mongodb update exception 'document fragment is too large' - php

Question

Updating my collection record field with 'MongoBinData', exception is triggered:
"document fragment is too large: 21216456, max: 16777216"
I find some web discussion about 'allowDiskUse:true' for aggregate, but nothing ubout 'update'.
Here a part of code in PHP:
try {
$criteria = array( '_id' => $intReleaseId);
$fileData = file_get_contents( $_FILES[ $fileKey]["tmp_name"]);
$mongoBinData = new MongoBinData( $fileData, MongoBinData::GENERIC)
$docItem['data'] = $mongoBinData;
$docItem['fileType'] = $strFileType;
$docItem['fileSize'] = $intFileSize;
$docItem['fileExtension'] = $strFileExtension;
$docItem['fileName'] = $strFileName;
$options = array( "upsert" => true,
'safe' => true, 'fsync' => true,
'allowDiskUse' => true ); // this option doesn't change anything
$reportJson = self::GetCollection('releases')->update( $criteria, $docItem, $options);
...
MongoDb release is db version v3.0.6
Some idea ?

Answer 1

Self resolved.
Use gridFS is immediate and simple.
$_mongo = new MongoClient();
$_db = $_mongo->selectDB($_mDbName);
$_gridFS = $_db->getGridFS();
/* */
function saveFileData($intReleaseId, $binData) {
$criteria = array( '_id' => $intReleaseId);
// if exist or not, remove previous value
try {
$_gridFS->remove( $criteria);
}
catch(Exception $e) {}
// store new file content
$storeByteCompleted = false;
try {
$reportId = $_gridFS->storeBytes(
$binData,
array("_id" => $intReleaseId));
if ($reportId == $intReleaseId) {
$storeByteCompleted = true;
}
catch(Exception $e) {}
return $storeByteCompleted;
}
function loadFileData($intReleaseId) {
$gridfsFile = null;
$binData = null;
try {
$gridfsFile = $_gridFS->get($intReleaseId);
}
catch(Exception $e) {}
if ($gridfsFile != null) {
$binData = $gridfsFile->getBytes()
}
return $binData;
}
That's all.