????
Your IP : 18.226.28.28
import { Writer } from './buffer-writer'
const enum code {
startup = 0x70,
query = 0x51,
parse = 0x50,
bind = 0x42,
execute = 0x45,
flush = 0x48,
sync = 0x53,
end = 0x58,
close = 0x43,
describe = 0x44,
copyFromChunk = 0x64,
copyDone = 0x63,
copyFail = 0x66,
}
const writer = new Writer()
const startup = (opts: Record<string, string>): Buffer => {
// protocol version
writer.addInt16(3).addInt16(0)
for (const key of Object.keys(opts)) {
writer.addCString(key).addCString(opts[key])
}
writer.addCString('client_encoding').addCString('UTF8')
var bodyBuffer = writer.addCString('').flush()
// this message is sent without a code
var length = bodyBuffer.length + 4
return new Writer().addInt32(length).add(bodyBuffer).flush()
}
const requestSsl = (): Buffer => {
const response = Buffer.allocUnsafe(8)
response.writeInt32BE(8, 0)
response.writeInt32BE(80877103, 4)
return response
}
const password = (password: string): Buffer => {
return writer.addCString(password).flush(code.startup)
}
const sendSASLInitialResponseMessage = function (mechanism: string, initialResponse: string): Buffer {
// 0x70 = 'p'
writer.addCString(mechanism).addInt32(Buffer.byteLength(initialResponse)).addString(initialResponse)
return writer.flush(code.startup)
}
const sendSCRAMClientFinalMessage = function (additionalData: string): Buffer {
return writer.addString(additionalData).flush(code.startup)
}
const query = (text: string): Buffer => {
return writer.addCString(text).flush(code.query)
}
type ParseOpts = {
name?: string
types?: number[]
text: string
}
const emptyArray: any[] = []
const parse = (query: ParseOpts): Buffer => {
// expect something like this:
// { name: 'queryName',
// text: 'select * from blah',
// types: ['int8', 'bool'] }
// normalize missing query names to allow for null
const name = query.name || ''
if (name.length > 63) {
/* eslint-disable no-console */
console.error('Warning! Postgres only supports 63 characters for query names.')
console.error('You supplied %s (%s)', name, name.length)
console.error('This can cause conflicts and silent errors executing queries')
/* eslint-enable no-console */
}
const types = query.types || emptyArray
var len = types.length
var buffer = writer
.addCString(name) // name of query
.addCString(query.text) // actual query text
.addInt16(len)
for (var i = 0; i < len; i++) {
buffer.addInt32(types[i])
}
return writer.flush(code.parse)
}
type ValueMapper = (param: any, index: number) => any
type BindOpts = {
portal?: string
binary?: boolean
statement?: string
values?: any[]
// optional map from JS value to postgres value per parameter
valueMapper?: ValueMapper
}
const paramWriter = new Writer()
// make this a const enum so typescript will inline the value
const enum ParamType {
STRING = 0,
BINARY = 1,
}
const writeValues = function (values: any[], valueMapper?: ValueMapper): void {
for (let i = 0; i < values.length; i++) {
const mappedVal = valueMapper ? valueMapper(values[i], i) : values[i]
if (mappedVal == null) {
// add the param type (string) to the writer
writer.addInt16(ParamType.STRING)
// write -1 to the param writer to indicate null
paramWriter.addInt32(-1)
} else if (mappedVal instanceof Buffer) {
// add the param type (binary) to the writer
writer.addInt16(ParamType.BINARY)
// add the buffer to the param writer
paramWriter.addInt32(mappedVal.length)
paramWriter.add(mappedVal)
} else {
// add the param type (string) to the writer
writer.addInt16(ParamType.STRING)
paramWriter.addInt32(Buffer.byteLength(mappedVal))
paramWriter.addString(mappedVal)
}
}
}
const bind = (config: BindOpts = {}): Buffer => {
// normalize config
const portal = config.portal || ''
const statement = config.statement || ''
const binary = config.binary || false
const values = config.values || emptyArray
const len = values.length
writer.addCString(portal).addCString(statement)
writer.addInt16(len)
writeValues(values, config.valueMapper)
writer.addInt16(len)
writer.add(paramWriter.flush())
// format code
writer.addInt16(binary ? ParamType.BINARY : ParamType.STRING)
return writer.flush(code.bind)
}
type ExecOpts = {
portal?: string
rows?: number
}
const emptyExecute = Buffer.from([code.execute, 0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00])
const execute = (config?: ExecOpts): Buffer => {
// this is the happy path for most queries
if (!config || (!config.portal && !config.rows)) {
return emptyExecute
}
const portal = config.portal || ''
const rows = config.rows || 0
const portalLength = Buffer.byteLength(portal)
const len = 4 + portalLength + 1 + 4
// one extra bit for code
const buff = Buffer.allocUnsafe(1 + len)
buff[0] = code.execute
buff.writeInt32BE(len, 1)
buff.write(portal, 5, 'utf-8')
buff[portalLength + 5] = 0 // null terminate portal cString
buff.writeUInt32BE(rows, buff.length - 4)
return buff
}
const cancel = (processID: number, secretKey: number): Buffer => {
const buffer = Buffer.allocUnsafe(16)
buffer.writeInt32BE(16, 0)
buffer.writeInt16BE(1234, 4)
buffer.writeInt16BE(5678, 6)
buffer.writeInt32BE(processID, 8)
buffer.writeInt32BE(secretKey, 12)
return buffer
}
type PortalOpts = {
type: 'S' | 'P'
name?: string
}
const cstringMessage = (code: code, string: string): Buffer => {
const stringLen = Buffer.byteLength(string)
const len = 4 + stringLen + 1
// one extra bit for code
const buffer = Buffer.allocUnsafe(1 + len)
buffer[0] = code
buffer.writeInt32BE(len, 1)
buffer.write(string, 5, 'utf-8')
buffer[len] = 0 // null terminate cString
return buffer
}
const emptyDescribePortal = writer.addCString('P').flush(code.describe)
const emptyDescribeStatement = writer.addCString('S').flush(code.describe)
const describe = (msg: PortalOpts): Buffer => {
return msg.name
? cstringMessage(code.describe, `${msg.type}${msg.name || ''}`)
: msg.type === 'P'
? emptyDescribePortal
: emptyDescribeStatement
}
const close = (msg: PortalOpts): Buffer => {
const text = `${msg.type}${msg.name || ''}`
return cstringMessage(code.close, text)
}
const copyData = (chunk: Buffer): Buffer => {
return writer.add(chunk).flush(code.copyFromChunk)
}
const copyFail = (message: string): Buffer => {
return cstringMessage(code.copyFail, message)
}
const codeOnlyBuffer = (code: code): Buffer => Buffer.from([code, 0x00, 0x00, 0x00, 0x04])
const flushBuffer = codeOnlyBuffer(code.flush)
const syncBuffer = codeOnlyBuffer(code.sync)
const endBuffer = codeOnlyBuffer(code.end)
const copyDoneBuffer = codeOnlyBuffer(code.copyDone)
const serialize = {
startup,
password,
requestSsl,
sendSASLInitialResponseMessage,
sendSCRAMClientFinalMessage,
query,
parse,
bind,
execute,
describe,
close,
flush: () => flushBuffer,
sync: () => syncBuffer,
end: () => endBuffer,
copyData,
copyDone: () => copyDoneBuffer,
copyFail,
cancel,
}
export { serialize }