perf(archive): parallel deflate workers for archive creation (#3316)

Archive creation compressed every entry through a single zip.Writer,
pinning the task to one CPU core. Entries are now enumerated first, then
deflated on a worker pool (adaptive: min(GOMAXPROCS, 8), tunable via
fs.WithArchiveWorkers): each worker spools its deflate stream to a temp
file with precomputed CRC32/sizes, and a single writer drains results
via zip.CreateRaw. Store/dry-run paths stay sequential.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

pkg/filemanager/fs/fs.go

@@ -327,6 +327,7 @@ type (
 		SysSkipSoftDelete  bool
 		Metadata           map[string]string
 		ArchiveCompression bool
+		ArchiveWorkers     int
 		ProgressFunc
 		MaxArchiveSize  int64
 		DryRun          CreateArchiveDryRunFunc
@@ -586,6 +587,15 @@ func WithArchiveCompression(b bool) Option {
 	})
 }
 
+// WithArchiveWorkers sets the number of parallel compression workers for
+// archive creation. <=0 selects an adaptive default, 1 keeps the
+// sequential single-writer path.
+func WithArchiveWorkers(n int) Option {
+	return OptionFunc(func(o *FsOption) {
+		o.ArchiveWorkers = n
+	})
+}
+
 // WithMaxArchiveSize sets maximum size of to be archived file or to-be decompressed
 // size, 0 for unlimited.
 func WithMaxArchiveSize(s int64) Option {

pkg/filemanager/manager/archive.go

@@ -2,13 +2,18 @@ package manager
 
 import (
 	"archive/zip"
+	"compress/flate"
 	"context"
 	"encoding/gob"
 	"fmt"
+	"hash/crc32"
 	"io"
+	"os"
 	"path"
 	"path/filepath"
+	"runtime"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/bodgit/sevenzip"
@@ -172,48 +177,48 @@ func (m *manager) CreateArchive(ctx context.Context, uris []*fs.URI, writer io.W
 	zipWriter := zip.NewWriter(writer)
 	defer zipWriter.Close()
 
-	var compressed int64
+	// Enumerate all archive entries up front; compression itself then runs
+	// either sequentially or fanned out to workers (#3316).
+	jobs := make([]createArchiveJob, 0, len(files))
 	for _, file := range files {
 		if file.Type() == types.FileTypeFile {
-			if err := m.compressFileToArchive(ctx, "/", file, zipWriter, o.ArchiveCompression, o.DryRun); err != nil {
-				failed++
-				m.l.Warning("Failed to compress file %s: %s, skipping it...", file.Uri(false), err)
-			}
-
-			compressed += file.Size()
-			if o.ProgressFunc != nil {
-				o.ProgressFunc(compressed, file.Size(), 0)
-			}
+			jobs = append(jobs, createArchiveJob{parent: "/", file: file})
+			continue
+		}
 
-			if o.MaxArchiveSize > 0 && compressed > o.MaxArchiveSize {
-				return 0, fs.ErrArchiveSrcSizeTooBig
+		if err := m.Walk(ctx, file.Uri(false), intsets.MaxInt, func(f fs.File, level int) error {
+			if f.Type() == types.FileTypeFolder || f.IsSymbolic() {
+				return nil
 			}
+			jobs = append(jobs, createArchiveJob{
+				parent: strings.TrimPrefix(f.Uri(false).Dir(), file.Uri(false).Dir()),
+				file:   f,
+			})
+			return nil
+		}); err != nil {
+			m.l.Warning("Failed to walk folder %s: %s, skipping it...", file.Uri(false), err)
+			failed++
+		}
+	}
 
-		} else {
-			if err := m.Walk(ctx, file.Uri(false), intsets.MaxInt, func(f fs.File, level int) error {
-				if f.Type() == types.FileTypeFolder || f.IsSymbolic() {
-					return nil
-				}
-				if err := m.compressFileToArchive(ctx, strings.TrimPrefix(f.Uri(false).Dir(),
-					file.Uri(false).Dir()), f, zipWriter, o.ArchiveCompression, o.DryRun); err != nil {
-					failed++
-					m.l.Warning("Failed to compress file %s: %s, skipping it...", f.Uri(false), err)
-				}
+	if o.DryRun == nil && o.ArchiveCompression && o.ArchiveWorkers != 1 && len(jobs) > 1 {
+		return m.createArchiveParallel(ctx, jobs, zipWriter, o)
+	}
 
-				compressed += f.Size()
-				if o.ProgressFunc != nil {
-					o.ProgressFunc(compressed, f.Size(), 0)
-				}
+	var compressed int64
+	for _, job := range jobs {
+		if err := m.compressFileToArchive(ctx, job.parent, job.file, zipWriter, o.ArchiveCompression, o.DryRun); err != nil {
+			failed++
+			m.l.Warning("Failed to compress file %s: %s, skipping it...", job.file.Uri(false), err)
+		}
 
-				if o.MaxArchiveSize > 0 && compressed > o.MaxArchiveSize {
-					return fs.ErrArchiveSrcSizeTooBig
-				}
+		compressed += job.file.Size()
+		if o.ProgressFunc != nil {
+			o.ProgressFunc(compressed, job.file.Size(), 0)
+		}
 
-				return nil
-			}); err != nil {
-				m.l.Warning("Failed to walk folder %s: %s, skipping it...", file.Uri(false), err)
-				failed++
-			}
+		if o.MaxArchiveSize > 0 && compressed > o.MaxArchiveSize {
+			return 0, fs.ErrArchiveSrcSizeTooBig
 		}
 	}
 
@@ -257,6 +262,163 @@ func (m *manager) compressFileToArchive(ctx context.Context, parent string, file
 
 }
 
+// maxArchiveWorkers caps the adaptive default so disk spooling stays sane.
+const maxArchiveWorkers = 8
+
+type (
+	// createArchiveJob is a single file scheduled into an archive.
+	createArchiveJob struct {
+		parent string
+		file   fs.File
+	}
+	// archiveEntryResult carries a pre-compressed entry ready for a raw
+	// zip write, along with the temp file holding its deflate stream.
+	archiveEntryResult struct {
+		header  *zip.FileHeader
+		tmpPath string
+		file    fs.File
+		err     error
+	}
+)
+
+// countingWriter tracks bytes written for zip header sizes.
+type countingWriter struct {
+	w io.Writer
+	n int64
+}
+
+func (c *countingWriter) Write(p []byte) (int, error) {
+	n, err := c.w.Write(p)
+	c.n += int64(n)
+	return n, err
+}
+
+// createArchiveParallel deflates archive entries on a worker pool while a
+// single writer drains results in completion order via CreateRaw (#3316).
+// Compressed data is spooled to temp files so zip's sequential layout is
+// preserved without holding entries in memory.
+func (m *manager) createArchiveParallel(ctx context.Context, jobs []createArchiveJob, zipWriter *zip.Writer, o *fs.FsOption) (int, error) {
+	workers := o.ArchiveWorkers
+	if workers <= 0 {
+		workers = min(runtime.GOMAXPROCS(0), maxArchiveWorkers)
+	}
+
+	jobCh := make(chan createArchiveJob)
+	resCh := make(chan archiveEntryResult, workers)
+	var wg sync.WaitGroup
+	for i := 0; i < workers; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for job := range jobCh {
+				resCh <- m.spoolEntry(ctx, job)
+			}
+		}()
+	}
+	go func() {
+		for _, job := range jobs {
+			jobCh <- job
+		}
+		close(jobCh)
+		wg.Wait()
+		close(resCh)
+	}()
+
+	failed := 0
+	var compressed int64
+	for res := range resCh {
+		if res.err != nil {
+			failed++
+			m.l.Warning("Failed to compress file %s: %s, skipping it...", res.file.Uri(false), res.err)
+		} else {
+			if err := writeRawEntry(zipWriter, res); err != nil {
+				failed++
+				m.l.Warning("Failed to write archive entry %s: %s, skipping it...", res.file.Uri(false), err)
+			}
+		}
+
+		compressed += res.file.Size()
+		if o.ProgressFunc != nil {
+			o.ProgressFunc(compressed, res.file.Size(), 0)
+		}
+		if o.MaxArchiveSize > 0 && compressed > o.MaxArchiveSize {
+			return 0, fs.ErrArchiveSrcSizeTooBig
+		}
+	}
+
+	return failed, nil
+}
+
+// spoolEntry deflates one file into a temp file and returns a header with
+// precomputed CRC32 and sizes for zip.Writer.CreateRaw.
+func (m *manager) spoolEntry(ctx context.Context, job createArchiveJob) archiveEntryResult {
+	res := archiveEntryResult{file: job.file}
+	es, err := m.GetEntitySource(ctx, job.file.PrimaryEntityID())
+	if err != nil {
+		res.err = fmt.Errorf("failed to get entity source: %w", err)
+		return res
+	}
+	defer es.Close()
+
+	tmp, err := os.CreateTemp("", "cloudreve-zip-*")
+	if err != nil {
+		res.err = err
+		return res
+	}
+
+	cw := &countingWriter{w: tmp}
+	crc := crc32.NewIEEE()
+	fw, err := flate.NewWriter(cw, flate.DefaultCompression)
+	if err != nil {
+		tmp.Close()
+		os.Remove(tmp.Name())
+		res.err = err
+		return res
+	}
+	es.Apply(entitysource.WithContext(ctx))
+	_, copyErr := io.Copy(fw, io.TeeReader(es, crc))
+	closeErr := fw.Close()
+	tmp.Close()
+	if copyErr != nil {
+		os.Remove(tmp.Name())
+		res.err = copyErr
+		return res
+	}
+	if closeErr != nil {
+		os.Remove(tmp.Name())
+		res.err = closeErr
+		return res
+	}
+
+	res.header = &zip.FileHeader{
+		Name:               filepath.FromSlash(path.Join(job.parent, job.file.DisplayName())),
+		Method:             zip.Deflate,
+		Modified:           job.file.UpdatedAt(),
+		CRC32:              crc.Sum32(),
+		CompressedSize64:   uint64(cw.n),
+		UncompressedSize64: uint64(job.file.Size()),
+	}
+	res.tmpPath = tmp.Name()
+	return res
+}
+
+// writeRawEntry writes a pre-compressed entry's local header and streams
+// its spooled deflate data, then removes the temp file.
+func writeRawEntry(zipWriter *zip.Writer, res archiveEntryResult) error {
+	defer os.Remove(res.tmpPath)
+	raw, err := zipWriter.CreateRaw(res.header)
+	if err != nil {
+		return err
+	}
+	tmp, err := os.Open(res.tmpPath)
+	if err != nil {
+		return err
+	}
+	defer tmp.Close()
+	_, err = io.Copy(raw, tmp)
+	return err
+}
+
 func getZipFileList(ctx context.Context, file io.ReaderAt, size int64, textEncoding encoding.Encoding) ([]ArchivedFile, error) {
 	zr, err := zip.NewReader(file, size)
 	if err != nil {

pkg/filemanager/manager/archive_parallel_test.go

@@ -0,0 +1,65 @@
+package manager
+
+import (
+	"archive/zip"
+	"bytes"
+	"compress/flate"
+	"hash/crc32"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestWriteRawEntryRoundTrip verifies that a deflate stream spooled to a
+// temp file with precomputed CRC32/sizes produces a valid zip entry via
+// CreateRaw — the invariant the parallel path relies on (#3316).
+func TestWriteRawEntryRoundTrip(t *testing.T) {
+	payload := []byte("hello cloudreve parallel zip payload, repeat repeat repeat")
+
+	var compBuf bytes.Buffer
+	cw := &countingWriter{w: &compBuf}
+	crc := crc32.NewIEEE()
+	fw, err := flate.NewWriter(cw, flate.DefaultCompression)
+	require.NoError(t, err)
+	_, err = io.Copy(fw, io.TeeReader(bytes.NewReader(payload), crc))
+	require.NoError(t, err)
+	require.NoError(t, fw.Close())
+
+	tmp := filepath.Join(t.TempDir(), "entry.deflate")
+	require.NoError(t, os.WriteFile(tmp, compBuf.Bytes(), 0o600))
+
+	var zipBuf bytes.Buffer
+	zw := zip.NewWriter(&zipBuf)
+	err = writeRawEntry(zw, archiveEntryResult{
+		header: &zip.FileHeader{
+			Name:               "dir/a.txt",
+			Method:             zip.Deflate,
+			CRC32:              crc.Sum32(),
+			CompressedSize64:   uint64(cw.n),
+			UncompressedSize64: uint64(len(payload)),
+		},
+		tmpPath: tmp,
+	})
+	require.NoError(t, err)
+	require.NoError(t, zw.Close())
+
+	// Temp file is consumed and removed.
+	_, statErr := os.Stat(tmp)
+	require.True(t, os.IsNotExist(statErr))
+
+	zr, err := zip.NewReader(bytes.NewReader(zipBuf.Bytes()), int64(zipBuf.Len()))
+	require.NoError(t, err)
+	require.Len(t, zr.File, 1)
+	require.Equal(t, "dir/a.txt", zr.File[0].Name)
+	require.Equal(t, uint64(len(payload)), zr.File[0].UncompressedSize64)
+
+	rc, err := zr.File[0].Open()
+	require.NoError(t, err)
+	got, err := io.ReadAll(rc)
+	require.NoError(t, err)
+	require.NoError(t, rc.Close())
+	require.Equal(t, payload, got)
+}