prismarine-provider-raw

Raw (prismarine-chunk based) Storage Provider implementation. Supports all versions that prismarine-chunk supports thereby providing a stop-gap measure until prismarine-provider-anvil is updated.

Usage

const RawStorage = require('prismarine-provider-raw')('1.16.1')
const Chunk = require('prismarine-chunk')('1.16.1')

const storage = new RawStorage('./world/')

const chunk = new Chunk()
storage.save(0, 1, chunk).then(() => {
  console.log('saved!')
  storage.load(0, 1).then(c => {
    console.log('loaded!')
  }).catch(e => {
    console.error(e.stack)
  })
}).catch(e => {
  console.error(e.stack)
})

API

RawStorage

new RawStorage(path, compress = true)

Create a new RawStorage instance which uses the folder at path for storage (Optionally disable zlib compression with compress)

RawStorage.save(x, z, chunk)

Store a prismarine-chunk chunk at pos x, y. Returns a promise.

RawStorage.load(x, z)

Load the prismarine-chunk at pos x, y. Returns a promise.

RawStorage.defrag()

Load and defrag all region files (reduces wasted storage space)

NOTE: there is no need to run this regularly

Format

The format is loosely based on minecraft's Anvil Region format. The world is divided into 32*32 (1024) chunk sections, called 'regions'. The region a chunk belongs to can be found by dividing and then flooring the chunk coordinates by 32 (Bit-shift right by 5):

const regionX = chunkX >> 5
const regionY = chunkY >> 5

File Header

Offset	Size (Bytes)	Field	Purpose
0x0	0x4	Magic Number	CHNK (43 48 4e 4b) in ASCII
0x4	0x1	Prismarine Version	Prismarine format version
0x5	0x2	MC World Version	Minecraft protocol version for the chunks (e.g. 1.16.1 => 736)
0x7	0x4	X Position	X Position of the region file
0xB	0x4	Y Position	Y Position of the region file
0xF	0x2000	Chunk Info x1024	Chunk locations and sizes in the file (see Chunk Info below)
0x200F	-	Chunk Data	Sparse chunk data, referenced by Chunk Info entries, variable size

Chunk Info

Offset	Size (Bytes)	Field	Purpose
0x0	0x4	Offset	Chunk data offset, in bytes, after the File Header
0x4	0x4	Size	Chunk data size, in bytes

Chunk Data

Offset	Size (Bytes)	Field	Purpose
0x0	0x1	Compression	If the rest of the data is GZip compressed or not
0x1	0x1	Features	BitMask (0: Full Chunk (Ground Up), 1: Includes SkyLight, 2-7: Reserved)
0x2	0x2	BitMask	Section Bitmask with bits set to 1 for every 16x16x16 chunk section whose data is included in Data
0x4	0x4	Data Length	Length of the following Block Data
0x8	-	Data	Block Data
Unk+0x8	0x3	SkyLight Mask	Only the first 18 bits are actually used (missing for versions 1.13 and below)
Unk+0xB	0x3	BlockLight Mask	Only the first 18 bits are actually used (missing for versions 1.13 and below)
Unk+0xE	0x3	Empty SkyLight Mask	Only the first 18 bits are actually used (missing for versions 1.13 and below)
Unk+0x11	0x3	Empty BlockLight Mask	Only the first 18 bits are actually used (missing for versions 1.13 and below)
Unk+0x14	0x4	Light Data Length	Length of the following Light Data (missing for versions 1.13 and below)
Unk+0x18	-	Light Data	Light Data (missing for versions 1.13 and below)
Unk2+0x18	0x1000	Biomes	1024 Biome IDs (missing for versions 1.14 and below)