Fix /languages timing out + make it cache

[cdrini]

Fix /languages page timing out, and make it more performant by caching the results to avoid frequent solr hits of this expensive query.

Technical

Testing

Before: https://openlibrary.org/languages (times out, re-fetched every time)

After: https://testing.openlibrary.org/languages

Also not still works with i18n: https://testing.openlibrary.org/languages?lang=es

Screenshot

Stakeholders

[Copilot]

Pull Request Overview

This pull request addresses timeouts observed on the /languages endpoint by introducing a configurable timeout parameter for Solr queries and adding caching to improve performance.

• Added a _timeout parameter in solr.py to allow customizable query timeouts
• Introduced caching for language count queries in languages.py using a memoization decorator with a one-hour expiration

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
openlibrary/utils/solr.py	Added _timeout parameter and replaced literal timeout values with variable reference
openlibrary/plugins/worksearch/languages.py	Updated get_top_languages for type hints and implemented caching in get_all_top_language_counts

Comments suppressed due to low confidence (1)

openlibrary/plugins/worksearch/languages.py:51

• [nitpick] The cache key 'get_top_language_counts' does not correspond with the function name 'get_all_top_language_counts'; consider renaming the key for better clarity and consistency.

@cache.memoize("memcache", key='get_top_language_counts', expires=60 * 60)

[Copilot]

Consider defining a shared constant for the default timeout (10 seconds) rather than hardcoding the value in multiple places, which can improve maintainability.

Suggested change

	timeout = 10
	timeout = DEFAULT_TIMEOUT