Doc #80940 [Com]: async function addFromString work incorrect

From: Date: Mon, 26 Dec 2022 10:27:24 +0000
Subject: Doc #80940 [Com]: async function addFromString work incorrect
References: 1  Groups: php.doc.bugs 
Request: Send a blank email to doc-bugs+get-19528@lists.php.net to get a copy of this message
Edit report at https://bugs.php.net/bug.php?id=80940&edit=1

 ID:                 80940
 Comment by:         janettabloomquist at gmail dot com
 Reported by:        skuratovichalex at gmail dot com
 Summary:            async function addFromString work incorrect
 Status:             Verified
 Type:               Documentation Problem
 Package:            Zip Related
 Operating System:   Debian 9
 PHP Version:        7.4.16
 Block user comment: N
 Private report:     N

 New Comment:

Try this: onDeviceReady.then(async function () { await howManyRecords(); console.log("after
calling function records are: " + records);}.
(https://www.hebpartnernet.org/)github.com


Previous Comments:
------------------------------------------------------------------------
[2022-12-10 04:20:40] JonathanLeach at armyspy dot com

In this way, an async function without an await expression will run synchronously. If there is an
await expression inside the function body, however, the async function will always complete
asynchronously. Code after each await expression can be thought of as existing in a .then callback.

<https://www.aceflareaccount.net/>github.com

------------------------------------------------------------------------
[2021-04-08 10:45:12] cmb@php.net

> It seems that ZipArchive does not handle the case where the ZIP
> file is modified between calls to open and close.

Actually, ZipArchive does not really touch the ZIP file before
::close() is called.  Only when ::close() is called, the ZIP is
written.  This stems from the underlying libzip which is
implemented this way for performance reasons (adding individual
files to a ZIP archive would be way slower).  Thus, you can't
write to the same archive from multiple process/threads
concurrently, and this is not necessary to improve performance
anyway.

This also implies, that whenever you want to successfully add a
file to an archive, that file needs still to exist when close is
called.

I think this needs to be documented.

------------------------------------------------------------------------
[2021-04-07 19:40:39] sjoerd@php.net

As I understand it, you run the test script several times concurrently, everything seems to succeed,
except the resulting ZIP file contains less files than expected. This seems like a classic race
condition. It seems that ZipArchive does not handle the case where the ZIP file is modified between
calls to open and close. Perhaps you can use flock or similar file locking to avoid multiple
processes opening the ZIP file at the same time.

------------------------------------------------------------------------
[2021-04-07 19:08:11] skuratovichalex at gmail dot com

The following patch has been added/updated:

Patch Name: async-add-fromstring-wrong
Revision:   1617822491
URL:        https://bugs.php.net/patch-display.php?bug=80940&patch=async-add-fromstring-wrong&revision=1617822491

------------------------------------------------------------------------
[2021-04-07 19:00:44] skuratovichalex at gmail dot com

Description:
------------
The essence of the problem is that when using the ZipArchive methods asynchronously, at the output I
get the required archive, but only with the last processed file within the framework of asynchrony
(To be more precise, the archive contains N / t files, where N is the total files to be added , t is
the number of processing threads)
PS-The initial presence of the archive does not change the situation.

Example: (6 files)
https://drive.google.com/file/d/1BAHn4iSElaADwfxQ_3_ZaTOmPKvggwH6/view?usp=sharing

Test script:
---------------
//one stream
$za = new \ZipArchive();
 ($za->open($zipFile, \ZipArchive::CREATE) !== TRUE) {
      throw new \Exception('Cannot create a zip file');
 } 
$arFile = $dir . '/' . $newFileName . '.json';
$result = $za->addFromString($arFile, $stringData);
$error = $za->getStatusString( );
$arIndex = $za->locateName($arFile);
$arInfo = $za->statName($arFile);
$closeResult = $za->close();
 var_dump($error, $arIndex, $arInfo, $closeResult);

Expected result:
----------------
file2
file1
file3
file4
string(8) "No error"
int(0)
array(8) {
  ["name"]=>
  string(17) "/order/file2.json"
  ["index"]=>
  int(0)
  ["crc"]=>
  int(0)
  ["size"]=>
  int(811758)
  ["mtime"]=>
  int(1617821517)
  ["comp_size"]=>
  int(811758)
  ["comp_method"]=>
  int(0)
  ["encryption_method"]=>
  int(0)
}
bool(true)
string(8) "No error"
int(0)
array(8) {
  ["name"]=>
  string(17) "/order/file3.json"
  ["index"]=>
  int(0)
  ["crc"]=>
  int(0)
  ["size"]=>
  int(811758)
  ["mtime"]=>
  int(1617821517)                                                                                   
                                                                                                    
         
  ["comp_size"]=>                                                                      
                                                                                                    
                      
  int(811758)                                                                                       
                                                                                                    
         
  ["comp_method"]=>                                                                    
                                                                                                    
                      
  int(0)                                                                                            
                                                                                                    
         
  ["encryption_method"]=>                                                              
                                                                                                    
                      
  int(0)                                                                                            
                                                                                                    
         
}                                                                                                   
                                                                                                    
         
bool(true)                                                                                          
                                                                                                    
         
string(8) "No error"                                                                      
                                                                                                    
                   
int(0)                                                                                              
                                                                                                    
         
array(8) {
  ["name"]=>
  string(17) "/order/file4.json"
  ["index"]=>
  int(0)
  ["crc"]=>
  int(0)
  ["size"]=>
  int(811758)
  ["mtime"]=>
  int(1617821517)
  ["comp_size"]=>
  int(811758)
  ["comp_method"]=>
  int(0)
  ["encryption_method"]=>
  int(0)
}
bool(true)
string(8) "No error"
int(0)
array(8) {
  ["name"]=>
  string(17) "/order/file1.json"
  ["index"]=>
  int(0)
  ["crc"]=>
  int(0)
  ["size"]=>
  int(811758)
  ["mtime"]=>
  int(1617821517)
  ["comp_size"]=>
  int(811758)
  ["comp_method"]=>
  int(0)
  ["encryption_method"]=>
  int(0)
}
bool(true)


Actual result:
--------------
4 JSON-files in ZIP-archive.


------------------------------------------------------------------------



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Edit this bug report at https://bugs.php.net/bug.php?id=80940&edit=1


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