Add Jérémie Galarneau as co-maintainer

[babeltrace.git] / lib / iterator.c

diff --git a/lib/iterator.c b/lib/iterator.c
index 4190e65286d914021133ea110e936a27ce51c208..a2a7bb578adca29313b9bda620382bfe67b8248c 100644 (file)
--- a/lib/iterator.c
+++ b/lib/iterator.c
@@ -65,6 +65,9 @@ static int stream_read_event(struct ctf_file_stream *sin)
        ret = sin->pos.parent.event_cb(&sin->pos.parent, &sin->parent);
        if (ret == EOF)
                return EOF;
+       else if (ret == EAGAIN)
+               /* Stream is inactive for now (live reading). */
+               return EAGAIN;
        else if (ret) {
                fprintf(stderr, "[error] Reading event failed.\n");
                return ret;
@@ -73,16 +76,24 @@ static int stream_read_event(struct ctf_file_stream *sin)
 }
 
 /*
- * returns true if a < b, false otherwise.
+ * Return true if a < b, false otherwise.
+ * If time stamps are exactly the same, compare by stream path. This
+ * ensures we get the same result between runs on the same trace
+ * collection on different environments.
+ * The result will be random for memory-mapped traces since there is no
+ * fixed path leading to those (they have empty path string).
  */
 static int stream_compare(void *a, void *b)
 {
        struct ctf_file_stream *s_a = a, *s_b = b;
 
-       if (s_a->parent.real_timestamp < s_b->parent.real_timestamp)
+       if (s_a->parent.real_timestamp < s_b->parent.real_timestamp) {
                return 1;
-       else
+       } else if (likely(s_a->parent.real_timestamp > s_b->parent.real_timestamp)) {
                return 0;
+       } else {
+               return strcmp(s_a->parent.path, s_b->parent.path);
+       }
 }
 
 void bt_iter_free_pos(struct bt_iter_pos *iter_pos)
@@ -694,27 +705,21 @@ int bt_iter_init(struct bt_iter *iter,
                        for (filenr = 0; filenr < stream->streams->len;
                                        filenr++) {
                                struct ctf_file_stream *file_stream;
+                               struct bt_iter_pos pos;
 
                                file_stream = g_ptr_array_index(stream->streams,
                                                filenr);
                                if (!file_stream)
                                        continue;
-                               if (begin_pos) {
-                                       ret = babeltrace_filestream_seek(
-                                                       file_stream,
-                                                       begin_pos,
-                                                       stream_id);
-                               } else {
-                                       struct bt_iter_pos pos;
-                                       pos.type = BT_SEEK_BEGIN;
-                                       ret = babeltrace_filestream_seek(
-                                                       file_stream, &pos,
-                                                       stream_id);
-                               }
+
+                               pos.type = BT_SEEK_BEGIN;
+                               ret = babeltrace_filestream_seek(file_stream,
+                                       &pos, stream_id);
+
                                if (ret == EOF) {
                                        ret = 0;
                                        continue;
-                               } else if (ret) {
+                               } else if (ret != 0 && ret != EAGAIN) {
                                        goto error;
                                }
                                /* Add to heap */
@@ -726,7 +731,11 @@ int bt_iter_init(struct bt_iter *iter,
        }
 
        ctx->current_iterator = iter;
-       return 0;
+       if (begin_pos && begin_pos->type != BT_SEEK_BEGIN) {
+               ret = bt_iter_set_pos(iter, begin_pos);
+       }
+
+       return ret;
 
 error:
        bt_heap_free(iter->stream_heap);
@@ -795,13 +804,28 @@ int bt_iter_next(struct bt_iter *iter)
                assert(removed == file_stream);
                ret = 0;
                goto end;
+       } else if (ret == EAGAIN) {
+               /*
+                * The stream is inactive for now, we just updated the timestamp_end
+                * to skip over this stream up to a certain point in time.
+                */
+               goto reinsert;
        } else if (ret) {
                goto end;
        }
+
+reinsert:
        /* Reinsert the file stream into the heap, and rebalance. */
        removed = bt_heap_replace_max(iter->stream_heap, file_stream);
        assert(removed == file_stream);
 
+       file_stream = bt_heap_maximum(iter->stream_heap);
+       if (file_stream->pos.content_size == 0) {
+               ret = EAGAIN;
+       } else {
+               ret = 0;
+       }
+
 end:
        return ret;
 }