From 8546cbf89b92ab008d3fa0a2dc9522c4b2f8660c Mon Sep 17 00:00:00 2001
From: Matthias <5011972+fasmat@users.noreply.github.com>
Date: Fri, 4 Aug 2023 09:09:58 +0000
Subject: [PATCH] Cleanup

---
 cmd/postcli/main.go                     |  4 +-
 go.mod                                  |  1 +
 go.sum                                  |  2 +
 initialization/initialization.go        |  8 ++--
 initialization/initialization_errors.go |  1 +
 initialization/initialization_test.go   | 22 +++++------
 initialization/metadata.go              | 49 +++++++++++++++++++++++++
 initialization/migrate_metadata.go      |  8 ++--
 initialization/vrf_search.go            |  4 +-
 initialization/vrf_search_test.go       |  6 +--
 proving/proving_options.go              |  3 +-
 shared/post_metadata.go                 | 45 -----------------------
 12 files changed, 81 insertions(+), 72 deletions(-)
 create mode 100644 initialization/metadata.go

diff --git a/cmd/postcli/main.go b/cmd/postcli/main.go
index 4d239f9bd..bedc7d36f 100644
--- a/cmd/postcli/main.go
+++ b/cmd/postcli/main.go
@@ -292,8 +292,8 @@ func cmdVerifyPos(opts config.InitOpts, fraction float64, logger *zap.Logger) {
 	}
 	pub := ed25519.NewKeyFromSeed(dst[:ed25519.SeedSize]).Public().(ed25519.PublicKey)
 
-	metafile := filepath.Join(opts.DataDir, shared.MetadataFileName)
-	meta, err := shared.LoadMetadata(opts.DataDir)
+	metafile := filepath.Join(opts.DataDir, initialization.MetadataFileName)
+	meta, err := initialization.LoadMetadata(opts.DataDir)
 	if err != nil {
 		log.Fatalf("failed to load metadata from %s: %s\n", opts.DataDir, err)
 	}
diff --git a/go.mod b/go.mod
index a009e8299..6b2a5cf90 100644
--- a/go.mod
+++ b/go.mod
@@ -5,6 +5,7 @@ go 1.19
 require (
 	github.com/davecgh/go-spew v1.1.1
 	github.com/golang/mock v1.6.0
+	github.com/natefinch/atomic v1.0.1
 	github.com/stretchr/testify v1.8.4
 	github.com/zeebo/blake3 v0.2.3
 	go.uber.org/zap v1.24.0
diff --git a/go.sum b/go.sum
index 67df62ba0..2a024beb2 100644
--- a/go.sum
+++ b/go.sum
@@ -16,6 +16,8 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/natefinch/atomic v1.0.1 h1:ZPYKxkqQOx3KZ+RsbnP/YsgvxWQPGxjC0oBt2AhwV0A=
+github.com/natefinch/atomic v1.0.1/go.mod h1:N/D/ELrljoqDyT3rZrsUmtsuzvHkeB/wWjHV22AZRbM=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
diff --git a/initialization/initialization.go b/initialization/initialization.go
index f9545f125..20a01b851 100644
--- a/initialization/initialization.go
+++ b/initialization/initialization.go
@@ -407,7 +407,7 @@ func removeRedundantFiles(cfg config.Config, opts config.InitOpts, logger *zap.L
 	for _, file := range files {
 		name := file.Name()
 		fileIndex, err := shared.ParseFileIndex(name)
-		if err != nil && name != shared.MetadataFileName {
+		if err != nil && name != MetadataFileName {
 			logger.Warn("found unrecognized file", zap.String("fileName", name))
 			continue
 		}
@@ -457,7 +457,7 @@ func (init *Initializer) Reset() error {
 			continue
 		}
 		name := file.Name()
-		if shared.IsInitFile(info) || name == shared.MetadataFileName {
+		if shared.IsInitFile(info) || name == MetadataFileName {
 			path := filepath.Join(init.opts.DataDir, name)
 			if err := os.Remove(path); err != nil {
 				return fmt.Errorf("failed to delete file (%v): %w", path, err)
@@ -689,10 +689,10 @@ func (init *Initializer) saveMetadata() error {
 	if init.nonceValue.Load() != nil {
 		v.NonceValue = *init.nonceValue.Load()
 	}
-	return shared.SaveMetadata(init.opts.DataDir, &v)
+	return SaveMetadata(init.opts.DataDir, &v)
 }
 
 func (init *Initializer) loadMetadata() (*shared.PostMetadata, error) {
 	// TODO(mafa): migrate metadata if needed before loading it
-	return shared.LoadMetadata(init.opts.DataDir)
+	return LoadMetadata(init.opts.DataDir)
 }
diff --git a/initialization/initialization_errors.go b/initialization/initialization_errors.go
index 304b9889c..9e3c11847 100644
--- a/initialization/initialization_errors.go
+++ b/initialization/initialization_errors.go
@@ -8,6 +8,7 @@ import (
 var (
 	ErrAlreadyInitializing          = errors.New("already initializing")
 	ErrCannotResetWhileInitializing = errors.New("cannot reset while initializing")
+	ErrStateMetadataFileMissing     = errors.New("metadata file is missing")
 )
 
 type ErrReferenceLabelMismatch struct {
diff --git a/initialization/initialization_test.go b/initialization/initialization_test.go
index c7e2a1ba9..4f44928dd 100644
--- a/initialization/initialization_test.go
+++ b/initialization/initialization_test.go
@@ -95,7 +95,7 @@ func TestInitialize_BeforeNonceValue(t *testing.T) {
 	cancel()
 	require.Equal(t, uint64(cfg.MinNumUnits)*cfg.LabelsPerUnit, init.NumLabelsWritten())
 
-	meta, err := shared.LoadMetadata(opts.DataDir)
+	meta, err := LoadMetadata(opts.DataDir)
 	require.NoError(t, err)
 	require.NotNil(t, meta.Nonce)
 	require.NotNil(t, meta.NonceValue)
@@ -103,7 +103,7 @@ func TestInitialize_BeforeNonceValue(t *testing.T) {
 
 	// delete nonce value
 	meta.NonceValue = nil
-	require.NoError(t, shared.SaveMetadata(opts.DataDir, meta))
+	require.NoError(t, SaveMetadata(opts.DataDir, meta))
 
 	// just creating a new initializer should update the metadata
 	init, err = NewInitializer(
@@ -116,7 +116,7 @@ func TestInitialize_BeforeNonceValue(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, init)
 
-	meta, err = shared.LoadMetadata(opts.DataDir)
+	meta, err = LoadMetadata(opts.DataDir)
 	require.NoError(t, err)
 	require.NotNil(t, meta.Nonce)
 	require.NotNil(t, meta.NonceValue)
@@ -218,7 +218,7 @@ func TestInitialize_ContinueWithLastPos(t *testing.T) {
 	r.NoError(init.Initialize(context.Background()))
 	r.Equal(uint64(cfg.MinNumUnits)*cfg.LabelsPerUnit, init.NumLabelsWritten())
 
-	m, err := shared.LoadMetadata(opts.DataDir)
+	m, err := LoadMetadata(opts.DataDir)
 	r.NoError(err)
 	r.Equal(origNonce, *m.Nonce)
 	r.EqualValues(origNonceValue, m.NonceValue)
@@ -227,7 +227,7 @@ func TestInitialize_ContinueWithLastPos(t *testing.T) {
 	// lastPos lower than numLabels is ignored
 	m.LastPosition = new(uint64)
 	*m.LastPosition = uint64(cfg.MinNumUnits)*cfg.LabelsPerUnit - 10
-	r.NoError(shared.SaveMetadata(opts.DataDir, m))
+	r.NoError(SaveMetadata(opts.DataDir, m))
 
 	init, err = NewInitializer(
 		WithNodeId(nodeId),
@@ -241,7 +241,7 @@ func TestInitialize_ContinueWithLastPos(t *testing.T) {
 	r.NoError(init.Initialize(context.Background()))
 	r.Equal(uint64(cfg.MinNumUnits)*cfg.LabelsPerUnit, init.NumLabelsWritten())
 
-	m, err = shared.LoadMetadata(opts.DataDir)
+	m, err = LoadMetadata(opts.DataDir)
 	r.NoError(err)
 	r.Equal(origNonce, *m.Nonce)
 
@@ -251,7 +251,7 @@ func TestInitialize_ContinueWithLastPos(t *testing.T) {
 	// the range of the PoST
 	m.Nonce = nil
 	m.LastPosition = nil
-	r.NoError(shared.SaveMetadata(opts.DataDir, m))
+	r.NoError(SaveMetadata(opts.DataDir, m))
 
 	init, err = NewInitializer(
 		WithNodeId(nodeId),
@@ -265,7 +265,7 @@ func TestInitialize_ContinueWithLastPos(t *testing.T) {
 	r.NoError(init.Initialize(context.Background()))
 	r.Equal(uint64(cfg.MinNumUnits)*cfg.LabelsPerUnit, init.NumLabelsWritten())
 
-	m, err = shared.LoadMetadata(opts.DataDir)
+	m, err = LoadMetadata(opts.DataDir)
 	r.NoError(err)
 	r.NotNil(m.Nonce)
 	r.NotNil(m.NonceValue)
@@ -285,7 +285,7 @@ func TestInitialize_ContinueWithLastPos(t *testing.T) {
 	lastPos := *m.Nonce + 10
 	*m.LastPosition = lastPos
 	m.Nonce = nil
-	r.NoError(shared.SaveMetadata(opts.DataDir, m))
+	r.NoError(SaveMetadata(opts.DataDir, m))
 
 	init, err = NewInitializer(
 		WithNodeId(nodeId),
@@ -299,7 +299,7 @@ func TestInitialize_ContinueWithLastPos(t *testing.T) {
 	r.NoError(init.Initialize(context.Background()))
 	r.Equal(uint64(cfg.MinNumUnits)*cfg.LabelsPerUnit, init.NumLabelsWritten())
 
-	m, err = shared.LoadMetadata(opts.DataDir)
+	m, err = LoadMetadata(opts.DataDir)
 	r.NoError(err)
 	r.NotNil(m.Nonce)
 	r.NotNil(m.LastPosition)
@@ -1073,7 +1073,7 @@ func TestInitializeSubset_NoNonce(t *testing.T) {
 	require.Nil(t, init.Nonce())
 	require.Nil(t, init.NonceValue())
 
-	meta, err := shared.LoadMetadata(opts.DataDir)
+	meta, err := LoadMetadata(opts.DataDir)
 	require.NoError(t, err)
 	require.Nil(t, meta.Nonce)
 
diff --git a/initialization/metadata.go b/initialization/metadata.go
new file mode 100644
index 000000000..ae8bf562b
--- /dev/null
+++ b/initialization/metadata.go
@@ -0,0 +1,49 @@
+package initialization
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/spacemeshos/post/shared"
+)
+
+const MetadataFileName = "postdata_metadata.json"
+
+func SaveMetadata(dir string, v *shared.PostMetadata) error {
+	err := os.MkdirAll(dir, shared.OwnerReadWriteExec)
+	if err != nil && !os.IsExist(err) {
+		return fmt.Errorf("dir creation failure: %w", err)
+	}
+
+	data, err := json.Marshal(v)
+	if err != nil {
+		return fmt.Errorf("serialization failure: %w", err)
+	}
+
+	err = os.WriteFile(filepath.Join(dir, MetadataFileName), data, shared.OwnerReadWrite)
+	if err != nil {
+		return fmt.Errorf("write to disk failure: %w", err)
+	}
+
+	return nil
+}
+
+func LoadMetadata(dir string) (*shared.PostMetadata, error) {
+	filename := filepath.Join(dir, MetadataFileName)
+	data, err := os.ReadFile(filename)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, ErrStateMetadataFileMissing
+		}
+		return nil, fmt.Errorf("read file failure: %w", err)
+	}
+
+	metadata := shared.PostMetadata{}
+	if err := json.Unmarshal(data, &metadata); err != nil {
+		return nil, err
+	}
+
+	return &metadata, nil
+}
diff --git a/initialization/migrate_metadata.go b/initialization/migrate_metadata.go
index 15391f753..db3c89d4d 100644
--- a/initialization/migrate_metadata.go
+++ b/initialization/migrate_metadata.go
@@ -29,11 +29,11 @@ type MetadataVersion struct {
 func MigratePoST(dir string, logger *zap.Logger) (err error) {
 	logger.Info("checking PoST for migrations")
 
-	filename := filepath.Join(dir, shared.MetadataFileName)
+	filename := filepath.Join(dir, MetadataFileName)
 	file, err := os.Open(filename)
 	switch {
 	case os.IsNotExist(err):
-		return shared.ErrStateMetadataFileMissing
+		return ErrStateMetadataFileMissing
 	case err != nil:
 		return fmt.Errorf("could not open metadata file: %w", err)
 	}
@@ -85,11 +85,11 @@ type postMetadataV0 struct {
 // - add NonceValue field to postdata_metadata.json if missing (was introduced before migrations, not every PoST version 0 metadata file has it)
 // - re-encode NodeId and CommitmentAtxId as hex strings.
 func migrateV0(dir string, logger *zap.Logger) (err error) {
-	filename := filepath.Join(dir, shared.MetadataFileName)
+	filename := filepath.Join(dir, MetadataFileName)
 	file, err := os.Open(filename)
 	switch {
 	case os.IsNotExist(err):
-		return shared.ErrStateMetadataFileMissing
+		return ErrStateMetadataFileMissing
 	case err != nil:
 		return fmt.Errorf("could not read metadata file: %w", err)
 	}
diff --git a/initialization/vrf_search.go b/initialization/vrf_search.go
index 9d593f3d6..a2f44ded6 100644
--- a/initialization/vrf_search.go
+++ b/initialization/vrf_search.go
@@ -54,7 +54,7 @@ func SearchForNonce(ctx context.Context, cfg Config, initOpts InitOpts, opts ...
 	}
 	logger := options.logger
 
-	metadata, err := shared.LoadMetadata(initOpts.DataDir)
+	metadata, err := LoadMetadata(initOpts.DataDir)
 	if err != nil {
 		return 0, nil, fmt.Errorf("failed to load metadata: %w", err)
 	}
@@ -145,7 +145,7 @@ func persistNonce(nonce uint64, label []byte, metadata *shared.PostMetadata, dat
 	logger.Info("found nonce: updating postdata_metadata.json", zap.Uint64("nonce", nonce), zap.String("NonceValue", hex.EncodeToString(label)))
 	metadata.Nonce = &nonce
 	metadata.NonceValue = shared.NonceValue(label)
-	if err := shared.SaveMetadata(datadir, metadata); err != nil {
+	if err := SaveMetadata(datadir, metadata); err != nil {
 		return fmt.Errorf("failed to save metadata: %w", err)
 	}
 	return nil
diff --git a/initialization/vrf_search_test.go b/initialization/vrf_search_test.go
index 57d108354..6fad38fd8 100644
--- a/initialization/vrf_search_test.go
+++ b/initialization/vrf_search_test.go
@@ -93,7 +93,7 @@ func TestSearchForNonce(t *testing.T) {
 	err = init.Initialize(context.Background())
 	require.NoError(t, err)
 
-	metadata, err := shared.LoadMetadata(opts.DataDir)
+	metadata, err := LoadMetadata(opts.DataDir)
 	require.NoError(t, err)
 
 	expectedNonce := metadata.Nonce
@@ -101,7 +101,7 @@ func TestSearchForNonce(t *testing.T) {
 	// remove Nonce and NonceValue from metadata
 	metadata.Nonce = nil
 	metadata.NonceValue = nil
-	err = shared.SaveMetadata(opts.DataDir, metadata)
+	err = SaveMetadata(opts.DataDir, metadata)
 	require.NoError(t, err)
 
 	nonce, value, err := SearchForNonce(
@@ -115,7 +115,7 @@ func TestSearchForNonce(t *testing.T) {
 	require.EqualValues(t, expectedNonceValue, value)
 
 	// Verify that nonce was written to the metatada file
-	metadata, err = shared.LoadMetadata(opts.DataDir)
+	metadata, err = LoadMetadata(opts.DataDir)
 	require.NoError(t, err)
 	require.Equal(t, expectedNonce, metadata.Nonce)
 	require.EqualValues(t, expectedNonceValue, metadata.NonceValue)
diff --git a/proving/proving_options.go b/proving/proving_options.go
index 239bfa76b..c2c11ee1b 100644
--- a/proving/proving_options.go
+++ b/proving/proving_options.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 
 	"github.com/spacemeshos/post/config"
+	"github.com/spacemeshos/post/initialization"
 	"github.com/spacemeshos/post/shared"
 )
 
@@ -38,7 +39,7 @@ type OptionFunc func(*option) error
 // WithDataSource sets the data source to use for the proof.
 func WithDataSource(cfg config.Config, nodeId, commitmentAtxId []byte, datadir string) OptionFunc {
 	return func(o *option) error {
-		m, err := shared.LoadMetadata(datadir)
+		m, err := initialization.LoadMetadata(datadir)
 		if err != nil {
 			return err
 		}
diff --git a/shared/post_metadata.go b/shared/post_metadata.go
index eaa55b564..69a48d25c 100644
--- a/shared/post_metadata.go
+++ b/shared/post_metadata.go
@@ -4,14 +4,8 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
-	"fmt"
-	"os"
-	"path/filepath"
 )
 
-// ErrStateMetadataFileMissing is returned when the metadata file is missing.
-var ErrStateMetadataFileMissing = errors.New("metadata file is missing")
-
 // PostMetadata is the data associated with the PoST init procedure, persisted in the datadir next to the init files.
 type PostMetadata struct {
 	Version int `json:",omitempty"`
@@ -90,42 +84,3 @@ func (a *ATXID) UnmarshalJSON(data []byte) (err error) {
 	*a, err = hex.DecodeString(hexString)
 	return
 }
-
-const MetadataFileName = "postdata_metadata.json"
-
-func SaveMetadata(dir string, v *PostMetadata) error {
-	err := os.MkdirAll(dir, OwnerReadWriteExec)
-	if err != nil && !os.IsExist(err) {
-		return fmt.Errorf("dir creation failure: %w", err)
-	}
-
-	data, err := json.Marshal(v)
-	if err != nil {
-		return fmt.Errorf("serialization failure: %w", err)
-	}
-
-	err = os.WriteFile(filepath.Join(dir, MetadataFileName), data, OwnerReadWrite)
-	if err != nil {
-		return fmt.Errorf("write to disk failure: %w", err)
-	}
-
-	return nil
-}
-
-func LoadMetadata(dir string) (*PostMetadata, error) {
-	filename := filepath.Join(dir, MetadataFileName)
-	data, err := os.ReadFile(filename)
-	if err != nil {
-		if os.IsNotExist(err) {
-			return nil, ErrStateMetadataFileMissing
-		}
-		return nil, fmt.Errorf("read file failure: %w", err)
-	}
-
-	metadata := PostMetadata{}
-	if err := json.Unmarshal(data, &metadata); err != nil {
-		return nil, err
-	}
-
-	return &metadata, nil
-}