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Diffstat (limited to 'vendor/github.com/ncruces/go-sqlite3/vfs/os_ofd.go')
-rw-r--r--vendor/github.com/ncruces/go-sqlite3/vfs/os_ofd.go59
1 files changed, 59 insertions, 0 deletions
diff --git a/vendor/github.com/ncruces/go-sqlite3/vfs/os_ofd.go b/vendor/github.com/ncruces/go-sqlite3/vfs/os_ofd.go
new file mode 100644
index 000000000..15730fe62
--- /dev/null
+++ b/vendor/github.com/ncruces/go-sqlite3/vfs/os_ofd.go
@@ -0,0 +1,59 @@
+//go:build (linux || darwin) && !(sqlite3_flock || sqlite3_nosys)
+
+package vfs
+
+import (
+ "os"
+ "time"
+
+ "golang.org/x/sys/unix"
+)
+
+func osGetSharedLock(file *os.File) _ErrorCode {
+ // Test the PENDING lock before acquiring a new SHARED lock.
+ if lock, _ := osTestLock(file, _PENDING_BYTE, 1); lock == unix.F_WRLCK {
+ return _BUSY
+ }
+ // Acquire the SHARED lock.
+ return osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0)
+}
+
+func osGetReservedLock(file *os.File) _ErrorCode {
+ // Acquire the RESERVED lock.
+ return osWriteLock(file, _RESERVED_BYTE, 1, 0)
+}
+
+func osGetExclusiveLock(file *os.File, state *LockLevel) _ErrorCode {
+ if *state == LOCK_RESERVED {
+ // A PENDING lock is needed before acquiring an EXCLUSIVE lock.
+ if rc := osWriteLock(file, _PENDING_BYTE, 1, -1); rc != _OK {
+ return rc
+ }
+ *state = LOCK_PENDING
+ }
+ // Acquire the EXCLUSIVE lock.
+ return osWriteLock(file, _SHARED_FIRST, _SHARED_SIZE, time.Millisecond)
+}
+
+func osDowngradeLock(file *os.File, state LockLevel) _ErrorCode {
+ if state >= LOCK_EXCLUSIVE {
+ // Downgrade to a SHARED lock.
+ if rc := osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0); rc != _OK {
+ // notest // this should never happen
+ return _IOERR_RDLOCK
+ }
+ }
+ // Release the PENDING and RESERVED locks.
+ return osUnlock(file, _PENDING_BYTE, 2)
+}
+
+func osReleaseLock(file *os.File, _ LockLevel) _ErrorCode {
+ // Release all locks.
+ return osUnlock(file, 0, 0)
+}
+
+func osCheckReservedLock(file *os.File) (bool, _ErrorCode) {
+ // Test the RESERVED lock.
+ lock, rc := osTestLock(file, _RESERVED_BYTE, 1)
+ return lock == unix.F_WRLCK, rc
+}