beginning fuse filesystem impl

README.md

@@ -1,2 +1,3 @@
 # litestream
+
 Streaming replication for SQLite.

fs.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"context"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"syscall"
+	"time"
+
+	"bazil.org/fuse"
+	"bazil.org/fuse/fs"
+)
+
+var _ fs.FS = (*FS)(nil)
+
+type FS struct {
+	SourcePath string
+}
+
+// Root returns the file system root.
+func (f *FS) Root() (fs.Node, error) {
+	return &File{fs: f}, nil
+}
+
+var _ fs.Node = (*File)(nil)
+
+type File struct {
+	fs   *FS    // base filesystem
+	path string // path within file system
+}
+
+func (f *File) srcpath() string {
+	return filepath.Join(f.fs.SourcePath, f.path)
+}
+
+func (f *File) Attr(ctx context.Context, a *fuse.Attr) error {
+	fi, err := os.Stat(f.srcpath())
+	if err != nil {
+		return err
+	}
+	statt := fi.Sys().(*syscall.Stat_t)
+
+	// TODO: Cache attr w/ a.Valid?
+
+	if f.path == "" {
+		a.Inode = 1
+	} else {
+		a.Inode = statt.Ino
+	}
+	a.Size = uint64(fi.Size())
+	a.Blocks = uint64(statt.Blocks)
+	a.Atime = time.Unix(statt.Atim.Sec, statt.Atim.Nsec).UTC()
+	a.Mtime = time.Unix(statt.Mtim.Sec, statt.Mtim.Nsec).UTC()
+	a.Ctime = time.Unix(statt.Ctim.Sec, statt.Ctim.Nsec).UTC()
+	a.Mode = fi.Mode()
+	a.Nlink = uint32(statt.Nlink)
+	a.Uid = uint32(statt.Uid)
+	a.Gid = uint32(statt.Gid)
+	a.Rdev = uint32(statt.Rdev)
+	a.BlockSize = uint32(statt.Blksize)
+
+	return nil
+}
+
+func (f *File) Lookup(ctx context.Context, name string) (fs.Node, error) {
+	path := filepath.Join(f.path, name)
+	srcpath := filepath.Join(f.fs.SourcePath, path)
+	if _, err := os.Stat(srcpath); os.IsNotExist(err) {
+		return nil, syscall.ENOENT
+	}
+	return &File{fs: f.fs, path: path}, nil
+}
+
+func (f *File) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
+	fis, err := ioutil.ReadDir(f.srcpath())
+	if err != nil {
+		return nil, err
+	}
+
+	ents := make([]fuse.Dirent, len(fis))
+	for i, fi := range fis {
+		statt := fi.Sys().(*syscall.Stat_t)
+		ents[i] = fuse.Dirent{Inode: statt.Ino, Name: fi.Name()}
+	}
+	return ents, nil
+}

go.mod

@@ -0,0 +1,7 @@
+module github.com/middlemost/litestream
+
+go 1.14
+
+require (
+	bazil.org/fuse v0.0.0-20200524192727-fb710f7dfd05
+)

go.sum

@@ -0,0 +1,31 @@
+bazil.org/fuse v0.0.0-20200524192727-fb710f7dfd05 h1:UrYe9YkT4Wpm6D+zByEyCJQzDqTPXqTDUI7bZ41i9VE=
+bazil.org/fuse v0.0.0-20200524192727-fb710f7dfd05/go.mod h1:h0h5FBYpXThbvSfTqthw+0I4nmHnhTHkO5BoOHsBWqg=
+github.com/Julusian/godocdown v0.0.0-20170816220326-6d19f8ff2df8/go.mod h1:INZr5t32rG59/5xeltqoCJoNY7e5x/3xoY9WSWVWg74=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dvyukov/go-fuzz v0.0.0-20200318091601-be3528f3a813/go.mod h1:11Gm+ccJnvAhCNLlf5+cS9KjtbaD5I5zaZpFMsTHWTw=
+github.com/elazarl/go-bindata-assetfs v1.0.0/go.mod h1:v+YaWX3bdea5J/mo8dSETolEo7R71Vk1u8bnjau5yw4=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/robertkrimen/godocdown v0.0.0-20130622164427-0bfa04905481/go.mod h1:C9WhFzY47SzYBIvzFqSvHIR6ROgDo4TtdTuRaOMjF/s=
+github.com/stephens2424/writerset v1.0.2/go.mod h1:aS2JhsMn6eA7e82oNmW4rfsgAOp9COBTTl8mzkwADnc=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/tv42/httpunix v0.0.0-20191220191345-2ba4b9c3382c/go.mod h1:hzIxponao9Kjc7aWznkXaL4U4TWaDSs8zcsY4Ka08nM=
+github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191210023423-ac6580df4449 h1:gSbV7h1NRL2G1xTg/owz62CST1oJBmxy4QpMMregXVQ=
+golang.org/x/sys v0.0.0-20191210023423-ac6580df4449/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20200423201157-2723c5de0d66/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

main.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+
+	"bazil.org/fuse"
+	"bazil.org/fuse/fs"
+)
+
+func main() {
+	m := NewMain()
+	if err := m.Run(os.Args[1:]); err == flag.ErrHelp {
+		os.Exit(1)
+	} else if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+type Main struct {
+	logger *log.Logger
+
+	SourcePath string
+	MountPath  string
+}
+
+func NewMain() *Main {
+	return &Main{
+		logger: log.New(ioutil.Discard, "", log.LstdFlags),
+	}
+}
+
+func (m *Main) Run(args []string) (err error) {
+	flagSet := flag.NewFlagSet("litestream", flag.ContinueOnError)
+	verbose := flagSet.Bool("v", false, "verbose")
+	flagSet.Usage = m.usage
+	if err := flagSet.Parse(args); err != nil {
+		return err
+	}
+	if m.SourcePath = flagSet.Arg(0); m.SourcePath == "" {
+		return errors.New("source path required")
+	} else if m.MountPath = flagSet.Arg(1); m.MountPath == "" {
+		return errors.New("mount path required")
+	}
+
+	// Setup logging, if verbose specified.
+	if *verbose {
+		m.logger = log.New(os.Stderr, "", log.LstdFlags)
+	}
+
+	// Mount FUSE filesystem.
+	conn, err := fuse.Mount(m.MountPath, fuse.FSName("litestream"), fuse.Subtype("litestreamfs"))
+	if err != nil {
+		return err
+	}
+	defer fuse.Unmount(m.MountPath)
+	defer conn.Close()
+
+	return fs.Serve(conn, &FS{SourcePath: m.SourcePath})
+}
+
+func (m *Main) usage() {
+	fmt.Println(`
+Litestream is a FUSE file system that automatically replicates SQLite databases.
+
+Usage:
+
+	litestream [arguments] source_dir mount_dir
+
+Arguments:
+
+	-v
+	    Enable verbose logging.
+
+`[1:])
+}

server.go

@@ -0,0 +1,237 @@
+package main
+
+/*
+import (
+	"context"
+	"io"
+	"sync"
+
+	"bazil.org/fuse"
+)
+
+type Server struct {
+	wg sync.WaitGroup
+
+	SourcePath string
+}
+
+func NewServer() *Server {
+	return &Server{}
+}
+
+func (s *Server) Close() error {
+	s.wg.Wait()
+	return nil
+}
+
+func (s *Server) Serve(ctx context.Context, conn *fuse.Conn) error {
+	for {
+		r, err := conn.ReadRequest()
+		if err == io.EOF {
+			return nil
+		} else if err != nil {
+			return err
+		}
+
+		s.wg.Add(1)
+		go func() { defer s.wg.Done(); s.handleRequest(ctx, r) }()
+	}
+}
+
+func (s *Server) handleRequest(ctx context.Context, r fuse.Request) {
+	switch r := r.(type) {
+	case *fuse.AccessRequest:
+		s.handleAccessRequest(ctx, r)
+	case *fuse.BatchForgetRequest:
+		s.handleBatchForgetRequest(ctx, r)
+	case *fuse.CreateRequest:
+		s.handleCreateRequest(ctx, r)
+	case *fuse.DestroyRequest:
+		s.handleDestroyRequest(ctx, r)
+	case *fuse.ExchangeDataRequest:
+		s.handleExchangeDataRequest(ctx, r)
+	case *fuse.FlushRequest:
+		s.handleFlushRequest(ctx, r)
+	case *fuse.ForgetRequest:
+		s.handleForgetRequest(ctx, r)
+	case *fuse.FsyncRequest:
+		s.handleFsyncRequest(ctx, r)
+	case *fuse.GetattrRequest:
+		s.handleGetattrRequest(ctx, r)
+	case *fuse.GetxattrRequest:
+		s.handleGetxattrRequest(ctx, r)
+	case *fuse.InterruptRequest:
+		s.handleInterruptRequest(ctx, r)
+	case *fuse.LinkRequest:
+		s.handleLinkRequest(ctx, r)
+	case *fuse.ListxattrRequest:
+		s.handleListxattrRequest(ctx, r)
+	case *fuse.LockRequest:
+		s.handleLockRequest(ctx, r)
+	case *fuse.LookupRequest:
+		s.handleLookupRequest(ctx, r)
+	case *fuse.MkdirRequest:
+		s.handleMkdirRequest(ctx, r)
+	case *fuse.MknodRequest:
+		s.handleMknodRequest(ctx, r)
+	case *fuse.OpenRequest:
+		s.handleOpenRequest(ctx, r)
+	case *fuse.PollRequest:
+		s.handlePollRequest(ctx, r)
+	case *fuse.QueryLockRequest:
+		s.handleQueryLockRequest(ctx, r)
+	case *fuse.ReadRequest:
+		s.handleReadRequest(ctx, r)
+	case *fuse.ReadlinkRequest:
+		s.handleReadlinkRequest(ctx, r)
+	case *fuse.ReleaseRequest:
+		s.handleReleaseRequest(ctx, r)
+	case *fuse.RemoveRequest:
+		s.handleRemoveRequest(ctx, r)
+	case *fuse.RemovexattrRequest:
+		s.handleRemovexattrRequest(ctx, r)
+	case *fuse.RenameRequest:
+		s.handleRenameRequest(ctx, r)
+	case *fuse.SetattrRequest:
+		s.handleSetattrRequest(ctx, r)
+	case *fuse.SetxattrRequest:
+		s.handleSetxattrRequest(ctx, r)
+	case *fuse.StatfsRequest:
+		s.handleStatfsRequest(ctx, r)
+	case *fuse.SymlinkRequest:
+		s.handleSymlinkRequest(ctx, r)
+	case *fuse.UnrecognizedRequest:
+		s.handleUnrecognizedRequest(ctx, r)
+	case *fuse.WriteRequest:
+		s.handleWriteRequest(ctx, r)
+	}
+}
+
+func (s *Server) handleAccessRequest(ctx context.Context, r *fuse.AccessRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleBatchForgetRequest(ctx context.Context, r *fuse.BatchForgetRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleCreateRequest(ctx context.Context, r *fuse.CreateRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleDestroyRequest(ctx context.Context, r *fuse.DestroyRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleExchangeDataRequest(ctx context.Context, r *fuse.ExchangeDataRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleFlushRequest(ctx context.Context, r *fuse.FlushRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleForgetRequest(ctx context.Context, r *fuse.ForgetRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleFsyncRequest(ctx context.Context, r *fuse.FsyncRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleGetattrRequest(ctx context.Context, r *fuse.GetattrRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleGetxattrRequest(ctx context.Context, r *fuse.GetxattrRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleInterruptRequest(ctx context.Context, r *fuse.InterruptRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleLinkRequest(ctx context.Context, r *fuse.LinkRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleListxattrRequest(ctx context.Context, r *fuse.ListxattrRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleLockRequest(ctx context.Context, r *fuse.LockRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleLookupRequest(ctx context.Context, r *fuse.LookupRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleMkdirRequest(ctx context.Context, r *fuse.MkdirRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleMknodRequest(ctx context.Context, r *fuse.MknodRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleOpenRequest(ctx context.Context, r *fuse.OpenRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handlePollRequest(ctx context.Context, r *fuse.PollRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleQueryLockRequest(ctx context.Context, r *fuse.QueryLockRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleReadRequest(ctx context.Context, r *fuse.ReadRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleReadlinkRequest(ctx context.Context, r *fuse.ReadlinkRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleReleaseRequest(ctx context.Context, r *fuse.ReleaseRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleRemoveRequest(ctx context.Context, r *fuse.RemoveRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleRemovexattrRequest(ctx context.Context, r *fuse.RemovexattrRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleRenameRequest(ctx context.Context, r *fuse.RenameRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleSetattrRequest(ctx context.Context, r *fuse.SetattrRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleSetxattrRequest(ctx context.Context, r *fuse.SetxattrRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleStatfsRequest(ctx context.Context, r *fuse.StatfsRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleSymlinkRequest(ctx context.Context, r *fuse.SymlinkRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleUnrecognizedRequest(ctx context.Context, r *fuse.UnrecognizedRequest) {
+	panic("TODO")
+}
+
+func (s *Server) handleWriteRequest(ctx context.Context, r *fuse.WriteRequest) {
+	panic("TODO")
+}
+*/