From b127607ac68ad6f430faf084be87109af89c9043 Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Tue, 17 Nov 2020 19:29:00 +0300
Subject: [PATCH] [#176] localstore: Implement primary BlobStor

Implement primary local BLOB storage based on filesystem tree.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 go.mod                                        |   1 +
 go.sum                                        |   2 +
 pkg/local_object_storage/blobstor/blobstor.go | 100 ++++++++++++++++++
 pkg/local_object_storage/blobstor/compress.go |  35 ++++++
 pkg/local_object_storage/blobstor/delete.go   |  54 ++++++++++
 pkg/local_object_storage/blobstor/fstree.go   |  49 +++++++++
 pkg/local_object_storage/blobstor/get.go      |  83 +++++++++++++++
 pkg/local_object_storage/blobstor/getrange.go |  82 ++++++++++++++
 pkg/local_object_storage/blobstor/put.go      |  61 +++++++++++
 9 files changed, 467 insertions(+)
 create mode 100644 pkg/local_object_storage/blobstor/blobstor.go
 create mode 100644 pkg/local_object_storage/blobstor/compress.go
 create mode 100644 pkg/local_object_storage/blobstor/delete.go
 create mode 100644 pkg/local_object_storage/blobstor/fstree.go
 create mode 100644 pkg/local_object_storage/blobstor/get.go
 create mode 100644 pkg/local_object_storage/blobstor/getrange.go
 create mode 100644 pkg/local_object_storage/blobstor/put.go

diff --git a/go.mod b/go.mod
index 701c683b..bdff4ed3 100644
--- a/go.mod
+++ b/go.mod
@@ -8,6 +8,7 @@ require (
 	github.com/golang/protobuf v1.4.3
 	github.com/google/uuid v1.1.1
 	github.com/hashicorp/golang-lru v0.5.4
+	github.com/klauspost/compress v1.11.3
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/mr-tron/base58 v1.1.3
 	github.com/multiformats/go-multiaddr v0.2.0
diff --git a/go.sum b/go.sum
index 38bd8018..6ffdced8 100644
--- a/go.sum
+++ b/go.sum
@@ -207,6 +207,8 @@ github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+o
 github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
 github.com/klauspost/compress v1.8.2 h1:Bx0qjetmNjdFXASH02NSAREKpiaDwkO1DRZ3dV2KCcs=
 github.com/klauspost/compress v1.8.2/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
+github.com/klauspost/compress v1.11.3 h1:dB4Bn0tN3wdCzQxnS8r06kV74qN/TAfaIS0bVE8h3jc=
+github.com/klauspost/compress v1.11.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/klauspost/cpuid v1.2.1 h1:vJi+O/nMdFt0vqm8NZBI6wzALWdA2X+egi0ogNyrC/w=
 github.com/klauspost/cpuid v1.2.1/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
diff --git a/pkg/local_object_storage/blobstor/blobstor.go b/pkg/local_object_storage/blobstor/blobstor.go
new file mode 100644
index 00000000..e0d4dc1e
--- /dev/null
+++ b/pkg/local_object_storage/blobstor/blobstor.go
@@ -0,0 +1,100 @@
+package blobstor
+
+import (
+	"encoding/hex"
+	"os"
+	"sync"
+)
+
+// BlobStor represents NeoFS local BLOB storage.
+type BlobStor struct {
+	*cfg
+
+	mtx *sync.RWMutex
+}
+
+// Option represents BlobStor's constructor option.
+type Option func(*cfg)
+
+type cfg struct {
+	fsTree fsTree
+
+	compressor func([]byte) []byte
+
+	decompressor func([]byte) ([]byte, error)
+}
+
+const (
+	defaultShallowDepth = 4
+	defaultPerm         = 0700
+)
+
+func defaultCfg() *cfg {
+	return &cfg{
+		fsTree: fsTree{
+			depth:      defaultShallowDepth,
+			dirNameLen: hex.EncodedLen(dirNameLen),
+			perm:       defaultPerm,
+			rootDir:    "./",
+		},
+		compressor:   noOpCompressor,
+		decompressor: noOpDecompressor,
+	}
+}
+
+// New creates, initializes and returns new BlobStor instance.
+func New(opts ...Option) *BlobStor {
+	c := defaultCfg()
+
+	for i := range opts {
+		opts[i](c)
+	}
+
+	return &BlobStor{
+		cfg: c,
+	}
+}
+
+// WithShallowDepth returns option to set the
+// depth of the object file subdirectory tree.
+//
+// Depth is reduced to maximum value in case of overflow.
+func WithShallowDepth(depth int) Option {
+	return func(c *cfg) {
+		if depth <= maxDepth {
+			depth = maxDepth
+		}
+
+		c.fsTree.depth = depth
+	}
+}
+
+// WithCompressObjects returns option to toggle
+// compression of the stored objects.
+func WithCompressObjects(comp bool) Option {
+	return func(c *cfg) {
+		if comp {
+			c.compressor = zstdCompressor()
+			c.decompressor = zstdDecompressor()
+		} else {
+			c.compressor = noOpCompressor
+			c.decompressor = noOpDecompressor
+		}
+	}
+}
+
+// WithTreeRootPath returns option to set path to root directory
+// of the fs tree to write the objects.
+func WithTreeRootPath(rootDir string) Option {
+	return func(c *cfg) {
+		c.fsTree.rootDir = rootDir
+	}
+}
+
+// WithTreeRootPerm returns option to set permission
+// bits of the fs tree.
+func WithTreeRootPerm(perm os.FileMode) Option {
+	return func(c *cfg) {
+		c.fsTree.perm = perm
+	}
+}
diff --git a/pkg/local_object_storage/blobstor/compress.go b/pkg/local_object_storage/blobstor/compress.go
new file mode 100644
index 00000000..01eee100
--- /dev/null
+++ b/pkg/local_object_storage/blobstor/compress.go
@@ -0,0 +1,35 @@
+package blobstor
+
+import (
+	"github.com/klauspost/compress/zstd"
+)
+
+func noOpCompressor(data []byte) []byte {
+	return data
+}
+
+func noOpDecompressor(data []byte) ([]byte, error) {
+	return data, nil
+}
+
+func zstdCompressor() func([]byte) []byte {
+	enc, err := zstd.NewWriter(nil)
+	if err != nil {
+		panic(err)
+	}
+
+	return func(data []byte) []byte {
+		return enc.EncodeAll(data, make([]byte, 0, len(data)))
+	}
+}
+
+func zstdDecompressor() func([]byte) ([]byte, error) {
+	dec, err := zstd.NewReader(nil)
+	if err != nil {
+		panic(err)
+	}
+
+	return func(data []byte) ([]byte, error) {
+		return dec.DecodeAll(data, nil)
+	}
+}
diff --git a/pkg/local_object_storage/blobstor/delete.go b/pkg/local_object_storage/blobstor/delete.go
new file mode 100644
index 00000000..e219d62d
--- /dev/null
+++ b/pkg/local_object_storage/blobstor/delete.go
@@ -0,0 +1,54 @@
+package blobstor
+
+import (
+	"os"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/object"
+	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/pkg/errors"
+)
+
+// DeletePrm groups the parameters of Delete operation.
+type DeletePrm struct {
+	addr *objectSDK.Address
+}
+
+// DeleteRes groups resulting values of Delete operation.
+type DeleteRes struct{}
+
+// WithAddress is a Delete option to set the address of the object to delete.
+//
+// Option is required.
+func (p *DeletePrm) WithAddress(addr *objectSDK.Address) *DeletePrm {
+	if p != nil {
+		p.addr = addr
+	}
+
+	return p
+}
+
+// Delete removes object from BLOB storage.
+//
+// Returns any error encountered that did not allow
+// to completely remove the object.
+func (b *BlobStor) Delete(prm *DeletePrm) (*DeleteRes, error) {
+	b.mtx.Lock()
+	defer b.mtx.Unlock()
+
+	err := b.fsTree.delete(prm.addr)
+	if errors.Is(err, errFileNotFound) {
+		err = nil
+	}
+
+	return nil, err
+}
+
+func (t *fsTree) delete(addr *object.Address) error {
+	p := t.treePath(addr)
+
+	if _, err := os.Stat(p); os.IsNotExist(err) {
+		return errFileNotFound
+	}
+
+	return os.Remove(p)
+}
diff --git a/pkg/local_object_storage/blobstor/fstree.go b/pkg/local_object_storage/blobstor/fstree.go
new file mode 100644
index 00000000..29dd6048
--- /dev/null
+++ b/pkg/local_object_storage/blobstor/fstree.go
@@ -0,0 +1,49 @@
+package blobstor
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"os"
+	"path"
+
+	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
+)
+
+type fsTree struct {
+	depth int
+
+	dirNameLen int
+
+	perm os.FileMode
+
+	rootDir string
+}
+
+const dirNameLen = 2 // in bytes
+
+var maxDepth = (hex.EncodedLen(sha256.Size) - 1) / dirNameLen
+
+var errFileNotFound = errors.New("file not found")
+
+func stringifyAddress(addr *objectSDK.Address) string {
+	h := sha256.Sum256([]byte(addr.String()))
+
+	return hex.EncodeToString(h[:])
+}
+
+func (t *fsTree) treePath(addr *objectSDK.Address) string {
+	sAddr := stringifyAddress(addr)
+
+	dirs := make([]string, 0, t.depth+1+1) // 1 for root, 1 for file
+	dirs = append(dirs, t.rootDir)
+
+	for i := 0; i < t.depth; i++ {
+		dirs = append(dirs, sAddr[:t.dirNameLen])
+		sAddr = sAddr[t.dirNameLen:]
+	}
+
+	dirs = append(dirs, sAddr)
+
+	return path.Join(dirs...)
+}
diff --git a/pkg/local_object_storage/blobstor/get.go b/pkg/local_object_storage/blobstor/get.go
new file mode 100644
index 00000000..94826b50
--- /dev/null
+++ b/pkg/local_object_storage/blobstor/get.go
@@ -0,0 +1,83 @@
+package blobstor
+
+import (
+	"io/ioutil"
+	"os"
+
+	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/nspcc-dev/neofs-node/pkg/core/object"
+	"github.com/pkg/errors"
+)
+
+// GetPrm groups the parameters of Get operation.
+type GetPrm struct {
+	addr *objectSDK.Address
+}
+
+// GetRes groups resulting values of Get operation.
+type GetRes struct {
+	obj *object.Object
+}
+
+// ErrObjectNotFound is returns on read operations requested on a missing object.
+var ErrObjectNotFound = errors.New("object not found")
+
+// WithAddress is a Get option to set the address of the requested object.
+//
+// Option is required.
+func (p *GetPrm) WithAddress(addr *objectSDK.Address) *GetPrm {
+	if p != nil {
+		p.addr = addr
+	}
+
+	return p
+}
+
+// Object returns the requested object.
+func (r *GetRes) Object() *object.Object {
+	return r.obj
+}
+
+// Get reads the object from BLOB storage.
+//
+// Returns any error encountered that
+// did not allow to completely read the object part.
+func (b *BlobStor) Get(prm *GetPrm) (*GetRes, error) {
+	b.mtx.RLock()
+	defer b.mtx.RUnlock()
+
+	// get compressed object data
+	data, err := b.fsTree.get(prm.addr)
+	if err != nil {
+		if errors.Is(err, errFileNotFound) {
+			return nil, ErrObjectNotFound
+		}
+
+		return nil, errors.Wrap(err, "could not read object from fs tree")
+	}
+
+	data, err = b.decompressor(data)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not decompress object data")
+	}
+
+	// unmarshal the object
+	obj := object.New()
+	if err := obj.Unmarshal(data); err != nil {
+		return nil, errors.Wrap(err, "could not unmarshal the object")
+	}
+
+	return &GetRes{
+		obj: obj,
+	}, nil
+}
+
+func (t *fsTree) get(addr *objectSDK.Address) ([]byte, error) {
+	p := t.treePath(addr)
+
+	if _, err := os.Stat(p); os.IsNotExist(err) {
+		return nil, errFileNotFound
+	}
+
+	return ioutil.ReadFile(p)
+}
diff --git a/pkg/local_object_storage/blobstor/getrange.go b/pkg/local_object_storage/blobstor/getrange.go
new file mode 100644
index 00000000..021608ef
--- /dev/null
+++ b/pkg/local_object_storage/blobstor/getrange.go
@@ -0,0 +1,82 @@
+package blobstor
+
+import (
+	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/nspcc-dev/neofs-node/pkg/core/object"
+	"github.com/pkg/errors"
+)
+
+// GetRangePrm groups the parameters of GetRange operation.
+type GetRangePrm struct {
+	off, ln uint64
+
+	addr *objectSDK.Address
+}
+
+// GetRangeRes groups resulting values of GetRange operation.
+type GetRangeRes struct {
+	rngData []byte
+}
+
+// WithAddress is a GetRange option to set the address of the requested object.
+//
+// Option is required.
+func (p *GetRangePrm) WithAddress(addr *objectSDK.Address) *GetRangePrm {
+	if p != nil {
+		p.addr = addr
+	}
+
+	return p
+}
+
+// WithPayloadRange is a GetRange option to set range of requested payload data.
+//
+// Option is required.
+func (p *GetRangePrm) WithPayloadRange(off, ln uint64) *GetRangePrm {
+	if p != nil {
+		p.off, p.ln = off, ln
+	}
+
+	return p
+}
+
+// RangeData returns data of the requested payload range.
+func (r *GetRangeRes) RangeData() []byte {
+	return r.rngData
+}
+
+// GetRange reads data of object payload range from BLOB storage.
+//
+// Returns any error encountered that
+// did not allow to completely read the object payload range.
+func (b *BlobStor) GetRange(prm *GetRangePrm) (*GetRangeRes, error) {
+	b.mtx.RLock()
+	defer b.mtx.RUnlock()
+
+	// get compressed object data
+	data, err := b.fsTree.get(prm.addr)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not read object from fs tree")
+	}
+
+	data, err = b.decompressor(data)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not decompress object data")
+	}
+
+	// unmarshal the object
+	obj := object.New()
+	if err := obj.Unmarshal(data); err != nil {
+		return nil, errors.Wrap(err, "could not unmarshal the object")
+	}
+
+	payload := obj.Payload()
+	if pLen := uint64(len(payload)); pLen < prm.ln+prm.off {
+		return nil, errors.Errorf("range is out-of-bounds (payload %d, off %d, ln %d)",
+			pLen, prm.off, prm.ln)
+	}
+
+	return &GetRangeRes{
+		rngData: payload[prm.off : prm.off+prm.ln],
+	}, nil
+}
diff --git a/pkg/local_object_storage/blobstor/put.go b/pkg/local_object_storage/blobstor/put.go
new file mode 100644
index 00000000..112988bd
--- /dev/null
+++ b/pkg/local_object_storage/blobstor/put.go
@@ -0,0 +1,61 @@
+package blobstor
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+
+	objectSDK "github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/nspcc-dev/neofs-node/pkg/core/object"
+	"github.com/pkg/errors"
+)
+
+// PutPrm groups the parameters of Put operation.
+type PutPrm struct {
+	obj *object.Object
+}
+
+// PutRes groups resulting values of Put operation.
+type PutRes struct{}
+
+// WithObject is a Put option to set object to save.
+//
+// Option is required.
+func (p *PutPrm) WithObject(obj *object.Object) *PutPrm {
+	if p != nil {
+		p.obj = obj
+	}
+
+	return p
+}
+
+// Put saves the object in BLOB storage.
+//
+// Returns any error encountered that
+// did not allow to completely save the object.
+func (b *BlobStor) Put(prm *PutPrm) (*PutRes, error) {
+	b.mtx.Lock()
+	defer b.mtx.Unlock()
+
+	// marshal object
+	data, err := prm.obj.Marshal()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not marshal the object")
+	}
+
+	// compress object data
+	data = b.compressor(data)
+
+	// save object in fs tree
+	return nil, b.fsTree.put(prm.obj.Address(), data)
+}
+
+func (t *fsTree) put(addr *objectSDK.Address, data []byte) error {
+	p := t.treePath(addr)
+
+	if err := os.MkdirAll(path.Dir(p), t.perm); err != nil {
+		return err
+	}
+
+	return ioutil.WriteFile(p, data, t.perm)
+}