google-gax
Version:
Google API Extensions
163 lines • 6.81 kB
JavaScript
;
/**
* Copyright 2020 Google LLC
*
* 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.PageDescriptor = void 0;
const stream_1 = require("stream");
const normalApiCaller_1 = require("../normalCalls/normalApiCaller");
const warnings_1 = require(".././warnings");
const pagedApiCaller_1 = require("./pagedApiCaller");
const maxAttemptsEmptyResponse = 10;
/**
* A descriptor for methods that support pagination.
*/
class PageDescriptor {
requestPageTokenField;
responsePageTokenField;
requestPageSizeField;
resourceField;
constructor(requestPageTokenField, responsePageTokenField, resourceField) {
this.requestPageTokenField = requestPageTokenField;
this.responsePageTokenField = responsePageTokenField;
this.resourceField = resourceField;
}
/**
* Creates a new object Stream which emits the resource on 'data' event.
*/
createStream(apiCall, request, options) {
if (options?.autoPaginate) {
(0, warnings_1.warn)('autoPaginate true', 'Autopaginate will always be set to false in stream paging methods. See more info at https://github.com/googleapis/gax-nodejs/blob/main/client-libraries.md#auto-pagination for more information on how to configure paging calls', 'AutopaginateTrueWarning');
}
const stream = new stream_1.PassThrough({ objectMode: true });
options = Object.assign({}, options, { autoPaginate: false });
const maxResults = 'maxResults' in options ? options.maxResults : -1;
let pushCount = 0;
let started = false;
function callback(err, resources, next, apiResp) {
if (err) {
stream.emit('error', err);
return;
}
// emit full api response with every page.
stream.emit('response', apiResp);
for (let i = 0; i < resources.length; ++i) {
// TODO: rewrite without accessing stream internals
if (stream
._readableState.ended) {
return;
}
if (resources[i] === null) {
continue;
}
stream.push(resources[i]);
pushCount++;
if (pushCount === maxResults) {
stream.end();
}
}
// TODO: rewrite without accessing stream internals
if (stream._readableState
.ended) {
return;
}
if (!next) {
stream.end();
return;
}
// When pageToken is specified in the original options, it will overwrite
// the page token field in the next request. Therefore it must be cleared.
if ('pageToken' in options) {
delete options.pageToken;
}
if (stream.isPaused()) {
request = next;
started = false;
}
else {
setImmediate(apiCall, next, options, callback);
}
}
stream.on('resume', async () => {
if (!started) {
started = true;
await apiCall(request, options, callback);
}
});
return stream;
}
/**
* Create an async iterable which can be recursively called for data on-demand.
*/
asyncIterate(apiCall, request, options) {
if (options?.autoPaginate) {
(0, warnings_1.warn)('autoPaginate true', 'Autopaginate will always be set to false in Async paging methods. See more info at https://github.com/googleapis/gax-nodejs/blob/main/client-libraries.md#auto-pagination for more information on how to configure paging calls', 'AutopaginateTrueWarning');
}
options = Object.assign({}, options, { autoPaginate: false });
const iterable = this.createIterator(apiCall, request, options);
return iterable;
}
createIterator(apiCall, request, options) {
const asyncIterable = {
[Symbol.asyncIterator]() {
let nextPageRequest = request;
const cache = [];
return {
async next() {
if (cache.length > 0) {
return Promise.resolve({
done: false,
value: cache.shift(),
});
}
let attempts = 0;
while (cache.length === 0 && nextPageRequest) {
let result;
[result, nextPageRequest] = (await apiCall(nextPageRequest, options));
// For pagination response with protobuf map type, use tuple as representation.
if (result && !Array.isArray(result)) {
for (const [key, value] of Object.entries(result)) {
cache.push([key, value]);
}
}
else {
cache.push(...result);
}
if (cache.length === 0) {
++attempts;
if (attempts > maxAttemptsEmptyResponse) {
break;
}
}
}
if (cache.length === 0) {
return Promise.resolve({ done: true, value: undefined });
}
return Promise.resolve({ done: false, value: cache.shift() });
},
};
},
};
return asyncIterable;
}
getApiCaller(settings) {
if (!settings.autoPaginate) {
return new normalApiCaller_1.NormalApiCaller();
}
return new pagedApiCaller_1.PagedApiCaller(this);
}
}
exports.PageDescriptor = PageDescriptor;
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