Fix: flush stream without packet_context

Ensure we can flush a stream with only one packet if it does not have a
packet_context or the packet_size field.

Also truncate the stream to the content_size instead of the default 32kB
packet size.

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/lib/ctf-ir/stream.c b/lib/ctf-ir/stream.c
index 3348eaed057ee2b05a13b2ffa1605ab744baa8b2..cf30d09d964037749b52828cdf24b1ac17b8b558 100644 (file)
--- a/lib/ctf-ir/stream.c
+++ b/lib/ctf-ir/stream.c
@@ -1463,6 +1463,7 @@ int bt_ctf_stream_flush(struct bt_ctf_stream *stream)
        struct bt_ctf_stream_pos packet_context_pos;
        struct bt_ctf_trace *trace;
        enum bt_ctf_byte_order native_byte_order;
+       bool has_packet_size = false;
 
        if (!stream) {
                BT_LOGW_STR("Invalid parameter: stream is NULL.");
@@ -1476,19 +1477,23 @@ int bt_ctf_stream_flush(struct bt_ctf_stream *stream)
                goto end;
        }
 
-       if (stream->flushed_packet_count == 1) {
+       if (stream->packet_context) {
                struct bt_ctf_field *packet_size_field;
 
+               packet_size_field = bt_ctf_field_structure_get_field(
+                               stream->packet_context, "packet_size");
+               has_packet_size = (packet_size_field != NULL);
+               bt_put(packet_size_field);
+       }
+
+       if (stream->flushed_packet_count == 1) {
                if (!stream->packet_context) {
                        BT_LOGW_STR("Cannot flush a stream which has no packet context field more than once.");
                        ret = -1;
                        goto end;
                }
 
-               packet_size_field = bt_ctf_field_structure_get_field(
-                       stream->packet_context, "packet_size");
-               bt_put(packet_size_field);
-               if (!packet_size_field) {
+               if (!has_packet_size) {
                        BT_LOGW_STR("Cannot flush a stream which has no packet context's `packet_size` field more than once.");
                        ret = -1;
                        goto end;
@@ -1594,8 +1599,24 @@ int bt_ctf_stream_flush(struct bt_ctf_stream *stream)
                }
        }
 
+       if (!has_packet_size && stream->pos.offset % 8 != 0) {
+               BT_LOGW("Stream's packet context field type has no `packet_size` field, "
+                       "but current content size is not a multiple of 8 bits: "
+                       "content-size=%" PRId64 ", "
+                       "packet-size=%" PRIu64,
+                       stream->pos.offset,
+                       stream->pos.packet_size);
+               ret = -1;
+               goto end;
+       }
+
        assert(stream->pos.packet_size % 8 == 0);
 
+       /*
+        * Remove extra padding bytes.
+        */
+       stream->pos.packet_size = (stream->pos.offset + 7) & ~7;
+
        if (stream->packet_context) {
                /*
                 * The whole packet is serialized at this point. Make sure that,
@@ -1648,13 +1669,26 @@ int bt_ctf_stream_flush(struct bt_ctf_stream *stream)
        g_ptr_array_set_size(stream->events, 0);
        stream->flushed_packet_count++;
        stream->size += stream->pos.packet_size / CHAR_BIT;
+
+       do {
+               ret = ftruncate(stream->pos.fd, stream->size);
+       } while (ret == -1 && errno == EINTR);
+       if (ret == -1) {
+               BT_LOGE_ERRNO("Cannot ftruncate() stream file to new size",
+                               "size = %" PRIu64 ", name = %s",
+                               stream->size,
+                               stream->name ? stream->name->str : "(null)");
+       }
+
 end:
        /* Reset automatically-set fields. */
-       reset_structure_field(stream->packet_context, "timestamp_begin");
-       reset_structure_field(stream->packet_context, "timestamp_end");
-       reset_structure_field(stream->packet_context, "packet_size");
-       reset_structure_field(stream->packet_context, "content_size");
-       reset_structure_field(stream->packet_context, "events_discarded");
+       if (stream->packet_context) {
+               reset_structure_field(stream->packet_context, "timestamp_begin");
+               reset_structure_field(stream->packet_context, "timestamp_end");
+               reset_structure_field(stream->packet_context, "packet_size");
+               reset_structure_field(stream->packet_context, "content_size");
+               reset_structure_field(stream->packet_context, "events_discarded");
+       }
 
        if (ret < 0) {
                /*