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Fix iterate and greedyIterate methods #16

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Fix iterate and greedyIterate methods #16

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64c8eda
fix dataset client methods
gullmar Mar 3, 2025
a2cb0fe
test dataset-client.iterate
gullmar Mar 3, 2025
a84a19d
fix dataset.iterate: pass options
gullmar Mar 10, 2025
9b98078
fix dataset.iterate: actually apply initial offset when using pagination
gullmar Apr 11, 2025
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88 changes: 40 additions & 48 deletions src/clients/dataset-client.ts
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
import { ActorRun, Dataset, DatasetClient } from 'apify-client';
import { DatasetClient } from 'apify-client';

import { RunsTracker } from '../tracker.js';
import { DatasetItem, GreedyIterateOptions, ExtendedDatasetClient, IterateOptions } from '../types.js';
Expand Down Expand Up @@ -26,82 +26,74 @@ export class ExtDatasetClient<T extends DatasetItem> extends DatasetClient<T> im
const { pageSize, ...listItemOptions } = options;
this.customLogger.info('Iterating Dataset', { pageSize }, { url: this.url });

let totalItems = 0;
const initialOffset = listItemOptions.offset ?? 0;
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nit: I feel weird about this being in the outer scope as it really doesn't matter when we don't have a pageSize - that would entail duplicating the log, but TBH I'm not against that as it's actually two implementations masquerading as one function..

let readItems = 0;

if (pageSize) {
let offset = 0;
let currentPage = await this.superClient.listItems({ ...listItemOptions, offset, limit: pageSize });
let currentPage = await this.superClient.listItems({
...listItemOptions,
limit: pageSize,
});
while (currentPage.items.length > 0) {
totalItems += currentPage.items.length;
readItems += currentPage.items.length;
for (const item of currentPage.items) {
yield item;
}

offset += pageSize;
currentPage = await this.superClient.listItems({ offset, limit: pageSize });
currentPage = await this.superClient.listItems({
...listItemOptions,
offset: initialOffset + readItems,
limit: pageSize,
});
}
} else {
const itemList = await this.superClient.listItems(listItemOptions);
totalItems += itemList.items.length;
readItems += itemList.items.length;
for (const item of itemList.items) {
yield item;
}
}

this.customLogger.info('Finished reading dataset', { totalItems }, { url: this.url });
this.customLogger.info('Finished reading dataset', { initialOffset, readItems }, { url: this.url });
}

async* greedyIterate(options: GreedyIterateOptions = {}): AsyncGenerator<T, void, void> {
const { pageSize = 100, itemsThreshold = 100, pollIntervalSecs = 10, ...listItemOptions } = options;
this.customLogger.info('Greedily iterating Dataset', { pageSize }, { url: this.url });
const { pollIntervalSecs = 10, ...iterateOptions } = options;
this.customLogger.info('Greedily iterating Dataset', { pageSize: iterateOptions.pageSize }, { url: this.url });

let readItemsCount = 0;
let currentOffset = iterateOptions.offset ?? 0;

let dataset: Dataset | undefined;
let run: ActorRun | undefined;
const runId = (await this.get())?.actRunId;

// TODO: breaking change - remove itemsThreshold and just listItems at every iteration
while (true) {
dataset = await this.get();
if (!dataset || !dataset.actRunId) {
this.customLogger.error('Error getting Dataset while iterating greedily', { id: this.id });
return;
}

run = await this.apifyClient.run(dataset.actRunId).get();
if (!run) {
this.customLogger.error('Error getting Run while iterating Dataset greedily', { id: this.id });
return;
}
let runStatus = runId ? (await this.apifyClient.run(runId).get())?.status : undefined;

if (run.status !== 'READY' && run.status !== 'RUNNING') {
break;
}

if (dataset.itemCount >= readItemsCount + itemsThreshold) {
const itemList = await this.superClient.listItems({ ...listItemOptions, offset: readItemsCount, limit: pageSize });
readItemsCount += itemList.count;
for (const item of itemList.items) {
if (runId) {
while (runStatus && ['READY', 'RUNNING'].includes(runStatus)) {
const datasetIterator = this.iterate({ ...iterateOptions, offset: currentOffset });
for await (const item of datasetIterator) {
currentOffset++;
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@halvko halvko Mar 5, 2025 •
edited
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I don't like this, and postponed adding my review till I had let it settle a bit. I ended up having to do pretty much the same when using the library to do "reasonable segmentation". I think this shows that our abstraction is leaky - whether there will actually be an await before we get to the next element. I think it would be better if we just returned AsyncGenerator<T[], void, void>, only yielding if there actually were any elements. I think iterate should have the same signature, even though it may often be used without a page size such it only actually yields once.

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I think that would simplify both this code, and most (if not all) usages

yield item;
}
}

await new Promise((resolve) => setTimeout(resolve, pollIntervalSecs * 1000));
await new Promise((resolve) => setTimeout(resolve, pollIntervalSecs * 1000));

runStatus = (await this.apifyClient.run(runId).get())?.status;
}
} else {
this.customLogger.error(
'Greedy iterate: error getting Dataset or associated run\'s ID; trying to read the remaining items.',
);
}

dataset = await this.get();
if (!dataset || !dataset.actRunId) {
this.customLogger.error('Error getting Dataset while iterating greedily', { id: this.id });
return;
if (runId && !runStatus) {
this.customLogger.error(
'Greedy iterate: error getting associated run\'s status: trying to read the remaining items.',
);
}

while (readItemsCount < dataset.itemCount) {
const itemList = await this.superClient.listItems({ ...listItemOptions, offset: readItemsCount, limit: pageSize });
if (itemList.count === 0) { break; }
readItemsCount += itemList.count;
for (const item of itemList.items) {
yield item;
}
const datasetIterator = this.iterate({ ...iterateOptions, offset: currentOffset });
for await (const item of datasetIterator) {
yield item;
}
}
}
7 changes: 0 additions & 7 deletions src/types.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -387,13 +387,6 @@ export type IterateOptions = DatasetClientListItemOptions & {
}

export type GreedyIterateOptions = IterateOptions & {
/**
* Download new items when they are more than the specified threshold, or when the Run terminates.\
* If zero, the new items are downloaded as soon as they are detected.
*
* @default 100
*/
itemsThreshold?: number
/**
* Check the run's status regularly at the specified interval, in seconds.
*
Expand Down
55 changes: 45 additions & 10 deletions test/clients/dataset-client.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -76,7 +76,7 @@ describe('dataset-client', () => {
expect(listItemsSpy).toHaveBeenCalledWith({});
});

it('iterates the items from the dataset, using pagination', async () => {
it('iterates the items from the dataset, using pagination, passing the given options', async () => {
const listItemsSpy = vi.spyOn(DatasetClient.prototype, 'listItems')
.mockImplementationOnce(async () => ({
count: 2,
Expand All @@ -102,26 +102,61 @@ describe('dataset-client', () => {
limit: 2,
desc: true,
}));
const datasetIterator = datasetClient.iterate({ pageSize: 2 });
const datasetIterator = datasetClient.iterate({ pageSize: 2, fields: ['title'] });
let index = 0;
for await (const item of datasetIterator) {
expect(item).toEqual(testItems[index]);
index++;
}
expect(index).toBe(3);
expect(listItemsSpy).toHaveBeenCalledTimes(3);
expect(listItemsSpy).toHaveBeenNthCalledWith(1, { offset: 0, limit: 2 });
expect(listItemsSpy).toHaveBeenNthCalledWith(2, { offset: 2, limit: 2 });
expect(listItemsSpy).toHaveBeenNthCalledWith(3, { offset: 4, limit: 2 });
expect(listItemsSpy).toHaveBeenNthCalledWith(1, { offset: 0, limit: 2, fields: ['title'] });
expect(listItemsSpy).toHaveBeenNthCalledWith(2, { offset: 2, limit: 2, fields: ['title'] });
expect(listItemsSpy).toHaveBeenNthCalledWith(3, { offset: 4, limit: 2, fields: ['title'] });
});
});

describe('greedyIterate', () => {
it('iterates the items from the dataset as soon as one batch is available, using pagination', () => {
// TODO: test
it('iterates the items using pagination and starting from the desired offset', async () => {
const listItemsSpy = vi.spyOn(DatasetClient.prototype, 'listItems')
.mockImplementationOnce(async () => ({
count: 2,
items: testItems.slice(0, 2),
total: 8,
offset: 5,
limit: 2,
desc: true,
}))
.mockImplementationOnce(async () => ({
count: 1,
items: testItems.slice(2, 3),
total: 8,
offset: 7,
limit: 2,
desc: true,
}))
.mockImplementationOnce(async () => ({
count: 0,
items: [],
total: 8,
offset: 9,
limit: 2,
desc: true,
}));
const datasetIterator = datasetClient.iterate({ pageSize: 2, offset: 5 });
let index = 0;
for await (const item of datasetIterator) {
expect(item).toEqual(testItems[index]);
index++;
}
expect(index).toBe(3);
expect(listItemsSpy).toHaveBeenCalledTimes(3);
expect(listItemsSpy).toHaveBeenNthCalledWith(1, { offset: 5, limit: 2 });
expect(listItemsSpy).toHaveBeenNthCalledWith(2, { offset: 7, limit: 2 });
expect(listItemsSpy).toHaveBeenNthCalledWith(3, { offset: 9, limit: 2 });
});
});

it('iterates the items from the dataset as soon as new items are available, setting pageSize to 0', () => {
describe('greedyIterate', () => {
it('iterates the items from the dataset until the run has finished', () => {
// TODO: test
});
});
Expand Down