expose rd_kafka_global_init (#515)

* expose rd_kafka_global_init

* fix patch reference

Author: mensfeld

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Rdkafka Changelog
 
+## 0.19.1 (Unreleased)
+- [Enhancement] Expose `rd_kafka_global_init` to mitigate macos forking issues.
+
 ## 0.19.0 (2024-10-01)
 - **[Breaking]** Drop Ruby 3.0 support
 - [Enhancement] Update `librdkafka` to `2.5.3`

dist/patches/rdkafka_global_init.patch

@@ -0,0 +1,15 @@
+# This patch is released under the 2-clause BSD license, same as librdkafka
+#
+--- librdkafka_2.5.3/src/rdkafka.h
++++ librdkafka_2.5.3/src/rdkafka.h
+@@ -1101,6 +1101,10 @@ rd_kafka_topic_partition_t *rd_kafka_topic_partition_list_find(
+     const char *topic,
+     int32_t partition);
+ 
++/**
++ * @brief Allows for the global init of rdkafka when required in the Ruby process.
++ */
++RD_EXPORT void rd_kafka_global_init(void);
+ 
+ /**
+  * @brief Sort list using comparator \p cmp.

lib/rdkafka.rb

@@ -49,3 +49,5 @@
 # Main Rdkafka namespace of this gem
 module Rdkafka
 end
+
+Rdkafka::Bindings.rd_kafka_global_init

lib/rdkafka/bindings.rb

@@ -30,6 +30,11 @@ class SizePtr < FFI::Struct
       layout :value, :size_t
     end
 
+    # This function comes from our patch on top of librdkafka. It allows os to load all the
+    # librdkafka components without initializing the client
+    # @see https://github.com/confluentinc/librdkafka/issues/4590
+    attach_function :rd_kafka_global_init, [], :void
+
     # Polling
 
     attach_function :rd_kafka_flush, [:pointer, :int], :int, blocking: true

lib/rdkafka/version.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module Rdkafka
-  VERSION = "0.19.0"
+  VERSION = "0.19.1"
   LIBRDKAFKA_VERSION = "2.5.3"
   LIBRDKAFKA_SOURCE_SHA256 = "eaa1213fdddf9c43e28834d9a832d9dd732377d35121e42f875966305f52b8ff"
 end