![]() This is from my detailed answer to How disk space is used on Android device?. So the following is generally true for Android 4.4+ and particularly 6+. Some major changes occurred to storage in Android 4.4 (see Android's Storage Journey). Usually, these files and directories are only accessible by the app itself (and root, of course) - other than those stored on the SDCard, which are accessible by all apps. In its own "home directory" (and that's what it basically is, spoken Linux-wise) they can place files where they want. There might be several more directories in this place, or fewer - it all depends on the app. shared_prefs/: preferences and settings.lib/: libraries and helpers for the app.databases/: here go the app's databases.For your specific question I might add some more details on the /data/data/ (and corresponding SD-part): You can find a general explanation of the Android directory hierarchy in my answer here. Though, as Tom pointed out, root-apps could store their data almost everywhere on your device, they usually follow the same rules as other apps. They can use directory names freely (and they again do), which is what often makes it hard to decide what all that "junk" on the card is intended for, and what of it can be deleted. If an app expects huge amounts of data to be stored, or for other reasons wants to "be nice to internal storage", there's a corresponding directory on the SDCard ( Android/data/).Īpart from that, all apps can store data anywhere on the SDCard, as there are no restrictions - and many apps do so. This directory is "private" to the app – which means no other app and not even the user can access data in it (without root permissions). By default, the apps databases, settings, and all other data go here. If (!db.objectStoreNames.All apps (root or not) have a default data directory, which is /data/data/. You can check if an object store already exists by calling the objectStoreNames() method: const storeName = 'store1' Use auto increment if your values do not contain a unique key already (for example, if you collect email addresses without an associated name). The simplest way is to use unpkg, by adding this to the page header: īefore using the IndexedDB API, always make sure you check for support in the browser, even though it's widely available, you never know which browser the user is using: (() => ) This library is also used on all the examples on the Google Developers website regarding IndexedDB Create an IndexedDB Database While there's nothing wrong in it, in all the examples that I'll explain I'll use the IndexedDB Promised Library by Jake Archibald, which is a tiny layer on top of the IndexedDB API to make it easier to use. ![]() Since the advent of Promises in ES6, and the subsequent move of APIs to using promises, the IndexedDB API seems a bit old school. You can alter those stores using transactions, by performing add, edit and delete operations, and iterating over the items they contain. While you can technically create multiple databases per site, you generally create one single database, and inside that database you can create multiple object stores.Ī database is private to a domain, so any other site cannot access another website IndexedDB stores.Įach store usually contains a set of things, which can beįor example you might have a store that contains posts, another that contains comments.Ī store contains a number of items which have a unique key, which represents the way by which an object can be identified. ![]() In the past we also had Web SQL, a wrapper around SQLite, but now this is deprecated and unsupported on some modern browsers, it's never been a recognized standard and so it should not be used, although 83% of users have this technology on their devices according to Can I Use. Local/session storage have the disadvantage of being capped at a small (and inconsistent) size, with browsers implementation offering from 2MB to 10MB of space per site. sessionStorage, does not retain data, which is cleared when the session ends, while localStorage keeps the data across sessions Web Storage (or DOM Storage), a term that commonly identifies localStorage and sessionStorage, two key/value stores.Cookies: can host a very small amount of strings.It supports transactions, versioning and gives good performance. It can store an indefinite amount of data, although once over a certain threshold the user is prompted to give the site higher limits. It's an asynchronous API, which means that performing costly operations won't block the UI thread providing a sloppy experience to users. It's a key/value store (a noSQL database) considered to be the definitive solution for storing data in browsers. IndexedDB is one of the storage capabilities introduced into browsers over the years. Interested in learning JavaScript? Get my JavaScript ebook at Introduction to IndexedDB
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