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[CORE][Cache][DOCS] Add documentation to complex private function 'Cache::redisMaybeRecompute'

This commit is contained in:
Hugo Sales 2021-12-16 10:44:23 +00:00
parent b0d5ce8aab
commit 24291a268a
Signed by: someonewithpc
GPG Key ID: 7D0C7EAFC9D835A0
1 changed files with 29 additions and 10 deletions
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39
src/Core/Cache.php
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@ -135,6 +135,11 @@ abstract class Cache
}
}
/**
* Worker function for doing redis requests that may need to be recomputed. Given a key, it
* either uses the configuration value or the object lifetime to statistically determine if a
* cache entry specified by $key should be recomputed, to avoid cache stampedes (when a lot of keys expire at once)
*/
private static function redisMaybeRecompute(string $key, callable $recompute, callable $no_recompute, string $pool = 'default', float $beta = 1.0): mixed
{
$should_recompute = $beta === \INF || !self::$redis[$pool]->exists($key);
@ -226,7 +231,10 @@ abstract class Cache
if (isset(self::$redis[$pool])) {
return self::redisMaybeRecompute(
$key,
recompute: function () use ($key, $calculate, $pool, $max_count, $left, $right, $beta) {
recompute: /**
* Caculate and trim the list to the correct size
*/
function () use ($key, $calculate, $pool, $max_count, $left, $right, $beta) {
$save = true; // Pass by reference
$res = $calculate(null, $save);
if ($save) {
@ -240,19 +248,30 @@ abstract class Cache
}
return \array_slice($res, $offset, $length);
},
no_recompute: fn () => self::$redis[$pool]->lRange($key, $left ?? 0, ($right ?? $max_count ?? 0) - 1),
no_recompute: /**
* Fetch (a portion of) the list from the cache
*/
fn () => self::$redis[$pool]->lRange($key, $left ?? 0, ($right ?? $max_count ?? 0) - 1),
pool: $pool,
beta: $beta,
);
} else {
return self::get($key, function () use ($calculate, $max_count) {
$save = true;
$res = $calculate(null, $save);
if ($max_count != -1) {
$res = \array_slice($res, 0, $max_count);
}
return $res;
}, $pool, $beta);
return self::get(
$key,
/**
* Fetch the list from the cache and possibly trim the length
*/
function () use ($calculate, $max_count) {
$save = true;
$res = $calculate(null, $save);
if ($max_count != -1) {
$res = \array_slice($res, 0, $max_count);
}
return $res;
},
$pool,
$beta,
);
}
}