Corrupted PowerPoint Files from mysql

[mmilam]

I have created a file library that stores binary files in mysql and everything works fine except for some reason some poerpoint files become corrupted when they are downloaded from the library. It only happens to powerpoint files and doesn't happen to all powerpoint files and the size of the file doesn't seem to matter either. The only commonality between all the corrupted files is that the certain people seem to consistently have problems with ppt files they upload while others have had no problems whatsoever. Anybody ever hear of a similar problem/solution?

[drawmack]

post your storage and retrieval code

[mmilam]

First off some clarification, I break the file up into 64k chunks and store each chunk as a record in the db. Here is the code...

The Code to upload the file into the database in pieces

if($action == "add"){ //adding file to library
// File Information
$SrcPathName = $HTTP_POST_FILES["file_to_add"]["tmp_name"];
$SrcFileType = $HTTP_POST_FILES["file_to_add"]["type"];
$DstFileName = $HTTP_POST_FILES["file_to_add"]["name"];

//check permissions
$allow_query = mysql_query("SELECT * FROM projectUsers WHERE userID = '$curr_user' AND projectID = '$curr_project'");
$allow_results = mysql_num_rows($allow_query);
if((mysql_num_rows($allow_query) > 0) || ($sess_access_level == "admin")){  //user has permission to upload file
  if($SrcPathName){
    if(!file_exists($SrcPathName)){
      $error = "ERROR: File Was Not Uploaded Correctly";
    }
    else{
      $fp = fopen($SrcPathName, "r");
      if(!$fp){
        $error = "ERROR: Cannot open uploaded file";
      }
      else{

        //ok to insert file into database
        $extension = "";
        $filename  = "";
        $filesize  = filesize($SrcPathName);
        $name_array = explode(".", $DstFileName);
        $num_str = count($name_array);
        if($num_str > 1){
          end($name_array);
          $extension = current($name_array);
          $explode_arg = ".";
          $explode_arg .= $extension;
          $just_name_array = explode($explode_arg, $DstFileName);
          $filename = $just_name_array[0];
        }
        $time = date("Y-m-d H:i:00");
        $add_result = mysql_query("INSERT INTO documents VALUES('','$curr_project','$filename','$SrcFileType','$filesize',
                                   '$curr_user','1','$time','$time','$curr_user','0','','$extension','no','$parent')");
    if(mysql_errno() == 0) {
	$fileid = mysql_insert_id();
	while(!feof($fp)) {
		$binarydata = addslashes(fread($fp,65535));

// $binarydata = mysql_escape_string(fread($fp,65535));
$SQL = "insert into document_store (masterid, filedata)";
$SQL .= " values ( " . $fileid . ", '" . $binarydata . "' )";
if(!mysql_query($SQL,$dbh)) {
$error .= "Document $DstFileName corrupted: Insert failed: " . mysql_error();
$del = "delete from documents where id=$fileid";
mysql_query($del,$dbh);
$del = "delete from document_store where masterid=$fileid";
mysql_query($del,$dbh);
} //end if
} //end while
} //end if
else {
// default: //error occurred adding file information
$error = "ERROR: File information not inserted correctly.";
$error .= "<br>" . mysql_error();
}//end else
fclose($fp);
unlink($SrcPathName);

---

The Code to get the file from the database send it to the client

// Send down the header to the client
Header ( "Content-Type: $FileObj->type" );
Header ( "Content-Length: " . $FileObj->size );
Header ( "Content-Disposition: attachment; filename=$FileObj->name.$FileObj->extension" );
Header ( "Cache-Control: private" );
// Loop thru and stream the nodes 1 by 1
for ($Z = 0 ; $Z < count($nodelist) ; $Z++) {
$SQL = "select filedata from document_store where id = " . $nodelist[$Z];
if (!$RESX = mysql_query($SQL, $linkid)) {
die("Failure to retrive file node data: " . @mysql_error());
}
$DataObj = mysql_fetch_object($RESX);
echo $DataObj->filedata;
}
}

...Any Help?

[drawmack]

there is an autonumber field in the table where you're storing the file info?

also can you post the code that fills nodelist that is important to this problem.

[mmilam]

--"there is an autonumber field in the table where you're storing the file info?"

Yes, there is an autonumber field in the table. Here is the table structure...
id: mediumint (unsigned), autoincrement
masterid: mediumint
filedata: blob

--"also can you post the code that fills nodelist that is important to this problem."

Here it is...

$nodelist = array();

// Pull file meta-data

$SQL = "select * from documents where id = " . $_GET["fileID"];

if (!$RES = mysql_query($SQL, $linkid)) {

die("Failure to retrive file metadata");

}

if (mysql_num_rows($RES) != 1) {

die("Not a valid file id!");

}

$FileObj = mysql_fetch_object($RES);

// Pull the list of file inodes

$SQL = "SELECT id FROM document_store WHERE masterid = " . $_GET["fileID"] . " order by id";

if (!$RES = mysql_query($SQL, $linkid)) {

die("Failure to retrive list of file inodes");

}

while ($CUR = mysql_fetch_object($RES)) {

$nodelist[] = $CUR->id;

}