correctBlockNodeIds does 2 lookups for each loaded node, one to translate DB ID to name and a second to translate name to real ID. Name to real ID is very consumming if done on every node. As mapblocks are in most cases composed of many identical adjacent nodes, cache previous source and destination id and use them on the next node to prevent any lookup on those maps.
This reduce the function load from 15% of my CPU usage to ~0.7%, on the test, calls was reduced from 2.5M lookups to 42k lookups, it's a huge performance gain
* C++11 patchset 10: continue cleanup on constructors
* Drop obsolete bool MainMenuData::enable_public (setting is called with cURL in server loop)
* More classes cleanup
* More classes cleanup + change NULL tests to boolean tests
-> Don't pass pointer to whole IGameDef to NodeMetadata constructors
and deserializers, but only to IItemDefManager, which is needed
-> Remove the unused content_mapnode_get_new_name() method
-> Fix style for MapBlock::deSerialize and MapBlock::deSerialize_pre22,
improving accuracy of error messages a bit
-> Fix style at other serialisation methods too
-> Improve accuracy of some comments
1. Do two renames:
* SER_FMT_CLIENT_VER_LOWEST -> SER_FMT_VER_LOWEST_WRITE
* SER_FMT_VER_LOWEST -> SER_FMT_VER_LOWEST_READ
Now the two define values are consistently named with the _WRITE defines
SER_FMT_VER_{HIGHEST,LOWEST}_WRITE, and to better point out what the two
serialisation versions actually are for.
2. wrap some lines in doc/worldformat.txt, and point out that the node
timers are serialized at a later point, as this can cause confusion about
what now happens (if one doesn't strictly read the if block's conditions).
3. some whitespace fixes in NodeTimerList::serialize, and one new comment.
* Rename everything.
* Strip J prefix.
* Change UpperCamelCase functions to lowerCamelCase.
* Remove global (!) semaphore count mutex on OSX.
* Remove semaphore count getter (unused, unsafe, depended on internal
API functions on Windows, and used a hack on OSX).
* Add `Atomic<type>`.
* Make `Thread` handle thread names.
* Add support for C++11 multi-threading.
* Combine pthread and win32 sources.
* Remove `ThreadStarted` (unused, unneeded).
* Move some includes from the headers to the sources.
* Move all of `Event` into its header (allows inlining with no new includes).
* Make `Event` use `Semaphore` (except on Windows).
* Move some porting functions into `Thread`.
* Integrate logging with `Thread`.
* Add threading test.
* Use enum for GENERIC_CMD_*
* Rename m_attachements to attachement_parent_ids (public member and clearer name)
* Rename GENERIC_CMD_SET_ATTACHMENT to GENERIC_CMD_ATTACH_TO
* USHRT_MAX + 1 buffer sizes to prevent overflows as @kahrl suggested
* Remove unneccessary m_id from GenericCAO (shadowing protected superclass member for no reason) as @kahrl suggested
Spare direct multoplication, use constant MapBlock::nodecount instead of
local nodecount variables.
Also use strides at one place instead of multiplications.
When SER_FMT_VER_LOWEST is set to zero, then the test is stupid in INIT because all client works. In mapblock we check if client's serialization version is < 24, but if client sent serialization version < 24 (15 for example) the server set it and tried to send nodes, then BOOM
To resolve the problem:
* Create a different CLIENT_MIN_VERSION to handle this problem
* Remove the exception
* Use an assert in case of bad developer code
nerzhul is (may?) be working on a new solution. For the moment this is reverted because old worlds cannot be loaded (see discussion on github for the commit).
This reverts commit 800d19270250bb13cc6b2d330199815bf8e96446.
