docs: remove leveldb, localstorage and memory references

Author: AlbaHerrerias

.github/ISSUE_TEMPLATE/issue.md

@@ -15,7 +15,7 @@ Write the description of the issue here
 ### Info
 - Environment: (Node.js/browser/hybrid app/etc.)
 - Platform: (Chrome/FF/Safari/Edge/iOS/Android/etc.)
-- Adapter: (idb/indexeddb/memory/leveldb/nodesqlite/etc.)
+- Adapter: (idb/indexeddb/nodesqlite/etc.)
 - Server: (CouchDB/Cloudant/PouchDB Server/etc.)
 
 ### Reproduce

TESTING.md

@@ -65,8 +65,7 @@ The main test suite can be run using the following command:
 > If the tests don‘t pass on `main`, try building once before running the tests: `$npm run build`.
 
 PouchDB runs in the browser and on Node.js, and has multiple different storage
-backends known as _adapters_. In the browser these are `idb`, `indexeddb` and
-`memory` and on Node.js they're `nodesqlite`, `leveldb` and `memory`.
+backends known as _adapters_. In the browser these are `idb` and `indexeddb` and on Node.js there is `nodesqlite`.
 
 It also includes an adapter named `http`, which works by delegating operations
 to CouchDB (or anything that's API-compatible with it) over the network. Since
@@ -92,8 +91,8 @@ databases. These are selected automatically based on the execution environment,
 but this variable overrides the default choice and causes additional adapters to
 be loaded if they're not part of the default distribution.
 
-On Node.js the available local adapters are `nodesqlite`, `leveldb` and `memory`. In the
-browser they're `idb`, `indexeddb` and `memory`.
+On Node.js the available local adapter is `nodesqlite`. In the
+browser they're `idb` and `indexeddb`.
 
 You can also set `ADAPTERS=http` to force all PouchDB databases to be created on
 a remote server, identified by `COUCH_HOST`. This is not necessary for
@@ -181,14 +180,14 @@ following values:
 
 Set this to `1` to skip the migration tests.
 
-#### `VIEW_ADAPTERS` (default: `memory`) <!-- omit from toc -->
+#### `VIEW_ADAPTERS` (default: `nodesqlite`) <!-- omit from toc -->
 
 Comma-separated list of preferred view adapter backends that PouchDB will use. 
 This variable overrides the default choice and causes additional adapters to
 be loaded if they're not part of the default distribution.
 
-On Node.js the available adapters are `nodesqlite`, `leveldb` and `memory`. In the
-browser they're `idb`, `indexeddb` and `memory`.
+On Node.js the available adapter is `nodesqlite`. In the
+browser they're `idb` and `indexeddb`.
 
 
 ## Other sets of tests
@@ -213,8 +212,8 @@ These suites support most of the same options as the integration tests.
 You'll want to test specific adapters by specifying them on the command-line,
 for example:
 
-    # run the "find" tests with the memory client on node.js
-    $ TYPE=find PLUGINS=pouchdb-find CLIENT=node ADAPTERS=memory npm test
+    # run the "find" tests with the nodesqlite client on node.js
+    $ TYPE=find PLUGINS=pouchdb-find CLIENT=node ADAPTERS=nodesqlite npm test
 
     # run the "mapreduce" tests with indexeddb in firefox
     $ TYPE=mapreduce CLIENT=firefox ADAPTERS=indexeddb npm test

docs/_includes/api/batch_fetch.html

@@ -17,7 +17,7 @@
 * `options.startkey` & `options.endkey`: Get documents with IDs in a certain range (inclusive/inclusive).
 * `options.inclusive_end`: Include documents having an ID equal to the given `options.endkey`. Default: `true`.
 * `options.limit`: Maximum number of documents to return.
-* `options.skip`: Number of docs to skip before returning (warning: poor performance on IndexedDB/LevelDB!).
+* `options.skip`: Number of docs to skip before returning (warning: poor performance on IndexedDB!).
 * `options.descending`: Reverse the order of the output documents. Note that the order of `startkey` and `endkey` is reversed when `descending`:`true`.
 * `options.key`: Only return documents with IDs matching this string key.
 * `options.keys`: Array of string keys to fetch in a single shot.

docs/_includes/api/create_database.html

@@ -13,7 +13,7 @@
 **Options for local databases:**
 
 * `auto_compaction`: This turns on auto compaction, which means `compact()` is called after every change to the database. Defaults to `false`.
-* `adapter`: One of `'indexeddb'`, `'idb'`, `'leveldb'`, `'nodesqlite'`, or `'http'`.
+* `adapter`: One of `'indexeddb'`, `'idb'`, `'nodesqlite'`, or `'http'`.
 * `revs_limit`: Specify how many old revisions we keep track (not a copy) of. Specifying a low value means Pouch may not be able to figure out whether a new revision received via replication is related to any it currently has which could result in a conflict. Defaults to `1000`.
 * `deterministic_revs`: Use a md5 hash to create a deterministic revision number for documents. Setting it to false will mean that the revision number will be a random UUID. Defaults to true.
 * `view_update_changes_batch_size`: Specify how many change records will be consumed at a time when rebuilding view indexes when the `query()` method is used. Defaults to 50.
@@ -30,12 +30,9 @@
 
 1. In IndexedDB PouchDB will use `_pouch_` to prefix the internal database names. Do not manually create databases with the same prefix.
 2. When acting as a client on Node, any other options given will be passed to [request][].
-3. When using the `'leveldb'` adapter (the default on Node), any other options given will be passed to [levelup][].
-4. If you are using the jwt auth handler, please use the fetch option to add the required headers and handle connected logic like token refreshes.
+3. If you are using the jwt auth handler, please use the fetch option to add the required headers and handle connected logic like token refreshes.
 
 [request]: https://github.com/mikeal/request
-[levelup]: https://github.com/rvagg/node-levelup
-[levelup_options]: https://github.com/rvagg/node-levelup/#options
 
 #### Example Usage:
 {% highlight "js" %}

docs/_includes/api/database_information.html

@@ -54,6 +54,6 @@
 
 There are also some details you can use for debugging. These are unofficial and may change at any time:
 
-* `adapter`: The name of the adapter being used (idb, leveldb, ...).
+* `adapter`: The name of the adapter being used (idb, ...).
 * `idb_attachment_format`: (IndexedDB) either `'base64'` or `'binary'`, depending on whether the browser [supports binary blobs](/faq.html#data_types).
 * `backend_adapter`: (Node.JS) the backend *DOWN adapter being used (MemDOWN, RiakDOWN, ...).

docs/_includes/api/defaults.html

@@ -23,7 +23,7 @@
 const MyPrefixedPouch = PouchDB.defaults({
   prefix: '/path/to/my/db/'
 });
-// db will be named '/path/to/my/db/dbname', useful for LevelDB
+// db will be named '/path/to/my/db/dbname'
 const myPrefixedPouch = new MyPrefixedPouch('dbname');
 
 const HTTPPouch = PouchDB.defaults({

docs/_includes/api/query_database.html

@@ -41,7 +41,7 @@
 * `options.startkey` & `options.endkey`: Get rows with keys in a certain range (inclusive/inclusive).
 * `options.inclusive_end`: Include rows having a key equal to the given `options.endkey`. Default: `true`.
 * `options.limit`: Maximum number of rows to return.
-* `options.skip`: Number of rows to skip before returning (warning: poor performance on IndexedDB/LevelDB!).
+* `options.skip`: Number of rows to skip before returning (warning: poor performance on IndexedDB!).
 * `options.descending`: Reverse the order of the output rows.
 * `options.key`: Only return rows matching this key.
 * `options.keys`: Array of keys to fetch in a single shot.

docs/_layouts/default.html

@@ -122,20 +122,6 @@ <h4>{{ sub_title}}</h4>
             </a>
           </div>
 
-          <div class="col-xs-4 col-md-2">
-            <a
-              href="https://github.com/rvagg/node-levelup"
-              target="_blank"
-              rel="noopener noreferrer"
-            >
-              <img
-                class="icon"
-                src="{{ site.baseurl}}/static/img/friends/leveldb.svg"
-                alt="Node Levelup"
-              />
-            </a>
-          </div>
-
           <div class="col-xs-4 col-md-2">
             <a
               href="https://github.com/apache/pouchdb"

docs/adapters.md

@@ -4,7 +4,7 @@ title: Adapters
 sidebar: nav.html
 ---
 
-PouchDB is not a self-contained database; it is a CouchDB-style abstraction layer over other databases. By default, PouchDB ships with the [IndexedDB][] adapter for the browser, and a [LevelDB][] adapter in Node.js. This can be visualized as so:
+PouchDB is not a self-contained database; it is a CouchDB-style abstraction layer over other databases. By default, PouchDB ships with the [IndexedDB][] adapter for the browser, and a [nodesqlite][] adapter in Node.js. This can be visualized as so:
 
 <object data="static/svg/pouchdb_adapters.svg" type="image/svg+xml">
     <img src="static/img/pouchdb_adapters.png" alt="adapters">
@@ -66,83 +66,6 @@ The built-in IndexedDB adapter is nearly always more performant and stable.
 
 PouchDB also offers separate browser plugins that use backends other than IndexedDB. These plugins fully pass the PouchDB test suite and are rigorously tested in our CI process.
 
-**Downloads:**
-
-* [pouchdb.memory.js](https://github.com/apache/pouchdb/releases/download/{{ site.version }}/pouchdb.memory.js) (Minified: [pouchdb.memory.min.js](https://github.com/apache/pouchdb/releases/download/{{ site.version }}/pouchdb.memory.min.js))
-* [pouchdb.localstorage.js](https://github.com/apache/pouchdb/releases/download/{{ site.version }}/pouchdb.localstorage.js) (Minified: [pouchdb.localstorage.min.js](https://github.com/apache/pouchdb/releases/download/{{ site.version }}/pouchdb.localstorage.min.js))
-
-{% include alert/start.html variant="warning"%}
-{% markdown %}
-These plugins add a hefty footprint due to external dependencies, so take them with a grain of salt.
-{% endmarkdown %}
-{% include alert/end.html%}
-
-#### In-memory adapter
-
-If you want a quick database for your unit tests, you can use the `pouchdb.memory.js` plugin, which offers a pure in-memory PouchDB:
-
-```html
-<script src="pouchdb.js"></script>
-<script src="pouchdb.memory.js"></script>
-<script>
-  // this pouch is ephemeral; it only exists in memory
-  const pouch = new PouchDB('mydb', {adapter: 'memory'});
-</script>
-```
-
-This pouch will act exactly like a normal one &ndash; replicating, storing attachments, pagination, etc. &ndash; but it will be deleted as soon as the user closes their browser. However, multiple `PouchDB` objects with the same database name will share the same data:
-
-```js
-// pouch1 and pouch2 will share the same data
-const pouch1 = new PouchDB('myDB', {adapter: 'memory'});
-const pouch2 = new PouchDB('myDB', {adapter: 'memory'});
-
-// pouch3 will have its own data
-const pouch3 = new PouchDB('myOtherDB', {adapter: 'memory'});
-```
-
-#### LocalStorage adapter
-
-If you need to support very old browsers, such as IE &le; 9.0 and Opera Mini, you can use the `pouchdb.localstorage.js` plugin, which allows PouchDB to fall back to [LocalStorage][] on browsers that don't support either IndexedDB or WebSQL.  The [es5-shims][] will also be necessary.
-
-```html
-<script src="pouchdb.js"></script>
-<script src="pouchdb.localstorage.js"></script>
-<script>
-  // this pouch is backed by LocalStorage
-  const pouch = new PouchDB('mydb', {adapter: 'localstorage'});
-</script>
-```
-
-{% include alert/start.html variant="warning"%}
-The LocalStorage plugin should be considered highly experimental, and the underlying structure may change in the future.  Currently it stores all document IDs in memory, which works fine on small databases but may crash on larger databases.  You can follow <a href='https://github.com/No9/localstorage-down'>localstorage-down</a> to track our progress.
-{% include alert/end.html %}
-
-{% include anchor.html title="PouchDB in Node.js" hash="pouchdb_in_node_js"%}
-
-#### In-memory
-
-{% include alert/start.html variant="warning"%}
-{% markdown %}
-**Warning: deprecation notice.** The `memory` adapter will be deprecated in PouchDB version 10.0.0 and removed in version 11.0.0. You can read [the migration guide here](https://pouchdb.com/2026/04/10/migration-to-nodesqlite.html) and more about the topic in [this link](https://github.com/apache/pouchdb/issues/9163). 
-{% endmarkdown %}
-{% include alert/end.html%}
-
-Just as in the browser, you can also create a pure in-memory PouchDB:
-
-```
-$ npm install pouchdb-adapter-memory
-```
-
-then:
-
-```js
-PouchDB.plugin(require('pouchdb-adapter-memory'));
-const pouch = new PouchDB('myDB', {adapter: 'memory'});
-```
-
-This implementation is based on [MemDOWN](https://github.com/level/memdown), and will not write any changes to disk.
-
 #### Node SQLite adapter
 
 You can also use PouchDB in Node.js' [native SQLite module](https://nodejs.org/api/sqlite.html), when using Node.js' `>22.5.0` version. 
@@ -154,45 +77,6 @@ PouchDB.plugin(require('pouchdb-adapter-node-sqlite'));
 const db = new PouchDB('mydatabase.db', {adapter: 'nodesqlite'});
 ```
 
-#### Other LevelDOWN adapters
-
-{% include alert/start.html variant="warning"%}
-{% markdown %}
-**Warning: deprecation notice.** The `leveldb` adapter will be deprecated in PouchDB version 10.0.0 and removed in version 11.0.0. You can read [the migration guide here](https://pouchdb.com/2026/04/10/migration-to-nodesqlite.html) and more about the topic in [this link](https://github.com/apache/pouchdb/issues/9163).
-{% endmarkdown %}
-{% include alert/end.html%}
-
-Technically you are free to use
-[any LevelDOWN-based implementation](https://github.com/rvagg/node-levelup/wiki/Modules#storage-back-ends) in either Node or the browser.
-However this should be considered **extremely experimental** and not designed for production use.
-
-See [pouchdb-adapter-leveldb-core](https://www.npmjs.com/package/pouchdb-adapter-leveldb-core) for details.
-
-{% include anchor.html title="PouchDB over HTTP" hash="pouchdb_over_http"%}
-
-In both the browser and in Node.js, PouchDB can also function as a straightforward API on top of any [CouchDB](https://couchdb.apache.org/)-compliant database:
-
-```js
-const pouch = new PouchDB('http://my-site.com:5984/my-db');
-const securePouch = new PouchDB('https://my-secure-site.com:5984/my-secure-db');
-```
-
-You can also sync to and from these databases to your local PouchDB.
-
-Currently PouchDB has full support for:
-
-* CouchDB 1.x
-* [Smileupps](https://www.smileupps.com/) (same as 1.x)
-* CouchDB 2.x ([tested in CI](https://github.com/apache/pouchdb/actions))
-* CouchDB 3.x ([tested in CI](https://github.com/apache/pouchdb/actions))
-* [Cloudant](https://cloudant.com/) (roughly the same as 2.x)
-* [PouchDB Server](https://github.com/pouchdb/pouchdb-server) ([tested in CI](https://github.com/apache/pouchdb/actions))
-* [PouchDB Server --in-memory mode](https://github.com/pouchdb/pouchdb-server)
-
-[Drupal 8](http://wearepropeople.com/blog/a-content-staging-solution-for-drupal-8-and-more) has also announced support for PouchDB, and there is [rcouch](https://github.com/rcouch/rcouch) as well, but these are both untested by PouchDB.
-
-If you are ever unsure about a server, consider replicating from PouchDB to CouchDB, then from that CouchDB to the other server.
-
 #### PouchDB Server
 
 [PouchDB Server](https://github.com/pouchdb/pouchdb-server) is a standalone REST server that implements the CouchDB API, while using a LevelDB-based PouchDB under the hood. It also supports an `--in-memory` mode and any [LevelDOWN][] adapter, which you may find handy.
@@ -213,7 +97,6 @@ The best place to look for information on which browsers support which databases
 
 [IndexedDB]: http://www.w3.org/TR/IndexedDB/
 [WebSQL]: http://www.w3.org/TR/webdatabase/
-[LevelDB]: https://code.google.com/p/leveldb/
 [LocalStorage]: https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Storage
 [es5-shims]: https://github.com/es-shims/es5-shim
 [sqlite plugin]: https://github.com/brodysoft/Cordova-SQLitePlugin