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Diffstat (limited to 'frontend-old/node_modules/@grpc/grpc-js/src/subchannel-call.ts')
| -rw-r--r-- | frontend-old/node_modules/@grpc/grpc-js/src/subchannel-call.ts | 547 |
1 files changed, 547 insertions, 0 deletions
diff --git a/frontend-old/node_modules/@grpc/grpc-js/src/subchannel-call.ts b/frontend-old/node_modules/@grpc/grpc-js/src/subchannel-call.ts new file mode 100644 index 0000000..b9f3191 --- /dev/null +++ b/frontend-old/node_modules/@grpc/grpc-js/src/subchannel-call.ts @@ -0,0 +1,547 @@ +/* + * 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 * as http2 from 'http2'; +import * as os from 'os'; + +import { DEFAULT_MAX_RECEIVE_MESSAGE_LENGTH, Status } from './constants'; +import { Metadata } from './metadata'; +import { StreamDecoder } from './stream-decoder'; +import * as logging from './logging'; +import { LogVerbosity } from './constants'; +import { + InterceptingListener, + MessageContext, + StatusObject, + WriteCallback, +} from './call-interface'; +import { CallEventTracker, Transport } from './transport'; + +const TRACER_NAME = 'subchannel_call'; + +/** + * https://nodejs.org/api/errors.html#errors_class_systemerror + */ +interface SystemError extends Error { + address?: string; + code: string; + dest?: string; + errno: number; + info?: object; + message: string; + path?: string; + port?: number; + syscall: string; +} + +/** + * Should do approximately the same thing as util.getSystemErrorName but the + * TypeScript types don't have that function for some reason so I just made my + * own. + * @param errno + */ +function getSystemErrorName(errno: number): string { + for (const [name, num] of Object.entries(os.constants.errno)) { + if (num === errno) { + return name; + } + } + return 'Unknown system error ' + errno; +} + +export interface SubchannelCall { + cancelWithStatus(status: Status, details: string): void; + getPeer(): string; + sendMessageWithContext(context: MessageContext, message: Buffer): void; + startRead(): void; + halfClose(): void; + getCallNumber(): number; +} + +export interface StatusObjectWithRstCode extends StatusObject { + rstCode?: number; +} + +export interface SubchannelCallInterceptingListener + extends InterceptingListener { + onReceiveStatus(status: StatusObjectWithRstCode): void; +} + +export class Http2SubchannelCall implements SubchannelCall { + private decoder: StreamDecoder; + + private isReadFilterPending = false; + private isPushPending = false; + private canPush = false; + /** + * Indicates that an 'end' event has come from the http2 stream, so there + * will be no more data events. + */ + private readsClosed = false; + + private statusOutput = false; + + private unpushedReadMessages: Buffer[] = []; + + // Status code mapped from :status. To be used if grpc-status is not received + private mappedStatusCode: Status = Status.UNKNOWN; + + // This is populated (non-null) if and only if the call has ended + private finalStatus: StatusObject | null = null; + + private internalError: SystemError | null = null; + + constructor( + private readonly http2Stream: http2.ClientHttp2Stream, + private readonly callEventTracker: CallEventTracker, + private readonly listener: SubchannelCallInterceptingListener, + private readonly transport: Transport, + private readonly callId: number + ) { + const maxReceiveMessageLength = transport.getOptions()['grpc.max_receive_message_length'] ?? DEFAULT_MAX_RECEIVE_MESSAGE_LENGTH; + this.decoder = new StreamDecoder(maxReceiveMessageLength); + http2Stream.on('response', (headers, flags) => { + let headersString = ''; + for (const header of Object.keys(headers)) { + headersString += '\t\t' + header + ': ' + headers[header] + '\n'; + } + this.trace('Received server headers:\n' + headersString); + switch (headers[':status']) { + // TODO(murgatroid99): handle 100 and 101 + case 400: + this.mappedStatusCode = Status.INTERNAL; + break; + case 401: + this.mappedStatusCode = Status.UNAUTHENTICATED; + break; + case 403: + this.mappedStatusCode = Status.PERMISSION_DENIED; + break; + case 404: + this.mappedStatusCode = Status.UNIMPLEMENTED; + break; + case 429: + case 502: + case 503: + case 504: + this.mappedStatusCode = Status.UNAVAILABLE; + break; + default: + this.mappedStatusCode = Status.UNKNOWN; + } + + if (flags & http2.constants.NGHTTP2_FLAG_END_STREAM) { + this.handleTrailers(headers); + } else { + let metadata: Metadata; + try { + metadata = Metadata.fromHttp2Headers(headers); + } catch (error) { + this.endCall({ + code: Status.UNKNOWN, + details: (error as Error).message, + metadata: new Metadata(), + }); + return; + } + this.listener.onReceiveMetadata(metadata); + } + }); + http2Stream.on('trailers', (headers: http2.IncomingHttpHeaders) => { + this.handleTrailers(headers); + }); + http2Stream.on('data', (data: Buffer) => { + /* If the status has already been output, allow the http2 stream to + * drain without processing the data. */ + if (this.statusOutput) { + return; + } + this.trace('receive HTTP/2 data frame of length ' + data.length); + let messages: Buffer[]; + try { + messages = this.decoder.write(data); + } catch (e) { + this.cancelWithStatus(Status.RESOURCE_EXHAUSTED, (e as Error).message); + return; + } + + for (const message of messages) { + this.trace('parsed message of length ' + message.length); + this.callEventTracker!.addMessageReceived(); + this.tryPush(message); + } + }); + http2Stream.on('end', () => { + this.readsClosed = true; + this.maybeOutputStatus(); + }); + http2Stream.on('close', () => { + /* Use process.next tick to ensure that this code happens after any + * "error" event that may be emitted at about the same time, so that + * we can bubble up the error message from that event. */ + process.nextTick(() => { + this.trace('HTTP/2 stream closed with code ' + http2Stream.rstCode); + /* If we have a final status with an OK status code, that means that + * we have received all of the messages and we have processed the + * trailers and the call completed successfully, so it doesn't matter + * how the stream ends after that */ + if (this.finalStatus?.code === Status.OK) { + return; + } + let code: Status; + let details = ''; + switch (http2Stream.rstCode) { + case http2.constants.NGHTTP2_NO_ERROR: + /* If we get a NO_ERROR code and we already have a status, the + * stream completed properly and we just haven't fully processed + * it yet */ + if (this.finalStatus !== null) { + return; + } + code = Status.INTERNAL; + details = `Received RST_STREAM with code ${http2Stream.rstCode}`; + break; + case http2.constants.NGHTTP2_REFUSED_STREAM: + code = Status.UNAVAILABLE; + details = 'Stream refused by server'; + break; + case http2.constants.NGHTTP2_CANCEL: + code = Status.CANCELLED; + details = 'Call cancelled'; + break; + case http2.constants.NGHTTP2_ENHANCE_YOUR_CALM: + code = Status.RESOURCE_EXHAUSTED; + details = 'Bandwidth exhausted or memory limit exceeded'; + break; + case http2.constants.NGHTTP2_INADEQUATE_SECURITY: + code = Status.PERMISSION_DENIED; + details = 'Protocol not secure enough'; + break; + case http2.constants.NGHTTP2_INTERNAL_ERROR: + code = Status.INTERNAL; + if (this.internalError === null) { + /* This error code was previously handled in the default case, and + * there are several instances of it online, so I wanted to + * preserve the original error message so that people find existing + * information in searches, but also include the more recognizable + * "Internal server error" message. */ + details = `Received RST_STREAM with code ${http2Stream.rstCode} (Internal server error)`; + } else { + if ( + this.internalError.code === 'ECONNRESET' || + this.internalError.code === 'ETIMEDOUT' + ) { + code = Status.UNAVAILABLE; + details = this.internalError.message; + } else { + /* The "Received RST_STREAM with code ..." error is preserved + * here for continuity with errors reported online, but the + * error message at the end will probably be more relevant in + * most cases. */ + details = `Received RST_STREAM with code ${http2Stream.rstCode} triggered by internal client error: ${this.internalError.message}`; + } + } + break; + default: + code = Status.INTERNAL; + details = `Received RST_STREAM with code ${http2Stream.rstCode}`; + } + // This is a no-op if trailers were received at all. + // This is OK, because status codes emitted here correspond to more + // catastrophic issues that prevent us from receiving trailers in the + // first place. + this.endCall({ + code, + details, + metadata: new Metadata(), + rstCode: http2Stream.rstCode, + }); + }); + }); + http2Stream.on('error', (err: SystemError) => { + /* We need an error handler here to stop "Uncaught Error" exceptions + * from bubbling up. However, errors here should all correspond to + * "close" events, where we will handle the error more granularly */ + /* Specifically looking for stream errors that were *not* constructed + * from a RST_STREAM response here: + * https://github.com/nodejs/node/blob/8b8620d580314050175983402dfddf2674e8e22a/lib/internal/http2/core.js#L2267 + */ + if (err.code !== 'ERR_HTTP2_STREAM_ERROR') { + this.trace( + 'Node error event: message=' + + err.message + + ' code=' + + err.code + + ' errno=' + + getSystemErrorName(err.errno) + + ' syscall=' + + err.syscall + ); + this.internalError = err; + } + this.callEventTracker.onStreamEnd(false); + }); + } + + public onDisconnect() { + this.endCall({ + code: Status.UNAVAILABLE, + details: 'Connection dropped', + metadata: new Metadata(), + }); + } + + private outputStatus() { + /* Precondition: this.finalStatus !== null */ + if (!this.statusOutput) { + this.statusOutput = true; + this.trace( + 'ended with status: code=' + + this.finalStatus!.code + + ' details="' + + this.finalStatus!.details + + '"' + ); + this.callEventTracker.onCallEnd(this.finalStatus!); + /* We delay the actual action of bubbling up the status to insulate the + * cleanup code in this class from any errors that may be thrown in the + * upper layers as a result of bubbling up the status. In particular, + * if the status is not OK, the "error" event may be emitted + * synchronously at the top level, which will result in a thrown error if + * the user does not handle that event. */ + process.nextTick(() => { + this.listener.onReceiveStatus(this.finalStatus!); + }); + /* Leave the http2 stream in flowing state to drain incoming messages, to + * ensure that the stream closure completes. The call stream already does + * not push more messages after the status is output, so the messages go + * nowhere either way. */ + this.http2Stream.resume(); + } + } + + private trace(text: string): void { + logging.trace( + LogVerbosity.DEBUG, + TRACER_NAME, + '[' + this.callId + '] ' + text + ); + } + + /** + * On first call, emits a 'status' event with the given StatusObject. + * Subsequent calls are no-ops. + * @param status The status of the call. + */ + private endCall(status: StatusObjectWithRstCode): void { + /* If the status is OK and a new status comes in (e.g. from a + * deserialization failure), that new status takes priority */ + if (this.finalStatus === null || this.finalStatus.code === Status.OK) { + this.finalStatus = status; + this.maybeOutputStatus(); + } + this.destroyHttp2Stream(); + } + + private maybeOutputStatus() { + if (this.finalStatus !== null) { + /* The combination check of readsClosed and that the two message buffer + * arrays are empty checks that there all incoming data has been fully + * processed */ + if ( + this.finalStatus.code !== Status.OK || + (this.readsClosed && + this.unpushedReadMessages.length === 0 && + !this.isReadFilterPending && + !this.isPushPending) + ) { + this.outputStatus(); + } + } + } + + private push(message: Buffer): void { + this.trace( + 'pushing to reader message of length ' + + (message instanceof Buffer ? message.length : null) + ); + this.canPush = false; + this.isPushPending = true; + process.nextTick(() => { + this.isPushPending = false; + /* If we have already output the status any later messages should be + * ignored, and can cause out-of-order operation errors higher up in the + * stack. Checking as late as possible here to avoid any race conditions. + */ + if (this.statusOutput) { + return; + } + this.listener.onReceiveMessage(message); + this.maybeOutputStatus(); + }); + } + + private tryPush(messageBytes: Buffer): void { + if (this.canPush) { + this.http2Stream!.pause(); + this.push(messageBytes); + } else { + this.trace( + 'unpushedReadMessages.push message of length ' + messageBytes.length + ); + this.unpushedReadMessages.push(messageBytes); + } + } + + private handleTrailers(headers: http2.IncomingHttpHeaders) { + this.callEventTracker.onStreamEnd(true); + let headersString = ''; + for (const header of Object.keys(headers)) { + headersString += '\t\t' + header + ': ' + headers[header] + '\n'; + } + this.trace('Received server trailers:\n' + headersString); + let metadata: Metadata; + try { + metadata = Metadata.fromHttp2Headers(headers); + } catch (e) { + metadata = new Metadata(); + } + const metadataMap = metadata.getMap(); + let code: Status = this.mappedStatusCode; + if ( + code === Status.UNKNOWN && + typeof metadataMap['grpc-status'] === 'string' + ) { + const receivedStatus = Number(metadataMap['grpc-status']); + if (receivedStatus in Status) { + code = receivedStatus; + this.trace('received status code ' + receivedStatus + ' from server'); + } + metadata.remove('grpc-status'); + } + let details = ''; + if (typeof metadataMap['grpc-message'] === 'string') { + try { + details = decodeURI(metadataMap['grpc-message']); + } catch (e) { + details = metadataMap['grpc-message']; + } + metadata.remove('grpc-message'); + this.trace( + 'received status details string "' + details + '" from server' + ); + } + const status: StatusObject = { code, details, metadata }; + // This is a no-op if the call was already ended when handling headers. + this.endCall(status); + } + + private destroyHttp2Stream() { + // The http2 stream could already have been destroyed if cancelWithStatus + // is called in response to an internal http2 error. + if (!this.http2Stream.destroyed) { + /* If the call has ended with an OK status, communicate that when closing + * the stream, partly to avoid a situation in which we detect an error + * RST_STREAM as a result after we have the status */ + let code: number; + if (this.finalStatus?.code === Status.OK) { + code = http2.constants.NGHTTP2_NO_ERROR; + } else { + code = http2.constants.NGHTTP2_CANCEL; + } + this.trace('close http2 stream with code ' + code); + this.http2Stream.close(code); + } + } + + cancelWithStatus(status: Status, details: string): void { + this.trace( + 'cancelWithStatus code: ' + status + ' details: "' + details + '"' + ); + this.endCall({ code: status, details, metadata: new Metadata() }); + } + + getStatus(): StatusObject | null { + return this.finalStatus; + } + + getPeer(): string { + return this.transport.getPeerName(); + } + + getCallNumber(): number { + return this.callId; + } + + startRead() { + /* If the stream has ended with an error, we should not emit any more + * messages and we should communicate that the stream has ended */ + if (this.finalStatus !== null && this.finalStatus.code !== Status.OK) { + this.readsClosed = true; + this.maybeOutputStatus(); + return; + } + this.canPush = true; + if (this.unpushedReadMessages.length > 0) { + const nextMessage: Buffer = this.unpushedReadMessages.shift()!; + this.push(nextMessage); + return; + } + /* Only resume reading from the http2Stream if we don't have any pending + * messages to emit */ + this.http2Stream.resume(); + } + + sendMessageWithContext(context: MessageContext, message: Buffer) { + this.trace('write() called with message of length ' + message.length); + const cb: WriteCallback = (error?: Error | null) => { + /* nextTick here ensures that no stream action can be taken in the call + * stack of the write callback, in order to hopefully work around + * https://github.com/nodejs/node/issues/49147 */ + process.nextTick(() => { + let code: Status = Status.UNAVAILABLE; + if ( + (error as NodeJS.ErrnoException)?.code === + 'ERR_STREAM_WRITE_AFTER_END' + ) { + code = Status.INTERNAL; + } + if (error) { + this.cancelWithStatus(code, `Write error: ${error.message}`); + } + context.callback?.(); + }); + }; + this.trace('sending data chunk of length ' + message.length); + this.callEventTracker.addMessageSent(); + try { + this.http2Stream!.write(message, cb); + } catch (error) { + this.endCall({ + code: Status.UNAVAILABLE, + details: `Write failed with error ${(error as Error).message}`, + metadata: new Metadata(), + }); + } + } + + halfClose() { + this.trace('end() called'); + this.trace('calling end() on HTTP/2 stream'); + this.http2Stream.end(); + } +} |