prismarine-chunk/src/bedrock/1.18/ChunkColumn.js

A class to hold chunk data for prismarine

const ChunkColumn13 = require('../1.3/ChunkColumn')
const SubChunk = require('./SubChunk')
const BiomeSection = require('./BiomeSection')
const ProxyBiomeSection = require('./ProxyBiomeSection')

const { BlobType, BlobEntry } = require('../common/BlobCache')
const { StorageType } = require('../common/constants')
const Stream = require('../common/Stream')

const nbt = require('prismarine-nbt')

class ChunkColumn180 extends ChunkColumn13 {
  Section = SubChunk
  bounds = this.setBounds(-4, 20) // World height changed

  // BIOMES

  getBiome (pos) {
    return new this.Biome(this.getBiomeId(pos))
  }

  setBiome (pos, biome) {
    this.setBiomeId(pos, biome.id)
  }

  getBiomeId (pos) {
    const Y = pos.y >> 4
    const sec = this.biomes[this.co + Y]
    return sec?.getBiomeId(pos.x, pos.y & 0xf, pos.z) ?? 0
  }

  setBiomeId (pos, biomeId) {
    const Y = pos.y >> 4
    let sec = this.biomes[this.co + Y]
    if (!sec) {
      this.biomes[this.co + Y] = sec = new BiomeSection(this.registry, Y)
    } else if (!sec.setBiomeId) {
      this.biomes[this.co + Y] = sec = sec.promote(Y)
    }
    sec.setBiomeId(pos.x, pos.y & 0xf, pos.z, biomeId)
    this.biomesUpdated = true
  }

  // Load 3D biome data
  loadBiomes (buf, storageType) {
    if (buf instanceof Buffer) buf = new Stream(buf)
    this.biomes = []
    let last
    for (let y = this.minCY; buf.peek(); y++) {
      if (buf.peek() === 0xff) { // re-use the last data
        if (!last) throw new Error('No last biome')
        const biome = new ProxyBiomeSection(this.registry, last)
        this.biomes.push(biome)
        // skip peek'ed
        buf.readByte()
      } else {
        const biome = new BiomeSection(this.registry, y)
        biome.read(storageType, buf)
        last = biome
        this.biomes.push(biome)
      }
    }
  }

  writeBiomes (stream) {
    for (let i = 0; i < (this.worldHeight >> 4); i++) {
      let biomeSection = this.biomes[i]
      if (!biomeSection) {
        if (this.biomes[i - 1]) {
          this.biomes[i] = biomeSection = new ProxyBiomeSection(this.registry, this.biomes[i - 1])
        } else {
          this.biomes[i] = biomeSection = new BiomeSection(this.registry, i)
        }
      }
      biomeSection.export(StorageType.Runtime, stream)
    }
  }

  // CACHING

  /**
   * Encodes this chunk column for the network with no caching
   * @param buffer Full chunk buffer
   */
  async networkEncodeNoCache () {
    const stream = new Stream()
    for (const biomeSection of this.biomes) {
      biomeSection.export(StorageType.Runtime, stream)
    }
    const biomeBuf = stream.getBuffer()
    return Buffer.concat([
      biomeBuf,
      Buffer.from([0]) // border blocks count
    ])
  }

  /**
   * Encodes this chunk column for use over network with caching enabled
   *
   * @param blobStore The blob store to write chunks in this section to
   * @returns {Promise<Buffer[]>} The blob hashes for this chunk, the last one is biomes, rest are sections
   */
  async networkEncodeBlobs (blobStore, includeBiomes) {
    const blobHashes = []
    if (includeBiomes) {
      if (this.biomesUpdated || !this.biomesHash || !blobStore.get(this.biomesHash.toString())) {
        const stream = new Stream()
        for (const biomeSection of this.biomes) {
          biomeSection.export(StorageType.Runtime, stream)
        }
        const biomeBuf = stream.getBuffer()
        await this.updateBiomeHash(biomeBuf)

        this.biomesUpdated = false
        blobStore.set(this.biomesHash.toString(), new BlobEntry({ x: this.x, z: this.z, type: BlobType.Biomes, buffer: this.biomes }))
      }
      blobHashes.push({ hash: this.biomesHash, type: BlobType.Biomes })
    }

    return blobHashes
  }

  async networkEncode (blobStore) {
    const blobs = await this.networkEncodeBlobs(blobStore, true, false)

    return {
      blobs, // cache blobs
      payload: Buffer.concat([ // non-cached stuff
        Buffer.from([0]) // border blocks
      ])
    }
  }

  networkDecodeNoCache (buffer, sectionCount) {
    const stream = buffer instanceof Buffer ? new Stream(buffer) : buffer

    if (sectionCount !== -1 && sectionCount !== -2) { // In 1.18+, with sectionCount as -1/-2 we only get the biomes here
      this.sections = []
      for (let i = 0; i < sectionCount; i++) {
        // in 1.17.30+, chunk index is sent in payload
        const section = new SubChunk(this.registry, this.Block, { y: i, subChunkVersion: this.subChunkVersion })
        section.decode(StorageType.Runtime, stream)
        this.setSection(i, section)
      }
    }

    this.loadBiomes(stream, StorageType.Runtime)
    const borderBlocks = stream.readBuffer(stream.readZigZagVarInt())
    if (borderBlocks.length) {
      throw new Error(`Can't handle border blocks (length: ${borderBlocks.length})`)
    }

    let startOffset = stream.readOffset
    while (stream.peek() === 0x0A) {
      const { data, metadata } = nbt.protos.littleVarint.parsePacketBuffer('nbt', stream.buffer, startOffset)
      stream.readOffset += metadata.size
      startOffset += metadata.size
      this.addBlockEntity(data)
    }
  }

  /**
   * Decodes cached chunks sent over the network
   * @param blobs The blob hashes sent in the Chunk packet
   * @param blobStore Our blob store for cached data
   * @param {Buffer} payload The rest of the non-cached data
   * @returns {CCHash[]} A list of hashes we don't have and need. If len > 0, decode failed.
   */
  async networkDecode (blobs, blobStore, payload) {
    if (payload) {
      const stream = new Stream(payload)
      const borderblocks = stream.readBuffer(stream.readZigZagVarInt())

      if (borderblocks.length) {
        throw new Error(`Can't handle border blocks (length: ${borderblocks.length})`)
      }
    }

    // Block NBT data is now inside individual sections

    const misses = []
    for (const blob of blobs) {
      if (!blobStore.has(blob.toString())) {
        misses.push(blob)
      }
    }
    if (misses.length > 0) {
      // missing blobs, call this again once the server replies with our MISSing
      // blobs and don't try to load this column until we have all the data
      return misses
    }

    // Reset the sections & length, when we add a section, it will auto increment
    this.sections = []
    for (const blob of blobs) {
      const entry = blobStore.get(blob.toString())
      if (entry.type === BlobType.Biomes) {
        const stream = new Stream(entry.buffer)
        this.loadBiomes(stream, StorageType.NetworkPersistence, blob)
      } else if (entry.type === BlobType.ChunkSection) {
        throw new Error("Can't accept chunk sections in networkDecode, these Blobs should be sent as individual sections")
      } else {
        throw Error('Unknown blob type: ' + entry.type)
      }
    }

    return misses // return empty array if everything was loaded
  }

  async networkDecodeSubChunkNoCache (y, buffer) {
    const stream = new Stream(buffer)
    const section = new SubChunk(this.registry, this.Block, { y, subChunkVersion: this.subChunkVersion })
    section.decode(StorageType.Runtime, stream)
    this.setSection(y, section)

    let startOffset = stream.readOffset
    while (stream.peek() === 0x0A) {
      const { data, metadata } = nbt.protos.littleVarint.parsePacketBuffer('nbt', buffer, startOffset)
      stream.readOffset += metadata.size
      startOffset += metadata.size
      this.addBlockEntity(data)
    }
  }

  async networkEncodeSubChunkNoCache (y) {
    const tiles = this.getSectionBlockEntities(y)

    const section = this.getSectionAtIndex(y)
    const subchunk = await section.encode(StorageType.Runtime, false, this.compactOnSave)

    const tileBufs = []
    for (const tile of tiles) {
      tileBufs.push(nbt.writeUncompressed(tile, 'littleVarint'))
    }

    return Buffer.concat([subchunk, ...tileBufs])
  }

  async networkDecodeSubChunk (blobs, blobStore, payload) {
    if (payload) {
      const nbtStream = new Stream(payload)
      let startOffset = 0
      while (nbtStream.peekUInt8() === 0x0A) {
        const { data, metadata } = nbt.protos.littleVarint.parsePacketBuffer('nbt', payload, startOffset)
        nbtStream.readOffset += metadata.size
        startOffset += metadata.size
        this.addBlockEntity(data)
      }
    }

    const misses = []
    for (const blob of blobs) {
      if (!blobStore.has(blob.toString())) {
        misses.push(blob)
      }
    }
    if (misses.length > 0) {
      // missing blobs, call this again once the server replies with our MISSing
      // blobs and don't try to load this column until we have all the data
      return misses
    }

    // Reset the sections & length, when we add a section, it will auto increment
    this.sections = []
    this.sectionsLen = 0
    for (const blob of blobs) {
      const entry = blobStore.get(blob.toString())

      const stream = new Stream(entry.buffer)
      const subchunk = new SubChunk(this.registry, this.Block, { y: blob.y, subChunkVersion: this.subChunkVersion })
      await subchunk.decode(StorageType.Runtime, stream)
      this.setSection(subchunk.y, subchunk)
    }

    return misses // return empty array if everything was loaded
  }

  async networkEncodeSubChunk (y, blobStore) {
    const tiles = this.getSectionBlockEntities(y)
    const section = this.getSectionAtIndex(y)

    if (section.updated) {
      const terrainBuffer = await section.encode(StorageType.Runtime, true, this.compactOnSave) // note Runtime, not NetworkPersistence
      const blob = new BlobEntry({ x: this.x, y: section.y, z: this.z, type: BlobType.ChunkSection, buffer: terrainBuffer })
      blobStore.set(section.hash.toString(), blob)
    }

    const tileBufs = []
    for (const tile of tiles) {
      tileBufs.push(nbt.writeUncompressed(tile, 'littleVarint'))
    }

    return [section.hash, Buffer.concat(tileBufs)]
  }

  toObject () {
    return { ...super.toObject(), version: this.registry.version.minecraftVersion }
  }
}

module.exports = ChunkColumn180