@grpc/grpc-js
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gRPC Library for Node - pure JS implementation
256 lines • 10.3 kB
JavaScript
;
/*
* 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.
*
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.CompressionFilterFactory = exports.CompressionFilter = void 0;
const zlib = require("zlib");
const compression_algorithms_1 = require("./compression-algorithms");
const constants_1 = require("./constants");
const filter_1 = require("./filter");
const logging = require("./logging");
const isCompressionAlgorithmKey = (key) => {
return typeof key === 'number' && typeof compression_algorithms_1.CompressionAlgorithms[key] === 'string';
};
class CompressionHandler {
/**
* @param message Raw uncompressed message bytes
* @param compress Indicates whether the message should be compressed
* @return Framed message, compressed if applicable
*/
async writeMessage(message, compress) {
let messageBuffer = message;
if (compress) {
messageBuffer = await this.compressMessage(messageBuffer);
}
const output = Buffer.allocUnsafe(messageBuffer.length + 5);
output.writeUInt8(compress ? 1 : 0, 0);
output.writeUInt32BE(messageBuffer.length, 1);
messageBuffer.copy(output, 5);
return output;
}
/**
* @param data Framed message, possibly compressed
* @return Uncompressed message
*/
async readMessage(data) {
const compressed = data.readUInt8(0) === 1;
let messageBuffer = data.slice(5);
if (compressed) {
messageBuffer = await this.decompressMessage(messageBuffer);
}
return messageBuffer;
}
}
class IdentityHandler extends CompressionHandler {
async compressMessage(message) {
return message;
}
async writeMessage(message, compress) {
const output = Buffer.allocUnsafe(message.length + 5);
/* With "identity" compression, messages should always be marked as
* uncompressed */
output.writeUInt8(0, 0);
output.writeUInt32BE(message.length, 1);
message.copy(output, 5);
return output;
}
decompressMessage(message) {
return Promise.reject(new Error('Received compressed message but "grpc-encoding" header was identity'));
}
}
class DeflateHandler extends CompressionHandler {
compressMessage(message) {
return new Promise((resolve, reject) => {
zlib.deflate(message, (err, output) => {
if (err) {
reject(err);
}
else {
resolve(output);
}
});
});
}
decompressMessage(message) {
return new Promise((resolve, reject) => {
zlib.inflate(message, (err, output) => {
if (err) {
reject(err);
}
else {
resolve(output);
}
});
});
}
}
class GzipHandler extends CompressionHandler {
compressMessage(message) {
return new Promise((resolve, reject) => {
zlib.gzip(message, (err, output) => {
if (err) {
reject(err);
}
else {
resolve(output);
}
});
});
}
decompressMessage(message) {
return new Promise((resolve, reject) => {
zlib.unzip(message, (err, output) => {
if (err) {
reject(err);
}
else {
resolve(output);
}
});
});
}
}
class UnknownHandler extends CompressionHandler {
constructor(compressionName) {
super();
this.compressionName = compressionName;
}
compressMessage(message) {
return Promise.reject(new Error(`Received message compressed with unsupported compression method ${this.compressionName}`));
}
decompressMessage(message) {
// This should be unreachable
return Promise.reject(new Error(`Compression method not supported: ${this.compressionName}`));
}
}
function getCompressionHandler(compressionName) {
switch (compressionName) {
case 'identity':
return new IdentityHandler();
case 'deflate':
return new DeflateHandler();
case 'gzip':
return new GzipHandler();
default:
return new UnknownHandler(compressionName);
}
}
class CompressionFilter extends filter_1.BaseFilter {
constructor(channelOptions, sharedFilterConfig) {
var _a;
super();
this.sharedFilterConfig = sharedFilterConfig;
this.sendCompression = new IdentityHandler();
this.receiveCompression = new IdentityHandler();
this.currentCompressionAlgorithm = 'identity';
const compressionAlgorithmKey = channelOptions['grpc.default_compression_algorithm'];
if (compressionAlgorithmKey !== undefined) {
if (isCompressionAlgorithmKey(compressionAlgorithmKey)) {
const clientSelectedEncoding = compression_algorithms_1.CompressionAlgorithms[compressionAlgorithmKey];
const serverSupportedEncodings = (_a = sharedFilterConfig.serverSupportedEncodingHeader) === null || _a === void 0 ? void 0 : _a.split(',');
/**
* There are two possible situations here:
* 1) We don't have any info yet from the server about what compression it supports
* In that case we should just use what the client tells us to use
* 2) We've previously received a response from the server including a grpc-accept-encoding header
* In that case we only want to use the encoding chosen by the client if the server supports it
*/
if (!serverSupportedEncodings || serverSupportedEncodings.includes(clientSelectedEncoding)) {
this.currentCompressionAlgorithm = clientSelectedEncoding;
this.sendCompression = getCompressionHandler(this.currentCompressionAlgorithm);
}
}
else {
logging.log(constants_1.LogVerbosity.ERROR, `Invalid value provided for grpc.default_compression_algorithm option: ${compressionAlgorithmKey}`);
}
}
}
async sendMetadata(metadata) {
const headers = await metadata;
headers.set('grpc-accept-encoding', 'identity,deflate,gzip');
headers.set('accept-encoding', 'identity');
// No need to send the header if it's "identity" - behavior is identical; save the bandwidth
if (this.currentCompressionAlgorithm === 'identity') {
headers.remove('grpc-encoding');
}
else {
headers.set('grpc-encoding', this.currentCompressionAlgorithm);
}
return headers;
}
receiveMetadata(metadata) {
const receiveEncoding = metadata.get('grpc-encoding');
if (receiveEncoding.length > 0) {
const encoding = receiveEncoding[0];
if (typeof encoding === 'string') {
this.receiveCompression = getCompressionHandler(encoding);
}
}
metadata.remove('grpc-encoding');
/* Check to see if the compression we're using to send messages is supported by the server
* If not, reset the sendCompression filter and have it use the default IdentityHandler */
const serverSupportedEncodingsHeader = metadata.get('grpc-accept-encoding')[0];
if (serverSupportedEncodingsHeader) {
this.sharedFilterConfig.serverSupportedEncodingHeader = serverSupportedEncodingsHeader;
const serverSupportedEncodings = serverSupportedEncodingsHeader.split(',');
if (!serverSupportedEncodings.includes(this.currentCompressionAlgorithm)) {
this.sendCompression = new IdentityHandler();
this.currentCompressionAlgorithm = 'identity';
}
}
metadata.remove('grpc-accept-encoding');
return metadata;
}
async sendMessage(message) {
var _a;
/* This filter is special. The input message is the bare message bytes,
* and the output is a framed and possibly compressed message. For this
* reason, this filter should be at the bottom of the filter stack */
const resolvedMessage = await message;
let compress;
if (this.sendCompression instanceof IdentityHandler) {
compress = false;
}
else {
compress = (((_a = resolvedMessage.flags) !== null && _a !== void 0 ? _a : 0) & 2 /* WriteFlags.NoCompress */) === 0;
}
return {
message: await this.sendCompression.writeMessage(resolvedMessage.message, compress),
flags: resolvedMessage.flags,
};
}
async receiveMessage(message) {
/* This filter is also special. The input message is framed and possibly
* compressed, and the output message is deframed and uncompressed. So
* this is another reason that this filter should be at the bottom of the
* filter stack. */
return this.receiveCompression.readMessage(await message);
}
}
exports.CompressionFilter = CompressionFilter;
class CompressionFilterFactory {
constructor(channel, options) {
this.channel = channel;
this.options = options;
this.sharedFilterConfig = {};
}
createFilter() {
return new CompressionFilter(this.options, this.sharedFilterConfig);
}
}
exports.CompressionFilterFactory = CompressionFilterFactory;
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