What is a cache? Cache in the browser why you need to clean?

Information technology is very diverse, but the purpose of some is very difficult to understand. Take, for example, a cache - what is it? Why was it done? Is there any sense in this? Well, if you read these lines, there is a sense, you just do not know about it yet. And within the framework of the article this misunderstanding will be corrected.

What is a cache?

It is understood as an intermediate buffer, which contains information whose probability of query is the highest, for its rapid provision to the user of the computer. Access to the necessary data is faster than accessing a remote source or sampling from a slower memory source. But the downside of the cache is the fact that it has a small size, which makes it difficult to store large amounts of information in it.

How does this technology work?

Now that you know what a cache is, you should talk about the device. The basics of the cache are made up of record sets. Each set is associated with a specific block or data element, which is a copy of information located in the main memory. Each record has its own identifier (it is also sometimes called a tag), with which the connection between the "original" data in the main memory and the "copy" in the cache is maintained. A client refers to it, which can be an operating system, browser or CPU. When accessing a request object, the computer first examines the cache memory. If a match of identifiers is found, then data from it is used, and the process itself is called a hit. If the necessary information is not available, then the main memory starts to be loaded. This process is called a cache miss. The percentage of access to it, when the necessary response was received, is called the hit ratio.

Given the limited size that the cache has, a decision can be made to oust some of the information. For its adoption, various branching algorithms are used. If you change the items stored in the cache, changes will be made to the main memory of the computer. The write policy affects the speed of data entry. So, with the urgent option, all changes will be made synchronously into the main memory. With deferred (or reverse) writing, data is replaced only if they have been omitted from the cache by other elements. How is this mechanism implemented in the above parts of the technology? Let's look at what a cache is, and how it interacts with other parts of the computer.

Cache in the PC operating system

The most important is the Windows cache - the temporary storage of the operating system (or another if it is installed on your computer). It consists of the following elements:

1. Pages of RAM, which in turn are divided into buffers, the length of which is equal and depends on the memory device used.
2. A set of headers for the buffers themselves, whose task is to describe their state.
3. Hash tables, which indicate which header to which buffer belongs.
4. List of free buffers.

Cache programs

Many programs need to record their intermediate calculations to avoid the need for calculations each time. And, as you already guessed, they use the cache. The program benefits from this, because it allows you to significantly speed up its work and carrying out all the necessary calculations, but only if there is additional RAM or free disk space. In all other cases, the cache will not be able to help you feel the benefits of its work. But do not be upset - this remark applies exclusively to data storage, in any case - look in the task manager, and you will be able to see that part of the memory is cached.

Browser cache

How to reduce the traffic transmitted over the network? Here the cache memory comes to the rescue again! In it, the user's computer or proxy servers store part of the information used in the pages of browsers. Normally, an HTTP protocol is responsible for entering information into the cache memory and for using it. But in some cases, its functions can take over the site management system, which now is the user. The drawback of the whole system is that the changes made in one browser are not always or not immediately displayed in the other. Especially it's not worked out on mobile platforms. Next, you will learn how to install the cache on "Android", and you can understand why this aspect is not worked out.

Clearing the browser cache

Features of the cache in the browser are also manifested in the fact that it must be periodically cleaned. The fact is that this memory itself is quite large, and in addition it still stores data that is not very convenient to process. Therefore, from time to time, it will not hurt to clean the browser cache. In addition, this approach is advised even if there are problems with loading new data or temporary faults that are too frequent. In most browsers, cleaning the cache is not a difficult process, and you can do it in a couple of seconds. This is so universal that even with a general description you can do everything you need, regardless of what is the object of cleaning: the cache in "Mozile" or "Internet Explorer." To clear it, you need to go through the following points:

1. Click now on the settings menu.
2. Select the History button. If it's not there - "User settings", and there is already "History" or "Cookies".
3. Before you will be a menu in which you can choose what data you want to erase and for what period. Make the settings on your own.
4. Click on the "Clear" button.

A small warning: all the data you select will be deleted. By default, everything is removed, including automatic forms and passwords for different sites. So if you are used to filling out your login and password using pop-up help or do not remember the password to sites that you often visit, you need to make sure that you can then access.

Cache in mobile platform

We figured out what caches are on personal computers. And now to the most unusual - how things are with the cache memory on mobile platforms. In general, we can say that the implementation mechanism is similar to that used in personal computers, but with its limitations, which are limited by the hardware limitations of phones, smartphones and tablets. So, on them the data store has smaller sizes, less helps with browsers and is generally less noticeable than when working with a computer. Though it is possible to tell and in more details, using as an example Android-cache. Take the file with the extension .akr and click the "Install" button. In the folder where it will be installed, there will be one folder starting with com, and ending with the name of the program. This is the storage of temporary data, or the cache memory of a separate program. Here's how to install the cache on "Android" - you do not even need to do anything except a couple of clicks.