From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Wed, 4 Jun 2025 06:56:26 +0000 (+0300)
Subject: lib, lib-ssl-iostream: Split off o_stream_init_buffering_flush()
X-Git-Tag: 2.4.2~671
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=16f9d8128a0181aa185e1b492429d388f38a869e;p=thirdparty%2Fdovecot%2Fcore.git

lib, lib-ssl-iostream: Split off o_stream_init_buffering_flush()
---

diff --git a/src/lib-ssl-iostream/ostream-openssl.c b/src/lib-ssl-iostream/ostream-openssl.c
index fe50535376..530aa29bb2 100644
--- a/src/lib-ssl-iostream/ostream-openssl.c
+++ b/src/lib-ssl-iostream/ostream-openssl.c
@@ -217,29 +217,6 @@ static void o_stream_ssl_switch_ioloop_to(struct ostream_private *stream,
 	o_stream_switch_ioloop_to(sstream->ssl_io->plain_output, ioloop);
 }
 
-static int plain_flush_callback(struct ssl_ostream *sstream)
-{
-	struct ostream *ostream = &sstream->ostream.ostream;
-	int ret, ret2;
-
-	/* try to actually flush the pending data */
-	if ((ret = o_stream_flush(sstream->ssl_io->plain_output)) < 0)
-		return -1;
-
-	/* we may be able to copy more data, try it */
-	o_stream_ref(ostream);
-	if (sstream->ostream.callback != NULL)
-		ret2 = sstream->ostream.callback(sstream->ostream.context);
-	else
-		ret2 = o_stream_flush(&sstream->ostream.ostream);
-	if (ret2 == 0)
-		o_stream_set_flush_pending(sstream->ssl_io->plain_output, TRUE);
-	o_stream_unref(&ostream);
-	if (ret2 < 0)
-		return -1;
-	return ret > 0 && ret2 > 0 ? 1 : 0;
-}
-
 static size_t
 o_stream_ssl_get_buffer_used_size(const struct ostream_private *stream)
 {
@@ -310,10 +287,7 @@ struct ostream *openssl_o_stream_create_ssl(struct ssl_iostream *ssl_io)
 	sstream->ostream.iostream.set_max_buffer_size =
 		o_stream_ssl_set_max_buffer_size;
 
-	sstream->ostream.callback = ssl_io->plain_output->real_stream->callback;
-	sstream->ostream.context = ssl_io->plain_output->real_stream->context;
-	o_stream_set_flush_callback(ssl_io->plain_output,
-				    plain_flush_callback, sstream);
+	o_stream_init_buffering_flush(&sstream->ostream, ssl_io->plain_output);
 
 	return o_stream_create(&sstream->ostream, NULL,
 			       o_stream_get_fd(ssl_io->plain_output));
diff --git a/src/lib/ostream-private.h b/src/lib/ostream-private.h
index 6222aa08d3..b4d08f5b47 100644
--- a/src/lib/ostream-private.h
+++ b/src/lib/ostream-private.h
@@ -34,6 +34,7 @@ struct ostream_private {
 	size_t max_buffer_size;
 
 	struct ostream *parent; /* for filter streams */
+	struct ostream *buffering_parent;
 
 	int fd;
 	struct timeval last_write_timeval;
@@ -70,4 +71,12 @@ int o_stream_flush_parent_if_needed(struct ostream_private *_stream);
    copied to this stream. */
 int o_stream_flush_parent(struct ostream_private *_stream);
 
+/* ostreams that buffer data internally need to be able to continue the flush
+   after parent ostream has more space available. This function registers a
+   flush callback to the parent ostream, which triggers flushing on this
+   ostream. If the parent already had a flush callback, it gets first copied to
+   this ostream. */
+void o_stream_init_buffering_flush(struct ostream_private *_stream,
+				   struct ostream *parent);
+
 #endif
diff --git a/src/lib/ostream.c b/src/lib/ostream.c
index 11b358ff1d..55ecb8b826 100644
--- a/src/lib/ostream.c
+++ b/src/lib/ostream.c
@@ -139,6 +139,40 @@ void o_stream_close(struct ostream *stream)
 		o_stream_close_full(stream, TRUE);
 }
 
+static int o_stream_default_buffering_flush(struct ostream_private *_stream)
+{
+	struct ostream *ostream = &_stream->ostream;
+	int ret, ret2;
+
+	/* try to actually flush the pending data */
+	if ((ret = o_stream_flush(_stream->buffering_parent)) < 0)
+		return -1;
+
+	/* we may be able to copy more data, try it */
+	o_stream_ref(ostream);
+	if (_stream->callback != NULL)
+		ret2 = _stream->callback(_stream->context);
+	else
+		ret2 = o_stream_flush(ostream);
+	if (ret2 == 0)
+		o_stream_set_flush_pending(_stream->buffering_parent, TRUE);
+	o_stream_unref(&ostream);
+	if (ret2 < 0)
+		return -1;
+	return ret > 0 && ret2 > 0 ? 1 : 0;
+}
+
+void o_stream_init_buffering_flush(struct ostream_private *_stream,
+				   struct ostream *parent)
+{
+	_stream->buffering_parent = parent;
+	_stream->callback = parent->real_stream->callback;
+	_stream->context = parent->real_stream->context;
+
+	o_stream_set_flush_callback(parent, o_stream_default_buffering_flush,
+				    _stream);
+}
+
 #undef o_stream_set_flush_callback
 void o_stream_set_flush_callback(struct ostream *stream,
 				 stream_flush_callback_t *callback,
@@ -641,7 +675,7 @@ o_stream_default_set_flush_callback(struct ostream_private *_stream,
 				    stream_flush_callback_t *callback,
 				    void *context)
 {
-	if (_stream->parent != NULL)
+	if (_stream->parent != NULL && _stream->buffering_parent == NULL)
 		o_stream_set_flush_callback(_stream->parent, callback, context);
 
 	_stream->callback = callback;
@@ -734,8 +768,10 @@ o_stream_create(struct ostream_private *_stream, struct ostream *parent, int fd)
 		_stream->parent = parent;
 		o_stream_ref(parent);
 
-		_stream->callback = parent->real_stream->callback;
-		_stream->context = parent->real_stream->context;
+		if (_stream->buffering_parent == NULL) {
+			_stream->callback = parent->real_stream->callback;
+			_stream->context = parent->real_stream->context;
+		}
 		_stream->max_buffer_size = parent->real_stream->max_buffer_size;
 		_stream->error_handling_disabled =
 			parent->real_stream->error_handling_disabled;