diff options
Diffstat (limited to 'Server/Plugins/APIDump/UsingChunkStays.html')
| -rw-r--r-- | Server/Plugins/APIDump/UsingChunkStays.html | 43 |
1 files changed, 30 insertions, 13 deletions
diff --git a/Server/Plugins/APIDump/UsingChunkStays.html b/Server/Plugins/APIDump/UsingChunkStays.html index a7cb5302a..faedfdfaa 100644 --- a/Server/Plugins/APIDump/UsingChunkStays.html +++ b/Server/Plugins/APIDump/UsingChunkStays.html @@ -14,7 +14,7 @@ <p> A plugin may need to manipulate data in arbitrary chunks, and it needs a way to make the server guarantee that the chunks are available in memory.</p> - + <h2>The problem</h2> <p> Usually when plugins want to manipulate larger areas of world data, they need to make sure that the @@ -27,7 +27,7 @@ either the block area has incomplete data (Read() failed) or incomplete data has been written to the world (Write() failed). Recovery from this is near impossible - you can't simply read or write again later, because the world may have changed in the meantime.</p> - + <h2>The solution</h2> <p> The naive solution would be to monitor chunk loads and unloads, and postpone the operations until all @@ -47,7 +47,7 @@ despawned. So the callback must use the longer way to access such objects, such as calling <a href="cWorld.html">cWorld:DoWithEntityByID()</a> or <a href="cWorld.html">cWorld:DoWithPlayer()</a>.</p> - + <h2>The example</h2> <p> As a simple example, consider a theoretical plugin that allows a player to save the immediate @@ -66,13 +66,13 @@ function HandleCommandSaveSpawn(a_Split, a_Player) local SpawnZ = a_Player:GetWorld():GetSpawnZ() local Bounds = cCuboid(SpawnX - 25, SpawnY - 25, SpawnZ - 25, SpawnX + 25, SpawnY + 25, SpawnZ + 25) Bounds:ClampY(0, 255) - + -- Read the area around spawn into a cBlockArea, save to file: local Area = cBlockArea() local FileName = a_Player:GetName() .. "_spawn.schematic" Area:Read(a_Player:GetWorld(), Bounds, cBlockArea.baTypes + cBlockArea.baMetas) Area:SaveToSchematicFile(FileName) - + -- Notify the player: a_Player:SendMessage(cCompositeChat("The spawn has been saved", mtInfo)) return true @@ -96,7 +96,7 @@ function HandleCommandSaveSpawn(a_Split, a_Player) local SpawnZ = a_Player:GetWorld():GetSpawnZ() local Bounds = cCuboid(SpawnX - 25, SpawnY - 25, SpawnZ - 25, SpawnX + 25, SpawnY + 25, SpawnZ + 25) Bounds:ClampY(0, 255) - + -- Get a list of chunks that we need loaded: local MinChunkX = math.floor((SpawnX - 25) / 16) local MaxChunkX = math.ceil ((SpawnX + 25) / 16) @@ -108,11 +108,11 @@ function HandleCommandSaveSpawn(a_Split, a_Player) table.insert(Chunks, {x, z}) end end -- for x - + -- Store the player's name and world to use in the callback, because the a_Player object may no longer be valid: local PlayerName = a_Player:GetName() local World = a_Player:GetWorld() - + -- This is the callback that is executed once all the chunks are loaded: local OnAllChunksAvailable = function() -- Read the area around spawn into a cBlockArea, save to file: @@ -124,7 +124,7 @@ function HandleCommandSaveSpawn(a_Split, a_Player) else Msg = cCompositeChat("Cannot save the spawn", mtFailure) end - + -- Notify the player: -- Note that we cannot use a_Player here, because it may no longer be valid (if the player disconnected before the command completes) World:DoWithPlayer(PlayerName, @@ -133,14 +133,14 @@ function HandleCommandSaveSpawn(a_Split, a_Player) end ) end - + -- Ask the server to load our chunks and notify us once it's done: World:ChunkStay(Chunks, nil, OnAllChunksAvailable) - + -- Note that code here may get executed before the callback is called! -- The ChunkStay says "once you have the chunks", not "wait until you have the chunks" -- So you can't notify the player here, because the saving needn't have occurred yet. - + return true end </pre> @@ -150,7 +150,7 @@ end when we've got the chunks loaded, there's still the issue of free RAM - if the memory for the area cannot be allocated, it cannot be read even with all the chunks present. So we still do need that check.</p> - + <h2>The conclusion</h2> <p> Although it makes the code a little bit longer and is a bit more difficult to grasp at first, the @@ -163,5 +163,22 @@ end prettyPrint(); </script> </div> + + <!-- Piwik --> + <script type="text/javascript"> + var _paq = _paq || []; + _paq.push(['trackPageView']); + _paq.push(['enableLinkTracking']); + (function() { + var u="https://analytics.cuberite.org/"; + _paq.push(['setTrackerUrl', u+'piwik.php']); + _paq.push(['setSiteId', 5]); + var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; + g.type='text/javascript'; g.async=true; g.defer=true; g.src='piwik.js'; s.parentNode.insertBefore(g,s); + })(); + </script> + <noscript><p><img src="https://analytics.cuberite.org/piwik.php?idsite=5" style="border:0;" alt="" /></p></noscript> + <!-- End Piwik Code --> + </body> </html> |