fix: fall back when payload compression fails

.changeset/cold-buckets-gzip.md

@@ -0,0 +1,5 @@
+---
+'posthog-php': patch
+---
+
+Fall back to uncompressed batch uploads when local gzip compression fails.

lib/Consumer/ForkCurl.php

@@ -62,14 +62,17 @@ public function flushBatch($messages)
             $cmd2 = "echo " . $payload . " | gzip > " . $tmpfname;
             exec($cmd2, $output, $exit);
 
-            if (0 != $exit) {
+            if (0 == $exit) {
+                $cmd .= " -H 'Content-Encoding: gzip'";
+                $cmd .= " --data-binary '@" . $tmpfname . "'";
+            } else {
                 $this->handleError($exit, $output);
-                return self::FLUSH_BATCH_NON_RETRYABLE_FAILURE;
+                if (is_file($tmpfname)) {
+                    unlink($tmpfname);
+                }
+                $tmpfname = "";
+                $cmd .= " -d " . $payload;
             }
-
-            $cmd .= " -H 'Content-Encoding: gzip'";
-
-            $cmd .= " --data-binary '@" . $tmpfname . "'";
         } else {
             $cmd .= " -d " . $payload;
         }

lib/Consumer/LibCurl.php

@@ -68,25 +68,34 @@ public function flushBatch($messages)
             return self::FLUSH_BATCH_NON_RETRYABLE_FAILURE;
         }
 
+        $isCompressed = false;
         if ($this->compress_request) {
-            $payload = gzencode($payload);
+            $compressedPayload = gzencode($payload);
 
-            if (false === $payload) {
-                return self::FLUSH_BATCH_NON_RETRYABLE_FAILURE;
+            if (false !== $compressedPayload) {
+                $payload = $compressedPayload;
+                $isCompressed = true;
+            } else {
+                $this->handleError(0, "Failed to gzip batch payload; sending uncompressed.");
             }
         }
 
         $shouldVerify = $this->options['verify_batch_events_request'] ?? true;
+        $requestOptions = [
+            'shouldVerify' => $shouldVerify,
+        ];
+        if ($this->compress_request) {
+            $requestOptions['compressRequest'] = $isCompressed;
+        }
+
         $response = $this->httpClient->sendRequest(
             '/batch/',
             $payload,
             [
                 // Send user agent in the form of {library_name}/{library_version} as per RFC 7231.
                 "User-Agent: {$this->userAgent()}",
             ],
-            [
-                'shouldVerify' => $shouldVerify,
-            ]
+            $requestOptions
         );
 
         if (!$shouldVerify) {

lib/Consumer/Socket.php

@@ -196,15 +196,17 @@ private function createBody($host, $content)
         // Send user agent in the form of {library_name}/{library_version} as per RFC 7231.
         $req .= "User-Agent: " . $this->userAgent() . "\r\n";
 
-        // Compress content if compress_request is true
+        // Compress content if compress_request is true. If local compression fails,
+        // keep sending the original uncompressed payload.
         if ($this->compress_request) {
-            $content = gzencode($content);
+            $compressedContent = gzencode($content);
 
-            if (false === $content) {
-                return false;
+            if (false !== $compressedContent) {
+                $content = $compressedContent;
+                $req .= "Content-Encoding: gzip\r\n";
+            } else {
+                $this->handleError(0, "Failed to gzip batch payload; sending uncompressed.");
             }
-
-            $req .= "Content-Encoding: gzip\r\n";
         }
 
         $req .= "Content-length: " . strlen($content) . "\r\n";

lib/HttpClient.php

@@ -84,7 +84,8 @@ public function __construct(
      *     shouldRetry?: bool,
      *     shouldVerify?: bool,
      *     includeEtag?: bool,
-     *     timeout?: int
+     *     timeout?: int,
+     *     compressRequest?: bool
      * } $requestOptions
      * @return HttpResponse
      */
@@ -98,6 +99,7 @@ public function sendRequest(string $path, ?string $payload, array $extraHeaders
         $shouldRetry = $requestOptions['shouldRetry'] ?? true;
         $shouldVerify = $requestOptions['shouldVerify'] ?? true;
         $includeEtag = $requestOptions['includeEtag'] ?? false;
+        $compressRequest = $requestOptions['compressRequest'] ?? $this->compressRequests;
 
         do {
             // open connection
@@ -109,7 +111,7 @@ public function sendRequest(string $path, ?string $payload, array $extraHeaders
 
             $headers = [];
             $headers[] = 'Content-Type: application/json';
-            if ($this->compressRequests) {
+            if ($compressRequest) {
                 $headers[] = 'Content-Encoding: gzip';
             }