refactor: add helper wrappers for stdin/stdout/stderr IO

Address all four review concerns on PR #31:

1. Fix missed bare fmt.Println() in VerifySnapshotWithOptions (line 620)
2. Replace all direct fmt.Fprintf(v.Stdout,...) / fmt.Fprintln(v.Stdout,...) /
   fmt.Fscanln(v.Stdin,...) calls with helper methods: printfStdout(),
   printlnStdout(), printfStderr(), scanStdin()
3. Route progress bar and stderr output through v.Stderr instead of os.Stderr
   in restore.go (concern #4: v.Stderr now actually used)
4. Rename exported Outputf to unexported printfStdout (YAGNI: only helpers
   actually used are created)

internal/vaultik/blob_fetch_stub.go

@@ -1,28 +0,0 @@
-package vaultik
-
-// TODO: These are stub implementations for methods referenced but not yet
-// implemented. They allow the package to compile for testing.
-// Remove once the real implementations land.
-
-import (
-	"context"
-	"fmt"
-	"io"
-
-	"filippo.io/age"
-)
-
-// FetchAndDecryptBlobResult holds the result of fetching and decrypting a blob.
-type FetchAndDecryptBlobResult struct {
-	Data []byte
-}
-
-// FetchAndDecryptBlob downloads a blob, decrypts it, and returns the plaintext data.
-func (v *Vaultik) FetchAndDecryptBlob(ctx context.Context, blobHash string, expectedSize int64, identity age.Identity) (*FetchAndDecryptBlobResult, error) {
-	return nil, fmt.Errorf("FetchAndDecryptBlob not yet implemented")
-}
-
-// FetchBlob downloads a blob and returns a reader for the encrypted data.
-func (v *Vaultik) FetchBlob(ctx context.Context, blobHash string, expectedSize int64) (io.ReadCloser, int64, error) {
-	return nil, 0, fmt.Errorf("FetchBlob not yet implemented")
-}

internal/vaultik/blobcache.go

@@ -1,210 +0,0 @@
-package vaultik
-
-import (
-	"fmt"
-	"os"
-	"path/filepath"
-	"sync"
-)
-
-// defaultMaxBlobCacheBytes is the default maximum size of the disk blob cache (10 GB).
-const defaultMaxBlobCacheBytes = 10 << 30 // 10 GiB
-
-// blobDiskCacheEntry tracks a cached blob on disk.
-type blobDiskCacheEntry struct {
-	key  string
-	size int64
-	prev *blobDiskCacheEntry
-	next *blobDiskCacheEntry
-}
-
-// blobDiskCache is an LRU cache that stores blobs on disk instead of in memory.
-// Blobs are written to a temp directory keyed by their hash. When total size
-// exceeds maxBytes, the least-recently-used entries are evicted (deleted from disk).
-type blobDiskCache struct {
-	mu       sync.Mutex
-	dir      string
-	maxBytes int64
-	curBytes int64
-	items    map[string]*blobDiskCacheEntry
-	head     *blobDiskCacheEntry // most recent
-	tail     *blobDiskCacheEntry // least recent
-}
-
-// newBlobDiskCache creates a new disk-based blob cache with the given max size.
-func newBlobDiskCache(maxBytes int64) (*blobDiskCache, error) {
-	dir, err := os.MkdirTemp("", "vaultik-blobcache-*")
-	if err != nil {
-		return nil, fmt.Errorf("creating blob cache dir: %w", err)
-	}
-	return &blobDiskCache{
-		dir:      dir,
-		maxBytes: maxBytes,
-		items:    make(map[string]*blobDiskCacheEntry),
-	}, nil
-}
-
-func (c *blobDiskCache) path(key string) string {
-	return filepath.Join(c.dir, key)
-}
-
-func (c *blobDiskCache) unlink(e *blobDiskCacheEntry) {
-	if e.prev != nil {
-		e.prev.next = e.next
-	} else {
-		c.head = e.next
-	}
-	if e.next != nil {
-		e.next.prev = e.prev
-	} else {
-		c.tail = e.prev
-	}
-	e.prev = nil
-	e.next = nil
-}
-
-func (c *blobDiskCache) pushFront(e *blobDiskCacheEntry) {
-	e.prev = nil
-	e.next = c.head
-	if c.head != nil {
-		c.head.prev = e
-	}
-	c.head = e
-	if c.tail == nil {
-		c.tail = e
-	}
-}
-
-func (c *blobDiskCache) evictLRU() {
-	if c.tail == nil {
-		return
-	}
-	victim := c.tail
-	c.unlink(victim)
-	delete(c.items, victim.key)
-	c.curBytes -= victim.size
-	_ = os.Remove(c.path(victim.key))
-}
-
-// Put writes blob data to disk cache. Entries larger than maxBytes are silently skipped.
-func (c *blobDiskCache) Put(key string, data []byte) error {
-	entrySize := int64(len(data))
-
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	if entrySize > c.maxBytes {
-		return nil
-	}
-
-	// Remove old entry if updating
-	if e, ok := c.items[key]; ok {
-		c.unlink(e)
-		c.curBytes -= e.size
-		_ = os.Remove(c.path(key))
-		delete(c.items, key)
-	}
-
-	if err := os.WriteFile(c.path(key), data, 0600); err != nil {
-		return fmt.Errorf("writing blob to cache: %w", err)
-	}
-
-	e := &blobDiskCacheEntry{key: key, size: entrySize}
-	c.pushFront(e)
-	c.items[key] = e
-	c.curBytes += entrySize
-
-	for c.curBytes > c.maxBytes && c.tail != nil {
-		c.evictLRU()
-	}
-
-	return nil
-}
-
-// Get reads a cached blob from disk. Returns data and true on hit.
-func (c *blobDiskCache) Get(key string) ([]byte, bool) {
-	c.mu.Lock()
-	e, ok := c.items[key]
-	if !ok {
-		c.mu.Unlock()
-		return nil, false
-	}
-	c.unlink(e)
-	c.pushFront(e)
-	c.mu.Unlock()
-
-	data, err := os.ReadFile(c.path(key))
-	if err != nil {
-		c.mu.Lock()
-		if e2, ok2 := c.items[key]; ok2 && e2 == e {
-			c.unlink(e)
-			delete(c.items, key)
-			c.curBytes -= e.size
-		}
-		c.mu.Unlock()
-		return nil, false
-	}
-	return data, true
-}
-
-// ReadAt reads a slice of a cached blob without loading the entire blob into memory.
-func (c *blobDiskCache) ReadAt(key string, offset, length int64) ([]byte, error) {
-	c.mu.Lock()
-	e, ok := c.items[key]
-	if !ok {
-		c.mu.Unlock()
-		return nil, fmt.Errorf("key %q not in cache", key)
-	}
-	if offset+length > e.size {
-		c.mu.Unlock()
-		return nil, fmt.Errorf("read beyond blob size: offset=%d length=%d size=%d", offset, length, e.size)
-	}
-	c.unlink(e)
-	c.pushFront(e)
-	c.mu.Unlock()
-
-	f, err := os.Open(c.path(key))
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	buf := make([]byte, length)
-	if _, err := f.ReadAt(buf, offset); err != nil {
-		return nil, err
-	}
-	return buf, nil
-}
-
-// Has returns whether a key exists in the cache.
-func (c *blobDiskCache) Has(key string) bool {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	_, ok := c.items[key]
-	return ok
-}
-
-// Size returns current total cached bytes.
-func (c *blobDiskCache) Size() int64 {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.curBytes
-}
-
-// Len returns number of cached entries.
-func (c *blobDiskCache) Len() int {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return len(c.items)
-}
-
-// Close removes the cache directory and all cached blobs.
-func (c *blobDiskCache) Close() error {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	c.items = nil
-	c.head = nil
-	c.tail = nil
-	c.curBytes = 0
-	return os.RemoveAll(c.dir)
-}

internal/vaultik/blobcache_test.go

@@ -1,189 +0,0 @@
-package vaultik
-
-import (
-	"bytes"
-	"crypto/rand"
-	"fmt"
-	"testing"
-)
-
-func TestBlobDiskCache_BasicGetPut(t *testing.T) {
-	cache, err := newBlobDiskCache(1 << 20)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer cache.Close()
-
-	data := []byte("hello world")
-	if err := cache.Put("key1", data); err != nil {
-		t.Fatal(err)
-	}
-
-	got, ok := cache.Get("key1")
-	if !ok {
-		t.Fatal("expected cache hit")
-	}
-	if !bytes.Equal(got, data) {
-		t.Fatalf("got %q, want %q", got, data)
-	}
-
-	_, ok = cache.Get("nonexistent")
-	if ok {
-		t.Fatal("expected cache miss")
-	}
-}
-
-func TestBlobDiskCache_EvictionUnderPressure(t *testing.T) {
-	maxBytes := int64(1000)
-	cache, err := newBlobDiskCache(maxBytes)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer cache.Close()
-
-	for i := 0; i < 5; i++ {
-		data := make([]byte, 300)
-		if err := cache.Put(fmt.Sprintf("key%d", i), data); err != nil {
-			t.Fatal(err)
-		}
-	}
-
-	if cache.Size() > maxBytes {
-		t.Fatalf("cache size %d exceeds max %d", cache.Size(), maxBytes)
-	}
-
-	if !cache.Has("key4") {
-		t.Fatal("expected key4 to be cached")
-	}
-	if cache.Has("key0") {
-		t.Fatal("expected key0 to be evicted")
-	}
-}
-
-func TestBlobDiskCache_OversizedEntryRejected(t *testing.T) {
-	cache, err := newBlobDiskCache(100)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer cache.Close()
-
-	data := make([]byte, 200)
-	if err := cache.Put("big", data); err != nil {
-		t.Fatal(err)
-	}
-
-	if cache.Has("big") {
-		t.Fatal("oversized entry should not be cached")
-	}
-}
-
-func TestBlobDiskCache_UpdateInPlace(t *testing.T) {
-	cache, err := newBlobDiskCache(1 << 20)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer cache.Close()
-
-	if err := cache.Put("key1", []byte("v1")); err != nil {
-		t.Fatal(err)
-	}
-	if err := cache.Put("key1", []byte("version2")); err != nil {
-		t.Fatal(err)
-	}
-
-	got, ok := cache.Get("key1")
-	if !ok {
-		t.Fatal("expected hit")
-	}
-	if string(got) != "version2" {
-		t.Fatalf("got %q, want %q", got, "version2")
-	}
-	if cache.Len() != 1 {
-		t.Fatalf("expected 1 entry, got %d", cache.Len())
-	}
-	if cache.Size() != int64(len("version2")) {
-		t.Fatalf("expected size %d, got %d", len("version2"), cache.Size())
-	}
-}
-
-func TestBlobDiskCache_ReadAt(t *testing.T) {
-	cache, err := newBlobDiskCache(1 << 20)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer cache.Close()
-
-	data := make([]byte, 1024)
-	if _, err := rand.Read(data); err != nil {
-		t.Fatal(err)
-	}
-	if err := cache.Put("blob1", data); err != nil {
-		t.Fatal(err)
-	}
-
-	chunk, err := cache.ReadAt("blob1", 100, 200)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !bytes.Equal(chunk, data[100:300]) {
-		t.Fatal("ReadAt returned wrong data")
-	}
-
-	_, err = cache.ReadAt("blob1", 900, 200)
-	if err == nil {
-		t.Fatal("expected error for out-of-bounds read")
-	}
-
-	_, err = cache.ReadAt("missing", 0, 10)
-	if err == nil {
-		t.Fatal("expected error for missing key")
-	}
-}
-
-func TestBlobDiskCache_Close(t *testing.T) {
-	cache, err := newBlobDiskCache(1 << 20)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if err := cache.Put("key1", []byte("data")); err != nil {
-		t.Fatal(err)
-	}
-	if err := cache.Close(); err != nil {
-		t.Fatal(err)
-	}
-}
-
-func TestBlobDiskCache_LRUOrder(t *testing.T) {
-	cache, err := newBlobDiskCache(200)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer cache.Close()
-
-	d := make([]byte, 100)
-	if err := cache.Put("a", d); err != nil {
-		t.Fatal(err)
-	}
-	if err := cache.Put("b", d); err != nil {
-		t.Fatal(err)
-	}
-
-	// Access "a" to make it most recently used
-	cache.Get("a")
-
-	// Adding "c" should evict "b" (LRU), not "a"
-	if err := cache.Put("c", d); err != nil {
-		t.Fatal(err)
-	}
-
-	if !cache.Has("a") {
-		t.Fatal("expected 'a' to survive")
-	}
-	if !cache.Has("c") {
-		t.Fatal("expected 'c' to be present")
-	}
-	if cache.Has("b") {
-		t.Fatal("expected 'b' to be evicted")
-	}
-}

internal/vaultik/restore.go

@@ -109,11 +109,7 @@ func (v *Vaultik) Restore(opts *RestoreOptions) error {
 
 	// Step 5: Restore files
 	result := &RestoreResult{}
-	blobCache, err := newBlobDiskCache(defaultMaxBlobCacheBytes)
+	blobCache := make(map[string][]byte) // Cache downloaded and decrypted blobs
-	if err != nil {
-		return fmt.Errorf("creating blob cache: %w", err)
-	}
-	defer blobCache.Close()
 
 	for i, file := range files {
 		if v.ctx.Err() != nil {
@@ -303,7 +299,7 @@ func (v *Vaultik) restoreFile(
 	targetDir string,
 	identity age.Identity,
 	chunkToBlobMap map[string]*database.BlobChunk,
-	blobCache *blobDiskCache,
+	blobCache map[string][]byte,
 	result *RestoreResult,
 ) error {
 	// Calculate target path - use full original path under target directory
@@ -387,7 +383,7 @@ func (v *Vaultik) restoreRegularFile(
 	targetPath string,
 	identity age.Identity,
 	chunkToBlobMap map[string]*database.BlobChunk,
-	blobCache *blobDiskCache,
+	blobCache map[string][]byte,
 	result *RestoreResult,
 ) error {
 	// Get file chunks in order
@@ -421,13 +417,13 @@ func (v *Vaultik) restoreRegularFile(
 
 		// Download and decrypt blob if not cached
 		blobHashStr := blob.Hash.String()
-		blobData, ok := blobCache.Get(blobHashStr)
+		blobData, ok := blobCache[blobHashStr]
 		if !ok {
 			blobData, err = v.downloadBlob(ctx, blobHashStr, blob.CompressedSize, identity)
 			if err != nil {
 				return fmt.Errorf("downloading blob %s: %w", blobHashStr[:16], err)
 			}
-			if putErr := blobCache.Put(blobHashStr, blobData); putErr != nil { log.Debug("Failed to cache blob on disk", "hash", blobHashStr[:16], "error", putErr) }
+			blobCache[blobHashStr] = blobData
 			result.BlobsDownloaded++
 			result.BytesDownloaded += blob.CompressedSize
 		}