CHANGELOG.md - net/facil.io - Rivoreo Source Code Repositories

 # Server Writing Tools in C - Change Log

 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`)](#lib-react) - The Reactor library.

 * [Lib-Sock (`libsock`)](#lib-sock) - The socket helper library (development incomplete).

 * [Lib-Async (`libasync`)](#lib-async) - The thread pool and tasking library.

 * [Lib-Server (`lib-server`)](#lib-server) - The server writing library.

 * [MiniCrypt (`mini-crypt`)](#minicrypt) - Common simple crypto library (development incomplete).

 * [HTTP Protocol (`http`)](#http_protocol) - including HttpRequest, HttpResponse etc'.

 * [Websocket extension (`mini-crypt`)](#websocket_extension) - Websocket Protocol for the basic HTTP implementation provided.

 ## General notes and future plans

 Changes I plan to make in future versions:

 * I plan to change the pool (request pool, packet pool, etc') implementations for the different libraries, so as to minimize any possible memory fragmentation that occur when `malloc` and `free` are used.

 * `libsock`'s dynamic packet allocation should be possible to disable, meaning that user buffer would be limited in scope and calls to `sock_write(2)` will busy-hang until packets become available... there's a re-write in the future for this one.

 * Review code for use of Atomic types when Mutex use is avoidable (especially `libsock`, `lib-server` and `libasync`). Perfomance testing should be performed to check for performance differences.

 * Remove / fix server task container pooling (`FDTask` and `GroupTask` pools).

 ## A note about version numbers

 I attempt to follow semantic versioning, except that the libraries are still under development, so version numbers get updated only when a significant change occurs.

 Libraries with versions less then 0.1.0 have missing features (i.e. `libsock` is missing the `connect` implementation and `mini-crypt` is missing almost everything except what little published functions it offers).

 Minor bug fixes, implementation optimizations and short git push corrections (I pushed bad code and fixed it in the same day or two) might not prompt a change in version numbers (not even the really minor ones).

 Significant issue fixes cause the tiny version to bump.

 API breaking changes always cause version bumps (could be a tiny version bump for tiny API changes).

 ... In other words, since these libraries are still being developed, test before adopting any updates.

 ## Lib-React

 ### V. 0.2.2

 * Fixed support for `libsock`, where the `sock_flush` wasn't automatically called due to inline function optimizations used by the compiler (and my errant code).

 ### V. 0.2.1

 Baseline (changes not logged before this point in time).

 ## Lib-Sock (development incomplete)

 ### V. 0.0.5

 * 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.

 ### V. 0.0.4

 * 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`.

 ### V. 0.0.3

 * 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.

 ### V. 0.0.2

 * 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**).

 ### V. 0.0.1

 Baseline (changes not logged before this point in time).

 ## Lib-Async

 ### V. 0.3.0

 * `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).

 ## Lib-Server

 ### V. 0.3.5

 * 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.

 ### V. 0.3.4

 * Updated `sendfile` to only accept file descriptors (not `FILE *`). This is an optimization requirement.

 ### V. 0.3.3

 * 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.

 ### V. 0.3.2

 Baseline (changes not logged before this point in time).

 ## MiniCrypt (development incomplete)

 ### V. 0.1.1

 * added a "dirty" (and somewhat faster then libc) `gmtime` implementation that ignores localization.

 Baseline (changes not logged before this point in time).

 ## HTTP Protocol

 * Updated for new `lib-server` and `libsock`.

 ### Date 20160616

 * HttpResponse date handling now utilizes a faster (and dirtier) solution then the standard libc `gmtime_r` and `strftime` solutions.

 ### Date 20160612

 * 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.

 ### Date 20160609

 * 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.

 ### Date 20160608

 * The HttpRequest object is now being pooled within the request library (not the HTTP protocol implementation) using Atomics (less mutex locking) and minimizing memory fragmentation by pre-initializing the buffer on first request (preventing memory allocated after the first request from getting "stuck behind" any of the pool members).

 ### Date 20160607

 Baseline (changes not logged before this point in time).

 ## Websocket extension

 ### Date 20160607

 Baseline (changes not logged before this point in time).
	# Server Writing Tools in C - Change Log

	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`)](#lib-react) - The Reactor library.

	* [Lib-Sock (`libsock`)](#lib-sock) - The socket helper library (development incomplete).

	* [Lib-Async (`libasync`)](#lib-async) - The thread pool and tasking library.

	* [Lib-Server (`lib-server`)](#lib-server) - The server writing library.

	* [MiniCrypt (`mini-crypt`)](#minicrypt) - Common simple crypto library (development incomplete).

	* [HTTP Protocol (`http`)](#http_protocol) - including HttpRequest, HttpResponse etc'.

	* [Websocket extension (`mini-crypt`)](#websocket_extension) - Websocket Protocol for the basic HTTP implementation provided.

	## General notes and future plans

	Changes I plan to make in future versions:

	* I plan to change the pool (request pool, packet pool, etc') implementations for the different libraries, so as to minimize any possible memory fragmentation that occur when `malloc` and `free` are used.

	* `libsock`'s dynamic packet allocation should be possible to disable, meaning that user buffer would be limited in scope and calls to `sock_write(2)` will busy-hang until packets become available... there's a re-write in the future for this one.

	* Review code for use of Atomic types when Mutex use is avoidable (especially `libsock`, `lib-server` and `libasync`). Perfomance testing should be performed to check for performance differences.

	* Remove / fix server task container pooling (`FDTask` and `GroupTask` pools).

	## A note about version numbers

	I attempt to follow semantic versioning, except that the libraries are still under development, so version numbers get updated only when a significant change occurs.

	Libraries with versions less then 0.1.0 have missing features (i.e. `libsock` is missing the `connect` implementation and `mini-crypt` is missing almost everything except what little published functions it offers).

	Minor bug fixes, implementation optimizations and short git push corrections (I pushed bad code and fixed it in the same day or two) might not prompt a change in version numbers (not even the really minor ones).

	Significant issue fixes cause the tiny version to bump.

	API breaking changes always cause version bumps (could be a tiny version bump for tiny API changes).

	... In other words, since these libraries are still being developed, test before adopting any updates.

	## Lib-React

	### V. 0.2.2

	* Fixed support for `libsock`, where the `sock_flush` wasn't automatically called due to inline function optimizations used by the compiler (and my errant code).

	### V. 0.2.1

	Baseline (changes not logged before this point in time).

	## Lib-Sock (development incomplete)

	### V. 0.0.5

	* 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.

	### V. 0.0.4

	* 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`.

	### V. 0.0.3

	* 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.

	### V. 0.0.2

	* 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).

	### V. 0.0.1

	Baseline (changes not logged before this point in time).

	## Lib-Async

	### V. 0.3.0

	* `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).

	## Lib-Server

	### V. 0.3.5

	* 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.

	### V. 0.3.4

	* Updated `sendfile` to only accept file descriptors (not `FILE *`). This is an optimization requirement.

	### V. 0.3.3

	* 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.

	### V. 0.3.2

	Baseline (changes not logged before this point in time).

	## MiniCrypt (development incomplete)

	### V. 0.1.1

	* added a "dirty" (and somewhat faster then libc) `gmtime` implementation that ignores localization.

	Baseline (changes not logged before this point in time).

	## HTTP Protocol

	* Updated for new `lib-server` and `libsock`.

	### Date 20160616

	* HttpResponse date handling now utilizes a faster (and dirtier) solution then the standard libc `gmtime_r` and `strftime` solutions.

	### Date 20160612

	* 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.

	### Date 20160609

	* 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.

	### Date 20160608

	* The HttpRequest object is now being pooled within the request library (not the HTTP protocol implementation) using Atomics (less mutex locking) and minimizing memory fragmentation by pre-initializing the buffer on first request (preventing memory allocated after the first request from getting "stuck behind" any of the pool members).

	### Date 20160607

	Baseline (changes not logged before this point in time).

	## Websocket extension

	### Date 20160607

	Baseline (changes not logged before this point in time).