The core of the SFS programming libraries. sfslite as many useful components for simplifying the development of event-driven network programs in C++.

sfslite and the SFS libraries are also known as libasync, which is somewhat of a misnomer, since the sfslite/SFS suite contain libasync in addition to other libraries.

• Main event loop (amain and acheck) and mechanisms for registering callbacks to handle:
  • file descriptor read/write-ability using fdcb,
  • periodic actions using delaycb,
  • unix signals using sigcb.
• Reference counted data structures (refcnt.h)
• Closure-like syntax for generating callbacks and maintaining state across actions (wrap in callback.h)
• Reference counted string objects (str.h): immutable strings, string buffers, mutable strings and mutable strings that are explicitly wiped after use.
• suio in C++, a wrapper to simplify using iovec to efficiently buffering input and output.
• aios for writing line-oriented network servers/clients.
• Data structures:
  • generic linked list logic (list.h)
  • generic hash table logic: ihash for when you provide struct that knows it is in a hash table, qhash for generic structs into hash tables, bhash for when you just want to keep track of whether or not a key is present (ihash.h and qhash.h). A short tutorial on qhash is available here.
  • dynamic arrays (vec.h)
  • red black trees (itree.h)
• Functions/classes for common operations:
  • Allocating sockets (inetsocket, make_async, unixsocket)
  • asynchronous DNS lookups.
  • asynchronous TCP connections (tcpconnect)
  • Daemonizing servers
  • Logging, error output and traces (err.h)
  • Parsing configuration files (parseopt.h)
  • Regular expressions (via the pcre library)

Sfslite makes extensive use of C++ templates to provide flexibility without sacrificing type safety. sfslite does not use floating point operations. sfslite is designed to integrate well with the dmalloc debugging malloc library.

A basic tutorial on using the SFS/sfslite libraries is available from PDOS.

If you have any tips for using libasync, please contribute them!