The HTTP layer used to make a copy of each incoming header and its
value for a request. Stop doing that and make HTTP headers zero-copy
all across the board.
This change comes with some api function changes, notably the
http_request_header() function which now takes a const char ** rather
than a char ** out pointer.
This commit also constifies several members of http_request, beware.
Additional rework how the worker processes deal with the accept lock.
Before:
if a worker held the accept lock and it accepted a new connection
it would release the lock for others and back off for 500ms before
attempting to grab the lock again.
This approach worked but under high load this starts becoming obvious.
Now:
- workers not holding the accept lock and not having any connections
will wait less long before returning from kore_platform_event_wait().
- workers not holding the accept lock will no longer blindly wait
an arbitrary amount in kore_platform_event_wait() but will look
at how long until the next lock grab is and base their timeout
on that.
- if a worker its next_lock timeout is up and failed to grab the
lock it will try again in half the time again.
- the worker process holding the lock will when releasing the lock
double check if it still has space for newer connections, if it does
it will keep the lock until it is full. This prevents the lock from
bouncing between several non busy worker processes all the time.
Additional fixes:
- Reduce the number of times we check the timeout list, only do it twice
per second rather then every event tick.
- Fix solo worker count for TLS (we actually hold two processes, not one).
- Make sure we don't accidentally miscalculate the idle time causing new
connections under heavy load to instantly drop.
- Swap from gettimeofday() to clock_gettime() now that MacOS caught up.
- Change pools to use mmap() for allocating regions.
- Change kore_malloc() to use pools for commonly sized objects.
(split into multiple of 2 buckets, starting at 8 bytes up to 8192).
- Rename kore_mem_free() to kore_free().
The preallocated pools will hold up to 128K of elements per block size.
In case a larger object is to be allocated kore_malloc() will use
malloc() instead.
This commit is a flag day, your old modules will almost certainly
need to be updated in order to build properly with these changes.
Summary of changes:
- Offload HTTP bodies to disk if they are large (inspired by #100).
(disabled by default)
- The http_argument_get* macros now takes an explicit http_request parameter.
- Kore will now throw 404 errors almost immediately after an HTTP request
has come in instead of waiting until all data has arrived.
API changes:
- http_argument_get* macros now require an explicit http_request parameter.
(no more magic invokations).
- http_generic_404() is gone
- http_populate_arguments() is gone
- http_body_bytes() is gone
- http_body_text() is gone
- http_body_read() has been added
- http_populate_post() has been added
- http_populate_get() has been added
- http_file_read() has been added
- http_file_rewind() has been added
- http_file_lookup() no longer takes name, fname, data and len parameters.
- http_file_lookup() now returns a struct http_file pointer.
- http_populate_multipart_form() no longer takes an secondary parameter.
New configuration options:
- http_body_disk_offload:
Number of bytes after which Kore will offload the HTTP body to
disk instead of retaining it in memory. If 0 this feature is
disabled. (Default: 0)
- http_body_disk_path:
The path where Kore will store temporary HTTP body files.
(this directory does not get created if http_body_disk_offload is 0).
New example:
The upload example has been added, demonstrating how to deal with file
uploads from a multipart form.
request can be used for when you want to validate something for
authentication bmanually. Youur validator will receive the http_reques
passed down.
A practical use of this is doing IP based ACL's.
Using authentication blocks one can define "authentication" mechanisms
in Kore for page handlers.
This can be used to require a session cookie (validated by your own validator)
for certain page handlers, and hopefully in the future provide a framework
for adding more authentication things (like HTTP Auth).
Right now only cookie checking is available.
Joris Vink
Frederic Cambus