Neos\Flow\Security\Context::getContextHash PHP Method

    public function getContextHash()
    {
        if ($this->areAuthorizationChecksDisabled()) {
            return self::CONTEXT_HASH_UNINITIALIZED;
        }
        if (!$this->isInitialized()) {
            if (!$this->canBeInitialized()) {
                return self::CONTEXT_HASH_UNINITIALIZED;
            }
            $this->initialize();
        }
        if ($this->contextHash === null) {
            $this->contextHash = md5(implode('|', array_keys($this->getRoles())));
        }
        return $this->contextHash;
    }

 /**
  * Gets the SQL query part to add to a query.
  *
  * @param ClassMetaData $targetEntity Metadata object for the target entity to be filtered
  * @param string $targetTableAlias The target table alias used in the current query
  * @return string The constraint SQL if there is available, empty string otherwise
  */
 public function addFilterConstraint(ClassMetadata $targetEntity, $targetTableAlias)
 {
     $this->initializeDependencies();
     /*
      * TODO: Instead of checking for class account we could introduce some interface for white listing entities from entity security checks
      * Problem with checking the Account is, that this filter calls getRoles() on the security context while accounts are not
      * yet fully initialized. By this we get a half built account object that will end up in access denied exception,
      * as it has no roles (and other properties) set
      */
     if ($this->securityContext->areAuthorizationChecksDisabled() || $targetEntity->getName() === Account::class) {
         return '';
     }
     if (!$this->securityContext->isInitialized()) {
         if (!$this->securityContext->canBeInitialized()) {
             return '';
         }
         $this->securityContext->initialize();
     }
     // This is needed to include the current context of roles into query cache identifier
     $this->setParameter('__contextHash', $this->securityContext->getContextHash(), 'string');
     $sqlConstraints = [];
     $grantedConstraints = [];
     $deniedConstraints = [];
     foreach ($this->securityContext->getRoles() as $role) {
         $entityPrivileges = $role->getPrivilegesByType(EntityPrivilegeInterface::class);
         /** @var EntityPrivilegeInterface $privilege */
         foreach ($entityPrivileges as $privilege) {
             if (!$privilege->matchesEntityType($targetEntity->getName())) {
                 continue;
             }
             $sqlConstraint = $privilege->getSqlConstraint($targetEntity, $targetTableAlias);
             if ($sqlConstraint === null) {
                 continue;
             }
             $sqlConstraints[] = ' NOT (' . $sqlConstraint . ')';
             if ($privilege->isGranted()) {
                 $grantedConstraints[] = ' NOT (' . $sqlConstraint . ')';
             } elseif ($privilege->isDenied()) {
                 $deniedConstraints[] = ' NOT (' . $sqlConstraint . ')';
             }
         }
     }
     $grantedConstraints = array_diff($grantedConstraints, $deniedConstraints);
     $effectiveConstraints = array_diff($sqlConstraints, $grantedConstraints);
     if (count($effectiveConstraints) > 0) {
         return ' (' . implode(') AND (', $effectiveConstraints) . ') ';
     }
     return '';
 }