- Get rid of support for these callbacks in http_parser_settings.
- Retain state transitions between different URL portions in
http_parser_execute() so that we're making the same correctness
guarantees as before.
- These are being removed because making multiple callbacks for the same
byte makes it more difficult to pause the parser.
- Add http_errno enum w/ values for many parsing error conditions. Stash
this in http_parser.state if the 0x80 bit is set.
- Report line numbers on error generation if the (new) HTTP_PARSER_DEBUG
cpp symbol is set. Increases http_parser struct size by 8 bytes in
this case.
- Add http_errno_*() methods to help turning errno values into
human-readable messages.
This also fixes test failures from the previous commit.
It also adds support for the LOCK method, which was previously
missing.
This brings the size of http_parser from 44 bytes to 32 bytes. It
also makes the code substantially shorter, at a slight cost in
craziness.
This saves space in the structure (it is now 28 bytes on x86), and
makes the handling of content_length more consistent between chunked
encoding and non-chunked-encoding.
The *_mark members were actually being used as just boolean values to
the next call of the parser. However, you can calculate if the mark
members should be set or not purely based on the current state, so
they can just be gotten rid of entirely.
This is mostly done by using sized types instead of enums, and
reordering fields to allow better packing.
I also moved the 'upgrade' field out of the PRIVATE section and into
the READ-ONLY section, as I believe that it is supposed to be
non-private.
This does have some slight functional changes in cases where
MAX_FIELD_SIZE is hit, specficially if a URL is made up of many
components, each of which is smaller than MAX_FIELD_SIZE, but the
total together is greater than MAX_FIELD_SIZE, then we now might not
call callbacks for any of the components (even the ones that are
smaller than 80kb). With the old code, it was possible to get a
callback for query_string and never get a callback for the URL (or at
least the end of the URL that is past 80kb), if the callback for the
URL would have been larger than 80kb.
(to be honest, I'm surprised that the MAX_FIELD_SIZE is implemented in
http_parser at all, instead of requiring that callers pay attention to
it, as it feels like it should be the caller's responsibility)
That is, for a request parser do this:
http_parser_init(my_parser, HTTP_REQUEST)
for a response parser do this:
http_parser_init(my_parser, HTTP_RESPONSE)
Then http_parse_requests() and http_parse_responses() both turn
into http_parer_execute().
This sacrifices
- a little space (10 bytes),
- a few extra calculations, and
- introduces a dependency on strncmp()
to dramatically simplify the code of parsing methods and support almost
arbitrary extension methods.
In the future I will do as NGINX does and not use strncmp but bit level
blob comparisons.
Ryan Dahl
Ben Noordhuis
Fouad Mardini
Peter Griess
Nathan Rajlich
Aman Gupta
Ewen Cheslack-Postava
Cliff Frey