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Refactor snapshot cache initialization to better support nnbd #2761

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Merged
merged 1 commit into from
Aug 24, 2021
Merged

Refactor snapshot cache initialization to better support nnbd #2761

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2 changes: 1 addition & 1 deletion lib/dartdoc.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -262,7 +262,7 @@ class Dartdoc {
return dartdocResults;
} finally {
// Clear out any cached tool snapshots and temporary directories.
SnapshotCache.instance?.dispose();
SnapshotCache.instanceFor(config.resourceProvider).dispose();
// ignore: unawaited_futures
ToolTempFileTracker.instance?.dispose();
}
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20 changes: 11 additions & 9 deletions lib/src/tool_definition.dart
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Expand Up @@ -109,8 +109,8 @@ class DartToolDefinition extends ToolDefinition {
assert(args[0] == command.first);
// Set up flags to create a new snapshot, if needed, and use the first run
// as the training run.
SnapshotCache.createInstance(_resourceProvider);
var snapshot = SnapshotCache.instance.getSnapshot(command.first);
var snapshotCache = SnapshotCache.instanceFor(_resourceProvider);
var snapshot = snapshotCache.getSnapshot(command.first);
var snapshotFile = snapshot._snapshotFile;
var snapshotPath =
_resourceProvider.pathContext.absolute(snapshotFile.path);
Expand Down Expand Up @@ -212,11 +212,11 @@ class _Snapshot {
void _snapshotCompleted() => _snapshotCompleter.complete();
}

/// A singleton that keeps track of cached snapshot files. The [dispose]
/// A class that keeps track of cached snapshot files. The [dispose]
/// function must be called before process exit to clean up snapshots in the
/// cache.
class SnapshotCache {
static SnapshotCache _instance;
static final _instances = <ResourceProvider, SnapshotCache>{};
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Gnerally exactly one key/value pair in any given execution, yeah? Maybe like... two, for a test execution that uses mocks and real test packages.

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Yes. The cache pretended before that there was only ever one, but I was suspicious of how it handled mocks or other inputs by ignoring them after the first call to createInstance if you hadn't dispose()d of them. That seemed like a bad idea in an asynchronous program, and was a pain to migrate without a refactor.


final Folder snapshotCache;
final ResourceProvider _resourceProvider;
Expand All @@ -227,10 +227,12 @@ class SnapshotCache {
: snapshotCache =
_resourceProvider.createSystemTemp('dartdoc_snapshot_cache_');

static SnapshotCache get instance => _instance;

static SnapshotCache createInstance(ResourceProvider resourceProvider) =>
_instance ??= SnapshotCache._(resourceProvider);
/// Returns a [SnapshotCache] for a given [ResourceProvider], creating one
/// only if one doesn't exist yet for the given [ResourceProvider].
factory SnapshotCache.instanceFor(ResourceProvider resourceProvider) {
return _instances.putIfAbsent(
resourceProvider, () => SnapshotCache._(resourceProvider));
}

_Snapshot getSnapshot(String toolPath) {
if (snapshots.containsKey(toolPath)) {
Expand All @@ -243,7 +245,7 @@ class SnapshotCache {
}

void dispose() {
_instance = null;
_instances.remove(_resourceProvider);
if (snapshotCache != null && snapshotCache.exists) {
return snapshotCache.delete();
}
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2 changes: 1 addition & 1 deletion lib/src/tool_runner.dart
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Expand Up @@ -175,7 +175,7 @@ class ToolRunner {
// find out where their script was coming from as an absolute path on the
// filesystem.
envWithInput['DART_SNAPSHOT_CACHE'] = pathContext.absolute(
SnapshotCache.createInstance(resourceProvider).snapshotCache.path);
SnapshotCache.instanceFor(resourceProvider).snapshotCache.path);
if (toolDefinition.setupCommand != null) {
envWithInput['DART_SETUP_COMMAND'] = toolDefinition.setupCommand[0];
}
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3 changes: 2 additions & 1 deletion test/tool_runner_test.dart
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Expand Up @@ -95,7 +95,8 @@ echo:
tearDownAll(() {
tempDir?.deleteSync(recursive: true);
tracker?.dispose();
SnapshotCache.instance?.dispose();
SnapshotCache.instanceFor(pubPackageMetaProvider.resourceProvider)
.dispose();
setupFile = null;
tempDir = null;
});
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