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Implement Update method #134
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Thanks for the issue and PR. I have a similar use case.
I have a couple of suggestions, which combined will:
- Pass
exists
toUpdateCb
to allow distinguishing between zero-values and non-existent ones. This is also consistent withUpsert
,RemoveCb
- Allow
UpdateCb
to cancel the update if needed.Update
would return the final value and a bool to indicate whether the update went through.
concurrent_map.go
Outdated
// It is called while lock is held, therefore it MUST NOT | ||
// try to access other keys in same map, as it can lead to deadlock since | ||
// Go sync.RWLock is not reentrant | ||
type UpdateCb[V any] func(valueInMap V) V |
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type UpdateCb[V any] func(valueInMap V) V | |
type UpdateCb[V any] func(exists bool, valueInMap V) (newVal V, ok bool) |
|
||
// Update an existing element using UpdateCb, assuming the key exists. | ||
// If it does not, the zero value for the value type is passed to the callback. | ||
func (m ConcurrentMap[K, V]) Update(key K, cb UpdateCb[V]) (res V) { |
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func (m ConcurrentMap[K, V]) Update(key K, cb UpdateCb[V]) (res V) { | |
func (m ConcurrentMap[K, V]) Update(key K, cb UpdateCb[V]) (res V, ok bool) { |
The update method allows atomically mutating a value in the map. If the key does not exist, the zero value for the value type is mutated and saved.
Thanks for the suggestion @ayushjain2809 , updated accordingly. |
The update method allows atomically mutating a value in the map. If the key does not exist, the zero value for the value type is mutated and saved.
Fixes #133