@@ -844,6 +844,109 @@ int odp_packet_concat(odp_packet_t *dst, odp_packet_t src);
*/
int odp_packet_split(odp_packet_t *pkt, uint32_t len, odp_packet_t *tail);
+/**
+ * Splice a packet
+ *
+ * Create a new packet by splicing a header onto an existing packet. The
+ * spliced packet consists of the header followed by a shared reference to the
+ * base packet receiving the splice starting at a designated offset. If
+ * multiple splices are created on the same base packet, it is the
+ * application's responsibility to coordinate any changes to the shared
+ * segment(s) of the splice, otherwise results are undefined.
+ *
+ * @param hdr Handle of the header packet to be spliced onto the base packet
+ *
+ * @param pkt Handle of the base packet that is to receive the splice
+ *
+ * @param offset Byte offset within the base packet at which the splice is
+ * to be made.
+ *
+ * @return Handle of the spliced packet. This may or may not be the
+ * same as the input hdr packet. The caller should use this
+ * for any future references to the splice. The original hdr
+ * packet no longer has any independent existence.
+ *
+ * @retval ODP_PACKET_INVALID If the splice failed. In this case both hdr
+ * and pkt are unchanged.
+ *
+ * @note The base pkt remains valid after the completion of the splice,
+ * however changes that affect its length may yield unpredictable
+ * results when viewed through the returned splice handle. For best
+ * portability and predictable behavior, applications should regard the
+ * base packet as read only following a successful splice, with the
+ * exception of tailroom manipulation (which still requires application
+ * coordination if multiple splices exist on the same base packet whose
+ * tail is being pushed or pulled).
+ *
+ * @note Either packet input to this routine may itself be a splice, however
+ * individual implementations may impose limits on how deeply splices
+ * may be nested and fail the attempted splice if those limits are
+ * exceeded.
+ *
+ * @note The packets used to create a splice may reside in different pools,
+ * however individual implementations may require that both reside in
+ * the same pool and fail the attempted splice if this restriction is
+ * not observed. Upon return odp_packet_pool() returns the pool id of
+ * the header packet.
+ *
+ * @note Once successfully spliced, the base packet may be freed via
+ * odp_packet_free(), however the storage used to represent it will not
+ * be released until all splices based on it have themselves been freed.
+ */
+odp_packet_t odp_packet_splice(odp_packet_t hdr,
+ odp_packet_t pkt, uint32_t offset);
+
+/**
+ * Create a reference to a packet
+ *
+ * Create a (shared) reference to a base packet starting at a specified
+ * byte offset. A reference is simply a splice with a zero-length header.
+ *
+ * @param pkt Handle of the base packet for which a reference is to be
+ * created.
+ * @param offset Byte offset in the base packet at which shared reference is
+ * to begin.
+ *
+ * @return Handle of the reference packet
+ * @retval ODP_PACKET_INVALID Operation failed. Base packet remains unchanged.
+ *
+ * @note The zero-length header used to create a packet reference is always
+ * drawn from the same pool as the base packet.
+ *
+ * @note Because references are a type of splice, any bytes pushed onto the
+ * head of a reference (via odp_packet_push_head() or
+ * odp_packet_extend_head() are unique to this reference and are not
+ * seen by any other reference to the same base packet.
+ */
+odp_packet_t odp_packet_ref(odp_packet_t pkt, uint32_t offset);
+
+/**
+ * Tests if a packet is a splice
+ *
+ * A packet is a splice if it was created by odp_packet_splice() or
+ * odp_packet_ref(). Note that a splice may be a simple splice or a
+ * compound splice (a splice created from another splice).
+ *
+ * @param pkt Packet Handle
+ *
+ * @retval 0 Packet is not a splice
+ * @retval >0 Packet is a splice containing N individual packets
+ */
+int odp_packet_is_a_splice(odp_packet_t pkt);
+
+/**
+ * Tests if a packet is spliced
+ *
+ * A packet is spliced if a splice was created on it by odp_packet_splice()
+ * or odp_packet_ref().
+ *
+ * @param pkt Packet Handle
+ *
+ * @retval 0 Packet is not spliced
+ * @retval >0 Packet has N splices based on it
+ */
+int odp_packet_is_spliced(odp_packet_t pkt);
+
/*
*
* Copy
Introduce four new APIs that support efficient sharing of portions of packets. odp_packet_splice() creates a reference to a base packet by splicing a supplied header packet onto it at a specified offset. If multiple splices are created then each shares the base packet that was spliced. odp_packet_ref() creates a reference to a base packet by splicing a zero-length header onto it at a specified offset. This allows an application to "hold onto" a pointer to a packet so that it will not be freed until all references to it are freed. odp_packet_is_a_splice() allows an application to determine whether a packet is a splice and if so how many individual packets are contained within it. odp_packet_is_spliced() allows an application to determine whether a packet has a splice on it and if so how many splices are based on it. Signed-off-by: Bill Fischofer <bill.fischofer@linaro.org> --- include/odp/api/spec/packet.h | 103 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) -- 2.7.4