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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/* global AbortController */
/*
* Resource represents a remote network resource, identified by a URI.
* Create an instance like so:
*
*
* The 'resource' object has the following methods to issue HTTP requests
* of the corresponding HTTP methods:
*
* get(callback)
* put(data, callback)
* post(data, callback)
* delete(callback)
*/
export function Resource(uri) {
this._log = Log.repository.getLogger(this._logName);
this._log.manageLevelFromPref("services.sync.log.logger.network.resources");
this.uri = uri;
this._headers = {};
}
// (static) Caches the latest server timestamp (X-Weave-Timestamp header).
Resource.serverTime = null;
XPCOMUtils.defineLazyPreferenceGetter(
Resource,
"SEND_VERSION_INFO",
"services.sync.sendVersionInfo",
true
);
Resource.prototype = {
_logName: "Sync.Resource",
/**
* Callback to be invoked at request time to add authentication details.
* If the callback returns a promise, it will be awaited upon.
*
* By default, a global authenticator is provided. If this is set, it will
* be used instead of the global one.
*/
authenticator: null,
// Wait 5 minutes before killing a request.
ABORT_TIMEOUT: 300000,
// Headers to be included when making a request for the resource.
// Note: Header names should be all lower case, there's no explicit
// check for duplicates due to case!
get headers() {
return this._headers;
},
set headers(_) {
throw new Error("headers can't be mutated directly. Please use setHeader.");
},
setHeader(header, value) {
this._headers[header.toLowerCase()] = value;
},
// URI representing this resource.
get uri() {
return this._uri;
},
set uri(value) {
if (typeof value == "string") {
this._uri = CommonUtils.makeURI(value);
} else {
this._uri = value;
}
},
// Get the string representation of the URI.
get spec() {
if (this._uri) {
return this._uri.spec;
}
return null;
},
/**
* @param {string} method HTTP method
* @returns {Headers}
*/
async _buildHeaders(method) {
const headers = new Headers(this._headers);
if (Resource.SEND_VERSION_INFO) {
headers.append("user-agent", Utils.userAgent);
}
if (this.authenticator) {
const result = await this.authenticator(this, method);
if (result && result.headers) {
for (const [k, v] of Object.entries(result.headers)) {
headers.append(k.toLowerCase(), v);
}
}
} else {
this._log.debug("No authenticator found.");
}
// PUT and POST are treated differently because they have payload data.
if (("PUT" == method || "POST" == method) && !headers.has("content-type")) {
headers.append("content-type", "text/plain");
}
if (this._log.level <= Log.Level.Trace) {
for (const [k, v] of headers) {
if (k == "authorization" || k == "x-client-state") {
this._log.trace(`HTTP Header ${k}: ***** (suppressed)`);
} else {
this._log.trace(`HTTP Header ${k}: ${v}`);
}
}
}
if (!headers.has("accept")) {
headers.append("accept", "application/json;q=0.9,*/*;q=0.2");
}
return headers;
},
/**
* @param {string} method HTTP method
* @param {string} data HTTP body
* @param {object} signal AbortSignal instance
* @returns {Request}
*/
async _createRequest(method, data, signal) {
const headers = await this._buildHeaders(method);
const init = {
cache: "no-store", // No cache.
headers,
method,
signal,
mozErrors: true, // Return nsresult error codes instead of a generic
// NetworkError when fetch rejects.
};
if (data) {
if (!(typeof data == "string" || data instanceof String)) {
data = JSON.stringify(data);
}
this._log.debug(`${method} Length: ${data.length}`);
this._log.trace(`${method} Body: ${data}`);
init.body = data;
}
return new Request(this.uri.spec, init);
},
/**
* @param {string} method HTTP method
* @param {string} [data] HTTP body
* @returns {Response}
*/
async _doRequest(method, data = null) {
const controller = new AbortController();
const request = await this._createRequest(method, data, controller.signal);
const responsePromise = fetch(request); // Rejects on network failure.
let didTimeout = false;
const timeoutId = setTimeout(() => {
didTimeout = true;
this._log.error(
`Request timed out after ${this.ABORT_TIMEOUT}ms. Aborting.`
);
controller.abort();
}, this.ABORT_TIMEOUT);
let response;
try {
response = await responsePromise;
} catch (e) {
this._log.warn(`${method} request to ${this.uri.spec} failed`, e);
if (!didTimeout) {
throw e;
}
throw Components.Exception(
"Request aborted (timeout)",
Cr.NS_ERROR_NET_TIMEOUT
);
} finally {
clearTimeout(timeoutId);
}
return this._processResponse(response, method);
},
async _processResponse(response, method) {
const data = await response.text();
this._logResponse(response, method, data);
this._processResponseHeaders(response);
const ret = {
data,
url: response.url,
status: response.status,
success: response.ok,
headers: {},
};
for (const [k, v] of response.headers) {
ret.headers[k] = v;
}
// Make a lazy getter to convert the json response into an object.
// Note that this can cause a parse error to be thrown far away from the
// actual fetch, so be warned!
ChromeUtils.defineLazyGetter(ret, "obj", () => {
try {
return JSON.parse(ret.data);
} catch (ex) {
this._log.warn("Got exception parsing response body", ex);
// Stringify to avoid possibly printing non-printable characters.
this._log.debug(
"Parse fail: Response body starts",
(ret.data + "").slice(0, 100)
);
throw ex;
}
});
return ret;
},
_logResponse(response, method, data) {
const { status, ok: success, url } = response;
// Log the status of the request.
this._log.debug(
`${method} ${success ? "success" : "fail"} ${status} ${url}`
);
// Additionally give the full response body when Trace logging.
if (this._log.level <= Log.Level.Trace) {
this._log.trace(`${method} body`, data);
}
if (!success) {
this._log.warn(
`${method} request to ${url} failed with status ${status}`
);
}
},
_processResponseHeaders({ headers, ok: success }) {
if (headers.has("x-weave-timestamp")) {
Resource.serverTime = parseFloat(headers.get("x-weave-timestamp"));
}
// This is a server-side safety valve to allow slowing down
// clients without hurting performance.
if (headers.has("x-weave-backoff")) {
let backoff = headers.get("x-weave-backoff");
this._log.debug(`Got X-Weave-Backoff: ${backoff}`);
Observers.notify("weave:service:backoff:interval", parseInt(backoff, 10));
}
if (success && headers.has("x-weave-quota-remaining")) {
Observers.notify(
"weave:service:quota:remaining",
parseInt(headers.get("x-weave-quota-remaining"), 10)
);
}
},
get() {
return this._doRequest("GET");
},
put(data) {
return this._doRequest("PUT", data);
},
post(data) {
return this._doRequest("POST", data);
},
delete() {
return this._doRequest("DELETE");
},
};