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 are reading these lines, there is a meaning, you just don’t know about it yet. And within the framework of the article, this misunderstanding will be corrected.
What is cash?
It is understood as an intermediate buffer that contains information, the probability of which is the highest request, for its rapid provision to the computer user. Accessing the required data is faster than accessing a remote source or fetching from a slower memory source. But the disadvantage of the cache memory is the fact that it has a small size, which makes it problematic to store large amounts of information in it.
How does this technology work?
Now that you know what a cache is, let's talk about the device. The basics of cache memory are recordsets. Each set is associated with a specific block or element of data, which is a copy of the information located in the main memory. Each entry has its own identifier (sometimes called a tag), withwhich maintains a link between the "original" data in main memory and the "copy" in cache memory. It is accessed by a client, which can be an operating system, a browser, or a CPU. When accessing the presence of a request object, the computer first examines the cache. If a match of identifiers is found, then the data from it is used, and the process itself is called a hit. If there is no necessary information, then the main memory starts to be loaded. This process is called a cache miss. The percentage of access to it, when the required answer was received, is called the hit rate.
Given the limited size that the cache has, a decision can be made to evict some of the information. For its adoption, various branching algorithms are used. If you change the items stored in the cache memory, the changes will be made to the main memory of the computer. The rate of data entry is affected by the write policy. So, with the urgent option, all changes will be made synchronously to the main memory. With writeback (or writeback), data is replaced only if it has been evicted from the cache by other elements. How is this mechanism implemented in the above parts of 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 storage of temporary data of the operating system (or another, if it is installed on your computer). It consists of the following elements:
- Pages of RAM, which in turn are divided into buffers, the length of which is equal to and depends on the memory device used.
- A set of headers for the buffers themselves, whose task is to describe their state.
- Hash tables that indicate which header belongs to which buffer.
- List of free buffers.
Program cache
Many programs need to record their intermediate calculations to avoid having to calculate every time. And, you guessed it, they use cache. The program benefits from this, because it allows you to significantly speed up its work and carry out all the necessary calculations, but only if you have 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 don't be upset - this remark only applies to data storage, in any case - look in the task manager and you can see that part of the memory is cached.
Browser cache
How to reduce network traffic? Here cache memory comes to the rescue again! It stores part of the information used in browser pages on the user's computer or on proxy servers. Usually, the HTTP protocol is responsible for entering information into the cache memory and for its use. But in some cases, its functions can be taken over by the site management system on which the user is currently located. The disadvantage of the whole system is thatchanges made in one browser are not always or immediately reflected in another. This is especially not worked out on mobile platforms. Next, we will tell you how to install the cache on "Android", and you can understand why this aspect is not worked out there.
Clear browser cache
Features of the cache memory in the browser are also manifested in the fact that it must be cleaned periodically. The fact is that this memory itself is quite large, and additionally it also stores data that is not very convenient to process. Therefore, from time to time it does not hurt to clear the browser cache. In addition, this approach is also advised when problems are found with loading new data or in case of temporary malfunctions that are too frequent. For most browsers, clearing the cache is not a difficult process and can be completed in a couple of seconds. This is so versatile that even by the general description you can do everything you need, regardless of what is the object of cleaning: the cache in Mozilla or Internet Explorer. To clear it, you need to go through the following steps:
- Click now on the settings menu.
- Select the History button. If it is not there - "User Settings", and there already "History" or "Cookies".
- You will see a menu where you can choose what data to erase and for what period. Make the settings as you wish.
- Click on the "Clear" button.
Small warning: all data will be deleted,which you select. By default, everything is subject to deletion, including auto-fill forms and passwords to various sites. So if you are used to filling out your login and password using pop-up hints or don’t remember the password for sites you visit often, then you need to make sure that you can get access later.
Cash in the mobile platform
We figured out what a cache is on personal computers. And now to the most unusual - how things are with 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 own limitations, which rest on the hardware limitations of phones, smartphones and tablets. So, on them, the data storage is smaller, less helpful when working with browsers, and generally less noticeable than when working with a computer. Although you can tell in more detail, using the Android cache as an example. Take the.acre file and click the "Install" button. In the folder where it will be installed, one folder will appear, 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 set the cache to "Android" - you don't even have to do anything other than a couple of taps.
