verstak/internal/core/sync/blob.go

81 lines
1.7 KiB
Go

package sync
import (
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"os"
"path/filepath"
)
// BlobDir returns the path to .verstak/blobs/ inside the vault.
func BlobDir(vaultRoot string) string {
return filepath.Join(vaultRoot, ".verstak", "blobs")
}
// BlobPath returns the on-disk path for a SHA-256 hash.
func BlobPath(blobsDir, shaHex string) string {
return filepath.Join(blobsDir, shaHex[:2], shaHex[2:4], shaHex)
}
// HashFile computes SHA-256 of a file.
func HashFile(path string) (string, error) {
f, err := os.Open(path)
if err != nil {
return "", err
}
defer f.Close()
h := sha256.New()
if _, err := io.Copy(h, f); err != nil {
return "", err
}
return hex.EncodeToString(h.Sum(nil)), nil
}
// HashBytes computes SHA-256 of byte data.
func HashBytes(data []byte) string {
h := sha256.Sum256(data)
return hex.EncodeToString(h[:])
}
// StoreBlob copies a file into the blob store, returns its SHA-256.
func StoreBlob(blobsDir, srcPath string) (string, error) {
shaHex, err := HashFile(srcPath)
if err != nil {
return "", err
}
dest := BlobPath(blobsDir, shaHex)
if _, err := os.Stat(dest); err == nil {
return shaHex, nil // already exists
}
if err := os.MkdirAll(filepath.Dir(dest), 0750); err != nil {
return "", err
}
src, err := os.Open(srcPath)
if err != nil {
return "", err
}
defer src.Close()
dst, err := os.Create(dest)
if err != nil {
return "", err
}
defer dst.Close()
if _, err := io.Copy(dst, src); err != nil {
return "", err
}
_ = dst.Sync()
return shaHex, nil
}
// ReadBlob reads a blob by SHA-256 hash.
func ReadBlob(blobsDir, shaHex string) ([]byte, error) {
return os.ReadFile(BlobPath(blobsDir, shaHex))
}
// Ensure the package compiles without unused errors.
var _ = fmt.Sprintf