protected function generateIndexKey($cacheKey)
    {
        $cacheKeyStack = explode('.', $cacheKey);

        return implode('.', [
            $this->sanitizeCacheKeyPart($this->options['global_prefix']),
            $this->sanitizeCacheKeyPart($this->options['prefix']),
            $this->sanitizeCacheKeyPart($this->options['index_key']),
            $this->sanitizeCacheKeyPart($cacheKeyStack[2]), // filter
        ]);
    }
protected function generateIndexKey($cacheKey)
    {
        $cacheKeyStack = explode('.', $cacheKey);

        return implode('.', [
            $this->sanitizeCacheKeyPart($this->options['global_prefix']),
            $this->sanitizeCacheKeyPart($this->options['prefix']),
            $this->sanitizeCacheKeyPart($this->options['index_key']),
            $this->sanitizeCacheKeyPart($cacheKeyStack[2]), // filter
        ]);
    }
protected function generateIndexKey ( $ cacheKey ) { $ cacheKeyStack = explode ( '.' , $ cacheKey ) ; return implode ( '.' , [ $ this -> sanitizeCacheKeyPart ( $ this -> options [ 'global_prefix' ] ) , $ this -> sanitizeCacheKeyPart ( $ this -> options [ 'prefix' ] ) , $ this -> sanitizeCacheKeyPart ( $ this -> options [ 'index_key' ] ) , $ this -> sanitizeCacheKeyPart ( $ cacheKeyStack [ 2 ] ) , // filter ] ) ; }
Generate the index key for the given cacheKey.

The index contains a list of cache keys related to an image and a filter.

@param string $cacheKey

@return string
Generate the index key for the given cacheKey .