lib/filestream: change Create() to MustCreate()

Callers of this function log the returned error and exit.
It is better logging the error together with the path to the filename
and call stack directly inside the function. This simplifies
the code at callers' side without reducing the level of debuggability

lib/filestream/filestream.go

@@ -202,15 +202,15 @@ func OpenWriterAt(path string, offset int64, nocache bool) (*Writer, error) {
 	return newWriter(f, nocache), nil
 }
 
-// Create creates the file for the given path in nocache mode.
+// MustCreate creates the file for the given path in nocache mode.
 //
 // If nocache is set, the writer doesn't pollute OS page cache.
-func Create(path string, nocache bool) (*Writer, error) {
+func MustCreate(path string, nocache bool) *Writer {
 	f, err := os.Create(path)
 	if err != nil {
-		return nil, fmt.Errorf("cannot create file %q: %w", path, err)
+		logger.Panicf("FATAL: cannot create file %q: %s", path, err)
 	}
-	return newWriter(f, nocache), nil
+	return newWriter(f, nocache)
 }
 
 func newWriter(f *os.File, nocache bool) *Writer {

lib/filestream/filestream_test.go

@@ -29,10 +29,7 @@ func TestWriteRead(t *testing.T) {
 func testWriteRead(t *testing.T, nocache bool, testStr string) {
 	t.Helper()
 
-	w, err := Create("./nocache_test.txt", nocache)
+	w := MustCreate("./nocache_test.txt", nocache)
-	if err != nil {
-		t.Fatalf("cannot create file: %s", err)
-	}
 	defer func() {
 		_ = os.Remove("./nocache_test.txt")
 	}()

lib/fs/fs.go

@@ -34,10 +34,7 @@ func MustSyncPath(path string) {
 // Use MustWriteAtomic if the file at the path must be either written in full
 // or not written at all on app crash in the middle of the write.
 func MustWriteSync(path string, data []byte) {
-	f, err := filestream.Create(path, false)
+	f := filestream.MustCreate(path, false)
-	if err != nil {
-		logger.Panicf("FATAL: cannot create file: %s", err)
-	}
 	if _, err := f.Write(data); err != nil {
 		f.MustClose()
 		// Do not call MustRemoveAll(path), so the user could inspect

lib/mergeset/block_stream_writer.go

@@ -1,7 +1,6 @@
 package mergeset
 
 import (
-	"fmt"
 	"path/filepath"
 	"sync"
 
@@ -71,10 +70,10 @@ func (bsw *blockStreamWriter) InitFromInmemoryPart(mp *inmemoryPart, compressLev
 	bsw.lensWriter = &mp.lensData
 }
 
-// InitFromFilePart initializes bsw from a file-based part on the given path.
+// MustInitFromFilePart initializes bsw from a file-based part on the given path.
 //
 // The bsw doesn't pollute OS page cache if nocache is set.
-func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compressLevel int) error {
+func (bsw *blockStreamWriter) MustInitFromFilePart(path string, nocache bool, compressLevel int) {
 	path = filepath.Clean(path)
 
 	// Create the directory
@@ -85,38 +84,16 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	// Always cache metaindex file in OS page cache, since it is immediately
 	// read after the merge.
 	metaindexPath := filepath.Join(path, metaindexFilename)
-	metaindexFile, err := filestream.Create(metaindexPath, false)
+	metaindexFile := filestream.MustCreate(metaindexPath, false)
-	if err != nil {
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create metaindex file: %w", err)
-	}
 
 	indexPath := filepath.Join(path, indexFilename)
-	indexFile, err := filestream.Create(indexPath, nocache)
+	indexFile := filestream.MustCreate(indexPath, nocache)
-	if err != nil {
-		metaindexFile.MustClose()
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create index file: %w", err)
-	}
 
 	itemsPath := filepath.Join(path, itemsFilename)
-	itemsFile, err := filestream.Create(itemsPath, nocache)
+	itemsFile := filestream.MustCreate(itemsPath, nocache)
-	if err != nil {
-		metaindexFile.MustClose()
-		indexFile.MustClose()
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create items file: %w", err)
-	}
 
 	lensPath := filepath.Join(path, lensFilename)
-	lensFile, err := filestream.Create(lensPath, nocache)
+	lensFile := filestream.MustCreate(lensPath, nocache)
-	if err != nil {
-		metaindexFile.MustClose()
-		indexFile.MustClose()
-		itemsFile.MustClose()
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create lens file: %w", err)
-	}
 
 	bsw.reset()
 	bsw.compressLevel = compressLevel
@@ -125,8 +102,6 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	bsw.indexWriter = indexFile
 	bsw.itemsWriter = itemsFile
 	bsw.lensWriter = lensFile
-
-	return nil
 }
 
 // MustClose closes the bsw.

lib/mergeset/table.go

@@ -1121,9 +1121,7 @@ func (tb *Table) mergeParts(pws []*partWrapper, stopCh <-chan struct{}, isFinal
 		bsw.InitFromInmemoryPart(mpNew, compressLevel)
 	} else {
 		nocache := srcItemsCount > maxItemsPerCachedPart()
-		if err := bsw.InitFromFilePart(dstPartPath, nocache, compressLevel); err != nil {
+		bsw.MustInitFromFilePart(dstPartPath, nocache, compressLevel)
-			logger.Panicf("FATAL: cannot create destination part at %s: %s", dstPartPath, err)
-		}
 	}
 
 	// Merge source parts to destination part.

lib/persistentqueue/persistentqueue.go

@@ -93,10 +93,7 @@ func (q *queue) mustResetFiles() {
 	q.readerLocalOffset = 0
 
 	q.writerPath = q.chunkFilePath(q.writerOffset)
-	w, err := filestream.Create(q.writerPath, false)
+	w := filestream.MustCreate(q.writerPath, false)
-	if err != nil {
-		logger.Panicf("FATAL: cannot create chunk file %q: %s", q.writerPath, err)
-	}
 	q.writer = w
 
 	q.readerPath = q.writerPath
@@ -445,10 +442,7 @@ func (q *queue) nextChunkFileForWrite() error {
 	q.writerFlushedOffset = q.writerOffset
 	q.writerLocalOffset = 0
 	q.writerPath = q.chunkFilePath(q.writerOffset)
-	w, err := filestream.Create(q.writerPath, false)
+	w := filestream.MustCreate(q.writerPath, false)
-	if err != nil {
-		return fmt.Errorf("cannot create chunk file %q: %w", q.writerPath, err)
-	}
 	q.writer = w
 	if err := q.flushMetainfo(); err != nil {
 		return fmt.Errorf("cannot flush metainfo: %w", err)

lib/storage/block_stream_writer.go

@@ -2,7 +2,6 @@ package storage
 
 import (
 	"bytes"
-	"fmt"
 	"path/filepath"
 	"sync"
 	"sync/atomic"
@@ -78,10 +77,10 @@ func (bsw *blockStreamWriter) InitFromInmemoryPart(mp *inmemoryPart, compressLev
 	bsw.metaindexWriter = &mp.metaindexData
 }
 
-// InitFromFilePart initializes bsw from a file-based part on the given path.
+// MustInitFromFilePart initializes bsw from a file-based part on the given path.
 //
 // The bsw doesn't pollute OS page cache if nocache is set.
-func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compressLevel int) error {
+func (bsw *blockStreamWriter) MustInitFromFilePart(path string, nocache bool, compressLevel int) {
 	path = filepath.Clean(path)
 
 	// Create the directory
@@ -89,40 +88,18 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 
 	// Create part files in the directory.
 	timestampsPath := filepath.Join(path, timestampsFilename)
-	timestampsFile, err := filestream.Create(timestampsPath, nocache)
+	timestampsFile := filestream.MustCreate(timestampsPath, nocache)
-	if err != nil {
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create timestamps file: %w", err)
-	}
 
 	valuesPath := filepath.Join(path, valuesFilename)
-	valuesFile, err := filestream.Create(valuesPath, nocache)
+	valuesFile := filestream.MustCreate(valuesPath, nocache)
-	if err != nil {
-		timestampsFile.MustClose()
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create values file: %w", err)
-	}
 
 	indexPath := filepath.Join(path, indexFilename)
-	indexFile, err := filestream.Create(indexPath, nocache)
+	indexFile := filestream.MustCreate(indexPath, nocache)
-	if err != nil {
-		timestampsFile.MustClose()
-		valuesFile.MustClose()
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create index file: %w", err)
-	}
 
 	// Always cache metaindex file in OS page cache, since it is immediately
 	// read after the merge.
 	metaindexPath := filepath.Join(path, metaindexFilename)
-	metaindexFile, err := filestream.Create(metaindexPath, false)
+	metaindexFile := filestream.MustCreate(metaindexPath, false)
-	if err != nil {
-		timestampsFile.MustClose()
-		valuesFile.MustClose()
-		indexFile.MustClose()
-		fs.MustRemoveDirAtomic(path)
-		return fmt.Errorf("cannot create metaindex file: %w", err)
-	}
 
 	bsw.reset()
 	bsw.compressLevel = compressLevel
@@ -131,8 +108,6 @@ func (bsw *blockStreamWriter) InitFromFilePart(path string, nocache bool, compre
 	bsw.valuesWriter = valuesFile
 	bsw.indexWriter = indexFile
 	bsw.metaindexWriter = metaindexFile
-
-	return nil
 }
 
 // MustClose closes the bsw.

lib/storage/partition.go

@@ -1300,9 +1300,7 @@ func (pt *partition) mergeParts(pws []*partWrapper, stopCh <-chan struct{}, isFi
 			logger.Panicf("BUG: dstPartPath must be non-empty")
 		}
 		nocache := dstPartType == partBig
-		if err := bsw.InitFromFilePart(dstPartPath, nocache, compressLevel); err != nil {
+		bsw.MustInitFromFilePart(dstPartPath, nocache, compressLevel)
-			logger.Panicf("FATAL: cannot create destination part at %s: %s", dstPartPath, err)
-		}
 	}
 
 	// Merge source parts to destination part.