Here's how it works: every frame starts with a 9-byte header, consisting of 3 bytes for the payload length, 1 byte for the frame type, 1 byte for the flags, and 4 bytes for the stream identifier plus reserved bit. This is followed by the frame payload. The HEADER frame payload starts with an additional 6-byte header consisting of 1 byte for the padding length, 4 bytes for the stream dependency plus "exclusive" bit, and 1 byte for the priority weight. These HEADERS frame headers are present in addition to the generic frame headers. So, the HEADERS stream dependency is simply a different field from the stream identifier.
On Fri, Apr 12, 2019 at 1:22 PM chirag shah <[email protected]> wrote: > > Thanks for yoru response Michael. > I am however, still missing something to understand. > You said that > "The HEADERS frame still has the same general frame header with the > stream identifier." > > But from HEADER BLOCK's size point of view we have only 9 bytes > 3 bytes for length > 1 byte for frame-type > 1 byte for frame-flags > 4 bytes for stream-identifier (including reserved bit) > > If these 4 bytes are for the *parent *stream-identifier, where will the > *current > *stream-identifier be located ? > > > > Thanks. > > On Friday, April 12, 2019 at 11:56:44 AM UTC-5, Michael Lumish wrote: >> >> The parent frame identifier, also called the stream dependency, is part >> of the HEADERS frame payload. The HEADERS frame still has the same general >> frame header with the stream identifier. >> >> On Fri, Apr 12, 2019 at 9:46 AM chirag shah <[email protected]> wrote: >> >>> Hello, >>> >>> I am seeking one clarification about the Stream-ID of the HTTP/2 >>> frame. >>> >>> As we know all frames share a common 9-byte header (as shown below), >>> which contains the length of the frame, its type, a bit field for flags, >>> and a 31-bit stream identifier. >>> However, in HEADERS frame spec, they say that this stream-identifier >>> is actually the identifier of the parent stream. A 31-bit stream >>> identifier for the stream that this stream depends on. >>> I do understand this field is only present if the PRIORITY flag is set. >>> >>> So my question is, if this 31 bits are taken up by parent stream-id >>> then where are we fitting the stream-id of this stream in question. >>> >>> >>> >>> [image: http2_frame.png] >>> >>> >>> >>> >>> >>> Thanks. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "grpc.io" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/grpc-io. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/grpc-io/cba73533-89b3-46b7-9dbd-80b182cf66e7%40googlegroups.com >>> <https://groups.google.com/d/msgid/grpc-io/cba73533-89b3-46b7-9dbd-80b182cf66e7%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- > You received this message because you are subscribed to the Google Groups " > grpc.io" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/grpc-io. > To view this discussion on the web visit > https://groups.google.com/d/msgid/grpc-io/ef1b0393-f79b-45bc-a0a8-967902ae1c49%40googlegroups.com > <https://groups.google.com/d/msgid/grpc-io/ef1b0393-f79b-45bc-a0a8-967902ae1c49%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/grpc-io. To view this discussion on the web visit https://groups.google.com/d/msgid/grpc-io/CAPK2-4d-tFyStFcU_D2OEDnWTCgDY5R%2B0hduDO1K%3D-20RyjaQQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
smime.p7s
Description: S/MIME Cryptographic Signature
