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[Cache] Decrease the probability of invalidation loss on tag eviction #44015

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Merged
merged 1 commit into from
Nov 16, 2021
Merged

[Cache] Decrease the probability of invalidation loss on tag eviction #44015

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113 changes: 54 additions & 59 deletions src/Symfony/Component/Cache/Adapter/TagAwareAdapter.php
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Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,7 @@ class TagAwareAdapter implements TagAwareAdapterInterface, TagAwareCacheInterfac
private static $createCacheItem;
private static $setCacheItemTags;
private static $getTagsByKey;
private static $invalidateTags;
private static $saveTags;

public function __construct(AdapterInterface $itemsPool, AdapterInterface $tagsPool = null, float $knownTagVersionsTtl = 0.15)
{
Expand Down Expand Up @@ -95,8 +95,10 @@ static function ($deferred) {
null,
CacheItem::class
);
self::$invalidateTags ?? self::$invalidateTags = \Closure::bind(
self::$saveTags ?? self::$saveTags = \Closure::bind(
static function (AdapterInterface $tagsAdapter, array $tags) {
ksort($tags);

foreach ($tags as $v) {
$v->expiry = 0;
$tagsAdapter->saveDeferred($v);
Expand All @@ -114,40 +116,14 @@ static function (AdapterInterface $tagsAdapter, array $tags) {
*/
public function invalidateTags(array $tags)
{
$ok = true;
$tagsByKey = [];
$invalidatedTags = [];
$ids = [];
foreach ($tags as $tag) {
\assert('' !== CacheItem::validateKey($tag));
$invalidatedTags[$tag] = 0;
}

if ($this->deferred) {
$items = $this->deferred;
foreach ($items as $key => $item) {
if (!$this->pool->saveDeferred($item)) {
unset($this->deferred[$key]);
$ok = false;
}
}

$tagsByKey = (self::$getTagsByKey)($items);
$this->deferred = [];
}

$tagVersions = $this->getTagVersions($tagsByKey, $invalidatedTags);
$f = self::$createCacheItem;

foreach ($tagsByKey as $key => $tags) {
$this->pool->saveDeferred($f(static::TAGS_PREFIX.$key, array_intersect_key($tagVersions, $tags), $items[$key]));
}
$ok = $this->pool->commit() && $ok;

if ($invalidatedTags) {
$ok = (self::$invalidateTags)($this->tags, $invalidatedTags) && $ok;
unset($this->knownTagVersions[$tag]);
$ids[] = $tag.static::TAGS_PREFIX;
}

return $ok;
return !$tags || $this->tags->deleteItems($ids);
}

/**
Expand Down Expand Up @@ -176,7 +152,7 @@ public function hasItem($key)
}

foreach ($this->getTagVersions([$itemTags]) as $tag => $version) {
if ($itemTags[$tag] !== $version && 1 !== $itemTags[$tag] - $version) {
if ($itemTags[$tag] !== $version) {
return false;
}
}
Expand Down Expand Up @@ -314,7 +290,30 @@ public function saveDeferred(CacheItemInterface $item)
*/
public function commit()
{
return $this->invalidateTags([]);
if (!$this->deferred) {
return true;
}

$ok = true;
foreach ($this->deferred as $key => $item) {
if (!$this->pool->saveDeferred($item)) {
unset($this->deferred[$key]);
$ok = false;
}
}

$items = $this->deferred;
$tagsByKey = (self::$getTagsByKey)($items);
$this->deferred = [];

$tagVersions = $this->getTagVersions($tagsByKey);
$f = self::$createCacheItem;

foreach ($tagsByKey as $key => $tags) {
$this->pool->saveDeferred($f(static::TAGS_PREFIX.$key, array_intersect_key($tagVersions, $tags), $items[$key]));
}

return $this->pool->commit() && $ok;
}

/**
Expand Down Expand Up @@ -361,7 +360,7 @@ private function generateItems(iterable $items, array $tagKeys): \Generator

foreach ($itemTags as $key => $tags) {
foreach ($tags as $tag => $version) {
if ($tagVersions[$tag] !== $version && 1 !== $version - $tagVersions[$tag]) {
if ($tagVersions[$tag] !== $version) {
unset($itemTags[$key]);
continue 2;
}
Expand All @@ -377,57 +376,53 @@ private function generateItems(iterable $items, array $tagKeys): \Generator
}
}

private function getTagVersions(array $tagsByKey, array &$invalidatedTags = [])
private function getTagVersions(array $tagsByKey)
{
$tagVersions = $invalidatedTags;
$tagVersions = [];
$fetchTagVersions = false;

foreach ($tagsByKey as $tags) {
$tagVersions += $tags;

foreach ($tags as $tag => $version) {
if ($tagVersions[$tag] !== $version) {
unset($this->knownTagVersions[$tag]);
}
}
}

if (!$tagVersions) {
return [];
}

if (!$fetchTagVersions = 1 !== \func_num_args()) {
foreach ($tagsByKey as $tags) {
foreach ($tags as $tag => $version) {
if ($tagVersions[$tag] > $version) {
$tagVersions[$tag] = $version;
}
}
}
}

$now = microtime(true);
$tags = [];
foreach ($tagVersions as $tag => $version) {
$tags[$tag.static::TAGS_PREFIX] = $tag;
if ($fetchTagVersions || !isset($this->knownTagVersions[$tag])) {
if ($fetchTagVersions || ($this->knownTagVersions[$tag][1] ?? null) !== $version || $now - $this->knownTagVersions[$tag][0] >= $this->knownTagVersionsTtl) {
// reuse previously fetched tag versions up to the ttl
$fetchTagVersions = true;
continue;
}
$version -= $this->knownTagVersions[$tag][1];
if ((0 !== $version && 1 !== $version) || $now - $this->knownTagVersions[$tag][0] >= $this->knownTagVersionsTtl) {
// reuse previously fetched tag versions up to the ttl, unless we are storing items or a potential miss arises
$fetchTagVersions = true;
} else {
$this->knownTagVersions[$tag][1] += $version;
}
}

if (!$fetchTagVersions) {
return $tagVersions;
}

$newTags = [];
$newVersion = null;
foreach ($this->tags->getItems(array_keys($tags)) as $tag => $version) {
$tagVersions[$tag = $tags[$tag]] = $version->get() ?: 0;
if (isset($invalidatedTags[$tag])) {
$invalidatedTags[$tag] = $version->set(++$tagVersions[$tag]);
if (!$version->isHit()) {
$newTags[$tag] = $version->set($newVersion ?? $newVersion = random_int(\PHP_INT_MIN, \PHP_INT_MAX));
}
$tagVersions[$tag = $tags[$tag]] = $version->get();
$this->knownTagVersions[$tag] = [$now, $tagVersions[$tag]];
}

if ($newTags) {
(self::$saveTags)($this->tags, $newTags);
}

return $tagVersions;
}
}
20 changes: 1 addition & 19 deletions src/Symfony/Component/Cache/Tests/Adapter/TagAwareAdapterTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -40,25 +40,6 @@ public static function tearDownAfterClass(): void
(new Filesystem())->remove(sys_get_temp_dir().'/symfony-cache');
}

/**
* Test feature specific to TagAwareAdapter as it implicit needs to save deferred when also saving expiry info.
*/
public function testInvalidateCommitsSeperatePools()
{
$pool1 = $this->createCachePool();

$foo = $pool1->getItem('foo');
$foo->tag('tag');

$pool1->saveDeferred($foo->set('foo'));
$pool1->invalidateTags(['tag']);

$pool2 = $this->createCachePool();
$foo = $pool2->getItem('foo');

$this->assertTrue($foo->isHit());
}

public function testPrune()
{
$cache = new TagAwareAdapter($this->getPruneableMock());
Expand All @@ -84,6 +65,7 @@ public function testKnownTagVersionsTtl()

$tag = $this->createMock(CacheItemInterface::class);
$tag->expects(self::exactly(2))->method('get')->willReturn(10);
$tag->expects(self::exactly(2))->method('set')->willReturn($tag);

$tagsPool->expects(self::exactly(2))->method('getItems')->willReturn([
'baz'.TagAwareAdapter::TAGS_PREFIX => $tag,
Expand Down