1 files changed, 0 insertions, 87 deletions
diff --git a/vendor/github.com/ncruces/go-sqlite3/vfs/shm_copy.go b/vendor/github.com/ncruces/go-sqlite3/vfs/shm_copy.go
deleted file mode 100644
index db8ddb4b8..000000000
--- a/vendor/github.com/ncruces/go-sqlite3/vfs/shm_copy.go
+++ /dev/null
@@ -1,87 +0,0 @@
-//go:build (windows && (386 || arm || amd64 || arm64 || riscv64 || ppc64le)) || sqlite3_dotlk
-
-package vfs
-
-import (
-	"unsafe"
-
-	"github.com/ncruces/go-sqlite3/internal/util"
-)
-
-const (
-	_WALINDEX_HDR_SIZE = 136
-	_WALINDEX_PGSZ     = 32768
-)
-
-// This seems a safe way of keeping the WAL-index in sync.
-//
-// The WAL-index file starts with a header,
-// and the index doesn't meaningfully change if the header doesn't change.
-//
-// The header starts with two 48 byte, checksummed, copies of the same information,
-// which are accessed independently between memory barriers.
-// The checkpoint information that follows uses 4 byte aligned words.
-//
-// Finally, we have the WAL-index hash tables,
-// which are only modified holding the exclusive WAL_WRITE_LOCK.
-//
-// Since all the data is either redundant+checksummed,
-// 4 byte aligned, or modified under an exclusive lock,
-// the copies below should correctly keep memory in sync.
-//
-// https://sqlite.org/walformat.html#the_wal_index_file_format
-
-func (s *vfsShm) shmAcquire(ptr *_ErrorCode) {
-	if ptr != nil && *ptr != _OK {
-		return
-	}
-	if len(s.ptrs) == 0 || shmEqual(s.shadow[0][:], s.shared[0][:]) {
-		return
-	}
-	// Copies modified words from shared to private memory.
-	for id, p := range s.ptrs {
-		shared := shmPage(s.shared[id][:])
-		shadow := shmPage(s.shadow[id][:])
-		privat := shmPage(util.View(s.mod, p, _WALINDEX_PGSZ))
-		for i, shared := range shared {
-			if shadow[i] != shared {
-				shadow[i] = shared
-				privat[i] = shared
-			}
-		}
-	}
-}
-
-func (s *vfsShm) shmRelease() {
-	if len(s.ptrs) == 0 || shmEqual(s.shadow[0][:], util.View(s.mod, s.ptrs[0], _WALINDEX_HDR_SIZE)) {
-		return
-	}
-	// Copies modified words from private to shared memory.
-	for id, p := range s.ptrs {
-		shared := shmPage(s.shared[id][:])
-		shadow := shmPage(s.shadow[id][:])
-		privat := shmPage(util.View(s.mod, p, _WALINDEX_PGSZ))
-		for i, privat := range privat {
-			if shadow[i] != privat {
-				shadow[i] = privat
-				shared[i] = privat
-			}
-		}
-	}
-}
-
-func (s *vfsShm) shmBarrier() {
-	s.Lock()
-	s.shmAcquire(nil)
-	s.shmRelease()
-	s.Unlock()
-}
-
-func shmPage(s []byte) *[_WALINDEX_PGSZ / 4]uint32 {
-	p := (*uint32)(unsafe.Pointer(unsafe.SliceData(s)))
-	return (*[_WALINDEX_PGSZ / 4]uint32)(unsafe.Slice(p, _WALINDEX_PGSZ/4))
-}
-
-func shmEqual(v1, v2 []byte) bool {
-	return *(*[_WALINDEX_HDR_SIZE]byte)(v1[:]) == *(*[_WALINDEX_HDR_SIZE]byte)(v2[:])
-}