14af5fe04f* Switch to sync zlib with 512k chunks, adjustable compression level * update serverPlayer
74 lines
2 KiB
JavaScript
74 lines
2 KiB
JavaScript
const [readVarInt, writeVarInt, sizeOfVarInt] = require('protodef').types.varint
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const zlib = require('zlib')
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// Concatenates packets into one batch packet, and adds length prefixs.
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class Framer {
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constructor (compressionLevel) {
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// Encoding
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this.packets = []
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this.compressionLevel = compressionLevel
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}
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static decode (buf) {
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// Read header
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if (buf[0] !== 0xfe) throw Error('bad batch packet header ' + buf[0])
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const buffer = buf.slice(1)
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// Decode the payload with 512kb buffer
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try {
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const inflated = zlib.inflateRawSync(buffer, { chunkSize: 512000 })
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return Framer.getPackets(inflated)
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} catch (e) { // Try to decode without compression
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return Framer.getPackets(buffer)
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}
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}
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encode () {
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const buf = Buffer.concat(this.packets)
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const def = zlib.deflateRawSync(buf, { level: this.compressionLevel })
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return Buffer.concat([Buffer.from([0xfe]), def])
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}
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addEncodedPacket (chunk) {
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const varIntSize = sizeOfVarInt(chunk.byteLength)
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const buffer = Buffer.allocUnsafe(varIntSize + chunk.byteLength)
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writeVarInt(chunk.length, buffer, 0)
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chunk.copy(buffer, varIntSize)
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this.packets.push(buffer)
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}
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addEncodedPackets (packets) {
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let allocSize = 0
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for (const packet of packets) {
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allocSize += sizeOfVarInt(packet.byteLength)
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allocSize += packet.byteLength
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}
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const buffer = Buffer.allocUnsafe(allocSize)
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let offset = 0
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for (const chunk of packets) {
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offset = writeVarInt(chunk.length, buffer, offset)
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offset += chunk.copy(buffer, offset, 0)
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}
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this.packets.push(buffer)
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}
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getBuffer () {
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return Buffer.concat(this.packets)
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}
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static getPackets (buffer) {
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const packets = []
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let offset = 0
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while (offset < buffer.byteLength) {
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const { value, size } = readVarInt(buffer, offset)
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const dec = Buffer.allocUnsafe(value)
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offset += size
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offset += buffer.copy(dec, 0, offset, offset + value)
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packets.push(dec)
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}
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return packets
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}
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}
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module.exports = Framer
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