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authorLibravatar Daenney <daenney@users.noreply.github.com>2024-06-07 15:06:43 +0200
committerLibravatar GitHub <noreply@github.com>2024-06-07 15:06:43 +0200
commitcc4f773b0e0f45cdb28727853b9d253234a93b56 (patch)
tree455224a7cb489909906eda5778d0e700867358d4 /vendor/github.com/ncruces/go-sqlite3/vfs/shm_bsd.go
parent[feature] Implement filters_changed stream event (#2972) (diff)
downloadgotosocial-cc4f773b0e0f45cdb28727853b9d253234a93b56.tar.xz
[chore] Update WASM go-sqlite3 to v0.16.1 (#2976)
This includes support for journal mode set to WAL on the BSDs. Relates to: #1753, #2962
Diffstat (limited to 'vendor/github.com/ncruces/go-sqlite3/vfs/shm_bsd.go')
-rw-r--r--vendor/github.com/ncruces/go-sqlite3/vfs/shm_bsd.go259
1 files changed, 259 insertions, 0 deletions
diff --git a/vendor/github.com/ncruces/go-sqlite3/vfs/shm_bsd.go b/vendor/github.com/ncruces/go-sqlite3/vfs/shm_bsd.go
new file mode 100644
index 000000000..3b45b3087
--- /dev/null
+++ b/vendor/github.com/ncruces/go-sqlite3/vfs/shm_bsd.go
@@ -0,0 +1,259 @@
+//go:build (freebsd || openbsd || netbsd || dragonfly || illumos || sqlite3_flock) && (amd64 || arm64 || riscv64) && !(sqlite3_noshm || sqlite3_nosys)
+
+package vfs
+
+import (
+ "context"
+ "io"
+ "os"
+ "sync"
+
+ "github.com/ncruces/go-sqlite3/internal/util"
+ "github.com/tetratelabs/wazero/api"
+ "golang.org/x/sys/unix"
+)
+
+// SupportsSharedMemory is false on platforms that do not support shared memory.
+// To use [WAL without shared-memory], you need to set [EXCLUSIVE locking mode].
+//
+// [WAL without shared-memory]: https://sqlite.org/wal.html#noshm
+// [EXCLUSIVE locking mode]: https://sqlite.org/pragma.html#pragma_locking_mode
+const SupportsSharedMemory = true
+
+const _SHM_NLOCK = 8
+
+func (f *vfsFile) SharedMemory() SharedMemory { return f.shm }
+
+// NewSharedMemory returns a shared-memory WAL-index
+// backed by a file with the given path.
+// It will return nil if shared-memory is not supported,
+// or not appropriate for the given flags.
+// Only [OPEN_MAIN_DB] databases may need a WAL-index.
+// You must ensure all concurrent accesses to a database
+// use shared-memory instances created with the same path.
+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,
+ }
+}
+
+type vfsShmFile struct {
+ *os.File
+ info os.FileInfo
+
+ // +checklocks:vfsShmFilesMtx
+ refs int
+
+ // +checklocks:lockMtx
+ lock [_SHM_NLOCK]int16
+ lockMtx sync.Mutex
+}
+
+var (
+ // +checklocks:vfsShmFilesMtx
+ vfsShmFiles []*vfsShmFile
+ vfsShmFilesMtx sync.Mutex
+)
+
+type vfsShm struct {
+ *vfsShmFile
+ path string
+ lock [_SHM_NLOCK]bool
+ regions []*util.MappedRegion
+ readOnly bool
+}
+
+func (s *vfsShm) Close() error {
+ if s.vfsShmFile == nil {
+ return nil
+ }
+
+ // Unlock everything.
+ s.shmLock(0, _SHM_NLOCK, _SHM_UNLOCK)
+
+ vfsShmFilesMtx.Lock()
+ defer vfsShmFilesMtx.Unlock()
+
+ // Decrease reference count.
+ if s.vfsShmFile.refs > 1 {
+ s.vfsShmFile.refs--
+ s.vfsShmFile = nil
+ return nil
+ }
+ for i, g := range vfsShmFiles {
+ if g == s.vfsShmFile {
+ vfsShmFiles[i] = nil
+ break
+ }
+ }
+
+ err := s.File.Close()
+ s.vfsShmFile = nil
+ return err
+}
+
+func (s *vfsShm) shmOpen() (rc _ErrorCode) {
+ if s.vfsShmFile != nil {
+ return _OK
+ }
+
+ // Open file read-write, as it will be shared.
+ f, err := os.OpenFile(s.path,
+ unix.O_RDWR|unix.O_CREAT|unix.O_NOFOLLOW, 0666)
+ if err != nil {
+ return _CANTOPEN
+ }
+ // Close if file if it's not nil.
+ defer func() { f.Close() }()
+
+ fi, err := f.Stat()
+ if err != nil {
+ return _IOERR_FSTAT
+ }
+
+ vfsShmFilesMtx.Lock()
+ defer vfsShmFilesMtx.Unlock()
+
+ // Find a shared file, increase the reference count.
+ for _, g := range vfsShmFiles {
+ if g != nil && os.SameFile(fi, g.info) {
+ g.refs++
+ s.vfsShmFile = g
+ return _OK
+ }
+ }
+
+ // Lock and truncate the file, if not readonly.
+ if s.readOnly {
+ rc = _READONLY_CANTINIT
+ } else {
+ if rc := osWriteLock(f, 0, 0, 0); rc != _OK {
+ return rc
+ }
+ if err := f.Truncate(0); err != nil {
+ return _IOERR_SHMOPEN
+ }
+ }
+
+ // Add the new shared file.
+ s.vfsShmFile = &vfsShmFile{
+ File: f,
+ info: fi,
+ refs: 1,
+ }
+ f = nil
+ add := true
+ for i, g := range vfsShmFiles {
+ if g == nil {
+ vfsShmFiles[i] = s.vfsShmFile
+ add = false
+ }
+ }
+ if add {
+ vfsShmFiles = append(vfsShmFiles, s.vfsShmFile)
+ }
+ return rc
+}
+
+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)
+ return r.Ptr, _OK
+}
+
+func (s *vfsShm) shmLock(offset, n int32, flags _ShmFlag) _ErrorCode {
+ s.lockMtx.Lock()
+ defer s.lockMtx.Unlock()
+
+ switch {
+ case flags&_SHM_UNLOCK != 0:
+ for i := offset; i < offset+n; i++ {
+ if s.lock[i] {
+ if s.vfsShmFile.lock[i] <= 0 {
+ s.vfsShmFile.lock[i] = 0
+ } else {
+ s.vfsShmFile.lock[i]--
+ }
+ }
+ }
+ case flags&_SHM_SHARED != 0:
+ for i := offset; i < offset+n; i++ {
+ if s.vfsShmFile.lock[i] < 0 {
+ return _BUSY
+ }
+ }
+ for i := offset; i < offset+n; i++ {
+ s.vfsShmFile.lock[i]++
+ s.lock[i] = true
+ }
+ case flags&_SHM_EXCLUSIVE != 0:
+ for i := offset; i < offset+n; i++ {
+ if s.vfsShmFile.lock[i] != 0 {
+ return _BUSY
+ }
+ }
+ for i := offset; i < offset+n; i++ {
+ s.vfsShmFile.lock[i] = -1
+ s.lock[i] = true
+ }
+ }
+
+ return _OK
+}
+
+func (s *vfsShm) shmUnmap(delete bool) {
+ if s.vfsShmFile == 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.vfsShmFile = nil
+}