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Merged
dunglas merged 1 commit into from
Jul 20, 2017
Merged

Improve the performance of CachedIdentifiersExtractor #1257

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81 changes: 44 additions & 37 deletions src/Api/CachedIdentifiersExtractor.php
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Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,7 @@ final class CachedIdentifiersExtractor implements IdentifiersExtractorInterface
private $cacheItemPool;
private $propertyAccessor;
private $decorated;
private $memoryCache = [];

@teohhanhui teohhanhui Jul 19, 2017

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Naming... See #1256 (comment)


public function __construct(CacheItemPoolInterface $cacheItemPool, IdentifiersExtractorInterface $decorated, PropertyAccessorInterface $propertyAccessor = null)
{
Expand All @@ -46,60 +47,66 @@ public function __construct(CacheItemPoolInterface $cacheItemPool, IdentifiersEx
*/
public function getIdentifiersFromItem($item): array
{
$identifiers = [];
$resourceClass = $this->getObjectClass($item);

$cacheKey = self::CACHE_KEY_PREFIX.md5($resourceClass);

// This is to avoid setting the cache twice in the case where the related item cache doesn't exist
$cacheIsHit = false;
$keys = $this->getKeys($item, function ($item) use (&$identifiers) {
return $identifiers = $this->decorated->getIdentifiersFromItem($item);
});

@soyuka soyuka Jul 20, 2017

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this is cool stuff!

@teohhanhui teohhanhui Jul 20, 2017

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🤷‍♂️

@soyuka soyuka Jul 20, 2017

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Using a reference to an unknown variable and declaring it in a closure looks cool to me haha 😅


try {
$cacheItem = $this->cacheItemPool->getItem($cacheKey);
$isRelationCached = true;

if ($cacheIsHit = $cacheItem->isHit()) {
foreach ($cacheItem->get() as $propertyName) {
$identifiers[$propertyName] = $this->propertyAccessor->getValue($item, $propertyName);
if (null !== $identifiers) {
return $identifiers;
}

if (!is_object($identifiers[$propertyName])) {
continue;
}
$identifiers = [];
foreach ($keys as $propertyName) {
$identifiers[$propertyName] = $this->propertyAccessor->getValue($item, $propertyName);

$relatedItem = $identifiers[$propertyName];
$relatedCacheKey = self::CACHE_KEY_PREFIX.md5($this->getObjectClass($relatedItem));
if (!is_object($identifiers[$propertyName])) {
continue;
}

$relatedResourceClass = $this->getObjectClass($identifiers[$propertyName]);
if (!$relatedIdentifiers = $this->memoryCache[$relatedResourceClass] ?? false) {
$relatedCacheKey = self::CACHE_KEY_PREFIX.md5($relatedResourceClass);
try {
$relatedCacheItem = $this->cacheItemPool->getItem($relatedCacheKey);

if (!$relatedCacheItem->isHit()) {
$isRelationCached = false;
break;
return $this->decorated->getIdentifiersFromItem($item);
}
} catch (CacheException $e) {
return $this->decorated->getIdentifiersFromItem($item);
}

$relatedIdentifiers = $relatedCacheItem->get();
}

unset($identifiers[$propertyName]);
$identifiers[$propertyName] = $this->propertyAccessor->getValue($identifiers[$propertyName], $relatedIdentifiers[0]);
}

$identifiers[$propertyName] = $this->propertyAccessor->getValue($relatedItem, $relatedCacheItem->get()[0]);
}
return $identifiers;
}

if (true === $isRelationCached) {
return $identifiers;
}
private function getKeys($item, callable $retriever): array
{
$resourceClass = $this->getObjectClass($item);
if (isset($this->memoryCache[$resourceClass])) {
return $this->memoryCache[$resourceClass];
}

try {
$cacheItem = $this->cacheItemPool->getItem(self::CACHE_KEY_PREFIX.md5($resourceClass));
if ($cacheItem->isHit()) {
return $this->memoryCache[$resourceClass] = $cacheItem->get();
}
} catch (CacheException $e) {
// do nothing
}

$identifiers = $this->decorated->getIdentifiersFromItem($item);
$keys = array_keys($retriever($item));

if (isset($cacheItem) && false === $cacheIsHit) {
try {
$cacheItem->set(array_keys($identifiers));
$this->cacheItemPool->save($cacheItem);
} catch (CacheException $e) {
// do nothing
}
if (isset($cacheItem)) {
$cacheItem->set($keys);
$this->cacheItemPool->save($cacheItem);
}

return $identifiers;
return $this->memoryCache[$resourceClass] = $keys;
}
}
14 changes: 11 additions & 3 deletions tests/Api/CachedIdentifiersExtractorTest.php
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Expand Up @@ -45,7 +45,9 @@ public function testFirstPass()

$identifiersExtractor = new CachedIdentifiersExtractor($cacheItemPool->reveal(), $decoration->reveal(), null);

$this->assertEquals(['id' => 1], $identifiersExtractor->getIdentifiersFromItem($dummy));
$expectedResult = ['id' => 1];
$this->assertEquals($expectedResult, $identifiersExtractor->getIdentifiersFromItem($dummy));
$this->assertEquals($expectedResult, $identifiersExtractor->getIdentifiersFromItem($dummy), 'Trigger the local cache');

@teohhanhui teohhanhui Jul 20, 2017

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How does this test verify that we are triggering the local cache? Also, it should not matter in a unit test.

@soyuka soyuka Jul 20, 2017

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He's hacking coverage to please @Simperfit 😆

@teohhanhui teohhanhui Jul 20, 2017

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Actually, this second call is crucial to test correct behaviour, i.e. that we return the correct value when cache is used. But it's not testing whether we're triggering the local cache.

@teohhanhui teohhanhui Jul 20, 2017

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Oh wait, we already have different test cases for that... Lol

@dunglas dunglas Jul 20, 2017 •
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Not really for the coverage. You're right @teohhanhui, it doesn't verify that the local cache actually works (it's very hard to test reliably), however it tests if the local cache doesn't introduce a bug.

For instance, if some one contribute this patch:

-return $this->memoryCache[$resourceClass];
+return $this->memoryCache[$resourceC];

The test will detect the problem. Without this line, it will not.

@teohhanhui teohhanhui Jul 20, 2017

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@dunglas Doesn't testSecondPass already do that?

@dunglas dunglas Jul 20, 2017

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Good catch. testSecondPass should be update to bypass the local cache IMO (by creating a new instance).

@teohhanhui teohhanhui Jul 20, 2017

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$localCache is unambiguous. #preach

}

public function testSecondPass()
Expand All @@ -67,7 +69,9 @@ public function testSecondPass()

$identifiersExtractor = new CachedIdentifiersExtractor($cacheItemPool->reveal(), $decoration->reveal(), null);

$this->assertEquals(['id' => 1], $identifiersExtractor->getIdentifiersFromItem($dummy));
$expectedResult = ['id' => 1];
$this->assertEquals($expectedResult, $identifiersExtractor->getIdentifiersFromItem($dummy));
$this->assertEquals($expectedResult, $identifiersExtractor->getIdentifiersFromItem($dummy), 'Trigger the local cache');
}

public function testSecondPassWithRelatedNotCached()
Expand Down Expand Up @@ -98,7 +102,9 @@ public function testSecondPassWithRelatedNotCached()

$identifiersExtractor = new CachedIdentifiersExtractor($cacheItemPool->reveal(), $decoration->reveal(), null);

$expectedResult = ['id' => 1, 'relatedDummy' => 1];
$this->assertEquals(['id' => 1, 'relatedDummy' => 1], $identifiersExtractor->getIdentifiersFromItem($dummy));
$this->assertEquals($expectedResult, $identifiersExtractor->getIdentifiersFromItem($dummy), 'Trigger the local cache');
}

public function testSecondPassWithRelatedCached()
Expand Down Expand Up @@ -130,6 +136,8 @@ public function testSecondPassWithRelatedCached()

$identifiersExtractor = new CachedIdentifiersExtractor($cacheItemPool->reveal(), $decoration->reveal(), null);

$this->assertEquals(['id' => 1, 'relatedDummy' => 1], $identifiersExtractor->getIdentifiersFromItem($dummy));
$expectedResult = ['id' => 1, 'relatedDummy' => 1];
$this->assertEquals($expectedResult, $identifiersExtractor->getIdentifiersFromItem($dummy));
$this->assertEquals($expectedResult, $identifiersExtractor->getIdentifiersFromItem($dummy), 'Trigger the local cache');
}
}