Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Make language of representations consistent. #3133

Merged
merged 1 commit into from
Oct 29, 2019
Merged

Make language of representations consistent. #3133

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
95 changes: 46 additions & 49 deletions draft-ietf-quic-qpack.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -965,9 +965,8 @@ entry.

### Indexed Header Field

An indexed header field representation identifies an entry in either the static
table or the dynamic table and causes that header field to be added to the
decoded header list.
An indexed header field representation identifies an entry in the static table,
or an entry in the dynamic table with an absolute index less than the Base.
bencebeky marked this conversation as resolved.
Show resolved Hide resolved

~~~~~~~~~~ drawing
0 1 2 3 4 5 6 7
Expand All @@ -977,22 +976,18 @@ decoded header list.
~~~~~~~~~~
{: title="Indexed Header Field"}

If the entry is in the static table, or in the dynamic table with an absolute
index less than the Base, this representation starts with the '1' 1-bit pattern,
followed by the 'T' bit indicating whether the reference is into the static or
dynamic table. The 6-bit prefix integer (see {{prefixed-integers}}) that
follows is used to locate the table entry for the header field. When T=1, the
number represents the static table index; when T=0, the number is the relative
index of the entry in the dynamic table.
This representation starts with the '1' 1-bit pattern, followed by the 'T' bit
indicating whether the reference is into the static or dynamic table. The 6-bit
prefix integer (see {{prefixed-integers}}) that follows is used to locate the
table entry for the header field. When T=1, the number represents the static
table index; when T=0, the number is the relative index of the entry in the
dynamic table.


### Indexed Header Field With Post-Base Index

If the entry is in the dynamic table with an absolute index greater than or
equal to the Base, the representation starts with the '0001' 4-bit pattern,
followed by the post-base index (see {{post-base}}) of the matching header
field, represented as an integer with a 4-bit prefix (see
{{prefixed-integers}}).
An indexed header field with post-base index representation identifies an entry
in the dynamic table with an absolute index greater than or equal to the Base.

~~~~~~~~~~ drawing
0 1 2 3 4 5 6 7
Expand All @@ -1002,25 +997,17 @@ field, represented as an integer with a 4-bit prefix (see
~~~~~~~~~~
{: title="Indexed Header Field with Post-Base Index"}

This representation starts with the '0001' 4-bit pattern. This is followed by
the post-base index (see {{post-base}}) of the matching header field,
represented as an integer with a 4-bit prefix (see {{prefixed-integers}}).

### Literal Header Field With Name Reference {#literal-name-reference}

A literal header field with name reference represents a header field where the
header field name matches the header field name of an entry stored in the static
table or the dynamic table.

If the entry is in the static table, or in the dynamic table with an absolute
index less than the Base, this representation starts with the '01' two-bit
pattern.
### Literal Header Field With Name Reference {#literal-name-reference}

The following bit, 'N', indicates whether an intermediary is permitted to add
this header to the dynamic header table on subsequent hops. When the 'N' bit is
set, the encoded header MUST always be encoded with a literal representation. In
particular, when a peer sends a header field that it received represented as a
literal header field with the 'N' bit set, it MUST use a literal representation
to forward this header field. This bit is intended for protecting header field
values that are not to be put at risk by compressing them (see
{{security-considerations}} for more details).
A literal header field with name reference representation encodes a header field
where the header field name matches the header field name of an entry in the
static table, or the header field name of an entry in the dynamic table with an
absolute index less than the Base.

~~~~~~~~~~ drawing
0 1 2 3 4 5 6 7
Expand All @@ -1034,6 +1021,16 @@ values that are not to be put at risk by compressing them (see
~~~~~~~~~~
{: title="Literal Header Field With Name Reference"}

This representation starts with the '01' two-bit pattern. The following bit,
'N', indicates whether an intermediary is permitted to add this header to the
dynamic header table on subsequent hops. When the 'N' bit is set, the encoded
header MUST always be encoded with a literal representation. In particular, when
a peer sends a header field that it received represented as a literal header
field with the 'N' bit set, it MUST use a literal representation to forward this
header field. This bit is intended for protecting header field values that are
not to be put at risk by compressing them (see {{security-considerations}} for
more details).

The fourth ('T') bit indicates whether the reference is to the static or dynamic
table. The 4-bit prefix integer (see {{prefixed-integers}}) that follows is
used to locate the table entry for the header name. When T=1, the number
Expand All @@ -1047,18 +1044,9 @@ field value is encoded as an 8-bit prefix string literal (see

### Literal Header Field With Post-Base Name Reference

A literal header field with post-base name reference represents a header field
where the name matches the header field name of a dynamic table entry with an
absolute index greater than or equal to the Base.

This representation starts with the '0000' four-bit pattern. The fifth bit is
the 'N' bit as described in {{literal-name-reference}}. This is followed by a
post-base index of the dynamic table entry (see {{post-base}}) encoded as an
integer with a 3-bit prefix (see {{prefixed-integers}}).

Only the header field name is taken from the dynamic table entry; the header
field value is encoded as an 8-bit prefix string literal (see
{{string-literals}}).
A literal header field with post-base name reference representation encodes a
header field where the header field name matches the header field name of a
dynamic table entry with an absolute index greater than or equal to the Base.

~~~~~~~~~~ drawing
0 1 2 3 4 5 6 7
Expand All @@ -1072,16 +1060,20 @@ field value is encoded as an 8-bit prefix string literal (see
~~~~~~~~~~
{: title="Literal Header Field With Post-Base Name Reference"}

This representation starts with the '0000' four-bit pattern. The fifth bit is
the 'N' bit as described in {{literal-name-reference}}. This is followed by a
post-base index of the dynamic table entry (see {{post-base}}) encoded as an
integer with a 3-bit prefix (see {{prefixed-integers}}).

Only the header field name is taken from the dynamic table entry; the header
field value is encoded as an 8-bit prefix string literal (see
{{string-literals}}).


### Literal Header Field Without Name Reference

The literal header field without name reference representation encodes a header
field name and header field value as string literals.

This representation begins with the '001' three-bit pattern. The fourth bit is
the 'N' bit as described in {{literal-name-reference}}. The name follows,
represented as a 4-bit prefix string literal, then the value, represented as an
8-bit prefix string literal (see {{string-literals}}).
field name and a header field value as string literals.

~~~~~~~~~~ drawing
0 1 2 3 4 5 6 7
Expand All @@ -1097,6 +1089,11 @@ represented as a 4-bit prefix string literal, then the value, represented as an
~~~~~~~~~~
{: title="Literal Header Field Without Name Reference"}

This representation begins with the '001' three-bit pattern. The fourth bit is
the 'N' bit as described in {{literal-name-reference}}. The name follows,
represented as a 4-bit prefix string literal, then the value, represented as an
8-bit prefix string literal (see {{string-literals}}).


# Configuration

Expand Down