Lumiera
The new emerging NLE for GNU/Linux
State Idea
Date Fr 22 Apr 2011 10:46:50 CEST
Proposed by Christian Thaeter <ct@pipapo.org>

liblumiera contains alot useful and reuseable code which is already in use by other projects

Description

Over the time we’ve put some efforts into the liblumiera. I’ve added some from my code which predates the lumiera project which I am using on many other projects. This now caused that I maintain this sources in different unrelated projects and have to cross merge and update stuff when I do updates and fixes somewhere. I think its time to factor the reuseable parts out into a independent library (like glib does for gtk), in fact I had this plan long ago.

What parts are eligible for a standalone library

Anything which is something tool alike and useful for other projects and not tied to Lumiera only. This are the algorithms/datastructures, allocators, tool macros. Additionally some of the src/common things should be moved into the library. I give some lists below.

How to name it

Long time ago my plan was to name it ctlib or cehlib but meanwhile there is enough code done by others. So I’d propose a more neutral name, still lumieralib or lulib would be approbiate. The only thing we have to account for is that some parts which are too specific for Lumiera and should not be integrated into this spinoff need either to stay in a lumiera-internal lib (src/lib/) as currently or being moved to the respective subsystems using them (src/backend, src/proc, src/common, …), so the names should not clash.

C, C++ …

For myself I need the C parts, while there is C code which interfaces to the C implementations and also a lot code which does nice C things on its own. This possibly means that we should in fact make 2 packages out of this, one C and one C library (where the C part is more than just the wrappers, but also the tools and tricks which are currently in src/lib/ and reuseable).

Who maintains it

Despite a spin of I think we don’t want to change anything from our current practice and maintain it by the Lumiera developers. For many parts I feel responsible for it, but its really a part of the Lumiera codebase, despite independently useable.

How to maintain it

We need to decide about build system and documentation system. As build system we may right start using scons. For documentation the situation is a but different since some of my code uses pipadoc/asciidoc and other uses doxygen.

What not to do

Some of the code is currently quite specific to Lumiera while it could be made more generic. This is NOT subject of this RFC we may or may not do such a refactoring but this RFC and any work resulting from this should only restrict to simple things like necessary namespace and variable renaming and integration in the build system.

C Parts

Library

What belongs to the library

Containers

  • cuckoo hashing (cuckoo.c|h)

  • linked lists (llist.h slist.h)

  • cache lists (mrucache.c|h)

  • splay trees (psplay.c|h)

  • priority queues (not done yet)

Runtime tools

  • error handling (error.h error.c) used by the other facilities too

  • clib convinience wrapers (safeclib.c|h) needs better name, maybe refactor into new facilities

Multithreading

  • locking, condition variables etc. (condition.c|h (rec)mutex.c|h, rwlock …)

Memory management

  • Memory pools (mpool.c|h)

  • Temporary buffers (tmpbuf.c|h)

Metaprogramming

  • preprecessor tools (ppmpl.h) move common preprocessor macros here

  • polymorphic call helper for C (vcall.h)

Interface system and module loader

except for some hardcoded references to lumiera_org and .lum plugin names this is quite generic, possibly moving this over could be postponed, but might eventually be done.

From src/common

interface.c interfacedescriptor.h interface.h interfaceproxy.cpp
interfaceregistry.c interfaceregistry.h plugin.c plugin_dynlib.c plugin.h

The config system could become a candidate too if it ever gets finished and proved useful, but for the time being its better kept in Lumiera.

Not Library

Too specific to Lumiera:

luid.c luid.h time.h

C++ Parts

For most of the C++ parts I am not sure, ichthyo should decided upon these (please edit this here)

Library

These look generic or wrap the C parts:

singleton-factory.hpp singleton.hpp singleton-policies.hpp
singleton-preconfigure.hpp singleton-ref.hpp singleton-subclass.hpp
sync-classlock.hpp sync.cpp sync.hpp thread-local.hpp
typed-allocation-manager.hpp typed-counter.hpp util.cpp util-foreach.hpp
util.hpp variant.hpp

Not Sure

access-casted.hpp advice advice.hpp allocation-cluster.cpp
allocation-cluster.hpp bool-checkable.hpp cmdline.cpp cmdline.hpp del-stash.hpp
diagnostic-context.hpp element-tracker.hpp error.hpp (currently too
lumiera specific) exception.cpp (as before) factory.hpp format.hpp
frameid.hpp functor-util.hpp handle.hpp hash-indexed.hpp iter-adapter.hpp
iter-adapter-stl.hpp iter-source.hpp itertools.hpp iter-type-binding.hpp
lifecycle.cpp lifecycleregistry.hpp lumitime-fmt.hpp lumitime.hpp
multifact-arg.hpp multifact.hpp meta/* null-value.hpp observable-list.hpp
opaque-holder.hpp optional-ref.hpp p.hpp query.cpp query.hpp ref-array.hpp
ref-array-impl.hpp result.hpp scoped-holder.hpp scoped-holder-transfer.hpp
scoped-ptrvect.hpp searchpath.cpp searchpath.hpp sub-id.hpp symbol.hpp
symbol-impl.cpp visitor-dispatcher.hpp visitor.hpp visitor-policies.hpp
wrapper.hpp wrapperptr.hpp appstate.cpp appstate.hpp basic-setup.cpp
basic-setup.hpp DIR_INFO external guifacade.cpp instancehandle.hpp option.cpp
option.hpp query subsys.cpp subsys.hpp subsystem-runner.hpp

Not Library

logging.cpp nobug-init.cpp nobug-init.hpp streamtype.cpp streamtype.hpp test/*
time/* time.cpp tree.hpp

Tasks

  • decide on name, namespaces WIP

  • create git repository, setup boilerplace (build system, legalese) WIP

  • move all code over into the git repos, refactor (namespace renames) () WIP

  • make Lumiera use the new lib WIP

Discussion

Pros

  • I am already reuse much of its code, making it independent makes maintaining it less burden

Cons

  • new packages, new dependencies for Lumiera instead batteries included

Alternatives

Rationale

Comments

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