bump ncruces/go-sqlite3 to v0.20.2 (#3524)

vendor/github.com/ncruces/go-sqlite3/vfs/shm.go

@@ -1,20 +1,7 @@
-//go:build (darwin || linux) && (386 || arm || amd64 || arm64 || riscv64 || ppc64le) && !(sqlite3_flock || sqlite3_noshm || sqlite3_nosys)
+//go:build ((linux || darwin || windows || freebsd || openbsd || netbsd || dragonfly || illumos) && (386 || arm || amd64 || arm64 || riscv64 || ppc64le) && !sqlite3_nosys) || sqlite3_flock || sqlite3_dotlk
 
 package vfs
 
-import (
-	"context"
-	"io"
-	"os"
-	"sync"
-	"time"
-
-	"github.com/tetratelabs/wazero/api"
-	"golang.org/x/sys/unix"
-
-	"github.com/ncruces/go-sqlite3/internal/util"
-)
-
 // SupportsSharedMemory is false on platforms that do not support shared memory.
 // To use [WAL without shared-memory], you need to set [EXCLUSIVE locking mode].
 //
@@ -22,12 +9,6 @@ import (
 // [EXCLUSIVE locking mode]: https://sqlite.org/pragma.html#pragma_locking_mode
 const SupportsSharedMemory = true
 
-const (
-	_SHM_NLOCK = 8
-	_SHM_BASE  = 120
-	_SHM_DMS   = _SHM_BASE + _SHM_NLOCK
-)
-
 func (f *vfsFile) SharedMemory() SharedMemory { return f.shm }
 
 // NewSharedMemory returns a shared-memory WAL-index
@@ -41,172 +22,5 @@ func NewSharedMemory(path string, flags OpenFlag) SharedMemory {
 	if flags&OPEN_MAIN_DB == 0 || flags&(OPEN_DELETEONCLOSE|OPEN_MEMORY) != 0 {
 		return nil
 	}
-	return &vfsShm{
-		path:     path,
-		readOnly: flags&OPEN_READONLY != 0,
-	}
-}
-
-var _ blockingSharedMemory = &vfsShm{}
-
-type vfsShm struct {
-	*os.File
-	path     string
-	regions  []*util.MappedRegion
-	readOnly bool
-	blocking bool
-	sync.Mutex
-}
-
-func (s *vfsShm) shmOpen() _ErrorCode {
-	if s.File == nil {
-		var flag int
-		if s.readOnly {
-			flag = unix.O_RDONLY
-		} else {
-			flag = unix.O_RDWR
-		}
-		f, err := os.OpenFile(s.path,
-			flag|unix.O_CREAT|unix.O_NOFOLLOW, 0666)
-		if err != nil {
-			return _CANTOPEN
-		}
-		s.File = f
-	}
-
-	// Dead man's switch.
-	if lock, rc := osTestLock(s.File, _SHM_DMS, 1); rc != _OK {
-		return _IOERR_LOCK
-	} else if lock == unix.F_WRLCK {
-		return _BUSY
-	} else if lock == unix.F_UNLCK {
-		if s.readOnly {
-			return _READONLY_CANTINIT
-		}
-		// Do not use a blocking lock here.
-		// If the lock cannot be obtained immediately,
-		// it means some other connection is truncating the file.
-		// And after it has done so, it will not release its lock,
-		// but only downgrade it to a shared lock.
-		// So no point in blocking here.
-		// The call below to obtain the shared DMS lock may use a blocking lock.
-		if rc := osWriteLock(s.File, _SHM_DMS, 1, 0); rc != _OK {
-			return rc
-		}
-		if err := s.Truncate(0); err != nil {
-			return _IOERR_SHMOPEN
-		}
-	}
-	if rc := osReadLock(s.File, _SHM_DMS, 1, time.Millisecond); rc != _OK {
-		return rc
-	}
-	return _OK
-}
-
-func (s *vfsShm) shmMap(ctx context.Context, mod api.Module, id, size int32, extend bool) (uint32, _ErrorCode) {
-	// Ensure size is a multiple of the OS page size.
-	if int(size)&(unix.Getpagesize()-1) != 0 {
-		return 0, _IOERR_SHMMAP
-	}
-
-	if rc := s.shmOpen(); rc != _OK {
-		return 0, rc
-	}
-
-	// Check if file is big enough.
-	o, err := s.Seek(0, io.SeekEnd)
-	if err != nil {
-		return 0, _IOERR_SHMSIZE
-	}
-	if n := (int64(id) + 1) * int64(size); n > o {
-		if !extend {
-			return 0, _OK
-		}
-		err := osAllocate(s.File, n)
-		if err != nil {
-			return 0, _IOERR_SHMSIZE
-		}
-	}
-
-	var prot int
-	if s.readOnly {
-		prot = unix.PROT_READ
-	} else {
-		prot = unix.PROT_READ | unix.PROT_WRITE
-	}
-	r, err := util.MapRegion(ctx, mod, s.File, int64(id)*int64(size), size, prot)
-	if err != nil {
-		return 0, _IOERR_SHMMAP
-	}
-	s.regions = append(s.regions, r)
-	if s.readOnly {
-		return r.Ptr, _READONLY
-	}
-	return r.Ptr, _OK
-}
-
-func (s *vfsShm) shmLock(offset, n int32, flags _ShmFlag) _ErrorCode {
-	// Argument check.
-	if n <= 0 || offset < 0 || offset+n > _SHM_NLOCK {
-		panic(util.AssertErr())
-	}
-	switch flags {
-	case
-		_SHM_LOCK | _SHM_SHARED,
-		_SHM_LOCK | _SHM_EXCLUSIVE,
-		_SHM_UNLOCK | _SHM_SHARED,
-		_SHM_UNLOCK | _SHM_EXCLUSIVE:
-		//
-	default:
-		panic(util.AssertErr())
-	}
-	if n != 1 && flags&_SHM_EXCLUSIVE == 0 {
-		panic(util.AssertErr())
-	}
-
-	var timeout time.Duration
-	if s.blocking {
-		timeout = time.Millisecond
-	}
-
-	switch {
-	case flags&_SHM_UNLOCK != 0:
-		return osUnlock(s.File, _SHM_BASE+int64(offset), int64(n))
-	case flags&_SHM_SHARED != 0:
-		return osReadLock(s.File, _SHM_BASE+int64(offset), int64(n), timeout)
-	case flags&_SHM_EXCLUSIVE != 0:
-		return osWriteLock(s.File, _SHM_BASE+int64(offset), int64(n), timeout)
-	default:
-		panic(util.AssertErr())
-	}
-}
-
-func (s *vfsShm) shmUnmap(delete bool) {
-	if s.File == nil {
-		return
-	}
-
-	// Unmap regions.
-	for _, r := range s.regions {
-		r.Unmap()
-	}
-	clear(s.regions)
-	s.regions = s.regions[:0]
-
-	// Close the file.
-	if delete {
-		os.Remove(s.path)
-	}
-	s.Close()
-	s.File = nil
-}
-
-func (s *vfsShm) shmBarrier() {
-	s.Lock()
-	//lint:ignore SA2001 memory barrier.
-	s.Unlock()
-}
-
-func (s *vfsShm) shmEnableBlocking(block bool) {
-	s.blocking = block
+	return &vfsShm{path: path}
 }