File buf.h is one common cause of pain in the dependencies. Many files in
the code need it to get the struct buffer definition, and a few also need
the inlined functions to manipulate a buffer, but the file used to depend
on a long chain only for BUG_ON() (addressed by last commit).
Now buf.h is split into buf-t.h which only contains the type definitions,
and buf.h for all inlined functions. Callers who don't care can continue
to use buf.h but files in types/ must only use buf-t.h. sys/types.h had
to be added to buf.h to get ssize_t as used by b_move(). It's worth noting
that ssize_t is only supposed to be a size_t supporting -1, so b_move()
ought to be rethought regarding this.
The files were moved to haproxy/ and all their users were updated
accordingly. A dependency issue was addressed on fcgi whose C file didn't
include buf.h.
Fortunately that file wasn't made dependent upon haproxy since it was
integrated, better isolate it before it's too late. Its dependency on
api.h was the result of the change from config.h, which in turn wasn't
correct. It was changed back to stddef.h for size_t and sys/types.h for
ssize_t. The recently added reference to MAX() was changed as it was
placed only to avoid a zero length in the non-free-standing version and
was causing a build warning in the hpack encoder.
All files that were including one of the following include files have
been updated to only include haproxy/api.h or haproxy/api-t.h once instead:
- common/config.h
- common/compat.h
- common/compiler.h
- common/defaults.h
- common/initcall.h
- common/tools.h
The choice is simple: if the file only requires type definitions, it includes
api-t.h, otherwise it includes the full api.h.
In addition, in these files, explicit includes for inttypes.h and limits.h
were dropped since these are now covered by api.h and api-t.h.
No other change was performed, given that this patch is large and
affects 201 files. At least one (tools.h) was already freestanding and
didn't get the new one added.
I found on an (old) AIX 5.1 machine that stdint.h didn't exist while
inttypes.h which is expected to include it does exist and provides the
desired functionalities.
As explained here, stdint being just a subset of inttypes for use in
freestanding environments, it's probably always OK to switch to inttypes
instead:
https://pubs.opengroup.org/onlinepubs/009696799/basedefs/stdint.h.html
Also it's even clearer here in the autoconf doc :
https://www.gnu.org/software/autoconf/manual/autoconf-2.61/html_node/Header-Portability.html
"The C99 standard says that inttypes.h includes stdint.h, so there's
no need to include stdint.h separately in a standard environment.
Some implementations have inttypes.h but not stdint.h (e.g., Solaris
7), but we don't know of any implementation that has stdint.h but not
inttypes.h"
The new function hpack_encode_path() supports encoding a path into
the ":path" header. It knows about "/" and "/index.html" which use
a single byte, and falls back to literal encoding for other ones,
with a fast path for short paths < 127 bytes.
The new function hpack_encode_scheme() supports encoding a scheme
into the ":scheme" header. It knows about "https" and "http" which use
a single byte, and falls back to literal encoding for other ones.
The new function hpack_encode_method() supports encoding a method.
It knows about GET and POST which use a single byte, and falls back
to literal encoding for other ones.
This header exists with 7 different values, it's worth taking them
into account for the encoding, hence these functions. One of them
makes use of an integer only and computes the 3 output bytes in case
of literal. The other one benefits from the knowledge of an existing
string, which for example exists in the case of H1 to H2 encoding.
For long header values whose index is known, hpack_encodde_long_idx()
may now be used. This function emits the short index and follows with
the header's value.
Most direct calls to HPACK functions are made to encode short header
fields like methods, schemes or statuses, whose lengths and indexes
are known. Let's have a small function to do this.
We'll need these functions from other inline functions, let's make them
accessible. len_to_bytes() was renamed to hpack_len_to_bytes() since it's
now exposed.
Now all the code used to manipulate chunks uses a struct buffer instead.
The functions are still called "chunk*", and some of them will progressively
move to the generic buffer handling code as they are cleaned up.
For now it only supports literals and a bit of static header table
references for the 9 most common header field names (date, server,
content-type, content-length, last-modified, accept-ranges, etag,
cache-control, location).
A previous incarnation of this commit used to strip the forbidden H2
header names (connection, proxy-connection, upgrade, transfer-encoding,
keep-alive) but this is no longer the case as this filtering is irrelevant
to HPACK encoding and is specific to H2, so this will have to be done by
the caller.
It's quite not optimal but works fine enough to prepare some valid and
partially compressed responses during development.
