haproxy Lua support begins with Lua 5.2. In order to ease the diagnostic on
compilation error, a preprocessor error is added when an incompatible version
is used.
The compatibility is determined by the presence of LUA_VERSION_NUM and its
magic value (502 for Lua 5.2.x).
Actually, the Lua context is always initilized in each
session, even if the session doesn't use Lua. This
behavior cause 5% performances loss.
This patch initilize the Lua only if it is use by the
session. The initialization is now on demand.
The code was a bit of a pain to follow because of this, especially
when some of it heavily relies on longjmp... This refreshing makes
it slightly easier to read.
This patch provides a yield function. This function permits to
give back the hand at the HAProxy scheduler. It is used when the
lua processing consumes a lot of time.
The channel class permits manipulation of channels. A channel is
an FIFO buffer between the client and the server. This class provides
function to read, write, forward, destroy and alter data between
the input and the ouput of the buffer.
This patch adds the TCP I/O functionnality. The class implemented
provides the same functions than the "lua socket" project. This
make network compatibility with another LUA project. The documentation
is located here:
http://w3.impa.br/~diego/software/luasocket/tcp.html
This version of sleep is based on a coroutine. A sleeping
task is started and a signal is registered. This sleep version
must disapear to be replaced by a version using the internal
timers.
This patch permits to write LUA converters. Note that
all the converters declared trough LUA are automatically
prefixed by "lua.".
The Lua converters needs the current session to be executed,
but the writed and executed Lua code must be static and
contextless. The TXN object is not created for the converters.
This patch adds the browsing of all the HAProxy fetches and
create associated LUA functions. The HAProxy internal fetches
can be used in LUA trough the class "TXN".
Note that the symbols "-", "+" and "." in the name of current
sample fetch are rewrited as "_" in LUA because ".", "-" and "+"
are operators.
The shared context is a global reference dedicated to one Lua stack.
Even if the TXN is not required, the shared context it is associated
with a TXN object. In fact, the shared has no sense outside a TXN
context
This class of functions permit to access to all the functions
associated with the transaction like http header, HAProxy internal
fetches, etc ...
This patch puts the skeleton of this class. The class will be
enhanced later.
This system permits to execute some lua function after than HAProxy
complete his initialisation. These functions are executed between
the end of the configuration parsing and check and the begin of the
scheduler.
This system permits to send signals between lua tasks. A main lua stack can
register the signal in a coprocess. When the coprocess finish his job, it
send a signal, and the associated task is wakes. If the main lua execution
stack stop (with or without errors), the list or pending signals is purged.
This is the first step of the lua integration. We add the useful
files in the HAProxy project. These files contains the main
includes, the Makefile options and empty initialisation function.
Is is the LUA skeleton.
