recoder-code
Version:
Complete AI-powered development platform with ML model training, plugin registry, real-time collaboration, monitoring, infrastructure automation, and enterprise deployment capabilities
561 lines (518 loc) • 15.7 kB
JavaScript
import * as Y from 'yjs'
import * as encoding from 'lib0/encoding.js'
import * as decoding from 'lib0/decoding.js'
import * as binary from 'lib0/binary.js'
import * as promise from 'lib0/promise.js'
import * as buffer from 'lib0/buffer.js'
// @ts-ignore
import defaultLevel from 'level'
import { Buffer } from 'buffer'
export const PREFERRED_TRIM_SIZE = 500
const YEncodingString = 0
const YEncodingUint32 = 1
const valueEncoding = {
buffer: true,
type: 'y-value',
encode: /** @param {any} data */ data => data,
decode: /** @param {any} data */ data => data
}
/**
* Write two bytes as an unsigned integer in big endian order.
* (most significant byte first)
*
* @function
* @param {encoding.Encoder} encoder
* @param {number} num The number that is to be encoded.
*/
export const writeUint32BigEndian = (encoder, num) => {
for (let i = 3; i >= 0; i--) {
encoding.write(encoder, (num >>> (8 * i)) & binary.BITS8)
}
}
/**
* Read 4 bytes as unsigned integer in big endian order.
* (most significant byte first)
*
* @todo use lib0/decoding instead
*
* @function
* @param {decoding.Decoder} decoder
* @return {number} An unsigned integer.
*/
export const readUint32BigEndian = decoder => {
const uint =
(decoder.arr[decoder.pos + 3] +
(decoder.arr[decoder.pos + 2] << 8) +
(decoder.arr[decoder.pos + 1] << 16) +
(decoder.arr[decoder.pos] << 24)) >>> 0
decoder.pos += 4
return uint
}
export const keyEncoding = {
buffer: true,
type: 'y-keys',
/* istanbul ignore next */
encode: /** @param {Array<string|number>} arr */ arr => {
const encoder = encoding.createEncoder()
for (let i = 0; i < arr.length; i++) {
const v = arr[i]
if (typeof v === 'string') {
encoding.writeUint8(encoder, YEncodingString)
encoding.writeVarString(encoder, v)
} else /* istanbul ignore else */ if (typeof v === 'number') {
encoding.writeUint8(encoder, YEncodingUint32)
writeUint32BigEndian(encoder, v)
} else {
throw new Error('Unexpected key value')
}
}
return Buffer.from(encoding.toUint8Array(encoder))
},
decode: /** @param {Uint8Array} buf */ buf => {
const decoder = decoding.createDecoder(buf)
const key = []
while (decoding.hasContent(decoder)) {
switch (decoding.readUint8(decoder)) {
case YEncodingString:
key.push(decoding.readVarString(decoder))
break
case YEncodingUint32:
key.push(readUint32BigEndian(decoder))
break
}
}
return key
}
}
/**
* level returns an error if a value is not found.
*
* This helper method for level returns `null` instead if the key is not found.
*
* @param {any} db
* @param {any} key
*/
const levelGet = async (db, key) => {
let res
try {
res = await db.get(key)
} catch (err) {
/* istanbul ignore else */
if (err.notFound) {
return null
} else {
throw err
}
}
return res
}
/**
* Level expects a Buffer, but in Yjs we typically work with Uint8Arrays.
*
* Since Level thinks that these are two entirely different things,
* we transform the Uint8array to a Buffer before storing it.
*
* @param {any} db
* @param {any} key
* @param {Uint8Array} val
*/
const levelPut = async (db, key, val) => db.put(key, Buffer.from(val))
/**
* A "bulkier" implementation of level streams. Returns the result in one flush.
*
* @param {any} db
* @param {object} opts
* @return {Promise<Array<any>>}
*/
export const getLevelBulkData = (db, opts) => promise.create((resolve, reject) => {
/**
* @type {Array<any>} result
*/
const result = []
db.createReadStream(
opts
).on('data', /** @param {any} data */ data =>
result.push(data)
).on('end', () =>
resolve(result)
).on('error', reject)
})
/**
* Get all document updates for a specific document.
*
* @param {any} db
* @param {string} docName
* @param {any} [opts]
* @return {Promise<Array<Buffer>>}
*/
export const getLevelUpdates = (db, docName, opts = { values: true, keys: false }) => getLevelBulkData(db, {
gte: createDocumentUpdateKey(docName, 0),
lt: createDocumentUpdateKey(docName, binary.BITS32),
...opts
})
/**
* Get all document updates for a specific document.
*
* @param {any} db
* @param {boolean} values
* @param {boolean} keys
* @return {Promise<Array<any>>}
*/
export const getAllDocs = (db, values, keys) => getLevelBulkData(db, {
gte: ['v1_sv'],
lt: ['v1_sw'],
keys,
values
})
/**
* @param {any} db
* @param {string} docName
* @return {Promise<number>} Returns -1 if this document doesn't exist yet
*/
export const getCurrentUpdateClock = (db, docName) => getLevelUpdates(db, docName, { keys: true, values: false, reverse: true, limit: 1 }).then(keys => {
if (keys.length === 0) {
return -1
} else {
return keys[0][3]
}
})
/**
* @param {any} db
* @param {Array<string|number>} gte Greater than or equal
* @param {Array<string|number>} lt lower than (not equal)
* @return {Promise<void>}
*/
const clearRange = async (db, gte, lt) => {
/* istanbul ignore else */
if (db.supports.clear) {
await db.clear({ gte, lt })
} else {
const keys = await getLevelBulkData(db, { values: false, keys: true, gte, lt })
const ops = keys.map(key => ({ type: 'del', key }))
await db.batch(ops)
}
}
/**
* @param {any} db
* @param {string} docName
* @param {number} from Greater than or equal
* @param {number} to lower than (not equal)
* @return {Promise<void>}
*/
const clearUpdatesRange = async (db, docName, from, to) => clearRange(db, createDocumentUpdateKey(docName, from), createDocumentUpdateKey(docName, to))
/**
* Create a unique key for a update message.
* We encode the result using `keyEncoding` which expects an array.
*
* @param {string} docName
* @param {number} clock must be unique
* @return {Array<string|number>}
*/
const createDocumentUpdateKey = (docName, clock) => ['v1', docName, 'update', clock]
/**
* @param {string} docName
* @param {string} metaKey
*/
const createDocumentMetaKey = (docName, metaKey) => ['v1', docName, 'meta', metaKey]
/**
* @param {string} docName
*/
const createDocumentMetaEndKey = (docName) => ['v1', docName, 'metb'] // simple trick
/**
* We have a separate state vector key so we can iterate efficiently over all documents
* @param {string} docName
*/
const createDocumentStateVectorKey = (docName) => ['v1_sv', docName]
/**
* @param {string} docName
*/
const createDocumentFirstKey = (docName) => ['v1', docName]
/**
* We use this key as the upper limit of all keys that can be written.
* Make sure that all document keys are smaller! Strings are encoded using varLength string encoding,
* so we need to make sure that this key has the biggest size!
*
* @param {string} docName
*/
const createDocumentLastKey = (docName) => ['v1', docName, 'zzzzzzz']
// const emptyStateVector = (() => Y.encodeStateVector(new Y.Doc()))()
/**
* For now this is a helper method that creates a Y.Doc and then re-encodes a document update.
* In the future this will be handled by Yjs without creating a Y.Doc (constant memory consumption).
*
* @param {Array<Uint8Array>} updates
* @return {{update:Uint8Array, sv: Uint8Array}}
*/
const mergeUpdates = (updates) => {
const ydoc = new Y.Doc()
ydoc.transact(() => {
for (let i = 0; i < updates.length; i++) {
Y.applyUpdate(ydoc, updates[i])
}
})
return { update: Y.encodeStateAsUpdate(ydoc), sv: Y.encodeStateVector(ydoc) }
}
/**
* @param {any} db
* @param {string} docName
* @param {Uint8Array} sv state vector
* @param {number} clock current clock of the document so we can determine when this statevector was created
*/
const writeStateVector = async (db, docName, sv, clock) => {
const encoder = encoding.createEncoder()
encoding.writeVarUint(encoder, clock)
encoding.writeVarUint8Array(encoder, sv)
await levelPut(db, createDocumentStateVectorKey(docName), encoding.toUint8Array(encoder))
}
/**
* @param {Uint8Array} buf
* @return {{ sv: Uint8Array, clock: number }}
*/
const decodeLeveldbStateVector = buf => {
const decoder = decoding.createDecoder(buf)
const clock = decoding.readVarUint(decoder)
const sv = decoding.readVarUint8Array(decoder)
return { sv, clock }
}
/**
* @param {any} db
* @param {string} docName
*/
const readStateVector = async (db, docName) => {
const buf = await levelGet(db, createDocumentStateVectorKey(docName))
if (buf === null) {
// no state vector created yet or no document exists
return { sv: null, clock: -1 }
}
return decodeLeveldbStateVector(buf)
}
/**
* @param {any} db
* @param {string} docName
* @param {Uint8Array} stateAsUpdate
* @param {Uint8Array} stateVector
* @return {Promise<number>} returns the clock of the flushed doc
*/
const flushDocument = async (db, docName, stateAsUpdate, stateVector) => {
const clock = await storeUpdate(db, docName, stateAsUpdate)
await writeStateVector(db, docName, stateVector, clock)
await clearUpdatesRange(db, docName, 0, clock) // intentionally not waiting for the promise to resolve!
return clock
}
/**
* @param {any} db
* @param {string} docName
* @param {Uint8Array} update
* @return {Promise<number>} Returns the clock of the stored update
*/
const storeUpdate = async (db, docName, update) => {
const clock = await getCurrentUpdateClock(db, docName)
if (clock === -1) {
// make sure that a state vector is aways written, so we can search for available documents
const ydoc = new Y.Doc()
Y.applyUpdate(ydoc, update)
const sv = Y.encodeStateVector(ydoc)
await writeStateVector(db, docName, sv, 0)
}
await levelPut(db, createDocumentUpdateKey(docName, clock + 1), update)
return clock + 1
}
export class LeveldbPersistence {
/**
* @param {string} location
* @param {object} [opts]
* @param {any} [opts.level] Level-compatible adapter. E.g. leveldown, level-rem, level-indexeddb. Defaults to `level`
* @param {object} [opts.levelOptions] Options that are passed down to the level instance
*/
constructor (location, /* istanbul ignore next */ { level = defaultLevel, levelOptions = {} } = {}) {
const db = level(location, { ...levelOptions, valueEncoding, keyEncoding })
this.tr = promise.resolve()
/**
* Execute an transaction on a database. This will ensure that other processes are currently not writing.
*
* This is a private method and might change in the future.
*
* @todo only transact on the same room-name. Allow for concurrency of different rooms.
*
* @template T
*
* @param {function(any):Promise<T>} f A transaction that receives the db object
* @return {Promise<T>}
*/
this._transact = f => {
const currTr = this.tr
this.tr = (async () => {
await currTr
let res = /** @type {any} */ (null)
try {
res = await f(db)
} catch (err) {
/* istanbul ignore next */
console.warn('Error during y-leveldb transaction', err)
}
return res
})()
return this.tr
}
}
/**
* @param {string} docName
*/
flushDocument (docName) {
return this._transact(async db => {
const updates = await getLevelUpdates(db, docName)
const { update, sv } = mergeUpdates(updates)
await flushDocument(db, docName, update, sv)
})
}
/**
* @param {string} docName
* @return {Promise<Y.Doc>}
*/
getYDoc (docName) {
return this._transact(async db => {
const updates = await getLevelUpdates(db, docName)
const ydoc = new Y.Doc()
ydoc.transact(() => {
for (let i = 0; i < updates.length; i++) {
Y.applyUpdate(ydoc, updates[i])
}
})
if (updates.length > PREFERRED_TRIM_SIZE) {
await flushDocument(db, docName, Y.encodeStateAsUpdate(ydoc), Y.encodeStateVector(ydoc))
}
return ydoc
})
}
/**
* @param {string} docName
* @return {Promise<Uint8Array>}
*/
getStateVector (docName) {
return this._transact(async db => {
const { clock, sv } = await readStateVector(db, docName)
let curClock = -1
if (sv !== null) {
curClock = await getCurrentUpdateClock(db, docName)
}
if (sv !== null && clock === curClock) {
return sv
} else {
// current state vector is outdated
const updates = await getLevelUpdates(db, docName)
const { update, sv } = mergeUpdates(updates)
await flushDocument(db, docName, update, sv)
return sv
}
})
}
/**
* @param {string} docName
* @param {Uint8Array} update
* @return {Promise<number>} Returns the clock of the stored update
*/
storeUpdate (docName, update) {
return this._transact(db => storeUpdate(db, docName, update))
}
/**
* @param {string} docName
* @param {Uint8Array} stateVector
*/
async getDiff (docName, stateVector) {
const ydoc = await this.getYDoc(docName)
return Y.encodeStateAsUpdate(ydoc, stateVector)
}
/**
* @param {string} docName
* @return {Promise<void>}
*/
clearDocument (docName) {
return this._transact(async db => {
await db.del(createDocumentStateVectorKey(docName))
await clearRange(db, createDocumentFirstKey(docName), createDocumentLastKey(docName))
})
}
/**
* @param {string} docName
* @param {string} metaKey
* @param {any} value
* @return {Promise<void>}
*/
setMeta (docName, metaKey, value) {
return this._transact(db => levelPut(db, createDocumentMetaKey(docName, metaKey), buffer.encodeAny(value)))
}
/**
* @param {string} docName
* @param {string} metaKey
* @return {Promise<any>}
*/
delMeta (docName, metaKey) {
return this._transact(db => db.del(createDocumentMetaKey(docName, metaKey)))
}
/**
* @param {string} docName
* @param {string} metaKey
* @return {Promise<any>}
*/
getMeta (docName, metaKey) {
return this._transact(async db => {
const res = await levelGet(db, createDocumentMetaKey(docName, metaKey))
if (res === null) {
return// return void
}
return buffer.decodeAny(res)
})
}
/**
* @return {Promise<Array<string>>}
*/
getAllDocNames () {
return this._transact(async db => {
const docKeys = await getAllDocs(db, false, true)
return docKeys.map(key => key[1])
})
}
/**
* @return {Promise<Array<{ name: string, sv: Uint8Array, clock: number }>>}
*/
getAllDocStateVectors () {
return this._transact(async db => {
const docs = /** @type {any} */ (await getAllDocs(db, true, true))
return docs.map(doc => {
const { sv, clock } = decodeLeveldbStateVector(doc.value)
return { name: doc.key[1], sv, clock }
})
})
}
/**
* @param {string} docName
* @return {Promise<Map<string, any>>}
*/
getMetas (docName) {
return this._transact(async db => {
const data = await getLevelBulkData(db, {
gte: createDocumentMetaKey(docName, ''),
lt: createDocumentMetaEndKey(docName),
keys: true,
values: true
})
const metas = new Map()
data.forEach(v => { metas.set(v.key[3], buffer.decodeAny(v.value)) })
return metas
})
}
/**
* Close connection to a leveldb database and discard all state and bindings
*
* @return {Promise<void>}
*/
destroy () {
return this._transact(db => db.close())
}
/**
* Delete all data in database.
*/
clearAll () {
return this._transact(async db => db.clear())
}
}