KR20130033557A - File system for n-screen service - Google Patents

Abstract

PURPOSE: An N-screen file system is provided to reduce traffic according to file synchronization by having a file structure converted by a hash function by cluster. CONSTITUTION: An N-screen file system includes a PBR(Partition Boot Record) area, an FAT(File Allocation Table) area, an root directory area, and a data cluster area. The PBR area stores user account information and a hash value generated by converting data of the PBR area into a hash function by cluster. The FAT area, the root directory area, and the data cluster are encoded and stored by a cluster unit. An encode key value is generated from user information including a disk ID and a User UUID(Universally Unique IDentifier) of the PBR area. The FAT area includes a filed storing application data, a filed storing general data, and filed storing synchronization priority information.

Description

N-screen file system {FILE SYSTEM FOR N-SCREEN SERVICE}

The present invention relates to a structure of a file system optimized for synchronizing data of a user terminal with a server in a cloud computing environment implementing N-Screen.

N-Screen is a service that allows users to seamlessly use a single content on various devices such as TVs, PCs, tablet PCs, and smartphones. Such an N-Screen environment is generally implemented under a cloud computing environment in which content is stored and used in a server. In order to implement such an N-Screen service, many synchronization processes must be involved between various terminals and servers.

As an example, Korean Patent Laid-Open No. 10-2010-0003116 discloses a method of synchronizing data between heterogeneous terminals in order to apply a widget application to an N-Screen service.

However, such a data synchronization method between heterogeneous terminals has a problem in that the number of synchronization increases and the amount of communication due to synchronization increases.

Accordingly, the present invention uses a file system to which a hash function is applied in synchronizing data. Hereinafter, the file system of the related art will be described.

The file system refers to a system for archiving or organizing files or data on a computer so that they can be easily found and accessed. A structure of a FAT file system which is generally used is illustrated in FIG. 1.

As shown in the drawing, the conventional file system is divided into PBR, Reserved, FAT, Root Directory, and Data Cluster.

At this time, PBR serves as a header of the corresponding file system and stores basic information related to the entire system such as disk size, cluster size, volume name, and number of clusters.

The reserved area is reserved for the performance of the disk hardware.

In addition, the FAT area distinguishes free space from allocated space when a cluster is allocated, and records the number of the next connected cluster when a file occupies more than one cluster.

In the Root Directory area, entries (including files / sub directories) of files stored in the Root Directory are stored, and since they are usually provided in a fixed size, the number of files that can be stored in the Root Directory is limited.

In addition, the data cluster area is an area where actual file data is stored and is allocated in a cluster unit. Sub Directory information is also stored in the Data Cluster area.

On the other hand, Fig. 3A is a flowchart showing a method for searching for a file using a conventional file system, and Fig. 3B is a flowchart showing a method for synchronizing a file in the prior art.

As shown in FIG. 3A, in the file search by the conventional file system, all file accesses are PBR scanned (S11).

The file is searched through the search of RootDir and SubDir (S13, S15).

Next, access to the cluster through FAT scan (S17, S19), and determines whether the cluster is linked to read the file (S21).

On the other hand, as shown in Figure 3B, when the file is synchronized, changes of the file are tracked through the file reading process (S11 to S21) as described above (S31). That is, the change of the file is recognized through the last modification time, the file size, etc. by searching for RootDir and SubDir.

Then, the tracked change is transmitted to the server (S33), and the file of the path corresponding to the transmission path of the server is synchronized in the process of the same file read / write (S35).

Then, the above synchronization process is repeated until all the files to be synchronized are synchronized (S37).

On the other hand, Korean Patent Publication No. 10-2008-0006558 discloses a method of synchronizing a file system, which is to synchronize the file system itself, and not to synchronize the stored file using the file system, this is the N-Screen environment Is not applicable for synchronizing files on a terminal.

In addition, in the prior art, a technique of converting or encrypting a data into a hash function or encrypting the data is widely applied. However, since the conventional technology converts or encrypts data in units of files, the amount of used data is reduced or security is enhanced in the N-screen environment. Can not make the effect.

When using an existing file system by using the N-Screen platform or directly using a file system included in the terminal, the following problems are encountered.

The search process of modified files by searching RootDir and SubDir targets the entire file system, so the search time is long. In addition, the time taken to directly calculate the hash value to check for file changes causes a processing delay because it is proportional to the file size.

When using the file system included in the terminal directly, user data cannot be protected from illegal access. Even if the contents are encrypted by file, the file name and the list of installed programs are revealed.

Republic of Korea Patent Publication No. 10-2010-0003116 Republic of Korea Patent Publication No. 10-2008-0006558

The present invention is to solve the problems described above, to provide an effective N-Screen environment, to provide a file system with a reduced data amount and enhanced security in the data of the terminal is periodically synchronized.

As described above, the present invention includes a plurality of terminals and a server, and stores data of an application executed in any one of the terminals in a server, and when the same application is executed in another terminal, the data stored in the server. A method of synchronizing data between a terminal and a server to be provided to another terminal so that a plurality of terminals can be used as one terminal, the file system being applied includes a PBR area, a FAT area, a root directory area, and a data cluster area. The PBR area includes a hash value obtained by converting user account information and data of the PBR area into a hash function for each cluster.

In this case, the FAT area, the root directory area and the data cluster area may be encrypted and stored in cluster units.

In addition, the encryption key value may be a value generated from user information including UserUUID and DiskID of the PBR area.

The FAT area may include a field storing application data, a field storing general data, and a field storing synchronization priority information.

In addition, the FAT area and the root directory area may include a hash value obtained by converting cluster-specific data stored in the FAT area and the root directory area into a hash function.

In the FAT area, a hash value obtained by converting data in the Data Cluster area by using a hash function for each cluster may be stored.

According to the present invention, the data of the terminal is periodically synchronized to provide a screen system for the N-screen that can minimize the effect of whether or not the wireless communication of the terminal on the N-Screen implementation, while converting by the hash function for each cluster Since the file structure is reduced, the traffic volume due to file synchronization is reduced in N-Screen system implementation.

In addition, the present invention has the effect of providing a security enhanced N-screen file system because the data is encrypted and stored with a different key value for each user account.

1 is a conceptual diagram showing the structure of a conventional general file system.
2A-2B are flow diagrams illustrating a method for searching and synchronizing files using a conventional file system.
3 is a conceptual diagram showing the structure of a specific embodiment of a file system according to the present invention;
4 is a flowchart illustrating a specific embodiment of a file synchronization method according to the present invention.

Hereinafter, the characteristics of the N-Screen environment will be described first, and a specific embodiment of a file synchronization method according to the present invention will be described in detail with reference to the accompanying drawings.

N-Screen platform software must handle synchronization with server data quickly in preparation for user's mobile device.

Also, the creation of many files generated during synchronization complicates exception handling.

In addition, processing performance decreases due to the creation and deletion of a large amount of files.

On the other hand, the application of N-Screen has an ID according to the user and thus has a restoration capability using the data stored in the server.

And one application is given a unique ID according to the registered market and can be restored at any time through the network.

In addition, the application data does not change, so the client does not need to send the application data to the server during synchronization.

Only the application name / icon / short description is required on the N-Screen initial screen.

In addition, most of the actually installed applications have a usage feature that is not frequently performed.

Already most of the data resides on servers, and most of the data that is useful to users is stored primarily in cloud environments or other servers.

Only a small amount of data stored locally can be the target of actual synchronization.

Hereinafter, a specific embodiment of a file synchronization method according to the present invention will be described in detail with reference to the accompanying drawings.

As illustrated in FIG. 4, the file system according to the present invention includes a PBR, a FAT, a root directory, and a data cluster region as in a general file system.

The PBR area acts as a header of the file system and stores basic information related to the entire system such as disk size, cluster size, volume name, and number of clusters.

In addition, the PBR area according to the present invention stores user account information (seed value of the encryption key) and hash values for each cluster constituting the PBR area.

On the other hand, the FAT area includes a field for distinguishing applications and general data and a field for distinguishing synchronization priority.

Applications can handle comparisons of data and re-downloads from the server by exchanging only universally unique identifiers (UUIDs) because the data rarely changes.

On the other hand, in the case of general data, the hash function is converted and stored, thereby eliminating the need for a separate hash process at the time of synchronization.

In addition, the synchronization priority field stores synchronization priority. The synchronization priority field is divided into elements that can be synchronized according to a user's request and necessary parts for initial synchronization, thereby distributing synchronization time to enable faster synchronization.

Meanwhile, the root directory area, the FAT area, and the data cluster area are encrypted and stored in cluster units.

That is, the data of the root directory area, the FAT area, and the data cluster area are encrypted and stored in cluster units, and then hash values of the encrypted root directory area and the FAT area data are stored in the root directory area and the FAT area. Are stored respectively.

In the FAT area, a hash value for each cluster of the encrypted Data Cluster area is stored.

At this time, the key value used for encryption is set to have the seed value associated with the user account information. That is, UserUUID and DiskID of PBR are used as encryption key after performing arithmetic processing in system.

Also. The encryption method is preferably a symmetric encryption method.

Hereinafter, a detailed execution process of data synchronization according to the present invention will be described in detail with reference to FIG. 6 according to the present invention.

First, referring to the process of generating a file according to the present invention, the synchronization process is generated by two events.

The first is a case of a file request from a user, and the second is a synchronization process that is periodically executed between a server and a terminal.

Of course, the main synchronization process of the present invention is the second synchronization process between the server and the terminal.

First, referring to the case by the file request of the user, it is checked whether the requested file from the user is the same as a file already stored, and performs a synchronization process if not stored (S110).

Thereafter, it is determined whether the requested file data is an application (S120).

When the requested file is an application, the UUID of the application is transmitted to a server, and the corresponding application data is received to perform synchronization (S130).

On the other hand, if the requested file is not an application as a result of the determination of step 120, the server checks the synchronization order (S150), and if the synchronization order is a priority, transmits the corresponding cluster data to the terminal to perform synchronization (S160). ).

At this time, in file synchronization, after recording one cluster unit, a hash value is generated and recorded in the FAT area.

Thereafter, after performing steps 130, 140, and 150, a periodic synchronization process of the terminal is performed.

Hereinafter, a synchronization process that is periodically executed between the server and the terminal will be described.

Periodic synchronization between the server and the terminal is first converted into a hash function of the PBR area of the file stored in the terminal to read the basic information of the stored file system and transmitted to the server and the server compares it to determine whether the file has changed ( S210). Accordingly, basic information of the entire file system can be quickly read with a small amount of data.

Thereafter, if the file is not changed, the file synchronization process is terminated, and if the file is changed, hash conversion data existing for each cluster of the FAT area is transmitted to the server (S220).

Thereafter, the server compares the transmitted hash function conversion data for each cluster to determine the changed cluster (S240).

Accordingly, whether or not the entire file has been changed and the changed part can be determined with a small amount of communication in a short time. That is, it is possible to track whether or not changes are made in units of 204 clusters at a time.

Thereafter, if there are different portions of the hash transform data, the synchronization process is performed through the above-described steps 120 to 150.

That is, the changed data is identified, and when the changed data is an application, the UUID is transmitted to download the application again from the server, and in the case of general data, synchronization is performed through cluster units.

The synchronization process is repeated for all the synchronization target clusters (S250).

On the other hand, applications that are excluded from the initial synchronization and low-priority data are synchronized in real time when a user requests a corresponding file.

The rights of the present invention are not limited to the embodiments described above, but are defined by the claims, and those skilled in the art can make various modifications and adaptations within the scope of the claims. It is self-evident.

The present invention relates to a method in which a server synchronizes data of a using terminal in a cloud computing environment implementing N-Screen. According to the present invention, the data of the terminal is periodically synchronized so that wireless communication of the terminal is possible. It is possible to provide an en-screen file system that can minimize the impact on the screen implementation.

Claims (6)

Comprising a plurality of terminals and servers, and stores the data of the application executed in any one of the terminals in the server, and when the same application is executed in another terminal, by providing the data stored in the server to the other terminal In a file system applied to a method for synchronizing data between a terminal and a server so that a plurality of terminals can be used as one terminal,
It consists of a PBR zone, a FAT zone, a root directory zone, and a data cluster zone:
The NBR file system of claim 1, wherein the PBR area includes a user value and a hash value obtained by converting data of the PBR area into a hash function for each cluster.
The method of claim 1,
The FAT area, the root directory area and the data cluster area are
En Screen file system, characterized in that the cluster is encrypted in units.
The method of claim 2,
The encryption key value is,
N-Screen file system which is a value generated from user information including UserUUID and DiskID of PBR area.
The method of claim 3, wherein
The FAT area is
And a field for storing application data, a field for storing general data, and a field for storing synchronization priority information.
The method of claim 4, wherein
In the FAT area and the Root Directory area,
And a hash value obtained by converting cluster-specific data stored in the FAT area and the root directory area into a hash function.
The method of claim 5, wherein
In the FAT area,
N-Screen file system, characterized in that the hash value obtained by converting the data in the Data Cluster area by using the hash function for each cluster.

Images