Couchdb-iterator NPM

couchdb-iterator

A fast and easy to ease CouchDB iterator for views and all documents.

Installation

$ npm install couchdb-iterator

Usage

Concurrent row iteration

couchdbIterator(couchdbAddr, [view], iterator, [options])

Calls iterator for each row of the database referenced by couchdbAddr. If a view is supplied, iterates only over that view's rows.

This library aims to be fast, therefore iteration happens concurrently. The iterator function can be async but beware that order is not guaranteed.

Examples:

const couchdbIterator = require('couchdb-iterator');

// Iterate over all rows of a database
couchdbIterator('http://localhost:5984/my-db', (row, index) => {
    console.log(index, row.id, row.key, row.value);
    // Do something with `row`; you may return a promise here
})
.then((rowsCount) => {
    console.log(`Iteration completed! ${rowsCount}`);
}, (err) => {
    console.log('Iteration failed', err);
});

// Iterate over all rows of a view
couchdbIterator('http://localhost:5984/my-db', 'my-design-doc/my-view', (row, index) => {
    console.log(index, row.id, row.key, row.value);
    // Do something with `row`; you may return a promise here
})
.then((rowsCount) => {
    console.log(`Iteration completed! ${rowsCount}`);
}, (err) => {
    console.log('Iteration failed', err);
});

The couchdbAddr argument must be a connection string with protocol, host, port and database path (e.g.: http://localhost:5984/my-db) or a nano instance. The view argument is a string in the form of design-doc/view-name (e.g.: app/byUser).

Available options:

concurrency: The concurrency in which the iterator is called, defaults to 50.
nano: Custom options to be used when creating the nano instance, defaults to null.
The following querying options are available: limit, skip, stale, descending, startkey, startkey_docid, endkey, endkey_docid, include_docs and inclusive_end (can be camelCased).

All querying options have no default value, except for limit which is concurrency * 10. Also, stale is automatically set to ok after the first iteration to further improve performance.

Bulk iteration

couchdbIterator.bulk(couchdbAddr, [view], iterator, [options])

Calls iterator for a bulk of rows of the database referenced by couchdbAddr. If a view is supplied, iterates only over that view's rows.

This method is similar to couchdbIterator() but iterates in bulks and it respects the order of rows. The order is respected because since a bulk is ordered and the next bulk only comes when the current bulk is handled.

Examples:

const couchdbIterator = require('couchdb-iterator');

// Iterate over all rows of a database
couchdbIterator.bulk('http://localhost:5984/my-db', (rows) => {
    rows.forEach((row) => {
        console.log(row.index, row.id, row.key, row.value);
    });
    // Do something with `rows`; you may return a promise here
})
.then((rowsCount) => {
    console.log(`Iteration completed! ${rowsCount}`);
}, (err) => {
    console.log('Iteration failed', err);
});

// Iterate over all rows of a view
couchdbIterator.bulk('http://localhost:5984/my-db', 'my-design-doc/my-view', (rows) => {
    rows.forEach((row) => {
        console.log(row.index, row.id, row.key, row.value);
    });
    // Do something with `rows`; you may return a promise here
})
.then((rowsCount) => {
    console.log(`Iteration completed! ${rowsCount}`);
}, (err) => {
    console.log('Iteration failed', err);
});

Available options:

bulkSize: The bulkSize, defaults to 50.
nano: Custom options to be used when creating the nano instance, defaults to null.
The following querying options are available: limit, skip, stale, descending, startkey, startkey_docid, endkey, endkey_docid, include_docs and inclusive_end (can be camelCased).

All querying options have no default value, except for limit which is bulkSize * 10. Also, stale is automatically set to ok after the first iteration to further improve performance.

Tests

$ npm test
$ npm test-cov to get coverage report

The tests expect a running CouchDB in http://localhost:5984 and will create and destroy couchdb-iterator-tests database. You may specify a different address with COUCHDB, e.g.: $ COUCHDB=http://admin:admin@localhost:5984/my-custom-database-for-tests npm test.