User:BDavis (WMF)/Notes/ApiUpload

What happens inside ApiUpload?

Pseudo code walkthrough from rev cd74d6228df8d93565929244c202a5682228ddeb

ApiUpload::execute()

Main body for the API event.

• die( uploaddisabled ) unless UploadBase::isEnabled()
• toggle mParams['async'] off if not globally enabled
• mParams['file'] = $_FILES['file']
• mParams['chunk'] = $_FILES['chunk']
• mParams['filekey'] = mParams['sessionkey'] unless mParams['filekey']
• try :
  • return unless self::selectUploadModule()
  • die( nomodule ) unless isset( mUpload )
• catch UploadStashException && die( stasherror )
• die( mustbeloggedin | badaccess-groups ) unless mUpload->isAllowed()
• status = mUpload->fetchFile()
• die( status->errors[0] ) unless status->isGood()
• if mParams['chunk'] :
  • die( file-too-large ) if mParams['filesize'] > mUpload->getMaxUploadSize()
  • die( internal-error ) unless mUpload->getTitle()
  • self::verifyUpload() unless ( mParams['async'] && mParams['filekey'] )
• unless mParams['stash'] :
  • die(filename) unless mUpload->verifyTitlePermissions()
• try :
  • cr = self::getContextResult()
  • if cr['result'] === 'Success' :
    • cr['imageinfo'] = mUpload->getImageInfo()
• catch UploadStashException && die( stasherror )
• getResult()->addValue(cr)
• mUpload->cleanupTempFile()

ApiUpload::selectUploadModule()

Pick appropriate UploadBase child class to handle consuming this request.

• die( invalidparammix | missingparam ) unless ( mParams['chunk'] | mParams['filekey'] | mParams['file'] | mParams['url'] | mParams['statuskey'] )
• if mParams['checkstatus'] : # check stash status
  • add progress message to result
  • return false
• if mParams['statuskey'] : # check async upload status
  • sessionData = $_SESSION['wsUploadFromUrlJobData'][ mParams['statuskey'] ]
  • die( missingresult ) unless sessionData['result']
  • add sessionData to result
  • return false
• die( missingparam ) unless mParams['filename']
• if mParams['chunk'] :
  • mUpload = new UploadFromChunks
  • mParams['filekey'] ? mUpload->continueChunks() : mUpload->initialize()
• if mParams['filekey'] :
  • die( invalid-file-key ) unless UploadFromStash::isValidKey()
  • mUpload = new UploadFromStash
  • mUpload->initialize()
• if mParams['file'] :
  • mUpload = new UploadFromFile
  • mUpload->initialize()
• if mParams['url'] :
  • die( copyuploaddisabled ) unless UploadFromUrl::isEnabled()
  • die( copyuploadbaddomain ) unless UploadFromUrl::isAllowedHost()
  • die( copyuploadbadurl ) unless UploadFromUrl::isAllowedUrl()
  • if mParams['asyncdownload'] :
    • die( asynccopyuploaddisabled ) unless $wgAllowAsyncCopyUploads
    • die( missing-ignorewarnings ) if mParams['leavemessage'] && !mParams['ignorewarnings']
    • mUpload = new UploadFromUrl
    • mUpload->initialize()
• return true

ApiUpload::verifyUpload()

Verify the sanity of the upload via currently selected UploadBase child class

• v = mUpload->verifyUpload() # TODO follow this on down
• return if v === UploadBase::OK
• die( various ) # based on v['status'] value

ApiUpload::getContextResult()

Get the result of upload request based on request parameters and system status

• w = self::getApiWarnings()
• if ( w && !mParams['ignorewarnings']) :
  • return self::getWarningsResult()
• elif mParams['chunk']
  • self::getChunkResult()
• elif mParams['stash']
  • self::getStashResult()
• return self::performUpload()

ApiUpload::getChunkResult()

Get the result of a chunked upload request.

On receipt of final chunk this will queue assemble job of an async request or assemble inline otherwise.

• result['result'] = 'Continue'
• result['warnings'] = warnings if warnings
• if mParams['offset'] == 0 :
  • try :
    • filekey = self::performStash()
  • catch MWException && die( stashfailed ) #<-- Has FIXME from csteipp for differing error handling
• else :
  • die( stashfailed ) unless mUpload->addChunk()
• if final chunk added :
  • if mParams['async'] :
    • die( stashfailed ) if UploadBase::getSessionStatus() === 'Poll'
    • die( stashfailed ) unless JobQueue->push( new AssembleUploadChunksJob )
  • else : # not async
    • die( stashfailed ) unless mUpload->concatenateChunks()->isGood()
  • remove filekey from mUpload->stash
  • filekey = FileKey for LocalFile
  • result['result'] = 'Success'
• result['filekey'] = filekey
• result['offset'] = mParams['offset'] + chunkSize
• return result