From 72a911c11bee8a7b267814d8fc1c918acde1ea57 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Mangano-Tarumi?= <fmang@mg0.fr>
Date: Fri, 9 Nov 2018 18:00:52 -0500
Subject: [PATCH] RAII for the stream and sync states

---
 src/ogg.cc      | 22 ++++++++++++++++++++++
 src/opustags.cc |  7 -------
 src/opustags.h  | 28 ++++++++++++++++++++++++++--
 3 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/src/ogg.cc b/src/ogg.cc
index 2b67e4e..76e6cf5 100644
--- a/src/ogg.cc
+++ b/src/ogg.cc
@@ -2,6 +2,28 @@
 
 #include <cstdio>
 
+ot::ogg_reader::ogg_reader()
+{
+	ogg_sync_init(&sync);
+	memset(&stream, 0, sizeof(stream));
+}
+
+ot::ogg_reader::~ogg_reader()
+{
+	ogg_sync_clear(&sync);
+	ogg_stream_clear(&stream);
+}
+
+ot::ogg_writer::ogg_writer()
+{
+	memset(&stream, 0, sizeof(stream));
+}
+
+ot::ogg_writer::~ogg_writer()
+{
+	ogg_stream_clear(&stream);
+}
+
 int ot::write_page(ogg_page *og, FILE *stream)
 {
 	if((ssize_t) fwrite(og->header, 1, og->header_len, stream) < og->header_len)
diff --git a/src/opustags.cc b/src/opustags.cc
index fa0bde8..5e8baab 100644
--- a/src/opustags.cc
+++ b/src/opustags.cc
@@ -193,7 +193,6 @@ int main(int argc, char **argv){
         }
     }
     ot::opus_tags tags;
-    ogg_sync_init(&reader.sync);
     char *buf;
     size_t len;
     const char *error = NULL;
@@ -346,12 +345,6 @@ int main(int argc, char **argv){
         else if(packet_count >= 2) // Read-only mode
             break;
     }
-    if(packet_count >= 0){
-        ogg_stream_clear(&reader.stream);
-        if(writer.file)
-            ogg_stream_clear(&writer.stream);
-    }
-    ogg_sync_clear(&reader.sync);
     fclose(reader.file);
     if(writer.file)
         fclose(writer.file);
diff --git a/src/opustags.h b/src/opustags.h
index ae4edca..f949be2 100644
--- a/src/opustags.h
+++ b/src/opustags.h
@@ -42,13 +42,27 @@ private:
  */
 
 struct ogg_reader {
+	/**
+	 * Initialize the sync state and zero-initialize the stream. You'll need to initialize the
+	 * stream yourself once you have the serialno.
+	 */
+	ogg_reader();
+	/**
+	 * Clear all the internal memory allocated by libogg for the sync and stream state. The
+	 * page and the packet are owned by these states, so nothing to do with them.
+	 *
+	 * The input file is not closed.
+	 */
+	~ogg_reader();
 	/**
 	 * The file is our source of binary data. It is not integrated to libogg, so we need to
 	 * handle it ourselves.
 	 *
+	 * The file is not owned by the reader, you need to close it yourself when you're done.
+	 *
 	 * In the future, we should use an std::istream or something.
 	 */
-	FILE* file;
+	FILE* file = nullptr;
 	/**
 	 * The sync layer gets binary data and yields a sequence of pages.
 	 *
@@ -84,6 +98,14 @@ struct ogg_reader {
 };
 
 struct ogg_writer {
+	/**
+	 * Zeroes the stream state. You need to initialize it with the serialno.
+	 */
+	ogg_writer();
+	/**
+	 * Clears the stream state and any internal memory. Does not close the output file.
+	 */
+	~ogg_writer();
 	/**
 	 * The stream state receives packets and generates pages.
 	 *
@@ -94,8 +116,10 @@ struct ogg_writer {
 	/**
 	 * Output file. It should be opened in binary mode. We use it to write whole pages,
 	 * represented as a block of data and a length.
+	 *
+	 * The file is not owner by the writer. You need to close it yourself.
 	 */
-	FILE* file;
+	FILE* file = nullptr;
 };
 
 int write_page(ogg_page *og, FILE *stream);