gruf/go-storage/s3"
 	"github.com/minio/minio-go/v7"
 	"github.com/minio/minio-go/v7/pkg/credentials"
@@ -45,33 +43,11 @@ const (
 	urlCacheExpiryFrequency = time.Minute * 5
 )
 
-// PresignedURL represents a pre signed S3 URL with
-// an expiry time.
-type PresignedURL struct {
-	*url.URL
-	Expiry time.Time // link expires at this time
-}
-
-// IsInvalidKey returns whether error is an invalid-key
-// type error returned by the underlying storage library.
-func IsInvalidKey(err error) bool {
-	return errors.Is(err, storage.ErrInvalidKey)
-}
-
-// IsAlreadyExist returns whether error is an already-exists
-// type error returned by the underlying storage library.
-func IsAlreadyExist(err error) bool {
-	return errors.Is(err, storage.ErrAlreadyExists)
-}
-
-// IsNotFound returns whether error is a not-found error
-// type returned by the underlying storage library.
-func IsNotFound(err error) bool {
-	return errors.Is(err, storage.ErrNotFound)
-}
-
-// Driver wraps a kv.KVStore to also provide S3 presigned GET URLs.
+// Driver wraps a storage.Storage to
+// provide optimized write operations
+// and extra S3-specific utilities.
 type Driver struct {
+
 	// Underlying storage
 	Storage storage.Storage
 
@@ -82,21 +58,6 @@ type Driver struct {
 	RedirectURL    string
 }
 
-// Get returns the byte value for key in storage.
-func (d *Driver) Get(ctx context.Context, key string) ([]byte, error) {
-	return d.Storage.ReadBytes(ctx, key)
-}
-
-// GetStream returns an io.ReadCloser for the value bytes at key in the storage.
-func (d *Driver) GetStream(ctx context.Context, key string) (io.ReadCloser, error) {
-	return d.Storage.ReadStream(ctx, key)
-}
-
-// Put writes the supplied value bytes at key in the storage
-func (d *Driver) Put(ctx context.Context, key string, value []byte) (int, error) {
-	return d.Storage.WriteBytes(ctx, key, value)
-}
-
 // PutFile moves the contents of file at path, to storage.Driver{} under given key (with content-type if supported).
 func (d *Driver) PutFile(ctx context.Context, key, filepath, contentType string) (int64, error) {
 
@@ -143,26 +104,6 @@ func (d *Driver) PutFile(ctx context.Context, key, filepath, contentType string)
 	return sz, err
 }
 
-// Delete attempts to remove the supplied key (and corresponding value) from storage.
-func (d *Driver) Delete(ctx context.Context, key string) error {
-	return d.Storage.Remove(ctx, key)
-}
-
-// Has checks if the supplied key is in the storage.
-func (d *Driver) Has(ctx context.Context, key string) (bool, error) {
-	stat, err := d.Storage.Stat(ctx, key)
-	return (stat != nil), err
-}
-
-// WalkKeys walks the keys in the storage.
-func (d *Driver) WalkKeys(ctx context.Context, walk func(string) error) error {
-	return d.Storage.WalkKeys(ctx, storage.WalkKeysOpts{
-		Step: func(entry storage.Entry) error {
-			return walk(entry.Key)
-		},
-	})
-}
-
 // URL will return a presigned GET object URL, but only if running on S3 storage with proxying disabled.
 func (d *Driver) URL(ctx context.Context, key string) *PresignedURL {
 
@@ -277,37 +218,6 @@ func (d *Driver) ProbeCSPUri(ctx context.Context) (string, error) {
 	return uStripped.String(), nil
 }
 
-func AutoConfig() (*Driver, error) {
-	switch backend := config.GetStorageBackend(); backend {
-	case "s3":
-		return NewS3Storage()
-	case "local":
-		return NewFileStorage()
-	default:
-		return nil, fmt.Errorf("invalid storage backend: %s", backend)
-	}
-}
-
-func NewFileStorage() (*Driver, error) {
-	// Load runtime configuration
-	basePath := config.GetStorageLocalBasePath()
-
-	// Use default disk config with
-	// increased write buffer size.
-	diskCfg := disk.DefaultConfig()
-	diskCfg.WriteBufSize = int(16 * bytesize.KiB)
-
-	// Open the disk storage implementation
-	disk, err := disk.Open(basePath, &diskCfg)
-	if err != nil {
-		return nil, fmt.Errorf("error opening disk storage: %w", err)
-	}
-
-	return &Driver{
-		Storage: disk,
-	}, nil
-}
-
 func NewS3Storage() (*Driver, error) {
 	// Load runtime configuration
 	endpoint := config.GetStorageS3Endpoint()
diff --git a/internal/storage/storage_common.go b/internal/storage/storage_common.go
new file mode 100644
index 000000000..3e1311525
--- /dev/null
+++ b/internal/storage/storage_common.go
@@ -0,0 +1,121 @@
+// 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 storage
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"time"
+
+	"code.superseriousbusiness.org/gotosocial/internal/config"
+	"codeberg.org/gruf/go-bytesize"
+	"codeberg.org/gruf/go-storage"
+	"codeberg.org/gruf/go-storage/disk"
+)
+
+// PresignedURL represents a pre signed S3 URL with
+// an expiry time.
+type PresignedURL struct {
+	*url.URL
+	Expiry time.Time // link expires at this time
+}
+
+// IsInvalidKey returns whether error is an invalid-key
+// type error returned by the underlying storage library.
+func IsInvalidKey(err error) bool {
+	return errors.Is(err, storage.ErrInvalidKey)
+}
+
+// IsAlreadyExist returns whether error is an already-exists
+// type error returned by the underlying storage library.
+func IsAlreadyExist(err error) bool {
+	return errors.Is(err, storage.ErrAlreadyExists)
+}
+
+// IsNotFound returns whether error is a not-found error
+// type returned by the underlying storage library.
+func IsNotFound(err error) bool {
+	return errors.Is(err, storage.ErrNotFound)
+}
+
+// Get returns the byte value for key in storage.
+func (d *Driver) Get(ctx context.Context, key string) ([]byte, error) {
+	return d.Storage.ReadBytes(ctx, key)
+}
+
+// GetStream returns an io.ReadCloser for the value bytes at key in the storage.
+func (d *Driver) GetStream(ctx context.Context, key string) (io.ReadCloser, error) {
+	return d.Storage.ReadStream(ctx, key)
+}
+
+// Put writes the supplied value bytes at key in the storage
+func (d *Driver) Put(ctx context.Context, key string, value []byte) (int, error) {
+	return d.Storage.WriteBytes(ctx, key, value)
+}
+
+// Delete attempts to remove the supplied key (and corresponding value) from storage.
+func (d *Driver) Delete(ctx context.Context, key string) error {
+	return d.Storage.Remove(ctx, key)
+}
+
+// Has checks if the supplied key is in the storage.
+func (d *Driver) Has(ctx context.Context, key string) (bool, error) {
+	stat, err := d.Storage.Stat(ctx, key)
+	return (stat != nil), err
+}
+
+// WalkKeys walks the keys in the storage.
+func (d *Driver) WalkKeys(ctx context.Context, walk func(string) error) error {
+	return d.Storage.WalkKeys(ctx, storage.WalkKeysOpts{
+		Step: func(entry storage.Entry) error {
+			return walk(entry.Key)
+		},
+	})
+}
+
+func AutoConfig() (*Driver, error) {
+	switch backend := config.GetStorageBackend(); backend {
+	case "s3":
+		return NewS3Storage()
+	case "local":
+		return NewFileStorage()
+	default:
+		return nil, fmt.Errorf("invalid storage backend: %s", backend)
+	}
+}
+
+func NewFileStorage() (*Driver, error) {
+	// Load runtime configuration
+	basePath := config.GetStorageLocalBasePath()
+
+	// Use default disk config with
+	// increased write buffer size.
+	diskCfg := disk.DefaultConfig()
+	diskCfg.WriteBufSize = int(16 * bytesize.KiB)
+
+	// Open the disk storage implementation
+	disk, err := disk.Open(basePath, &diskCfg)
+	if err != nil {
+		return nil, fmt.Errorf("error opening disk storage: %w", err)
+	}
+
+	return &Driver{Storage: disk}, nil
+}
diff --git a/internal/storage/storage_nos3.go b/internal/storage/storage_nos3.go
new file mode 100644
index 000000000..73a95d50f
--- /dev/null
+++ b/internal/storage/storage_nos3.go
@@ -0,0 +1,75 @@
+// 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/>.
+
+//go:build nos3
+
+package storage
+
+import (
+	"context"
+	"errors"
+	"os"
+
+	"code.superseriousbusiness.org/gotosocial/internal/gtserror"
+	"code.superseriousbusiness.org/gotosocial/internal/log"
+	"codeberg.org/gruf/go-storage/disk"
+)
+
+// Driver wraps a disk.DiskStorage to
+// provide optimized write operations.
+type Driver struct{ Storage *disk.DiskStorage }
+
+// PutFile: see PutFile() in storage.go.
+func (d *Driver) PutFile(ctx context.Context, key, filepath, _ string) (int64, error) {
+
+	// Open file at path for reading.
+	file, err := os.Open(filepath)
+	if err != nil {
+		return 0, gtserror.Newf("error opening file %s: %w", filepath, err)
+	}
+
+	// Write the file data to storage under key. Note
+	// that for disk.DiskStorage{} this should end up
+	// being a highly optimized Linux sendfile syscall.
+	sz, err := d.Storage.WriteStream(ctx, key, file)
+
+	// Wrap write error.
+	if err != nil {
+		err = gtserror.Newf("error writing file %s: %w", key, err)
+	}
+
+	// Close the file: done with it.
+	if e := file.Close(); e != nil {
+		log.Errorf(ctx, "error closing file %s: %v", filepath, e)
+	}
+
+	return sz, err
+}
+
+// URL: not implemented for 'nos3'.
+func (d *Driver) URL(ctx context.Context, key string) *PresignedURL {
+	return nil
+}
+
+// ProbeCSPUri: not implemented for 'nos3'.
+func (d *Driver) ProbeCSPUri(ctx context.Context) (string, error) {
+	return "", nil
+}
+
+func NewS3Storage() (*Driver, error) {
+	return nil, errors.New("gotosocial was compiled without S3 storage support")
+}