[#83] Allow to split objects in the client

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

client/object_put_raw.go

@@ -0,0 +1,154 @@
+package client
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"errors"
+	"fmt"
+	"io"
+
+	v2object "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
+	rpcapi "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/rpc"
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/rpc/client"
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/signature"
+	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+)
+
+func (c *Client) objectPutInitRaw(ctx context.Context, prm PrmObjectPutInit) (*objectWriterRaw, error) {
+	var w objectWriterRaw
+	stream, err := rpcapi.PutObject(&c.c, &w.respV2, client.WithContext(ctx))
+	if err != nil {
+		return nil, fmt.Errorf("open stream: %w", err)
+	}
+
+	w.key = &c.prm.key
+	if prm.key != nil {
+		w.key = prm.key
+	}
+	w.client = c
+	w.stream = stream
+	w.partInit.SetCopiesNumber(prm.copyNum)
+	w.req.SetBody(new(v2object.PutRequestBody))
+	if prm.maxChunkLen > 0 {
+		w.maxChunkLen = prm.maxChunkLen
+	} else {
+		w.maxChunkLen = defaultGRPCPayloadChunkLen
+	}
+	c.prepareRequest(&w.req, &prm.meta)
+	return &w, nil
+}
+
+type objectWriterRaw struct {
+	client *Client
+	stream interface {
+		Write(*v2object.PutRequest) error
+		Close() error
+	}
+
+	key         *ecdsa.PrivateKey
+	res         ResObjectPut
+	err         error
+	chunkCalled bool
+	respV2      v2object.PutResponse
+	req         v2object.PutRequest
+	partInit    v2object.PutObjectPartInit
+	partChunk   v2object.PutObjectPartChunk
+	maxChunkLen int
+}
+
+func (x *objectWriterRaw) WriteHeader(_ context.Context, hdr object.Object) bool {
+	v2Hdr := hdr.ToV2()
+
+	x.partInit.SetObjectID(v2Hdr.GetObjectID())
+	x.partInit.SetHeader(v2Hdr.GetHeader())
+	x.partInit.SetSignature(v2Hdr.GetSignature())
+
+	x.req.GetBody().SetObjectPart(&x.partInit)
+	x.req.SetVerificationHeader(nil)
+
+	x.err = signature.SignServiceMessage(x.key, &x.req)
+	if x.err != nil {
+		x.err = fmt.Errorf("sign message: %w", x.err)
+		return false
+	}
+
+	x.err = x.stream.Write(&x.req)
+	return x.err == nil
+}
+
+func (x *objectWriterRaw) WritePayloadChunk(_ context.Context, chunk []byte) bool {
+	if !x.chunkCalled {
+		x.chunkCalled = true
+		x.req.GetBody().SetObjectPart(&x.partChunk)
+	}
+
+	for ln := len(chunk); ln > 0; ln = len(chunk) {
+		if ln > x.maxChunkLen {
+			ln = x.maxChunkLen
+		}
+
+		// we deal with size limit overflow above, but there is another case:
+		// what if method is called with "small" chunk many times? We write
+		// a message to the stream on each call. Alternatively, we could use buffering.
+		// In most cases, the chunk length does not vary between calls. Given this
+		// assumption, as well as the length of the payload from the header, it is
+		// possible to buffer the data of intermediate chunks, and send a message when
+		// the allocated buffer is filled, or when the last chunk is received.
+		// It is mentally assumed that allocating and filling the buffer is better than
+		// synchronous sending, but this needs to be tested.
+		x.partChunk.SetChunk(chunk[:ln])
+		x.req.SetVerificationHeader(nil)
+
+		x.err = signature.SignServiceMessage(x.key, &x.req)
+		if x.err != nil {
+			x.err = fmt.Errorf("sign message: %w", x.err)
+			return false
+		}
+
+		x.err = x.stream.Write(&x.req)
+		if x.err != nil {
+			return false
+		}
+
+		chunk = chunk[ln:]
+	}
+
+	return true
+}
+
+func (x *objectWriterRaw) Close(_ context.Context) (*ResObjectPut, error) {
+	// Ignore io.EOF error, because it is expected error for client-side
+	// stream termination by the server. E.g. when stream contains invalid
+	// message. Server returns an error in response message (in status).
+	if x.err != nil && !errors.Is(x.err, io.EOF) {
+		return nil, x.err
+	}
+
+	if x.err = x.stream.Close(); x.err != nil {
+		return nil, x.err
+	}
+
+	x.res.st, x.err = x.client.processResponse(&x.respV2)
+	if x.err != nil {
+		return nil, x.err
+	}
+
+	if !apistatus.IsSuccessful(x.res.st) {
+		return &x.res, nil
+	}
+
+	const fieldID = "ID"
+
+	idV2 := x.respV2.GetBody().GetObjectID()
+	if idV2 == nil {
+		return nil, newErrMissingResponseField(fieldID)
+	}
+
+	x.err = x.res.obj.ReadFromV2(*idV2)
+	if x.err != nil {
+		x.err = newErrInvalidResponseField(fieldID, x.err)
+	}
+
+	return &x.res, nil
+}