libobs/util: Add buffered file serializer

Adapted from 898256d

Co-authored-by: Richard Stanway <[email protected]>

docs/sphinx/reference-libobs-util-serializers.rst

@@ -181,3 +181,44 @@ File Output Serializer Functions
 .. function:: void file_output_serializer_free(struct serializer *s)
 
  Frees the file output serializer and saves the file.
+
+---------------------
+
+Buffered File Output Serializer
+===============================
+
+Provides a buffered file serializer that writes data asynchronously to prevent stalls due to slow disk I/O.
+
+Writes will only block when the buffer is full.
+
+The buffer and chunk size are configurable with the defaults being 256 MiB and 1 MiB respectively.
+
+.. versionadded:: 30.2
+
+.. code:: cpp
+
+ #include <util/buffered-file-serializer.h>
+
+
+Buffered File Output Serializer Functions
+-----------------------------------------
+
+.. function:: bool buffered_file_serializer_init_defaults(struct serializer *s, const char *path)
+
+ Initializes a buffered file output serializer with default buffer and chunk sizes.
+
+ :return: *true* if file created successfully, *false* otherwise
+
+---------------------
+
+.. function:: bool buffered_file_serializer_init(struct serializer *s, const char *path, size_t max_bufsize, size_t chunk_size)
+
+ Initialize buffered writer with specified buffer and chunk sizes. Setting either to `0` will use the default value.
+
+ :return: *true* if file created successfully, *false* otherwise
+
+---------------------
+
+.. function:: void buffered_file_serializer_free(struct serializer *s)
+
+ Frees the file output serializer and saves the file. Will block until I/O thread completes outstanding writes.

libobs/CMakeLists.txt

@@ -99,6 +99,8 @@ target_sources(
  util/bitstream.h
  util/bmem.c
  util/bmem.h
+ util/buffered-file-serializer.c
+ util/buffered-file-serializer.h
  util/c99defs.h
  util/cf-lexer.c
  util/cf-lexer.h