[#19] Extract downloading logic into a separate package

Signed-off-by: Pavel Korotkov <pavel@nspcc.ru>

app.go

@@ -6,8 +6,7 @@ import (
 	"strconv"
 
 	"github.com/fasthttp/router"
-	"github.com/nspcc-dev/neofs-api-go/pkg/client"
-	"github.com/nspcc-dev/neofs-api-go/pkg/token"
+	"github.com/nspcc-dev/neofs-http-gate/downloader"
 	"github.com/nspcc-dev/neofs-http-gate/logger"
 	"github.com/nspcc-dev/neofs-http-gate/neofs"
 	"github.com/nspcc-dev/neofs-http-gate/uploader"
@@ -19,14 +18,10 @@ import (
 
 type (
 	app struct {
-		plant         neofs.ClientPlant
-		getOperations struct {
-			client       client.Client
-			sessionToken *token.SessionToken
-		}
 		log                    *zap.Logger
+		plant                  neofs.ClientPlant
 		cfg                    *viper.Viper
-		wlog                   logger.Logger
+		auxiliaryLog           logger.Logger
 		web                    *fasthttp.Server
 		jobDone                chan struct{}
 		webDone                chan struct{}
@@ -62,24 +57,20 @@ func WithConfig(c *viper.Viper) Option {
 
 func newApp(ctx context.Context, opt ...Option) App {
 	a := &app{
-		log: zap.L(),
-		cfg: viper.GetViper(),
-		web: new(fasthttp.Server),
-
+		log:     zap.L(),
+		cfg:     viper.GetViper(),
+		web:     new(fasthttp.Server),
 		jobDone: make(chan struct{}),
 		webDone: make(chan struct{}),
 	}
-
 	for i := range opt {
 		opt[i](a)
 	}
-
 	a.enableDefaultTimestamp = a.cfg.GetBool(cfgUploaderHeaderEnableDefaultTimestamp)
-
-	a.wlog = logger.GRPC(a.log)
+	a.auxiliaryLog = logger.GRPC(a.log)
 
 	if a.cfg.GetBool(cmdVerbose) {
-		grpclog.SetLoggerV2(a.wlog)
+		grpclog.SetLoggerV2(a.auxiliaryLog)
 	}
 
 	// conTimeout := a.cfg.GetDuration(cfgConTimeout)
@@ -124,10 +115,6 @@ func newApp(ctx context.Context, opt ...Option) App {
 	if err != nil {
 		a.log.Fatal("failed to create neofs client")
 	}
-	a.getOperations.client, a.getOperations.sessionToken, err = a.plant.GetReusableArtifacts(ctx)
-	if err != nil {
-		a.log.Fatal("failed to get neofs client's reusable artifacts")
-	}
 	return a
 }
 
@@ -153,21 +140,25 @@ func (a *app) Serve(ctx context.Context) {
 		close(a.webDone)
 	}()
 	uploader := uploader.New(a.log, a.plant, a.enableDefaultTimestamp)
+	downloader, err := downloader.New(ctx, a.log, a.plant)
+	if err != nil {
+		a.log.Fatal("failed to create downloader", zap.Error(err))
+	}
 	// Configure router.
 	r := router.New()
 	r.RedirectTrailingSlash = true
 	r.POST("/upload/{cid}", uploader.Upload)
 	a.log.Info("added path /upload/{cid}")
-	r.GET("/get/{cid}/{oid}", a.byAddress)
+	r.GET("/get/{cid}/{oid}", downloader.DownloadByAddress)
 	a.log.Info("added path /get/{cid}/{oid}")
-	r.GET("/get_by_attribute/{cid}/{attr_key}/{attr_val:*}", a.byAttribute)
+	r.GET("/get_by_attribute/{cid}/{attr_key}/{attr_val:*}", downloader.DownloadByAttribute)
 	a.log.Info("added path /get_by_attribute/{cid}/{attr_key}/{attr_val:*}")
 	// attaching /-/(ready,healthy)
 	// attachHealthy(r, a.pool.Status)
 	// enable metrics
 	if a.cfg.GetBool(cmdMetrics) {
 		a.log.Info("added path /metrics/")
-		attachMetrics(r, a.wlog)
+		attachMetrics(r, a.auxiliaryLog)
 	}
 	// enable pprof
 	if a.cfg.GetBool(cmdPprof) {

downloader/download.go

@@ -1,6 +1,7 @@
-package main
+package downloader
 
 import (
+	"context"
 	"io"
 	"net/http"
 	"path"
@@ -9,8 +10,10 @@ import (
 	"sync"
 	"time"
 
+	"github.com/nspcc-dev/neofs-api-go/pkg/client"
 	"github.com/nspcc-dev/neofs-api-go/pkg/container"
 	"github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/nspcc-dev/neofs-api-go/pkg/token"
 	"github.com/nspcc-dev/neofs-http-gate/neofs"
 	"github.com/nspcc-dev/neofs-http-gate/tokens"
 	"github.com/pkg/errors"
@@ -20,6 +23,20 @@ import (
 	"google.golang.org/grpc/status"
 )
 
+var (
+	getOptionsPool = sync.Pool{
+		New: func() interface{} {
+			return new(neofs.GetOptions)
+		},
+	}
+
+	searchOptionsPool = sync.Pool{
+		New: func() interface{} {
+			return new(neofs.SearchOptions)
+		},
+	}
+)
+
 type (
 	detector struct {
 		io.Writer
@@ -29,8 +46,8 @@ type (
 
 	request struct {
 		*fasthttp.RequestCtx
-		log *zap.Logger
-		obj neofs.ObjectClient
+		log          *zap.Logger
+		objectClient neofs.ObjectClient
 	}
 
 	objectIDs []*object.ID
@@ -61,7 +78,7 @@ func (r *request) receiveFile(options *neofs.GetOptions) {
 	}
 	writer := newDetector(r.Response.BodyWriter())
 	options.Writer = writer
-	obj, err := r.obj.Get(r.RequestCtx, options)
+	obj, err := r.objectClient.Get(r.RequestCtx, options)
 	if err != nil {
 		r.log.Error(
 			"could not receive object",
@@ -120,15 +137,34 @@ func (o objectIDs) Slice() []string {
 	return res
 }
 
-func (a *app) request(ctx *fasthttp.RequestCtx, log *zap.Logger) *request {
-	return &request{
-		RequestCtx: ctx,
-		log:        log,
-		obj:        a.plant.Object(),
+type Downloader struct {
+	log           *zap.Logger
+	plant         neofs.ClientPlant
+	getOperations struct {
+		client       client.Client
+		sessionToken *token.SessionToken
 	}
 }
 
-func (a *app) byAddress(c *fasthttp.RequestCtx) {
+func New(ctx context.Context, log *zap.Logger, plant neofs.ClientPlant) (*Downloader, error) {
+	var err error
+	d := &Downloader{log: log, plant: plant}
+	d.getOperations.client, d.getOperations.sessionToken, err = d.plant.GetReusableArtifacts(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to get neofs client's reusable artifacts")
+	}
+	return d, nil
+}
+
+func (a *Downloader) newRequest(ctx *fasthttp.RequestCtx, log *zap.Logger) *request {
+	return &request{
+		RequestCtx:   ctx,
+		log:          log,
+		objectClient: a.plant.Object(),
+	}
+}
+
+func (a *Downloader) DownloadByAddress(c *fasthttp.RequestCtx) {
 	var (
 		err     error
 		address = object.NewAddress()
@@ -142,16 +178,16 @@ func (a *app) byAddress(c *fasthttp.RequestCtx) {
 		c.Error("wrong object address", fasthttp.StatusBadRequest)
 		return
 	}
-	// TODO: Take this from a sync-pool.
-	getOpts := new(neofs.GetOptions)
+	getOpts := getOptionsPool.Get().(*neofs.GetOptions)
+	defer getOptionsPool.Put(getOpts)
 	getOpts.Client = a.getOperations.client
 	getOpts.SessionToken = a.getOperations.sessionToken
 	getOpts.ObjectAddress = address
 	getOpts.Writer = nil
-	a.request(c, log).receiveFile(getOpts)
+	a.newRequest(c, log).receiveFile(getOpts)
 }
 
-func (a *app) byAttribute(c *fasthttp.RequestCtx) {
+func (a *Downloader) DownloadByAttribute(c *fasthttp.RequestCtx) {
 	var (
 		err     error
 		scid, _ = c.UserValue("cid").(string)
@@ -165,8 +201,8 @@ func (a *app) byAttribute(c *fasthttp.RequestCtx) {
 		c.Error("wrong container id", fasthttp.StatusBadRequest)
 		return
 	}
-	// TODO: Take this from a sync-pool.
-	searchOpts := new(neofs.SearchOptions)
+	searchOpts := searchOptionsPool.Get().(*neofs.SearchOptions)
+	defer searchOptionsPool.Put(searchOpts)
 	searchOpts.Client = a.getOperations.client
 	searchOpts.SessionToken = a.getOperations.sessionToken
 	searchOpts.BearerToken = nil
@@ -191,11 +227,11 @@ func (a *app) byAttribute(c *fasthttp.RequestCtx) {
 	address := object.NewAddress()
 	address.SetContainerID(cid)
 	address.SetObjectID(ids[0])
-	// TODO: Take this from a sync-pool.
-	getOpts := new(neofs.GetOptions)
+	getOpts := getOptionsPool.Get().(*neofs.GetOptions)
+	defer getOptionsPool.Put(getOpts)
 	getOpts.Client = a.getOperations.client
 	getOpts.SessionToken = a.getOperations.sessionToken
 	getOpts.ObjectAddress = address
 	getOpts.Writer = nil
-	a.request(c, log).receiveFile(getOpts)
+	a.newRequest(c, log).receiveFile(getOpts)
 }

uploader/upload.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"io"
 	"strconv"
+	"sync"
 	"time"
 
 	"github.com/nspcc-dev/neofs-api-go/pkg/container"
@@ -17,6 +18,12 @@ import (
 	"go.uber.org/zap"
 )
 
+var putOptionsPool = sync.Pool{
+	New: func() interface{} {
+		return new(neofs.PutOptions)
+	},
+}
+
 type Uploader struct {
 	log                    *zap.Logger
 	plant                  neofs.ClientPlant
@@ -89,15 +96,14 @@ func (u *Uploader) Upload(c *fasthttp.RequestCtx) {
 		attributes = append(attributes, timestamp)
 	}
 	oid, bt := u.fetchOwnerAndBearerToken(c)
-	// prepares new object and fill it
+	// Prepare a new object and fill it.
 	raw := object.NewRaw()
 	raw.SetContainerID(cid)
 	raw.SetOwnerID(oid)
 	raw.SetAttributes(attributes...)
-	// tries to put file into NeoFS or throw error
-	// if addr, err = a.plant.Object().Put(c, raw.Object(), sdk.WithPutReader(file)); err != nil {
-	// TODO: Take this from a sync pool.
-	putOpts := new(neofs.PutOptions)
+	putOpts := putOptionsPool.Get().(*neofs.PutOptions)
+	defer putOptionsPool.Put(putOpts)
+	// Try to put file into NeoFS or throw an error.
 	putOpts.Client, putOpts.SessionToken, err = u.plant.GetReusableArtifacts(c)
 	if err != nil {
 		log.Error("failed to get neofs client's reusable artifacts", zap.Error(err))
@@ -114,14 +120,14 @@ func (u *Uploader) Upload(c *fasthttp.RequestCtx) {
 		c.Error("could not store file in NeoFS", fasthttp.StatusBadRequest)
 		return
 	}
-	// tries to return response, otherwise, if something went wrong throw error
+	// Try to return the response, otherwise, if something went wrong, throw an error.
 	if err = newPutResponse(addr).encode(c); err != nil {
 		log.Error("could not prepare response", zap.Error(err))
 		c.Error("could not prepare response", fasthttp.StatusBadRequest)
 
 		return
 	}
-	// reports status code and content type
+	// Report status code and content type.
 	c.Response.SetStatusCode(fasthttp.StatusOK)
 	c.Response.Header.SetContentType(jsonHeader)
 }