grpc-node/packages/grpc-js/src/server-call.ts

718 lines
20 KiB
TypeScript

/*
* Copyright 2019 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
import { EventEmitter } from 'events';
import * as http2 from 'http2';
import { Duplex, Readable, Writable } from 'stream';
import { StatusObject } from './call-stream';
import { Status, DEFAULT_MAX_SEND_MESSAGE_LENGTH, DEFAULT_MAX_RECEIVE_MESSAGE_LENGTH } from './constants';
import { Deserialize, Serialize } from './make-client';
import { Metadata } from './metadata';
import { StreamDecoder } from './stream-decoder';
import { ObjectReadable, ObjectWritable } from './object-stream';
import { ChannelOptions } from './channel-options';
interface DeadlineUnitIndexSignature {
[name: string]: number;
}
const GRPC_ACCEPT_ENCODING_HEADER = 'grpc-accept-encoding';
const GRPC_ENCODING_HEADER = 'grpc-encoding';
const GRPC_MESSAGE_HEADER = 'grpc-message';
const GRPC_STATUS_HEADER = 'grpc-status';
const GRPC_TIMEOUT_HEADER = 'grpc-timeout';
const DEADLINE_REGEX = /(\d{1,8})\s*([HMSmun])/;
const deadlineUnitsToMs: DeadlineUnitIndexSignature = {
H: 3600000,
M: 60000,
S: 1000,
m: 1,
u: 0.001,
n: 0.000001,
};
const defaultResponseHeaders = {
// TODO(cjihrig): Remove these encoding headers from the default response
// once compression is integrated.
[GRPC_ACCEPT_ENCODING_HEADER]: 'identity',
[GRPC_ENCODING_HEADER]: 'identity',
[http2.constants.HTTP2_HEADER_STATUS]: http2.constants.HTTP_STATUS_OK,
[http2.constants.HTTP2_HEADER_CONTENT_TYPE]: 'application/grpc+proto',
};
const defaultResponseOptions = {
waitForTrailers: true,
} as http2.ServerStreamResponseOptions;
export type ServerStatusResponse = Partial<StatusObject>;
export type ServerErrorResponse = ServerStatusResponse & Error;
export type ServerSurfaceCall = {
cancelled: boolean;
getPeer(): string;
sendMetadata(responseMetadata: Metadata): void;
} & EventEmitter;
export type ServerUnaryCall<RequestType, ResponseType> = ServerSurfaceCall & {
request: RequestType | null;
};
export type ServerReadableStream<
RequestType,
ResponseType
> = ServerSurfaceCall & ObjectReadable<RequestType>;
export type ServerWritableStream<
RequestType,
ResponseType
> = ServerSurfaceCall &
ObjectWritable<ResponseType> & { request: RequestType | null };
export type ServerDuplexStream<RequestType, ResponseType> = ServerSurfaceCall &
ObjectReadable<RequestType> &
ObjectWritable<ResponseType>;
export class ServerUnaryCallImpl<RequestType, ResponseType> extends EventEmitter
implements ServerUnaryCall<RequestType, ResponseType> {
cancelled: boolean;
request: RequestType | null;
constructor(
private call: Http2ServerCallStream<RequestType, ResponseType>,
public metadata: Metadata
) {
super();
this.cancelled = false;
this.request = null;
this.call.setupSurfaceCall(this);
}
getPeer(): string {
throw new Error('not implemented yet');
}
sendMetadata(responseMetadata: Metadata): void {
this.call.sendMetadata(responseMetadata);
}
}
export class ServerReadableStreamImpl<RequestType, ResponseType>
extends Readable
implements ServerReadableStream<RequestType, ResponseType> {
cancelled: boolean;
constructor(
private call: Http2ServerCallStream<RequestType, ResponseType>,
public metadata: Metadata,
public deserialize: Deserialize<RequestType>
) {
super({ objectMode: true });
this.cancelled = false;
this.call.setupSurfaceCall(this);
this.call.setupReadable(this);
}
_read(size: number) {
if (!this.call.consumeUnpushedMessages(this)) {
return;
}
this.call.resume();
}
getPeer(): string {
throw new Error('not implemented yet');
}
sendMetadata(responseMetadata: Metadata): void {
this.call.sendMetadata(responseMetadata);
}
}
export class ServerWritableStreamImpl<RequestType, ResponseType>
extends Writable
implements ServerWritableStream<RequestType, ResponseType> {
cancelled: boolean;
request: RequestType | null;
private trailingMetadata: Metadata;
constructor(
private call: Http2ServerCallStream<RequestType, ResponseType>,
public metadata: Metadata,
public serialize: Serialize<ResponseType>
) {
super({ objectMode: true });
this.cancelled = false;
this.request = null;
this.trailingMetadata = new Metadata();
this.call.setupSurfaceCall(this);
this.on('error', err => {
this.call.sendError(err);
this.end();
});
}
getPeer(): string {
throw new Error('not implemented yet');
}
sendMetadata(responseMetadata: Metadata): void {
this.call.sendMetadata(responseMetadata);
}
async _write(
chunk: ResponseType,
encoding: string,
// tslint:disable-next-line:no-any
callback: (...args: any[]) => void
) {
try {
const response = await this.call.serializeMessage(chunk);
if (!this.call.write(response)) {
this.call.once('drain', callback);
return;
}
} catch (err) {
err.code = Status.INTERNAL;
this.emit('error', err);
}
callback();
}
_final(callback: Function): void {
this.call.sendStatus({
code: Status.OK,
details: 'OK',
metadata: this.trailingMetadata,
});
callback(null);
}
// tslint:disable-next-line:no-any
end(metadata?: any) {
if (metadata) {
this.trailingMetadata = metadata;
}
super.end();
}
}
export class ServerDuplexStreamImpl<RequestType, ResponseType> extends Duplex
implements ServerDuplexStream<RequestType, ResponseType> {
cancelled: boolean;
private trailingMetadata: Metadata;
constructor(
private call: Http2ServerCallStream<RequestType, ResponseType>,
public metadata: Metadata,
public serialize: Serialize<ResponseType>,
public deserialize: Deserialize<RequestType>
) {
super({ objectMode: true });
this.cancelled = false;
this.trailingMetadata = new Metadata();
this.call.setupSurfaceCall(this);
this.call.setupReadable(this);
this.on('error', err => {
this.call.sendError(err);
this.end();
});
}
getPeer(): string {
throw new Error('not implemented yet');
}
sendMetadata(responseMetadata: Metadata): void {
this.call.sendMetadata(responseMetadata);
}
}
ServerDuplexStreamImpl.prototype._read =
ServerReadableStreamImpl.prototype._read;
ServerDuplexStreamImpl.prototype._write =
ServerWritableStreamImpl.prototype._write;
ServerDuplexStreamImpl.prototype._final =
ServerWritableStreamImpl.prototype._final;
ServerDuplexStreamImpl.prototype.end = ServerWritableStreamImpl.prototype.end;
// Unary response callback signature.
export type sendUnaryData<ResponseType> = (
error: ServerErrorResponse | ServerStatusResponse | null,
value: ResponseType | null,
trailer?: Metadata,
flags?: number
) => void;
// User provided handler for unary calls.
export type handleUnaryCall<RequestType, ResponseType> = (
call: ServerUnaryCall<RequestType, ResponseType>,
callback: sendUnaryData<ResponseType>
) => void;
// User provided handler for client streaming calls.
export type handleClientStreamingCall<RequestType, ResponseType> = (
call: ServerReadableStream<RequestType, ResponseType>,
callback: sendUnaryData<ResponseType>
) => void;
// User provided handler for server streaming calls.
export type handleServerStreamingCall<RequestType, ResponseType> = (
call: ServerWritableStream<RequestType, ResponseType>
) => void;
// User provided handler for bidirectional streaming calls.
export type handleBidiStreamingCall<RequestType, ResponseType> = (
call: ServerDuplexStream<RequestType, ResponseType>
) => void;
export type HandleCall<RequestType, ResponseType> =
| handleUnaryCall<RequestType, ResponseType>
| handleClientStreamingCall<RequestType, ResponseType>
| handleServerStreamingCall<RequestType, ResponseType>
| handleBidiStreamingCall<RequestType, ResponseType>;
export interface UnaryHandler<RequestType, ResponseType> {
func: handleUnaryCall<RequestType, ResponseType>;
serialize: Serialize<ResponseType>;
deserialize: Deserialize<RequestType>;
type: HandlerType;
}
export interface ClientStreamingHandler<RequestType, ResponseType> {
func: handleClientStreamingCall<RequestType, ResponseType>;
serialize: Serialize<ResponseType>;
deserialize: Deserialize<RequestType>;
type: HandlerType;
}
export interface ServerStreamingHandler<RequestType, ResponseType> {
func: handleServerStreamingCall<RequestType, ResponseType>;
serialize: Serialize<ResponseType>;
deserialize: Deserialize<RequestType>;
type: HandlerType;
}
export interface BidiStreamingHandler<RequestType, ResponseType> {
func: handleBidiStreamingCall<RequestType, ResponseType>;
serialize: Serialize<ResponseType>;
deserialize: Deserialize<RequestType>;
type: HandlerType;
}
export type Handler<RequestType, ResponseType> =
| UnaryHandler<RequestType, ResponseType>
| ClientStreamingHandler<RequestType, ResponseType>
| ServerStreamingHandler<RequestType, ResponseType>
| BidiStreamingHandler<RequestType, ResponseType>;
export type HandlerType = 'bidi' | 'clientStream' | 'serverStream' | 'unary';
const noopTimer: NodeJS.Timer = setTimeout(() => {}, 0);
// Internal class that wraps the HTTP2 request.
export class Http2ServerCallStream<
RequestType,
ResponseType
> extends EventEmitter {
cancelled = false;
deadline: NodeJS.Timer = noopTimer;
private wantTrailers = false;
private metadataSent = false;
private canPush = false;
private isPushPending = false;
private bufferedMessages: Array<Buffer | null> = [];
private messagesToPush: Array<RequestType | null> = [];
private maxSendMessageSize: number = DEFAULT_MAX_SEND_MESSAGE_LENGTH;
private maxReceiveMessageSize: number = DEFAULT_MAX_RECEIVE_MESSAGE_LENGTH;
constructor(
private stream: http2.ServerHttp2Stream,
private handler: Handler<RequestType, ResponseType>,
private options: ChannelOptions
) {
super();
this.stream.once('error', (err: ServerErrorResponse) => {
/* We need an error handler to avoid uncaught error event exceptions, but
* there is nothing we can reasonably do here. Any error event should
* have a corresponding close event, which handles emitting the cancelled
* event. And the stream is now in a bad state, so we can't reasonably
* expect to be able to send an error over it. */
});
this.stream.once('close', () => {
this.cancelled = true;
this.emit('cancelled', 'cancelled');
});
this.stream.on('drain', () => {
this.emit('drain');
});
if ('grpc.max_send_message_length' in options) {
this.maxSendMessageSize = options['grpc.max_send_message_length']!;
}
if ('grpc.max_receive_message_length' in options) {
this.maxReceiveMessageSize = options['grpc.max_receive_message_length']!;
}
}
private checkCancelled(): boolean {
/* In some cases the stream can become destroyed before the close event
* fires. That creates a race condition that this check works around */
if (this.stream.destroyed) {
this.cancelled = true;
}
return this.cancelled;
}
sendMetadata(customMetadata?: Metadata) {
if (this.checkCancelled()) {
return;
}
if (this.metadataSent) {
return;
}
this.metadataSent = true;
const custom = customMetadata ? customMetadata.toHttp2Headers() : null;
// TODO(cjihrig): Include compression headers.
const headers = Object.assign(defaultResponseHeaders, custom);
this.stream.respond(headers, defaultResponseOptions);
}
receiveMetadata(headers: http2.IncomingHttpHeaders) {
const metadata = Metadata.fromHttp2Headers(headers);
// TODO(cjihrig): Receive compression metadata.
const timeoutHeader = metadata.get(GRPC_TIMEOUT_HEADER);
if (timeoutHeader.length > 0) {
const match = timeoutHeader[0].toString().match(DEADLINE_REGEX);
if (match === null) {
const err = new Error('Invalid deadline') as ServerErrorResponse;
err.code = Status.OUT_OF_RANGE;
this.sendError(err);
return;
}
const timeout = (+match[1] * deadlineUnitsToMs[match[2]]) | 0;
this.deadline = setTimeout(handleExpiredDeadline, timeout, this);
metadata.remove(GRPC_TIMEOUT_HEADER);
}
// Remove several headers that should not be propagated to the application
metadata.remove(http2.constants.HTTP2_HEADER_ACCEPT_ENCODING);
metadata.remove(http2.constants.HTTP2_HEADER_TE);
metadata.remove(http2.constants.HTTP2_HEADER_CONTENT_TYPE);
metadata.remove('grpc-encoding');
metadata.remove('grpc-accept-encoding');
return metadata;
}
receiveUnaryMessage(): Promise<RequestType> {
return new Promise((resolve, reject) => {
const stream = this.stream;
const chunks: Buffer[] = [];
let totalLength = 0;
stream.on('data', (data: Buffer) => {
chunks.push(data);
totalLength += data.byteLength;
});
stream.once('end', async () => {
try {
const requestBytes = Buffer.concat(chunks, totalLength);
if (this.maxReceiveMessageSize !== -1 && requestBytes.length > this.maxReceiveMessageSize) {
this.sendError({
code: Status.RESOURCE_EXHAUSTED,
details: `Received message larger than max (${requestBytes.length} vs. ${this.maxReceiveMessageSize})`
});
resolve();
}
resolve(await this.deserializeMessage(requestBytes));
} catch (err) {
err.code = Status.INTERNAL;
this.sendError(err);
resolve();
}
});
});
}
serializeMessage(value: ResponseType) {
const messageBuffer = this.handler.serialize(value);
// TODO(cjihrig): Call compression aware serializeMessage().
const byteLength = messageBuffer.byteLength;
const output = Buffer.allocUnsafe(byteLength + 5);
output.writeUInt8(0, 0);
output.writeUInt32BE(byteLength, 1);
messageBuffer.copy(output, 5);
return output;
}
async deserializeMessage(bytes: Buffer) {
// TODO(cjihrig): Call compression aware deserializeMessage().
const receivedMessage = bytes.slice(5);
return this.handler.deserialize(receivedMessage);
}
async sendUnaryMessage(
err: ServerErrorResponse | ServerStatusResponse | null,
value: ResponseType | null,
metadata?: Metadata,
flags?: number
) {
if (this.checkCancelled()) {
return;
}
if (!metadata) {
metadata = new Metadata();
}
if (err) {
if (!err.hasOwnProperty('metadata')) {
err.metadata = metadata;
}
this.sendError(err);
return;
}
try {
const response = await this.serializeMessage(value!);
this.write(response);
this.sendStatus({ code: Status.OK, details: 'OK', metadata });
} catch (err) {
err.code = Status.INTERNAL;
this.sendError(err);
}
}
sendStatus(statusObj: StatusObject) {
if (this.checkCancelled()) {
return;
}
clearTimeout(this.deadline);
if (!this.wantTrailers) {
this.wantTrailers = true;
this.stream.once('wantTrailers', () => {
const trailersToSend = Object.assign(
{
[GRPC_STATUS_HEADER]: statusObj.code,
[GRPC_MESSAGE_HEADER]: encodeURI(statusObj.details as string),
},
statusObj.metadata.toHttp2Headers()
);
this.stream.sendTrailers(trailersToSend);
});
this.sendMetadata();
this.stream.end();
}
}
sendError(error: ServerErrorResponse | ServerStatusResponse) {
if (this.checkCancelled()) {
return;
}
const status: StatusObject = {
code: Status.UNKNOWN,
details: 'message' in error ? error.message : 'Unknown Error',
metadata:
'metadata' in error && error.metadata !== undefined
? error.metadata
: new Metadata(),
};
if (
'code' in error &&
typeof error.code === 'number' &&
Number.isInteger(error.code)
) {
status.code = error.code;
if ('details' in error && typeof error.details === 'string') {
status.details = error.details!;
}
}
this.sendStatus(status);
}
write(chunk: Buffer) {
if (this.checkCancelled()) {
return;
}
if (this.maxSendMessageSize !== -1 && chunk.length > this.maxSendMessageSize) {
this.sendError({
code: Status.RESOURCE_EXHAUSTED,
details: `Sent message larger than max (${chunk.length} vs. ${this.maxSendMessageSize})`
});
return;
}
this.sendMetadata();
return this.stream.write(chunk);
}
resume() {
this.stream.resume();
}
setupSurfaceCall(call: ServerSurfaceCall) {
this.once('cancelled', reason => {
call.cancelled = true;
call.emit('cancelled', reason);
});
}
setupReadable(
readable:
| ServerReadableStream<RequestType, ResponseType>
| ServerDuplexStream<RequestType, ResponseType>
) {
const decoder = new StreamDecoder();
this.stream.on('data', async (data: Buffer) => {
const messages = decoder.write(data);
for (const message of messages) {
if (this.maxReceiveMessageSize !== -1 && message.length > this.maxReceiveMessageSize) {
this.sendError({
code: Status.RESOURCE_EXHAUSTED,
details: `Received message larger than max (${message.length} vs. ${this.maxReceiveMessageSize})`
});
return;
}
this.pushOrBufferMessage(readable, message);
}
});
this.stream.once('end', () => {
this.pushOrBufferMessage(readable, null);
});
}
consumeUnpushedMessages(
readable:
| ServerReadableStream<RequestType, ResponseType>
| ServerDuplexStream<RequestType, ResponseType>
): boolean {
this.canPush = true;
while (this.messagesToPush.length > 0) {
const nextMessage = this.messagesToPush.shift();
const canPush = readable.push(nextMessage);
if (nextMessage === null || canPush === false) {
this.canPush = false;
break;
}
}
return this.canPush;
}
private pushOrBufferMessage(
readable:
| ServerReadableStream<RequestType, ResponseType>
| ServerDuplexStream<RequestType, ResponseType>,
messageBytes: Buffer | null
): void {
if (this.isPushPending) {
this.bufferedMessages.push(messageBytes);
} else {
this.pushMessage(readable, messageBytes);
}
}
private async pushMessage(
readable:
| ServerReadableStream<RequestType, ResponseType>
| ServerDuplexStream<RequestType, ResponseType>,
messageBytes: Buffer | null
) {
if (messageBytes === null) {
if (this.canPush) {
readable.push(null);
} else {
this.messagesToPush.push(null);
}
return;
}
this.isPushPending = true;
try {
const deserialized = await this.deserializeMessage(messageBytes);
if (this.canPush) {
if (!readable.push(deserialized)) {
this.canPush = false;
this.stream.pause();
}
} else {
this.messagesToPush.push(deserialized);
}
} catch (err) {
// Ignore any remaining messages when errors occur.
this.bufferedMessages.length = 0;
err.code = Status.INTERNAL;
readable.emit('error', err);
}
this.isPushPending = false;
if (this.bufferedMessages.length > 0) {
this.pushMessage(
readable,
this.bufferedMessages.shift() as Buffer | null
);
}
}
}
// tslint:disable:no-any
type UntypedServerCall = Http2ServerCallStream<any, any>;
function handleExpiredDeadline(call: UntypedServerCall) {
const err = new Error('Deadline exceeded') as ServerErrorResponse;
err.code = Status.DEADLINE_EXCEEDED;
call.sendError(err);
call.cancelled = true;
call.emit('cancelled', 'deadline');
}