@hashgraph/sdk
Version:
238 lines (207 loc) • 8.68 kB
JavaScript
// SPDX-License-Identifier: Apache-2.0
import Channel, { encodeRequest, decodeUnaryResponse } from "./Channel.js";
import * as base64 from "../encoding/base64.native.js";
import HttpError from "../http/HttpError.js";
import HttpStatus from "../http/HttpStatus.js";
import { SDK_NAME, SDK_VERSION } from "../version.js";
import GrpcServiceError from "../grpc/GrpcServiceError.js";
import GrpcStatus from "../grpc/GrpcStatus.js";
export default class NativeChannel extends Channel {
/**
* @param {string} address
* @param {number=} grpcDeadline
*/
constructor(address, grpcDeadline) {
super(grpcDeadline);
/**
* @type {string}
* @private
*/
this._address = address;
/**
* Flag indicating if the connection is ready (health check has passed)
* Set to true after the first successful health check
*
* @type {boolean}
* @private
*/
this._isReady = false;
}
/**
* @override
* @returns {void}
*/
close() {
// do nothing
}
/**
* Check if the gRPC-Web proxy is reachable and healthy
* Performs a POST request and verifies the response has gRPC-Web headers,
* which indicates the proxy is running and processing gRPC requests.
* Results are cached per address for the entire lifecycle.
*
* @param {Date} deadline - Deadline for the health check
* @returns {Promise<void>}
* @private
*/
async _waitForReady(deadline) {
// Check if we've already validated this address
if (this._isReady) {
return; // Health check already passed for this address
}
const shouldUseHttps = !(
this._address.includes("localhost") ||
this._address.includes("127.0.0.1")
);
const address = shouldUseHttps
? `https://${this._address}`
: `http://${this._address}`;
// Calculate remaining time until deadline
const timeoutMs = deadline.getTime() - Date.now();
if (timeoutMs <= 0) {
throw new GrpcServiceError(GrpcStatus.Timeout);
}
const abortController = new AbortController();
const timeoutId = setTimeout(() => abortController.abort(), timeoutMs);
try {
// Make a POST request to verify the gRPC-Web proxy is running
// We use a minimal gRPC-Web compatible request
//eslint-disable-next-line n/no-unsupported-features/node-builtins
const response = await fetch(address, {
method: "POST",
headers: {
"content-type": "application/grpc-web-text",
"x-user-agent": `${SDK_NAME}/${SDK_VERSION}`,
"x-grpc-web": "1",
},
body: base64.encode(new Uint8Array(0)), // Empty body for health check
signal: abortController.signal,
});
clearTimeout(timeoutId);
// Check if response is successful (200) and has gRPC headers
if (response.status === 200) {
const grpcStatus = response.headers.get("grpc-status");
const grpcMessage = response.headers.get("grpc-message");
// If gRPC headers exist, the proxy is running and processing requests
if (grpcStatus != null || grpcMessage != null) {
// Mark this connection as ready
this._isReady = true;
return; // Healthy - gRPC-Web proxy is responding
}
}
// If we get here, either status isn't 200 or no gRPC headers present
// This means the proxy might not be configured correctly or not running
throw new GrpcServiceError(GrpcStatus.Unavailable);
} catch (error) {
clearTimeout(timeoutId);
if (error instanceof Error && error.name === "AbortError") {
throw new GrpcServiceError(GrpcStatus.Timeout);
}
if (error instanceof GrpcServiceError) {
throw error;
}
// Network error - server is not reachable
throw new GrpcServiceError(GrpcStatus.Unavailable);
}
}
/**
* @override
* @protected
* @param {string} serviceName
* @returns {import("protobufjs").RPCImpl}
*/
_createUnaryClient(serviceName) {
// eslint-disable-next-line @typescript-eslint/no-misused-promises
return async (method, requestData, callback) => {
// Calculate deadline for connection check
const deadline = new Date();
const milliseconds = this._grpcDeadline;
deadline.setMilliseconds(deadline.getMilliseconds() + milliseconds);
try {
// Wait for connection to be ready (similar to gRPC waitForReady)
await this._waitForReady(deadline);
const data = base64.encode(
new Uint8Array(encodeRequest(requestData)),
);
const shouldUseHttps = !(
this._address.includes("localhost") ||
this._address.includes("127.0.0.1")
);
const address = shouldUseHttps
? `https://${this._address}`
: `http://${this._address}`;
// this will be executed in react native environment sho
// fetch should be available
//eslint-disable-next-line n/no-unsupported-features/node-builtins
const response = await fetch(
`${address}/proto.${serviceName}/${method.name}`,
{
method: "POST",
headers: {
"content-type": "application/grpc-web-text",
"x-user-agent": `${SDK_NAME}/${SDK_VERSION}`,
"x-accept-content-transfer-encoding": "base64",
"x-grpc-web": "1",
},
body: data,
},
);
if (!response.ok) {
const error = new HttpError(
HttpStatus._fromValue(response.status),
);
callback(error, null);
}
const blob = await response.blob();
/** @type {string} */
const responseData = await new Promise((resolve, reject) => {
const reader = new FileReader();
reader.readAsDataURL(blob);
reader.onloadend = () => {
resolve(/** @type {string} */ (reader.result));
};
reader.onerror = reject;
});
let responseBuffer;
if (
responseData.startsWith(
"data:application/octet-stream;base64,",
)
) {
responseBuffer = base64.decode(
responseData.split(
"data:application/octet-stream;base64,",
)[1],
);
} else if (
responseData.startsWith(
"data:application/grpc-web+proto;base64,",
)
) {
responseBuffer = base64.decode(
responseData.split(
"data:application/grpc-web+proto;base64,",
)[1],
);
} else {
throw new Error(
`Expected response data to be base64 encode with a 'data:application/octet-stream;base64,' or 'data:application/grpc-web+proto;base64,' prefix, but found: ${responseData}`,
);
}
const unaryResponse = decodeUnaryResponse(
// @ts-ignore
responseBuffer.buffer,
responseBuffer.byteOffset,
responseBuffer.byteLength,
);
callback(null, unaryResponse);
} catch (error) {
if (error instanceof GrpcServiceError) {
callback(error, null);
return;
}
callback(/** @type {Error} */ (error), null);
}
};
}
}