Rearrange a paragraph and add some headings, so that the next patch adding a Structured Reply has less churn.
Signed-off-by: Eric Blake <[email protected]> --- doc/proto.md | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/doc/proto.md b/doc/proto.md index 04d4a13..c1e05c5 100644 --- a/doc/proto.md +++ b/doc/proto.md @@ -182,8 +182,22 @@ required to. ### Transmission -There are two message types in the transmission phase: the request, and -the response. +There are two message types in the transmission phase: the request, +and the reply. The phase consists of a series of transactions, where +the client submits requests and the server sends corresponding +replies, with a single reply message per request, and continues until +either side closes the connection. + +Replies need not be sent in the same order as requests (i.e., requests +may be handled by the server asynchronously). Clients SHOULD use a +handle that is distinct from all other currently pending transactions, +but MAY reuse handles that are no longer in flight; handles need not +be consecutive. In each reply, the server MUST use the same value for +handle as was sent by the client in the corresponding request. In +this way, the client can correlate which request is receiving a +response. + +#### Request message The request message, sent by the client, looks as follows: @@ -195,6 +209,8 @@ C: 64 bits, offset (unsigned) C: 32 bits, length (unsigned) C: (*length* bytes of data if the request is of type `NBD_CMD_WRITE`) +#### Reply message + The server replies with: S: 32 bits, 0x67446698, magic (`NBD_REPLY_MAGIC`) @@ -202,15 +218,6 @@ S: 32 bits, error S: 64 bits, handle S: (*length* bytes of data if the request is of type `NBD_CMD_READ`) -Replies need not be sent in the same order as requests (i.e., requests -may be handled by the server asynchronously). Clients SHOULD use a -handle that is distinct from all other currently pending transactions, -but MAY reuse handles that are no longer in flight; handles need not -be consecutive. In each reply, the server MUST use the same value for -handle as was sent by the client in the corresponding request. In -this way, the client can correlate which request is receiving a -response. - ## Values This section describes the value and meaning of constants (other than -- 2.5.5 ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785471&iu=/4140 _______________________________________________ Nbd-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/nbd-general
