By default, as RFC 7540 calls for, pushed stream depends on its
associated (parent) stream. There are some situations that this is
sub-optimal. For example, if associated stream is HTML, and server is
configured to push css and javascript files which are in critical
rendering path. Then the default priority scheme is sub-optimal,
since browser typically blocks rendering while waiting for critical
resources. In this case, it is better to at least give pushed stream
the same priority of associated stream, and interleave these streams.
This change gives pushed stream the same priority of associated stream
if pushed stream has content-type "application/javascript" or
"text/css". The pushed stream now depends on the stream which
associated stream depends on. We use the same weight of associated
stream.
This is required to avoid creation of temporary ImmutableString
like so:
std::string x;
ImmutableString y = ...;
StringRef ref = !x.empty() ? x : y;
First, temporary ImmutableString is created with x since
ImmutableString has constructor to accept std::string. After
StringRef gets this, the temporary ImmutableString is destroyed, and
ref has dangling pointer.
We modeled max_header_fields and header_field_buffer limit from Apache
configuration directives. In Apache, they are only applied to request
header fields, while we applied both request and response. Since
nghttpx is used as reverse proxy and backend server is relatively
"trusted", this commit removes the application to response header
fields.
This commits enables HTTP/2 server push from HTTP/2 backend to be
relayed to HTTP/2 frontend. To use this feature, --http2-bridge or
--client is required. Server push via Link header field contiues to
work.
This commit changes nghttpx's mruby script handling. Previously we
have 2 options to specify the mruby script file to be run on request
and on response. Now they are merged into 1 option, namely
--mruby-file. It now must return object. On request, the object's
on_req(env) method is invoked with env object. Similarly, on
response, the object's on_resp(env) method is invoked. The
specification of Env object has not changed.
Tatsuhiro Tsujikawa
Lucas Pardue