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authorLibravatar kim <89579420+NyaaaWhatsUpDoc@users.noreply.github.com>2024-11-07 00:16:28 +0000
committerLibravatar GitHub <noreply@github.com>2024-11-07 00:16:28 +0000
commit45e1609377631070765065ffb35ed7d29e8e81f1 (patch)
tree51d170ff0d5fab1ab0f8b1b79c9dd8c31d4ce5b9 /vendor/github.com/ncruces/go-sqlite3/vfs/shm_dotlk.go
parent[chore] update go ffmpreg to v0.6.0 (#3515) (diff)
downloadgotosocial-45e1609377631070765065ffb35ed7d29e8e81f1.tar.xz
bump ncruces/go-sqlite3 to v0.20.2 (#3524)
Diffstat (limited to 'vendor/github.com/ncruces/go-sqlite3/vfs/shm_dotlk.go')
-rw-r--r--vendor/github.com/ncruces/go-sqlite3/vfs/shm_dotlk.go224
1 files changed, 224 insertions, 0 deletions
diff --git a/vendor/github.com/ncruces/go-sqlite3/vfs/shm_dotlk.go b/vendor/github.com/ncruces/go-sqlite3/vfs/shm_dotlk.go
new file mode 100644
index 000000000..36e00a1cd
--- /dev/null
+++ b/vendor/github.com/ncruces/go-sqlite3/vfs/shm_dotlk.go
@@ -0,0 +1,224 @@
+//go:build sqlite3_dotlk
+
+package vfs
+
+import (
+ "context"
+ "errors"
+ "io/fs"
+ "os"
+ "sync"
+
+ "github.com/ncruces/go-sqlite3/internal/util"
+ "github.com/tetratelabs/wazero/api"
+)
+
+type vfsShmBuffer struct {
+ shared [][_WALINDEX_PGSZ]byte
+ refs int // +checklocks:vfsShmBuffersMtx
+
+ lock [_SHM_NLOCK]int16 // +checklocks:Mutex
+ sync.Mutex
+}
+
+var (
+ // +checklocks:vfsShmBuffersMtx
+ vfsShmBuffers = map[string]*vfsShmBuffer{}
+ vfsShmBuffersMtx sync.Mutex
+)
+
+type vfsShm struct {
+ *vfsShmBuffer
+ mod api.Module
+ alloc api.Function
+ free api.Function
+ path string
+ shadow [][_WALINDEX_PGSZ]byte
+ ptrs []uint32
+ stack [1]uint64
+ lock [_SHM_NLOCK]bool
+}
+
+func (s *vfsShm) Close() error {
+ if s.vfsShmBuffer == nil {
+ return nil
+ }
+
+ vfsShmBuffersMtx.Lock()
+ defer vfsShmBuffersMtx.Unlock()
+
+ // Unlock everything.
+ s.shmLock(0, _SHM_NLOCK, _SHM_UNLOCK)
+
+ // Decrease reference count.
+ if s.vfsShmBuffer.refs > 0 {
+ s.vfsShmBuffer.refs--
+ s.vfsShmBuffer = nil
+ return nil
+ }
+
+ err := os.Remove(s.path)
+ if err != nil && !errors.Is(err, fs.ErrNotExist) {
+ return _IOERR_UNLOCK
+ }
+ delete(vfsShmBuffers, s.path)
+ s.vfsShmBuffer = nil
+ return nil
+}
+
+func (s *vfsShm) shmOpen() _ErrorCode {
+ if s.vfsShmBuffer != nil {
+ return _OK
+ }
+
+ vfsShmBuffersMtx.Lock()
+ defer vfsShmBuffersMtx.Unlock()
+
+ // Find a shared buffer, increase the reference count.
+ if g, ok := vfsShmBuffers[s.path]; ok {
+ s.vfsShmBuffer = g
+ g.refs++
+ return _OK
+ }
+
+ // Create a directory on disk to ensure only this process
+ // uses this path to register a shared memory.
+ err := os.Mkdir(s.path, 0777)
+ if errors.Is(err, fs.ErrExist) {
+ return _BUSY
+ }
+ if err != nil {
+ return _IOERR_LOCK
+ }
+
+ // Add the new shared buffer.
+ s.vfsShmBuffer = &vfsShmBuffer{}
+ vfsShmBuffers[s.path] = s.vfsShmBuffer
+ return _OK
+}
+
+func (s *vfsShm) shmMap(ctx context.Context, mod api.Module, id, size int32, extend bool) (uint32, _ErrorCode) {
+ if size != _WALINDEX_PGSZ {
+ return 0, _IOERR_SHMMAP
+ }
+ if s.mod == nil {
+ s.mod = mod
+ s.free = mod.ExportedFunction("sqlite3_free")
+ s.alloc = mod.ExportedFunction("sqlite3_malloc64")
+ }
+ if rc := s.shmOpen(); rc != _OK {
+ return 0, rc
+ }
+
+ s.Lock()
+ defer s.Unlock()
+ defer s.shmAcquire()
+
+ // Extend shared memory.
+ if int(id) >= len(s.shared) {
+ if !extend {
+ return 0, _OK
+ }
+ s.shared = append(s.shared, make([][_WALINDEX_PGSZ]byte, int(id)-len(s.shared)+1)...)
+ }
+
+ // Allocate shadow memory.
+ if int(id) >= len(s.shadow) {
+ s.shadow = append(s.shadow, make([][_WALINDEX_PGSZ]byte, int(id)-len(s.shadow)+1)...)
+ s.shadow[0][4] = 1 // force invalidation
+ }
+
+ // Allocate local memory.
+ for int(id) >= len(s.ptrs) {
+ s.stack[0] = uint64(size)
+ if err := s.alloc.CallWithStack(ctx, s.stack[:]); err != nil {
+ panic(err)
+ }
+ if s.stack[0] == 0 {
+ panic(util.OOMErr)
+ }
+ clear(util.View(s.mod, uint32(s.stack[0]), _WALINDEX_PGSZ))
+ s.ptrs = append(s.ptrs, uint32(s.stack[0]))
+ }
+
+ return s.ptrs[id], _OK
+}
+
+func (s *vfsShm) shmLock(offset, n int32, flags _ShmFlag) _ErrorCode {
+ s.Lock()
+ defer s.Unlock()
+
+ switch {
+ case flags&_SHM_LOCK != 0:
+ defer s.shmAcquire()
+ case flags&_SHM_EXCLUSIVE != 0:
+ s.shmRelease()
+ }
+
+ switch {
+ case flags&_SHM_UNLOCK != 0:
+ for i := offset; i < offset+n; i++ {
+ if s.lock[i] {
+ if s.vfsShmBuffer.lock[i] == 0 {
+ panic(util.AssertErr())
+ }
+ if s.vfsShmBuffer.lock[i] <= 0 {
+ s.vfsShmBuffer.lock[i] = 0
+ } else {
+ s.vfsShmBuffer.lock[i]--
+ }
+ s.lock[i] = false
+ }
+ }
+ case flags&_SHM_SHARED != 0:
+ for i := offset; i < offset+n; i++ {
+ if s.lock[i] {
+ panic(util.AssertErr())
+ }
+ if s.vfsShmBuffer.lock[i]+1 <= 0 {
+ return _BUSY
+ }
+ }
+ for i := offset; i < offset+n; i++ {
+ s.vfsShmBuffer.lock[i]++
+ s.lock[i] = true
+ }
+ case flags&_SHM_EXCLUSIVE != 0:
+ for i := offset; i < offset+n; i++ {
+ if s.lock[i] {
+ panic(util.AssertErr())
+ }
+ if s.vfsShmBuffer.lock[i] != 0 {
+ return _BUSY
+ }
+ }
+ for i := offset; i < offset+n; i++ {
+ s.vfsShmBuffer.lock[i] = -1
+ s.lock[i] = true
+ }
+ default:
+ panic(util.AssertErr())
+ }
+
+ return _OK
+}
+
+func (s *vfsShm) shmUnmap(delete bool) {
+ if s.vfsShmBuffer == nil {
+ return
+ }
+ defer s.Close()
+
+ s.Lock()
+ s.shmRelease()
+ defer s.Unlock()
+
+ for _, p := range s.ptrs {
+ s.stack[0] = uint64(p)
+ if err := s.free.CallWithStack(context.Background(), s.stack[:]); err != nil {
+ panic(err)
+ }
+ }
+ s.ptrs = nil
+ s.shadow = nil
+}