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author | 2024-11-07 00:16:28 +0000 | |
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committer | 2024-11-07 00:16:28 +0000 | |
commit | 45e1609377631070765065ffb35ed7d29e8e81f1 (patch) | |
tree | 51d170ff0d5fab1ab0f8b1b79c9dd8c31d4ce5b9 /vendor/github.com/ncruces/go-sqlite3/vfs/os_dotlk.go | |
parent | [chore] update go ffmpreg to v0.6.0 (#3515) (diff) | |
download | gotosocial-45e1609377631070765065ffb35ed7d29e8e81f1.tar.xz |
bump ncruces/go-sqlite3 to v0.20.2 (#3524)
Diffstat (limited to 'vendor/github.com/ncruces/go-sqlite3/vfs/os_dotlk.go')
-rw-r--r-- | vendor/github.com/ncruces/go-sqlite3/vfs/os_dotlk.go | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/vendor/github.com/ncruces/go-sqlite3/vfs/os_dotlk.go b/vendor/github.com/ncruces/go-sqlite3/vfs/os_dotlk.go new file mode 100644 index 000000000..1c1a49c11 --- /dev/null +++ b/vendor/github.com/ncruces/go-sqlite3/vfs/os_dotlk.go @@ -0,0 +1,143 @@ +//go:build sqlite3_dotlk + +package vfs + +import ( + "errors" + "io/fs" + "os" + "sync" +) + +var ( + // +checklocks:vfsDotLocksMtx + vfsDotLocks = map[string]*vfsDotLocker{} + vfsDotLocksMtx sync.Mutex +) + +type vfsDotLocker struct { + shared int // +checklocks:vfsDotLocksMtx + pending *os.File // +checklocks:vfsDotLocksMtx + reserved *os.File // +checklocks:vfsDotLocksMtx +} + +func osGetSharedLock(file *os.File) _ErrorCode { + vfsDotLocksMtx.Lock() + defer vfsDotLocksMtx.Unlock() + + name := file.Name() + locker := vfsDotLocks[name] + if locker == nil { + err := os.Mkdir(name+".lock", 0777) + if errors.Is(err, fs.ErrExist) { + return _BUSY // Another process has the lock. + } + if err != nil { + return _IOERR_LOCK + } + locker = &vfsDotLocker{} + vfsDotLocks[name] = locker + } + + if locker.pending != nil { + return _BUSY + } + locker.shared++ + return _OK +} + +func osGetReservedLock(file *os.File) _ErrorCode { + vfsDotLocksMtx.Lock() + defer vfsDotLocksMtx.Unlock() + + name := file.Name() + locker := vfsDotLocks[name] + if locker == nil { + return _IOERR_LOCK + } + + if locker.reserved != nil && locker.reserved != file { + return _BUSY + } + locker.reserved = file + return _OK +} + +func osGetExclusiveLock(file *os.File, _ *LockLevel) _ErrorCode { + vfsDotLocksMtx.Lock() + defer vfsDotLocksMtx.Unlock() + + name := file.Name() + locker := vfsDotLocks[name] + if locker == nil { + return _IOERR_LOCK + } + + if locker.pending != nil && locker.pending != file { + return _BUSY + } + locker.pending = file + if locker.shared > 1 { + return _BUSY + } + return _OK +} + +func osDowngradeLock(file *os.File, _ LockLevel) _ErrorCode { + vfsDotLocksMtx.Lock() + defer vfsDotLocksMtx.Unlock() + + name := file.Name() + locker := vfsDotLocks[name] + if locker == nil { + return _IOERR_UNLOCK + } + + if locker.reserved == file { + locker.reserved = nil + } + if locker.pending == file { + locker.pending = nil + } + return _OK +} + +func osReleaseLock(file *os.File, state LockLevel) _ErrorCode { + vfsDotLocksMtx.Lock() + defer vfsDotLocksMtx.Unlock() + + name := file.Name() + locker := vfsDotLocks[name] + if locker == nil { + return _IOERR_UNLOCK + } + + if locker.shared == 1 { + err := os.Remove(name + ".lock") + if err != nil && !errors.Is(err, fs.ErrNotExist) { + return _IOERR_UNLOCK + } + delete(vfsDotLocks, name) + } + + if locker.reserved == file { + locker.reserved = nil + } + if locker.pending == file { + locker.pending = nil + } + locker.shared-- + return _OK +} + +func osCheckReservedLock(file *os.File) (bool, _ErrorCode) { + vfsDotLocksMtx.Lock() + defer vfsDotLocksMtx.Unlock() + + name := file.Name() + locker := vfsDotLocks[name] + if locker == nil { + return false, _OK + } + return locker.reserved != nil, _OK +} |