wp-includes/class-wp-object-cache.php:519Decrements numeric cache item's value.
$keyint|string$offsetintoptional1$groupstringoptional'default'int|false public function decr( $key, $offset = 1, $group = 'default' ) { if ( ! $this->is_valid_key( $key ) ) { return false; } if ( empty( $group ) ) { $group = 'default'; } if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) ) { $key = $this->blog_prefix . $key; } if ( ! $this->_exists( $key, $group ) ) { return false; } if ( ! is_numeric( $this->cache[ $group ][ $key ] ) ) { $this->cache[ $group ][ $key ] = 0; } $offset = (int) $offset; $this->cache[ $group ][ $key ] -= $offset; if ( $this->cache[ $group ][ $key ] < 0 ) { $this->cache[ $group ][ $key ] = 0; } return $this->cache[ $group ][ $key ]; }Introduced in 3.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-object-cache.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.