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index.ts
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index.ts
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import { JsonObject } from '@dfinity/candid';
import { Principal } from '@dfinity/principal';
import { AgentError } from '../../errors';
import { AnonymousIdentity, Identity } from '../../auth';
import * as cbor from '../../cbor';
import { RequestId, requestIdOf } from '../../request_id';
import { fromHex } from '../../utils/buffer';
import {
Agent,
QueryFields,
QueryResponse,
ReadStateOptions,
ReadStateResponse,
SubmitResponse,
} from '../api';
import { Expiry, makeNonceTransform } from './transforms';
import {
CallRequest,
Endpoint,
HttpAgentRequest,
HttpAgentRequestTransformFn,
HttpAgentSubmitRequest,
makeNonce,
QueryRequest,
ReadRequestType,
SubmitRequestType,
} from './types';
export * from './transforms';
export { Nonce, makeNonce } from './types';
export enum RequestStatusResponseStatus {
Received = 'received',
Processing = 'processing',
Replied = 'replied',
Rejected = 'rejected',
Unknown = 'unknown',
Done = 'done',
}
// Default delta for ingress expiry is 5 minutes.
const DEFAULT_INGRESS_EXPIRY_DELTA_IN_MSECS = 5 * 60 * 1000;
// Root public key for the IC, encoded as hex
const IC_ROOT_KEY =
'308182301d060d2b0601040182dc7c0503010201060c2b0601040182dc7c05030201036100814' +
'c0e6ec71fab583b08bd81373c255c3c371b2e84863c98a4f1e08b74235d14fb5d9c0cd546d968' +
'5f913a0c0b2cc5341583bf4b4392e467db96d65b9bb4cb717112f8472e0d5a4d14505ffd7484' +
'b01291091c5f87b98883463f98091a0baaae';
// IC0 domain info
const IC0_DOMAIN = 'ic0.app';
const IC0_SUB_DOMAIN = '.ic0.app';
class HttpDefaultFetchError extends AgentError {
constructor(public readonly message: string) {
super(message);
}
}
export class IdentityInvalidError extends AgentError {
constructor(public readonly message: string) {
super(message);
}
}
// HttpAgent options that can be used at construction.
export interface HttpAgentOptions {
// Another HttpAgent to inherit configuration (pipeline and fetch) of. This
// is only used at construction.
source?: HttpAgent;
// A surrogate to the global fetch function. Useful for testing.
fetch?: typeof fetch;
// The host to use for the client. By default, uses the same host as
// the current page.
host?: string;
// The principal used to send messages. This cannot be empty at the request
// time (will throw).
identity?: Identity | Promise<Identity>;
credentials?: {
name: string;
password?: string;
};
/**
* Prevents the agent from providing a unique {@link Nonce} with each call.
* Enabling may cause rate limiting of identical requests
* at the boundary nodes.
*
* To add your own nonce generation logic, you can use the following:
* @example
* import {makeNonceTransform, makeNonce} from '@dfinity/agent';
* const agent = new HttpAgent({ disableNonce: true });
* agent.addTransform(makeNonceTransform(makeNonce);
* @default false
*/
disableNonce?: boolean;
/**
* Number of times to retry requests before throwing an error
* @default 3
*/
retryTimes?: number;
}
function getDefaultFetch(): typeof fetch {
let defaultFetch;
if (typeof window !== 'undefined') {
// Browser context
if (window.fetch) {
defaultFetch = window.fetch.bind(window);
} else {
throw new HttpDefaultFetchError(
'Fetch implementation was not available. You appear to be in a browser context, but window.fetch was not present.',
);
}
} else if (typeof global !== 'undefined') {
// Node context
if (global.fetch) {
defaultFetch = global.fetch.bind(global);
} else {
throw new HttpDefaultFetchError(
'Fetch implementation was not available. You appear to be in a Node.js context, but global.fetch was not available.',
);
}
} else if (typeof self !== 'undefined') {
if (self.fetch) {
defaultFetch = self.fetch.bind(self);
}
}
if (defaultFetch) {
return defaultFetch;
}
throw new HttpDefaultFetchError(
'Fetch implementation was not available. Please provide fetch to the HttpAgent constructor, or ensure it is available in the window or global context.',
);
}
type _RequestResponse = {
requestId: RequestId;
response: {
ok: Response['ok'];
status: Response['status'];
statusText: Response['statusText'];
};
};
// A HTTP agent allows users to interact with a client of the internet computer
// using the available methods. It exposes an API that closely follows the
// public view of the internet computer, and is not intended to be exposed
// directly to the majority of users due to its low-level interface.
//
// There is a pipeline to apply transformations to the request before sending
// it to the client. This is to decouple signature, nonce generation and
// other computations so that this class can stay as simple as possible while
// allowing extensions.
export class HttpAgent implements Agent {
public rootKey = fromHex(IC_ROOT_KEY);
private readonly _pipeline: HttpAgentRequestTransformFn[] = [];
private _identity: Promise<Identity> | null;
private readonly _fetch: typeof fetch;
private _timeDiffMsecs = 0;
private readonly _host: URL;
private readonly _credentials: string | undefined;
private _rootKeyFetched = false;
private _retryTimes = 3; // Retry requests 3 times before erroring by default
public readonly _isAgent = true;
constructor(options: HttpAgentOptions = {}) {
if (options.source) {
if (!(options.source instanceof HttpAgent)) {
throw new Error("An Agent's source can only be another HttpAgent");
}
this._pipeline = [...options.source._pipeline];
this._identity = options.source._identity;
this._fetch = options.source._fetch;
this._host = options.source._host;
this._credentials = options.source._credentials;
} else {
this._fetch = options.fetch || getDefaultFetch() || fetch.bind(global);
}
if (options.host !== undefined) {
if (!options.host.match(/^[a-z]+:/) && typeof window !== 'undefined') {
this._host = new URL(window.location.protocol + '//' + options.host);
} else {
this._host = new URL(options.host);
}
} else if (options.source !== undefined) {
// Safe to ignore here.
this._host = options.source._host;
} else {
const location = typeof window !== 'undefined' ? window.location : undefined;
if (!location) {
throw new Error('Must specify a host to connect to.');
}
this._host = new URL(location + '');
}
// Default is 3, only set if option is provided
if (options.retryTimes !== undefined) {
this._retryTimes = options.retryTimes;
}
// Rewrite to avoid redirects
if (this._host.hostname.endsWith(IC0_SUB_DOMAIN)) {
this._host.hostname = IC0_DOMAIN;
}
if (options.credentials) {
const { name, password } = options.credentials;
this._credentials = `${name}${password ? ':' + password : ''}`;
}
this._identity = Promise.resolve(options.identity || new AnonymousIdentity());
// Add a nonce transform to ensure calls are unique
if (!options.disableNonce) {
this.addTransform(makeNonceTransform(makeNonce));
}
}
public isLocal(): boolean {
const hostname = this._host.hostname;
return hostname === '127.0.0.1' || hostname.endsWith('localhost');
}
public addTransform(fn: HttpAgentRequestTransformFn, priority = fn.priority || 0): void {
// Keep the pipeline sorted at all time, by priority.
const i = this._pipeline.findIndex(x => (x.priority || 0) < priority);
this._pipeline.splice(i >= 0 ? i : this._pipeline.length, 0, Object.assign(fn, { priority }));
}
public async getPrincipal(): Promise<Principal> {
if (!this._identity) {
throw new IdentityInvalidError(
"This identity has expired due this application's security policy. Please refresh your authentication.",
);
}
return (await this._identity).getPrincipal();
}
public async call(
canisterId: Principal | string,
options: {
methodName: string;
arg: ArrayBuffer;
effectiveCanisterId?: Principal | string;
},
identity?: Identity | Promise<Identity>,
): Promise<SubmitResponse> {
const id = await (identity !== undefined ? await identity : await this._identity);
if (!id) {
throw new IdentityInvalidError(
"This identity has expired due this application's security policy. Please refresh your authentication.",
);
}
const canister = Principal.from(canisterId);
const ecid = options.effectiveCanisterId
? Principal.from(options.effectiveCanisterId)
: canister;
const sender: Principal = id.getPrincipal() || Principal.anonymous();
let ingress_expiry = new Expiry(DEFAULT_INGRESS_EXPIRY_DELTA_IN_MSECS);
// If the value is off by more than 30 seconds, reconcile system time with the network
if (Math.abs(this._timeDiffMsecs) > 1_000 * 30) {
ingress_expiry = new Expiry(DEFAULT_INGRESS_EXPIRY_DELTA_IN_MSECS + this._timeDiffMsecs);
}
const submit: CallRequest = {
request_type: SubmitRequestType.Call,
canister_id: canister,
method_name: options.methodName,
arg: options.arg,
sender,
ingress_expiry,
};
// eslint-disable-next-line @typescript-eslint/no-explicit-any
let transformedRequest: any = (await this._transform({
request: {
body: null,
method: 'POST',
headers: {
'Content-Type': 'application/cbor',
...(this._credentials ? { Authorization: 'Basic ' + btoa(this._credentials) } : {}),
},
},
endpoint: Endpoint.Call,
body: submit,
})) as HttpAgentSubmitRequest;
// Apply transform for identity.
transformedRequest = await id.transformRequest(transformedRequest);
const body = cbor.encode(transformedRequest.body);
// Run both in parallel. The fetch is quite expensive, so we have plenty of time to
// calculate the requestId locally.
const request = this._requestAndRetry(() =>
this._fetch('' + new URL(`/api/v2/canister/${ecid.toText()}/call`, this._host), {
...transformedRequest.request,
body,
}),
);
const [response, requestId] = await Promise.all([request, requestIdOf(submit)]);
return {
requestId,
response: {
ok: response.ok,
status: response.status,
statusText: response.statusText,
},
};
}
private async _requestAndRetry(request: () => Promise<Response>, tries = 0): Promise<Response> {
if (tries > this._retryTimes && this._retryTimes !== 0) {
throw new Error(
`AgentError: Exceeded configured limit of ${this._retryTimes} retry attempts. Please check your network connection or try again in a few moments`,
);
}
const response = await request();
if (!response.ok) {
const responseText = await response.clone().text();
const errorMessage =
`Server returned an error:\n` +
` Code: ${response.status} (${response.statusText})\n` +
` Body: ${responseText}\n`;
if (this._retryTimes > tries) {
console.warn(errorMessage + ` Retrying request.`);
return await this._requestAndRetry(request, tries + 1);
} else {
throw new Error(errorMessage);
}
}
return response;
}
public async query(
canisterId: Principal | string,
fields: QueryFields,
identity?: Identity | Promise<Identity>,
): Promise<QueryResponse> {
const id = await (identity !== undefined ? await identity : await this._identity);
if (!id) {
throw new IdentityInvalidError(
"This identity has expired due this application's security policy. Please refresh your authentication.",
);
}
const canister = typeof canisterId === 'string' ? Principal.fromText(canisterId) : canisterId;
const sender = id?.getPrincipal() || Principal.anonymous();
const request: QueryRequest = {
request_type: ReadRequestType.Query,
canister_id: canister,
method_name: fields.methodName,
arg: fields.arg,
sender,
ingress_expiry: new Expiry(DEFAULT_INGRESS_EXPIRY_DELTA_IN_MSECS),
};
// TODO: remove this any. This can be a Signed or UnSigned request.
// eslint-disable-next-line @typescript-eslint/no-explicit-any
let transformedRequest: any = await this._transform({
request: {
method: 'POST',
headers: {
'Content-Type': 'application/cbor',
...(this._credentials ? { Authorization: 'Basic ' + btoa(this._credentials) } : {}),
},
},
endpoint: Endpoint.Query,
body: request,
});
// Apply transform for identity.
transformedRequest = await id?.transformRequest(transformedRequest);
const body = cbor.encode(transformedRequest.body);
const response = await this._requestAndRetry(() =>
this._fetch('' + new URL(`/api/v2/canister/${canister.toText()}/query`, this._host), {
...transformedRequest.request,
body,
}),
);
return cbor.decode(await response.arrayBuffer());
}
public async createReadStateRequest(
fields: ReadStateOptions,
identity?: Identity | Promise<Identity>,
// eslint-disable-next-line @typescript-eslint/no-explicit-any
): Promise<any> {
const id = await (identity !== undefined ? await identity : await this._identity);
if (!id) {
throw new IdentityInvalidError(
"This identity has expired due this application's security policy. Please refresh your authentication.",
);
}
const sender = id?.getPrincipal() || Principal.anonymous();
// TODO: remove this any. This can be a Signed or UnSigned request.
// eslint-disable-next-line @typescript-eslint/no-explicit-any
const transformedRequest: any = await this._transform({
request: {
method: 'POST',
headers: {
'Content-Type': 'application/cbor',
...(this._credentials ? { Authorization: 'Basic ' + btoa(this._credentials) } : {}),
},
},
endpoint: Endpoint.ReadState,
body: {
request_type: ReadRequestType.ReadState,
paths: fields.paths,
sender,
ingress_expiry: new Expiry(DEFAULT_INGRESS_EXPIRY_DELTA_IN_MSECS),
},
});
// Apply transform for identity.
return id?.transformRequest(transformedRequest);
}
public async readState(
canisterId: Principal | string,
fields: ReadStateOptions,
identity?: Identity | Promise<Identity>,
// eslint-disable-next-line
request?: any,
): Promise<ReadStateResponse> {
const canister = typeof canisterId === 'string' ? Principal.fromText(canisterId) : canisterId;
const transformedRequest = request ?? (await this.createReadStateRequest(fields, identity));
const body = cbor.encode(transformedRequest.body);
const response = await this._fetch(
'' + new URL(`/api/v2/canister/${canister}/read_state`, this._host),
{
...transformedRequest.request,
body,
},
);
if (!response.ok) {
throw new Error(
`Server returned an error:\n` +
` Code: ${response.status} (${response.statusText})\n` +
` Body: ${await response.text()}\n`,
);
}
return cbor.decode(await response.arrayBuffer());
}
/**
* Allows agent to sync its time with the network. Can be called during intialization or mid-lifecycle if the device's clock has drifted away from the network time. This is necessary to set the Expiry for a request
* @param {PrincipalLike} canisterId - Pass a canister ID if you need to sync the time with a particular replica. Uses the management canister by default
*/
public async syncTime(canisterId?: Principal): Promise<void> {
const CanisterStatus = await import('../../canisterStatus');
const callTime = Date.now();
try {
if (!canisterId) {
console.log(
'Syncing time with the IC. No canisterId provided, so falling back to ryjl3-tyaaa-aaaaa-aaaba-cai',
);
}
const status = await CanisterStatus.request({
// Fall back with canisterId of the ICP Ledger
canisterId: canisterId ?? Principal.from('ryjl3-tyaaa-aaaaa-aaaba-cai'),
agent: this,
paths: ['time'],
});
const replicaTime = status.get('time');
if (replicaTime) {
this._timeDiffMsecs = Number(replicaTime as any) - Number(callTime);
}
} catch (error) {
console.error('Caught exception while attempting to sync time:', error);
}
}
public async status(): Promise<JsonObject> {
const headers: Record<string, string> = this._credentials
? {
Authorization: 'Basic ' + btoa(this._credentials),
}
: {};
const response = await this._requestAndRetry(() =>
this._fetch('' + new URL(`/api/v2/status`, this._host), { headers }),
);
return cbor.decode(await response.arrayBuffer());
}
public async fetchRootKey(): Promise<ArrayBuffer> {
if (!this._rootKeyFetched) {
// Hex-encoded version of the replica root key
this.rootKey = ((await this.status()) as any).root_key;
this._rootKeyFetched = true;
}
return this.rootKey;
}
public invalidateIdentity(): void {
this._identity = null;
}
public replaceIdentity(identity: Identity): void {
this._identity = Promise.resolve(identity);
}
protected _transform(request: HttpAgentRequest): Promise<HttpAgentRequest> {
let p = Promise.resolve(request);
for (const fn of this._pipeline) {
p = p.then(r => fn(r).then(r2 => r2 || r));
}
return p;
}
}