pools: Add a pool for buffers

internal/dis/component/auth/user.go

@@ -1,7 +1,6 @@
 package auth
 
 import (
-	"bytes"
 	"context"
 	"encoding/base64"
 	"fmt"
@@ -11,6 +10,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/pkg/password"
+	"github.com/FAU-CDI/wisski-distillery/pkg/pools"
 	"github.com/pkg/errors"
 	"github.com/pquerna/otp"
 	"github.com/pquerna/otp/totp"
@@ -186,8 +186,10 @@ func TOTPLink(secret *otp.Key, width, height int) (string, error) {
 	}
 
 	// encode image as base64
-	var buffer bytes.Buffer
-	if err := png.Encode(&buffer, img); err != nil {
+	buffer := pools.GetBuffer()
+	defer pools.ReleaseBuffer(buffer)
+
+	if err := png.Encode(buffer, img); err != nil {
 		return "", err
 	}
 

internal/dis/component/stack.go

@@ -3,7 +3,6 @@ package component
 
 import (
 	"bufio"
-	"bytes"
 	"context"
 	"io"
 	"io/fs"
@@ -13,6 +12,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
 	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/logging"
+	"github.com/FAU-CDI/wisski-distillery/pkg/pools"
 	"github.com/FAU-CDI/wisski-distillery/pkg/unpack"
 	"github.com/pkg/errors"
 	"github.com/tkw1536/goprogram/stream"
@@ -126,17 +126,18 @@ var errStackPs = errors.New("Stack.Ps: Down returned non-zero exit code")
 // Ps returns the ids of the containers currently running
 func (ds Stack) Ps(ctx context.Context, progress io.Writer) ([]string, error) {
 	// create a buffer
-	var buffer bytes.Buffer
+	buffer := pools.GetBuffer()
+	defer pools.ReleaseBuffer(buffer)
 
 	// read the ids from the command!
-	code := ds.compose(ctx, stream.NewIOStream(&buffer, progress, nil, 0), "ps", "-q")()
+	code := ds.compose(ctx, stream.NewIOStream(buffer, progress, nil, 0), "ps", "-q")()
 	if code != 0 {
 		return nil, errStackPs
 	}
 
 	// scan each of the lines
 	var results []string
-	scanner := bufio.NewScanner(&buffer)
+	scanner := bufio.NewScanner(buffer)
 	for scanner.Scan() {
 		if text := scanner.Text(); text != "" {
 			results = append(results, text)

internal/dis/component/triplestore/database.go

@@ -9,9 +9,10 @@ import (
 	"net/http"
 	"time"
 
+	"github.com/FAU-CDI/wisski-distillery/pkg/pools"
 	"github.com/FAU-CDI/wisski-distillery/pkg/timex"
 	"github.com/pkg/errors"
-	"github.com/tkw1536/goprogram/stream"
+	"github.com/rs/zerolog"
 )
 
 type TriplestoreUserPayload struct {
@@ -31,32 +32,38 @@ type TriplestoreUserAppSettings struct {
 //
 // When bodyName is non-empty, expect body to be a byte slice representing a multipart/form-data upload with the given name.
 // When bodyName is empty, simply marshal body as application/json
-func (ts Triplestore) OpenRaw(ctx context.Context, method, url string, body interface{}, bodyName string, accept string) (*http.Response, error) {
-	var reader io.Reader
-
-	var contentType string
+func (ts Triplestore) OpenRaw(ctx context.Context, method, url string, body any, bodyName string, accept string) (*http.Response, error) {
+	var reader io.Reader   // to read the body from
+	var contentType string // content-type of the request being sent
 
 	// for "PUT" and "POST" we setup a body
-	if method == "PUT" || method == "POST" {
+	if method == http.MethodPut || method == http.MethodPost {
 		if bodyName != "" {
-			buffer := &bytes.Buffer{}
-			writer := multipart.NewWriter(buffer)
-			contentType = writer.FormDataContentType()
+			// create a new buffer for the body
+			buffer := pools.GetBuffer()
+			defer pools.ReleaseBuffer(buffer)
 
-			part, err := writer.CreateFormFile(bodyName, "filename.txt")
-			if err != nil {
-				return nil, err
+			// write the file to it
+			writer := multipart.NewWriter(buffer)
+			{
+				part, err := writer.CreateFormFile(bodyName, "filename.txt")
+				if err != nil {
+					return nil, err
+				}
+				io.Copy(part, bytes.NewReader(body.([]byte)))
 			}
-			io.Copy(part, bytes.NewReader(body.([]byte)))
 			writer.Close()
+
+			// use it for the request
 			reader = buffer
+			contentType = writer.FormDataContentType()
 		} else {
-			contentType = "application/json"
 			mbytes, err := json.Marshal(body)
 			if err != nil {
 				return nil, err
 			}
 			reader = bytes.NewReader(mbytes)
+			contentType = "application/json"
 		}
 	}
 
@@ -88,10 +95,9 @@ func (ts Triplestore) OpenRaw(ctx context.Context, method, url string, body inte
 // Wait waits for the connection to the Triplestore to succeed.
 // This is achieved using a polling strategy.
 func (ts Triplestore) Wait(ctx context.Context) error {
-	n := stream.FromNil()
 	return timex.TickUntilFunc(func(time.Time) bool {
 		res, err := ts.OpenRaw(ctx, "GET", "/rest/repositories", nil, "", "")
-		n.EPrintf("[Triplestore.Wait]: %s\n", err)
+		zerolog.Ctx(ctx).Trace().Err(err).Msg("Triplestore wait")
 		if err != nil {
 			return false
 		}

internal/dis/component/triplestore/provision.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/FAU-CDI/wisski-distillery/internal/models"
 	"github.com/FAU-CDI/wisski-distillery/pkg/errorx"
+	"github.com/FAU-CDI/wisski-distillery/pkg/pools"
 	"github.com/FAU-CDI/wisski-distillery/pkg/unpack"
 	"github.com/tkw1536/goprogram/exit"
 )
@@ -38,8 +39,9 @@ func (ts *Triplestore) CreateRepository(ctx context.Context, name, domain, user,
 	}
 
 	// prepare the create repo request
-	var createRepo bytes.Buffer
-	err := unpack.WriteTemplate(&createRepo, map[string]string{
+	createRepo := pools.GetBuffer()
+	defer pools.ReleaseBuffer(createRepo)
+	err := unpack.WriteTemplate(createRepo, map[string]string{
 		"GRAPHDB_REPO":    name,
 		"INSTANCE_DOMAIN": domain,
 	}, bytes.NewReader(createRepoTTL))

pkg/environment/globals.go

@@ -1,12 +1,12 @@
 package environment
 
 import (
-	"bytes"
 	"context"
 	"io"
 	"io/fs"
 	"os"
 
+	"github.com/FAU-CDI/wisski-distillery/pkg/pools"
 	"github.com/tkw1536/goprogram/stream"
 )
 
@@ -60,8 +60,10 @@ func ReadFile(env Environment, path string) ([]byte, error) {
 	defer file.Close()
 
 	// copy everything into a buffer!
-	var buffer bytes.Buffer
-	if _, err := io.Copy(&buffer, file); err != nil {
+	buffer := pools.GetBuffer()
+	defer pools.ReleaseBuffer(buffer)
+
+	if _, err := io.Copy(buffer, file); err != nil {
 		return nil, err
 	}
 

pkg/pools/pools.go

@@ -1,6 +1,8 @@
+// Package pools holds various pools for reuse
 package pools
 
 import (
+	"bytes"
 	"strings"
 	"sync"
 )
@@ -17,3 +19,16 @@ func ReleaseBuilder(builder *strings.Builder) {
 	builder.Reset()
 	builders.Put(builder)
 }
+
+var buffers = sync.Pool{
+	New: func() any { return new(bytes.Buffer) },
+}
+
+func GetBuffer() *bytes.Buffer {
+	return buffers.Get().(*bytes.Buffer)
+}
+
+func ReleaseBuffer(buffer *bytes.Buffer) {
+	buffer.Reset()
+	buffers.Put(buffer)
+}