Add ParameterDescription message to pg-protocol (brianc#2464)

Author: spacedentist

packages/pg-protocol/src/inbound-parser.test.ts

@@ -144,6 +144,35 @@ var expectedTwoRowMessage = {
  ],
 }
 
+var emptyParameterDescriptionBuffer = new BufferList()
+ .addInt16(0) // number of parameters
+ .join(true, 't')
+
+var oneParameterDescBuf = buffers.parameterDescription([1111])
+
+var twoParameterDescBuf = buffers.parameterDescription([2222, 3333])
+
+var expectedEmptyParameterDescriptionMessage = {
+ name: 'parameterDescription',
+ length: 6,
+ parameterCount: 0,
+ dataTypeIDs: [],
+}
+
+var expectedOneParameterMessage = {
+ name: 'parameterDescription',
+ length: 10,
+ parameterCount: 1,
+ dataTypeIDs: [1111],
+}
+
+var expectedTwoParameterMessage = {
+ name: 'parameterDescription',
+ length: 14,
+ parameterCount: 2,
+ dataTypeIDs: [2222, 3333],
+}
+
 var testForMessage = function (buffer: Buffer, expectedMessage: any) {
  it('recieves and parses ' + expectedMessage.name, async () => {
  const messages = await parseBuffers([buffer])
@@ -245,6 +274,12 @@ describe('PgPacketStream', function () {
  testForMessage(twoRowBuf, expectedTwoRowMessage)
  })
 
+ describe('parameterDescription messages', function () {
+ testForMessage(emptyParameterDescriptionBuffer, expectedEmptyParameterDescriptionMessage)
+ testForMessage(oneParameterDescBuf, expectedOneParameterMessage)
+ testForMessage(twoParameterDescBuf, expectedTwoParameterMessage)
+ })
+
  describe('parsing rows', function () {
  describe('parsing empty row', function () {
  testForMessage(emptyRowFieldBuf, {

packages/pg-protocol/src/messages.ts

@@ -11,6 +11,7 @@ export type MessageName =
  | 'copyDone'
  | 'copyData'
  | 'rowDescription'
+ | 'parameterDescription'
  | 'parameterStatus'
  | 'backendKeyData'
  | 'notification'
@@ -152,6 +153,14 @@ export class RowDescriptionMessage {
  }
 }
 
+export class ParameterDescriptionMessage {
+ public readonly name: MessageName = 'parameterDescription'
+ public readonly dataTypeIDs: number[]
+ constructor(public readonly length: number, public readonly parameterCount: number) {
+ this.dataTypeIDs = new Array(this.parameterCount)
+ }
+}
+
 export class ParameterStatusMessage {
  public readonly name: MessageName = 'parameterStatus'
  constructor(

packages/pg-protocol/src/parser.ts

@@ -15,6 +15,7 @@ import {
  CopyResponse,
  NotificationResponseMessage,
  RowDescriptionMessage,
+ ParameterDescriptionMessage,
  Field,
  DataRowMessage,
  ParameterStatusMessage,
@@ -62,6 +63,7 @@ const enum MessageCodes {
  ErrorMessage = 0x45, // E
  NoticeMessage = 0x4e, // N
  RowDescriptionMessage = 0x54, // T
+ ParameterDescriptionMessage = 0x74, // t
  PortalSuspended = 0x73, // s
  ReplicationStart = 0x57, // W
  EmptyQuery = 0x49, // I
@@ -188,6 +190,8 @@ export class Parser {
  return this.parseErrorMessage(offset, length, bytes, 'notice')
  case MessageCodes.RowDescriptionMessage:
  return this.parseRowDescriptionMessage(offset, length, bytes)
+ case MessageCodes.ParameterDescriptionMessage:
+ return this.parseParameterDescriptionMessage(offset, length, bytes)
  case MessageCodes.CopyIn:
  return this.parseCopyInMessage(offset, length, bytes)
  case MessageCodes.CopyOut:
@@ -264,6 +268,16 @@ export class Parser {
  return new Field(name, tableID, columnID, dataTypeID, dataTypeSize, dataTypeModifier, mode)
  }
 
+ private parseParameterDescriptionMessage(offset: number, length: number, bytes: Buffer) {
+ this.reader.setBuffer(offset, bytes)
+ const parameterCount = this.reader.int16()
+ const message = new ParameterDescriptionMessage(length, parameterCount)
+ for (let i = 0; i < parameterCount; i++) {
+ message.dataTypeIDs[i] = this.reader.int32()
+ }
+ return message
+ }
+
  private parseDataRowMessage(offset: number, length: number, bytes: Buffer) {
  this.reader.setBuffer(offset, bytes)
  const fieldCount = this.reader.int16()

packages/pg-protocol/src/testing/test-buffers.ts

@@ -62,6 +62,16 @@ const buffers = {
  return buf.join(true, 'T')
  },
 
+ parameterDescription: function (dataTypeIDs: number[]) {
+ dataTypeIDs = dataTypeIDs || []
+ var buf = new BufferList()
+ buf.addInt16(dataTypeIDs.length)
+ dataTypeIDs.forEach(function (dataTypeID) {
+ buf.addInt32(dataTypeID)
+ })
+ return buf.join(true, 't')
+ },
+
  dataRow: function (columns: any[]) {
  columns = columns || []
  var buf = new BufferList()