Check if there would be any attachments/samples in the contest samples.zip

We always try to exit early and skip the actual adding. As checking and
creation are more or less the same code we wrap the check inside the actual
creation to prevent duplication.

Author: vmcj

webapp/src/Service/DOMJudgeService.php

@@ -830,7 +830,7 @@ public function getSamplesZipContent(ContestProblem $contestProblem): string
         return $zipFileContents;
     }
 
-    protected function addSamplesToZip(ZipArchive $zip, ContestProblem $problem, ?string $directory = null): void
+    protected function addSamplesToZip(?ZipArchive $zip, ContestProblem $problem, ?string $directory = null, bool $fullZip = true): bool
     {
         /** @var Testcase[] $testcases */
         $testcases = $this->em->createQueryBuilder()
@@ -849,6 +849,9 @@ protected function addSamplesToZip(ZipArchive $zip, ContestProblem $problem, ?st
             ->getResult();
 
         foreach ($testcases as $index => $testcase) {
+            if (!$fullZip) {
+                return true;
+            }
             foreach (['input', 'output'] as $type) {
                 $extension = Testcase::EXTENSION_MAPPING[$type];
 
@@ -870,6 +873,7 @@ protected function addSamplesToZip(ZipArchive $zip, ContestProblem $problem, ?st
                 $zip->addFromString($filename, $content);
             }
         }
+        return false;
     }
 
     public function getSamplesZipStreamedResponse(ContestProblem $contestProblem): StreamedResponse
@@ -879,7 +883,7 @@ public function getSamplesZipStreamedResponse(ContestProblem $contestProblem): S
         return Utils::streamAsBinaryFile($zipFileContent, $outputFilename, 'zip');
     }
 
-    public function getSamplesZipForContest(Contest $contest): StreamedResponse
+    public function helperSamplesZipForContest(Contest $contest, bool $fullZip): StreamedResponse|bool
     {
         // Note, we reload the contest with the problems and attachments, to reduce the number of queries
         // We do not load the testcases here since addSamplesToZip loads them
@@ -896,30 +900,42 @@ public function getSamplesZipForContest(Contest $contest): StreamedResponse
             ->getQuery()
             ->getSingleResult();
 
-        $zip = new ZipArchive();
-        if (!($tempFilename = tempnam($this->getDomjudgeTmpDir(), "export-"))) {
-            throw new ServiceUnavailableHttpException(null, 'Could not create temporary file.');
-        }
+        $zip = null;
+        if ($fullZip) {
+            $zip = new ZipArchive();
+            if (!($tempFilename = tempnam($this->getDomjudgeTmpDir(), "export-"))) {
+                throw new ServiceUnavailableHttpException(null, 'Could not create temporary file.');
+            }
 
-        $res = $zip->open($tempFilename, ZipArchive::OVERWRITE);
-        if ($res !== true) {
-            throw new ServiceUnavailableHttpException(null, 'Could not create temporary zip file.');
+            $res = $zip->open($tempFilename, ZipArchive::OVERWRITE);
+            if ($res !== true) {
+                throw new ServiceUnavailableHttpException(null, 'Could not create temporary zip file.');
+            }
         }
 
         /** @var ContestProblem $problem */
         foreach ($contest->getProblems() as $problem) {
             // We don't include the samples for interactive problems.
             if (!$problem->getProblem()->isInteractiveProblem()) {
-                $this->addSamplesToZip($zip, $problem, $problem->getShortname());
+                $samplesFound = $this->addSamplesToZip($zip, $problem, $problem->getShortname(), fullZip: $fullZip);;
+                if (!$fullZip && $samplesFound) {
+                    return true;
+                }
             }
 
             if ($problem->getProblem()->getProblemstatementType()) {
+                if (!$fullZip) {
+                    return true;
+                }
                 $filename    = sprintf('%s/statement.%s', $problem->getShortname(), $problem->getProblem()->getProblemstatementType());
                 $zip->addFromString($filename, $problem->getProblem()->getProblemstatement());
             }
 
             /** @var ProblemAttachment $attachment */
             foreach ($problem->getProblem()->getAttachments() as $attachment) {
+                if (!$fullZip) {
+                    return true;
+                }
                 $filename = sprintf('%s/attachments/%s', $problem->getShortname(), $attachment->getName());
                 $zip->addFromString($filename, $attachment->getContent()->getContent());
                 if ($attachment->getContent()->isExecutable()) {
@@ -934,17 +950,34 @@ public function getSamplesZipForContest(Contest $contest): StreamedResponse
         }
 
         if ($contest->getContestProblemsetType()) {
+            if (!$fullZip) {
+                return true;
+            }
             $filename = sprintf('contest.%s', $contest->getContestProblemsetType());
             $zip->addFromString($filename, $contest->getContestProblemset());
         }
 
+        if (!$fullZip) {
+            return false;
+        }
+
         $zip->close();
         $zipFileContents = file_get_contents($tempFilename);
         unlink($tempFilename);
 
         return Utils::streamAsBinaryFile($zipFileContents, 'samples.zip', 'zip');
     }
 
+    public function checkIfSamplesZipForContest(Contest $contest): bool
+    {
+        return self::helperSamplesZipForContest($contest, fullZip: false);
+    }
+
+    public function getSamplesZipForContest(Contest $contest): StreamedResponse
+    {
+        return self::helperSamplesZipForContest($contest, fullZip: true);
+    }
+
     /**
      * @throws NonUniqueResultException
      */