RevisionOutputCache: split metricSuffix into discrete components

Breaks up current usage of $metricSuffix into discrete components in
preparation for conversion to StatsLib.

Bug: T356815
Change-Id: I90517e0d5a1dc3f735a5b093529d7797be5ac063

includes/parser/RevisionOutputCache.php

@@ -106,10 +106,11 @@ public function __construct(
  }
 
  /**
- * @param string $metricSuffix
+ * @param string $status e.g. hit, miss etc.
+ * @param string|null $reason
  */
- private function incrementStats( string $metricSuffix ) {
- $metricSuffix = str_replace( '.', '_', $metricSuffix );
+ private function incrementStats( string $status, string $reason = null ) {
+ $metricSuffix = $reason ? "{$status}_{$reason}" : $status;
  $this->stats->increment( "RevisionOutputCache.{$this->name}.{$metricSuffix}" );
  }
 
@@ -193,21 +194,21 @@ public function get( RevisionRecord $revision, ParserOptions $parserOptions ) {
  }
 
  if ( !$parserOptions->isSafeToCache() ) {
- $this->incrementStats( 'miss.unsafe' );
+ $this->incrementStats( 'miss', 'unsafe' );
  return false;
  }
 
  $cacheKey = $this->makeParserOutputKey( $revision, $parserOptions );
  $json = $this->cache->get( $cacheKey );
 
  if ( $json === false ) {
- $this->incrementStats( 'miss.absent' );
+ $this->incrementStats( 'miss', 'absent' );
  return false;
  }
 
  $output = $this->restoreFromJson( $json, $cacheKey, ParserOutput::class );
  if ( $output === null ) {
- $this->incrementStats( 'miss.unserialize' );
+ $this->incrementStats( 'miss', 'unserialize' );
  return false;
  }
 
@@ -216,7 +217,7 @@ public function get( RevisionRecord $revision, ParserOptions $parserOptions ) {
  $expiryTime = max( $expiryTime, (int)MWTimestamp::now( TS_UNIX ) - $this->cacheExpiry );
 
  if ( $cacheTime < $expiryTime ) {
- $this->incrementStats( 'miss.expired' );
+ $this->incrementStats( 'miss', 'expired' );
  return false;
  }
 
@@ -278,23 +279,23 @@ public function save(
 
  $expiry = $output->getCacheExpiry();
  if ( $expiry <= 0 ) {
- $this->incrementStats( 'save.uncacheable' );
+ $this->incrementStats( 'save', 'uncacheable' );
  return;
  }
 
  if ( !$parserOptions->isSafeToCache() ) {
- $this->incrementStats( 'save.unsafe' );
+ $this->incrementStats( 'save', 'unsafe' );
  return;
  }
 
  $json = $this->encodeAsJson( $output, $cacheKey );
  if ( $json === null ) {
- $this->incrementStats( 'save.nonserializable' );
+ $this->incrementStats( 'save', 'nonserializable' );
  return;
  }
 
  $this->cache->set( $cacheKey, $json, $expiry );
- $this->incrementStats( 'save.success' );
+ $this->incrementStats( 'save', 'success' );
  }
 
  /**