56 lines
1.4 KiB
Go
56 lines
1.4 KiB
Go
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package restic
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import "sync"
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// repoLocker manages exclusive/non-exclusive locks for
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// operations against restic repositories. The semantics
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// of exclusive/non-exclusive locks are the same as for
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// a sync.RWMutex, where a non-exclusive lock is equivalent
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// to a read lock, and an exclusive lock is equivalent to
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// a write lock.
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type repoLocker struct {
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mu sync.Mutex
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locks map[string]*sync.RWMutex
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}
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func newRepoLocker() *repoLocker {
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return &repoLocker{
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locks: make(map[string]*sync.RWMutex),
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}
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}
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// LockExclusive acquires an exclusive lock for the specified
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// repository. This function blocks until no other locks exist
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// for the repo.
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func (rl *repoLocker) LockExclusive(name string) {
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rl.ensureLock(name).Lock()
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}
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// Lock acquires a non-exclusive lock for the specified
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// repository. This function blocks until no exclusive
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// locks exist for the repo.
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func (rl *repoLocker) Lock(name string) {
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rl.ensureLock(name).RLock()
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}
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// UnlockExclusive releases an exclusive lock for the repo.
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func (rl *repoLocker) UnlockExclusive(name string) {
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rl.ensureLock(name).Unlock()
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}
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// Unlock releases a non-exclusive lock for the repo.
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func (rl *repoLocker) Unlock(name string) {
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rl.ensureLock(name).RUnlock()
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}
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func (rl *repoLocker) ensureLock(name string) *sync.RWMutex {
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rl.mu.Lock()
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defer rl.mu.Unlock()
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if _, ok := rl.locks[name]; !ok {
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rl.locks[name] = new(sync.RWMutex)
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}
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return rl.locks[name]
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}
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