src.ctf.fs: implement stream indexing

[babeltrace.git] / plugins / ctf / common / notif-iter / notif-iter.h

diff --git a/plugins/ctf/common/notif-iter/notif-iter.h b/plugins/ctf/common/notif-iter/notif-iter.h
index c14146e3e297d794d3d62ee5a3738d90468feafa..444b945403e6594b38d21873def188201c307f4f 100644 (file)
--- a/plugins/ctf/common/notif-iter/notif-iter.h
+++ b/plugins/ctf/common/notif-iter/notif-iter.h
@@ -54,21 +54,24 @@ enum bt_ctf_notif_iter_medium_status {
         * The medium function called by the notification iterator
         * function reached the end of the file.
         */
-       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF =   1,
+       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF = 1,
 
        /**
         * There is no data available right now, try again later.
         */
-       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN = 11,
+       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN = 11,
+
+       /** Unsupported operation. */
+       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED = -3,
 
        /** Invalid argument. */
-       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL = -2,
+       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL = -2,
 
        /** General error. */
-       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR = -1,
+       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR = -1,
 
        /** Everything okay. */
-       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK =    0,
+       BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK = 0,
 };
 
 /**
@@ -97,6 +100,9 @@ enum bt_ctf_notif_iter_status {
        /** Invalid argument. */
        BT_CTF_NOTIF_ITER_STATUS_INVAL = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL,
 
+       /** Unsupported operation. */
+       BT_CTF_NOTIF_ITER_STATUS_UNSUPPORTED = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED,
+
        /** General error. */
        BT_CTF_NOTIF_ITER_STATUS_ERROR = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR,
 
@@ -104,6 +110,17 @@ enum bt_ctf_notif_iter_status {
        BT_CTF_NOTIF_ITER_STATUS_OK =   0,
 };
 
+/**
+ * CTF notification iterator seek operation directives.
+ */
+enum bt_ctf_notif_iter_seek_whence {
+       /**
+        * Set the iterator's position to an absolute offset in the underlying
+        * medium.
+        */
+       BT_CTF_NOTIF_ITER_SEEK_WHENCE_SET,
+};
+
 /**
  * Medium operations.
  *
@@ -181,6 +198,22 @@ struct bt_ctf_notif_iter_medium_ops {
                        size_t request_sz, uint8_t **buffer_addr,
                        size_t *buffer_sz, void *data);
 
+       /**
+        * Repositions the underlying stream's position.
+        *
+        * This *optional* method repositions the underlying stream
+        * to a given absolute or relative position, as indicated by
+        * the whence directive.
+        *
+        * @param whence        One of #bt_ctf_notif_iter_seek_whence values
+        * @param offset        Offset to use for the given directive
+        * @param data          User data
+        * @returns             One of #bt_ctf_notif_iter_medium_status values
+        */
+       enum bt_ctf_notif_iter_medium_status (* seek)(
+                       enum bt_ctf_notif_iter_seek_whence whence,
+                       off_t offset, void *data);
+
        /**
         * Returns a stream instance (weak reference) for the given
         * stream class.
@@ -308,6 +341,23 @@ BT_HIDDEN
 void bt_ctf_notif_iter_set_medops_data(struct bt_ctf_notif_iter *notit,
                void *medops_data);
 
+BT_HIDDEN
+enum bt_ctf_notif_iter_status bt_ctf_notif_iter_seek(
+               struct bt_ctf_notif_iter *notit, off_t offset);
+
+/*
+ * Get the current packet's offset in bytes relative to the media's initial
+ * position.
+ */
+BT_HIDDEN
+off_t bt_ctf_notif_iter_get_current_packet_offset(
+               struct bt_ctf_notif_iter *notit);
+
+/* Get the current packet's size (in bits). */
+BT_HIDDEN
+off_t bt_ctf_notif_iter_get_current_packet_size(
+               struct bt_ctf_notif_iter *notit);
+
 static inline
 const char *bt_ctf_notif_iter_medium_status_string(
                enum bt_ctf_notif_iter_medium_status status)