using

Description:

using

Using #
This package provides a Releasable mixin to upgrade classes with automatic
resource cleanup and finalization features.
Examples #
class Resource with Releasable {
// manage resource

@override
void release() {
// clean-up resource in this method
// and make sure super.release() is called!
super.release();
}
}

void main() {
Resource? res;
try {
res = Resource(); // allocate
// use resource
} finally {
// release in a finally block to ensure resources are released
// even when an error occurs
res?.release();
}
}
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Extension methods are provided to support syntaxes similar to C#'s using
and Java's try-with-resource. They also help make sure resources are
properly released!
void main() {
final data = Resource().use((res) {
// use `res` to load and return some data
});
// the instance created by `Resource()` is guaranteed to be released

final asyncData = await Resource().useAsync((res) async {
// use `res` to load and return some data
});
// the instance created by `Resource()` is guaranteed to be released
}
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Streams are also supported via the consume() extension method:
void main() {
final outputs = await Resource().consume(inputStream, (res, input) async {
// use `res` to process inputs and return outputs
}).toList();
// the instance created by `Resource()` is guaranteed to be released
}
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Automatic finalization is also available to try ensure resources will be released
even in situations where release() has not been called. However, no promises are
made that this will really happen. For more information, see Dart's documentation
for Finalizer.
class ResourceOwner with Releasable {
final _res1 = Resource();
final _res2 = Resource();

ResourceOwner() {
// non-deterministic clean-up relying on Dart's `Finalizer` class. If
// the resource owner goes out of scope and `release()` was not called,
// the two resources should eventually be released and reclaimed by a
// `Finalizer`.
autoRelease([_res1, _res2]);
}

// deterministic clean-up by explicitly calling `release()` on this
// instance, or when the instance is used via extension methods (`use()`,
// `consume()`...).
@override
void release() {
// clean-up resources
_res1.release();
_res2.release();
// call super method
super.release();
}
}
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License

For personal and professional use. You cannot resell or redistribute these repositories in their original state.

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