Resolves#1672
This API is intended to expose useful heightmaps found in the server to API. This exposes all of the live world heightmaps currently in the server.
If a heightmap becomes impossible to implement, api spec allows the implementation to throw UnsupportedOperationException (far better than returning some weird unexpected value).
Tested via:
https://gist.github.com/Spottedleaf/5d47f67c55a9fb870251ff344bfeb6b3
The cost of a call to sync() adds up quickly and especially for
HDDs. Playing around generating chunks for a while warranted a
3 min save time on a HDD. This is unacceptable default behaviour
and now the behaviour is hidden behind a flag for server owners
who are OK with taking a hit on saves (although SSDs will not have
this issue remotely as bad, since most of the time was spent seeking).
Previously we would write to header before writing our chunk data,
which opens a window for corruption (or we would overwrite entirely).
Now the saving process has been changed to follow this chain of events:
1. We always allocate a new space to write so we do not potentially
overwrite and corrupt the current data
2. Write the chunk data first (the order of the fields in
the chunk data isn't relevant though)
3. Flush to disk
4. Write to the region header last
5. Flush to disk
6. Then we free the previous space allocated
With this chain of events it is impossible for a chunk write to corrupt
a region file, unless the operating system has lied and we have NOT flushed
to disk.
However server administrators are still recommended to continue performing
regular backups.
Note that when Mojang finally decides to change their region format
to deal with oversized chunks this patch must be changed to deal with
whatever system they decide to impose.
We also make use of two flushes to disk per chunk save (to ensure
ordering and ensure data has gone to disk), so this will negatively
affect save performance.
Plugins that rely on the async login event to fire can miss the event
if a player tries to log in before the server has loaded.
The solution is to simply block the event threads from executing until
the server has loaded. This will not have an adverse affect on logins
since the event threads are cached and are only used for executing events
asynchronously.
* Add PlayerConnectionCloseEvent
This event is invoked when a player has disconnected. It is guaranteed that,
if the server is in online-mode, that the provided uuid and username have been
validated.
The event is invoked for players who have not yet logged into the world, whereas
PlayerQuitEvent is only invoked on players who have logged into the world.
The event is invoked for players who have already logged into the world,
although whether or not the player exists in the world at the time of
firing is undefined. (That is, whether the plugin can retrieve a Player object
using the event parameters is undefined). However, it is guaranteed that this
event is invoked AFTER PlayerQuitEvent, if the player has already logged into
the world.
This event is guaranteed to never fire unless AsyncPlayerPreLoginEvent has
been invoked beforehand, and this event may not be called in parallel with
AsyncPlayerPreLoginEvent for the same connection.
Cancelling the AsyncPlayerPreLoginEvent guarantees the corresponding
PlayerConnectionCloseEvent is never called.
The event may be invoked asynchronously or synchronously. As it stands,
it is never invoked asynchronously. However, plugins should check
Event#isAsynchronous to be future-proof.
On purpose, the deprecated PlayerPreLoginEvent event is left out of the
API spec for this event. Plugins should not be using that event, and
how PlayerPreLoginEvent interacts with PlayerConnectionCloseEvent
is undefined.
The key can be retrieved via methods Location#toBlockKey() and
Block#getBlockKey()
World provides lookup for blocks by long key via method World#getBlockAtKey(long)
The formatting for the key is as follows:
10 bit y|27 bit z|27 bit x
The y value is considered unsigned while z and x are considered two's complement
Y range: [0, 1023]
X, Z range: [-67 108 864, 67 108 863]
Checked encoding and decoding via https://gist.github.com/Spottedleaf/74f4e241012ca2fa67d8f1c7e8e34722
Spottedleaf