SCdF/index.html

## index.html
<!DOCTYPE html>
<html>
<head>
  <title></title>
</head>
<body>
<h1>Attachments make view generation slow in PouchDB</h1>
<p>(read the console for output)</p>
<button id="dothething">Do the thing</button>

<script src="//cdn.jsdelivr.net/npm/pouchdb@6.4.3/dist/pouchdb.min.js"></script>
<script>
  const docs = 500;
  const attachment = {
    data: 'this is some data'
  }
  const doc = {
    a_doc: true
  }
  const ddoc = {
    _id: '_design/test',
    views: {
      test: {
        map: 'function(doc) { if (doc.a_doc) { emit(); }}'
      }
    }
  };

  const withoutAttachments = async () => {
    console.log('Creating, populating and querying DB without attachments');
    const db = new PouchDB('' + new Date().getTime());
    await db.put(ddoc);
    for (i = 0; i < docs; i++) {
      const doc = {
        a_doc: true,
        attachment: 'this is some data'
      };
      await db.post(doc);
    }

    return db;
  };

  const withAttachments = async () => {
    console.log('Creating, populating and querying DB WITH attachments');
    const db = new PouchDB('' + new Date().getTime());
    await db.put(ddoc);
    for (i = 0; i < docs; i++) {
      const doc = {
        a_doc: true
      };
      const {id, rev} = await db.post(doc);
      await db.putAttachment(id, 'attachment', rev, new Blob(['this is some data'], {type: 'text/plain'}), 'text/plain');
    }

    return db;
  };

  const doubleWriteWithout = async () => {
    console.log('Creating, populating and querying DB without attachments, with double writes to emulate the same number of writes as attachments');
    const db = new PouchDB('' + new Date().getTime(), {auto_compaction: true});
    await db.put(ddoc);
    for (i = 0; i < docs; i++) {
      const doc = {
        a_doc: true,
        attachment: 'this is some data'
      };
      const {id, rev} = await db.post(doc);
      doc._id = id;
      doc._rev = rev;
      doc.changed = 'a change';
      await db.put(doc);
    }

    return db;
  };

  const query = async db => {
    const before = new Date().getTime();
    await db.query('test/test', {limit:1});
    console.log('View generation took ' + (new Date().getTime() - before) + ' millis');
  }

  const dothething = async () => {
    const without = await withoutAttachments();
    await query(without);
    const withA = await withAttachments();
    await query(withA);
    const double = await doubleWriteWithout();
    await query(double);
  };

  window.onload = () => {
    document.getElementById('dothething').addEventListener('click', function() {
      dothething();
    });
  };
</script>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<title></title>
	</head>
	<body>
	<h1>Attachments make view generation slow in PouchDB</h1>
	<p>(read the console for output)</p>
	<button id="dothething">Do the thing</button>

	<script src="//cdn.jsdelivr.net/npm/pouchdb@6.4.3/dist/pouchdb.min.js"></script>
	<script>
	const docs = 500;
	const attachment = {
	data: 'this is some data'
	}
	const doc = {
	a_doc: true
	}
	const ddoc = {
	_id: '_design/test',
	views: {
	test: {
	map: 'function(doc) { if (doc.a_doc) { emit(); }}'
	}
	}
	};

	const withoutAttachments = async () => {
	console.log('Creating, populating and querying DB without attachments');
	const db = new PouchDB('' + new Date().getTime());
	await db.put(ddoc);
	for (i = 0; i < docs; i++) {
	const doc = {
	a_doc: true,
	attachment: 'this is some data'
	};
	await db.post(doc);
	}

	return db;
	};

	const withAttachments = async () => {
	console.log('Creating, populating and querying DB WITH attachments');
	const db = new PouchDB('' + new Date().getTime());
	await db.put(ddoc);
	for (i = 0; i < docs; i++) {
	const doc = {
	a_doc: true
	};
	const {id, rev} = await db.post(doc);
	await db.putAttachment(id, 'attachment', rev, new Blob(['this is some data'], {type: 'text/plain'}), 'text/plain');
	}

	return db;
	};

	const doubleWriteWithout = async () => {
	console.log('Creating, populating and querying DB without attachments, with double writes to emulate the same number of writes as attachments');
	const db = new PouchDB('' + new Date().getTime(), {auto_compaction: true});
	await db.put(ddoc);
	for (i = 0; i < docs; i++) {
	const doc = {
	a_doc: true,
	attachment: 'this is some data'
	};
	const {id, rev} = await db.post(doc);
	doc._id = id;
	doc._rev = rev;
	doc.changed = 'a change';
	await db.put(doc);
	}

	return db;
	};

	const query = async db => {
	const before = new Date().getTime();
	await db.query('test/test', {limit:1});
	console.log('View generation took ' + (new Date().getTime() - before) + ' millis');
	}

	const dothething = async () => {
	const without = await withoutAttachments();
	await query(without);
	const withA = await withAttachments();
	await query(withA);
	const double = await doubleWriteWithout();
	await query(double);
	};

	window.onload = () => {
	document.getElementById('dothething').addEventListener('click', function() {
	dothething();
	});
	};
	</script>
	</body>
	</html>