Note: This change log is incomplete. I started it quite late, as interest in the libraries started to warrant better documentation of any changes made.
Although the libraries in this repo are designed to work together, they are also designed to work separately. Hence, the change logs for each library are managed separately. Here are the different libraries and changes:
Lib-React (libreact) - The Reactor library.
Lib-Sock (libsock) - The socket helper library (development incomplete).
Lib-Async (libasync) - The thread pool and tasking library.
Lib-Server (libserver) - The server writing library.
MiniCrypt (minicrypt) - Common simple crypto library (development incomplete).
HTTP Protocol (http) - including request and response helpers, etc'.
Websocket extension (websockets) - Websocket Protocol for the basic HTTP implementation provided.
Changes I plan to make in future versions:
Implement a Server.connect for client connections and a Websocket client implementation.
Implement Websocket writing using libsock packets instead of malloc.
Remove / fix server task container pooling (FDTask and GroupTask pools).
I attempt to follow semantic versioning, except that the libraries are still under pre-release development, so version numbers get updated only when a significant change occurs or API breaks.
Libraries with versions less then 0.1.0 have missing features (i.e. mini-crypt is missing almost everything except what little published functions it offers).
Minor bug fixes, implementation optimizations etc' might not prompt a change in version numbers (not even the really minor ones).
API breaking changes always cause version bumps (could be a tiny version bump for tiny API changes).
Git commits aren't automatically tested yet and they might introduce new issues or break existing code (I use Git also for backup purposes)...
... In other words, since these libraries are still in early development, test before adopting any updates.
Rewrite from core. The code is (I think) better organized.
Different API.
The reactor is now stateless instead of an object. All state data (except the reactor‘s ID, which remains static throughout during it’s existence), is managed by the OS implementation (kqueue/epoll).
Callbacks are statically linked instead of dynamically assigned.
Better integration with libsock.
(optional) Handles libsock's UUID instead of direct file descriptors, preventing file descriptor collisions.
libsock, where the sock_flush wasn't automatically called due to inline function optimizations used by the compiler (and my errant code).Baseline (changes not logged before this point in time).
Huge rewrite. Different API.
Uses connection UUIDs instead of direct file descriptors, preventing file descriptor collisions. Note that the UUIDs aren't random and cannot be used to identify the connections across machines or processes.
No global lock, spin-lock oriented design.
Better (optional) integration with libreact.
libsock experienced minor API changes, specifically to the init_socklib function (which now accepts 0 arguments).
The rw_hooks now support a flush callback for hooks that keep an internal buffer. Implementing the flush callback will allow these callbacks to prevent a pre-mature closure of the socket stream and ensure that all the data will be sent.
Added the client implementation (sock_connect).
Rewrote the whole library to allow for a fixed user-land buffer limit. This means that instead of having buffer packets automatically allocated when more memory is required, the sock_write(2) function will hang and flush any pending socket buffers until packets become available.
File sending is now offset based, so fseek data is ignored. This means that it would be possible to cache open fd files and send the same file descriptor to multiple clients.
Fixed issues with non-system sendfile and with underused packet pool memory.
Added the .metadata.keep_open flag, to allow file caching... however, keep in mind that the file offset for read/write is the file's lseek position and sending the same file to different sockets will create race conditions related to the file lseek position.
Fix for epoll's on_ready not being sent (sock flush must raise the EAGAIN error, or the on_ready event will not get called). Kqueue is better since the on_ready refers to the buffer being clear instead of available (less events to copy the same amount of data, as each data write is optimal when enough data is available to be written).
optional implementation of sendfile for Apple, BSD and Linux (BSD not tested).
Misc. optimizations. i.e. Buffer packet size now increased to 64Kb, to fit Linux buffer allocation.
File sending now supports file descriptors.
TLC support replaced with a simplified read/write hook.
Changed struct SockWriteOpt to a typedef sock_write_info_s.
Changed struct Packet to a typedef sock_packet_s.
fixed and issue where using sock_write(2) for big data chunks would cause errors when copying the data to the user buffer.
it should be noted, for performance reasons, that it is better to send big data using external pointers (especially if the data is cashed) using the sock_send_packet function - for cached data, do not set the packet->external flag, so the data isn't freed after it was sent.
fixed situations in which the send_packet might not close a file (if the packet buffer references a FILE) before returning an error.
The use of sock_free_packet is now required for any unused Packet object pointers checked out using sock_checkout_packet.
This requirement allows the pool management to minimize memory fragmentation for long running processes.
libsock memory requirements are now higher, as the user land buffer's Packet memory pool is pre-allocated to minimize memory fragmentation.
Corrected documentation mistakes, such as the one stating that the sock_send_packet function will not handle the Packet object's memory on error (it does handle the memory, always).
Baseline (changes not logged before this point in time).
I rewrote (almost) everything.
libasync now behaves as a global state machine. No more async_p objects.
Uses (by default) nanosleep instead of pipes (you can revert back to pipes by setting a simple flag). This, so far, seems to provide better performance (at the expense of a slightly increased CPU load).
Fixed task pool initialization to zero-out data that might cause segmentation faults.
libasync's task pool optimizations and limits were added to minimize memory fragmentation issues for long running processes.
Baseline (changes not logged before this point in time).
Rewrite from core. The code is more concise with less duplications.
Different API.
The server is now a global state machine instead of an object.
Better integration with libsock.
Handles libsock's UUID instead of direct file descriptors, preventing file descriptor collisions and preventing long running tasks from writing to the wrong client (i.e., if file descriptor 6 got disconnected and someone else connected and receive file descriptor 6 to identify the socket).
Better concurrency protection and protocol cleanup on_close. Now, deferred tasks (server_task / server_each), the on_data callback and even the on_close callback all run within a connection‘s “lock” (busy flag), limiting concurrency for a single connection to the on_ready and ping callbacks. No it is safe to free the protocol’s memory during an on_close callback, as it is (almost) guarantied that no running tasks are using that memory (this assumes that ping and on_ready don‘t use any data placed protocol’s memory).
Moved the global server lock (the one protecting global server data integrity) from a mutex to a spin-lock. Considering API design changes that might allow avoiding a lock.
File sending is now offset based, so lseek data is ignored. This means that it should be possible to cache open fd files and send the same file descriptor to multiple clients.
sendfile to only accept file descriptors (not FILE *). This is an optimization requirement.fixed situations in which the sendfile might not close the file before returning an error.
There was a chance that the on_data callback might return after the connection was disconnected and a new connection was established for the same fd. This could have caused the busy flag to be cleared even if the new connection was actually busy. This potential issue had been fixed by checking the connection against the UUID counter before clearing the busy flag.
reminder: The Server.rw_hooks feature is deprecated. Use libsock's TLC (Transport Layer Callbacks) features instead.
Baseline (changes not logged before this point in time).
gmtime implementation that ignores localization.Baseline (changes not logged before this point in time).
Fixed logging for static file range requests.
Moved URL decoding logic to the HttpRequest object.
Added basic logging support.
Added automatic Content-Length header constraints when setting status code to 1xx, 204 or 304.
Nicer messages on startup.
Updated for new lib-server and libsock.
gmtime_r and strftime solutions.HTTP protocol and HttpResponse sendfile and HttpResponse.sendfile fixes and optimizations. Now file sending uses file descriptors instead of FILE *, avoiding the memory allocations related to FILE * data.
HttpResponse copy optimizes the first header buffer packet to copy as much of the body as possible into the buffer packet, right after the headers.
Optimized mime type search for static file service.
Rewrote the HttpResponse implementation to leverage libsock's direct user-land buffer packet injection, minimizing user land data-copying.
rewrote the HTTP sendfile handling for public folder settings.
Fixed an issue related to the new pooling scheme, where old data would persist in some pooled request objects.
Baseline (changes not logged before this point in time).
Baseline (changes not logged before this point in time).