Patent Publication Number: US-9430198-B2

Title: Data processing method and apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of International Application No. PCT/CN2014/081141, filed on Jun. 30, 2014, which claims priority to Chinese Patent Application No. 201410055711.9, filed on Feb. 19, 2014, both of which are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates to the computer field, and in particular, to a data processing method and apparatus. 
     BACKGROUND 
     An external routine (External Routine) is generally a program that is compiled by using an advanced programming language and may be embedded in a structured query language (SQL) statement. Source code of the external routine, after being compiled, may be invoked by a database management system, so that a database function is extended. A database system includes a database and a database management system, where the database is used to store data, and the database management system is used to operate, manage, and maintain the database. Generally, the database management system may be a structured query language database management system (MySQL) and so on, and the database may be a structured query language database (SQL Server), an Oracle database (Oracle), and so on, and the database provides extensive support for the advanced programming language, where the advanced programming language may be a C language, a C++ language, a JAVA language, a Common Business Oriented Language (COBOL), and so on. 
     In the prior art, the database system may compile, by using an embedded database management system and an embedded extended language compiling module, the source code of the external routine compiled by using the advanced programming language, to obtain target code of the external routine, where the database management system may be a MySQL, Teradata, and so on, and the extended language compiling module may be a DB2, a PostgreSQL, and so on. Then, the target code of the external routine is stored to the database according to a target name and target address set by a user, where the target name is used to uniquely identify the target code of the external routine, and the target address is used to identify an address of the target code of the external routine stored in the database, so that the target code of the external routine is invoked according to the target name and the target address. Alternatively, after the source code of the external routine is compiled by using a programming tool of the advanced programming language, the target code of the external routine is copied to the database according to the target name and target address set by the user, and it is necessary to register information such as the target name and target address with the database, so that the database management system identifies and invokes the target code of the external routine. 
     However, central processors on different operating platforms are different, and instruction sets of different central processors are also different. Therefore, the external routine compiled by using the advanced programming language, when running on different operating platforms, needs to be compiled by different compilers to obtain target code of the external routine which is suitable for running on a current operating platform, where the operating platform is hardware and/or software required for running the target code of the external routine. The instruction set is used to convert the external routine into the target code of the external routine which is suitable for running on the operating platform. For example, when an external routine is compiled into target code of an x86 version, the target code can only run on a central processor that supports an x86 instruction set. Therefore, different compilers need to be embedded into the database system to compile the source code of the external routine, which limits scalability of the database system, and a security problem exists when the external routine is compiled. 
     SUMMARY 
     Embodiments of the present invention provide a data processing method and apparatus, which can effectively improve scalability of a database system. 
     To achieve the foregoing objectives, the following technical solutions are adopted in embodiments of the present invention: 
     According to a first aspect, a data processing method is provided, including receiving source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language, compiling the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform, converting, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform; and storing the machine code to a database. 
     According to the first aspect, in a first possible implementation manner, before the receiving source code of an external routine, the method further includes receiving a database access request sent by a first user equipment that sends the source code of the external routine, determining, according to the database access request, whether the first user equipment has a permission to access the database; and if the first user equipment has the permission to access the database, receiving the source code of the external routine sent by the first user equipment, so as to convert the source code into the machine code and store the machine code to the database. 
     With reference to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner, before the compiling the source code to obtain intermediate code, the method further includes checking whether a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database, and if the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database, compiling the source code to obtain the intermediate code. 
     With reference to the first aspect or the first possible implementation manner of the first aspect, in a third possible implementation manner, before the compiling the source code to obtain intermediate code, the method further includes checking whether an operation performed by the source code on an object in the database is a preset operation performed on the object in the database, where the operation includes modifying, adding, or deleting the object, and if the operation performed by the source code on the object in the database is the preset operation performed on the object in the database, compiling the source code to obtain the intermediate code. 
     With reference to the first aspect or any one of the first possible implementation manner to the third possible implementation manner of the first aspect, in a fourth possible implementation manner, after the compiling the source code to obtain intermediate code, the method further includes storing the intermediate code to the database. 
     With reference to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner, after the storing the intermediate code to the database, the method further includes generating a target name of the intermediate code, where the target name is used to uniquely identify the intermediate code, and generating a target address of the intermediate code, where the target address is used to identify an address of the intermediate code in the database. 
     With reference to the first aspect or any one of the first possible implementation manner to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner, after the storing the machine code to a database, the method further includes receiving a request, which is sent by a second user equipment, for invoking the external routine, determining, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine, and if the second user equipment has the permission to invoke the external routine, running the machine code, so as to invoke the external routine from the database. 
     According to a second aspect, a data processing apparatus is provided, including a first receiving unit configured to receive source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language, a compiling unit configured to compile the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform, a converting unit configured to convert, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform, and a storing unit configured to store the machine code to a database. 
     With reference to the second aspect, in a first possible implementation manner, the data processing apparatus further includes a second receiving unit configured to receive a database access request sent by a first user equipment that sends the source code of the external routine, and a first determining unit configured to determine, according to the database access request, whether the first user equipment has a permission to access the database, where the first receiving unit is specifically configured to receive, when the first determining unit determines that the first user equipment has the permission to access the database, the source code of the external routine sent by the first user equipment, so as to convert the source code into the machine code and store the machine code to the database. 
     With reference to the second aspect or the first possible implementation manner of the second aspect, in a second possible implementation manner, the data processing apparatus further includes a first checking unit configured to check whether a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database, where the compiling unit is specifically configured to compile the source code to obtain the intermediate code when the first checking unit determines that the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database. 
     With reference to the second aspect or the first possible implementation manner of the second aspect, in a third possible implementation manner, the data processing apparatus further includes a second checking unit configured to check whether an operation performed by the source code on an object in the database is a preset operation performed on the object in the database, where the operation includes modifying, adding, or deleting the object; where the compiling unit is specifically configured to compile the source code to obtain the intermediate code when the second checking unit determines that the operation performed by the source code on the object in the database is the preset operation performed on the object in the database. 
     With reference to the second aspect or any one of the first possible implementation manner to the third possible implementation manner of the second aspect, in a fourth possible implementation manner, the storing unit is further configured to store the intermediate code to the database. 
     With reference to the fourth possible implementation manner of the second aspect, in a fifth possible implementation manner, the data processing apparatus further includes a first generating unit configured to generate a target name of the intermediate code, where the target name is used to uniquely identify the intermediate code, and a second generating unit configured to generate a target address of the intermediate code, where the target address is used to identify an address of the intermediate code in the database. 
     With reference to the second aspect or any one of the first possible implementation manner to the fifth possible implementation manner of the second aspect, in a sixth possible implementation manner, the data processing apparatus further includes an invoking unit, where the second receiving unit is further configured to receive a request, which is sent by a second user equipment, for invoking the external routine, the first determining unit is further configured to determine, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine, and the invoking unit is configured to run the machine code when the first determining unit determines that the second user equipment has the permission to invoke the external routine, so as to invoke the external routine from the database. 
     Embodiments of the present invention provide a data processing method and apparatus. The data processing method includes: receiving source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language; compiling the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform; converting, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform; and storing the machine code to a database. In this way, the received source code of the external routine is compiled to obtain the intermediate code. In comparison with the prior art, the intermediate code is independent from the operating platform, and is a type of unified code for the operating platform, that is, a virtual machine on any operating platform can identify the intermediate code. Therefore, it is unnecessary to embed different compilers into a database system to compile the source code of the external routine, and convert, according to the instruction set on the operating platform, the intermediate code into the machine code capable of running on the operating platform. Thereby, scalability of the database system is effectively improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       To describe the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show merely some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts. 
         FIG. 1A  is a flowchart of a data processing method according to an embodiment of the present invention; 
         FIG. 1B  is a flowchart of another data processing method according to an embodiment of the present invention; 
         FIG. 2  is a flowchart of still another data processing method according to an embodiment of the present invention; 
         FIG. 3  is a flowchart of yet another data processing method according to an embodiment of the present invention; 
         FIG. 4  is a flowchart of yet another data processing method according to an embodiment of the present invention; 
         FIG. 5  is a schematic structural diagram of a data processing apparatus according to an embodiment of the present invention; 
         FIG. 6A  is a schematic structural diagram of another data processing apparatus according to an embodiment of the present invention; 
         FIG. 6B  is a schematic structural diagram of still another data processing apparatus according to an embodiment of the present invention; and 
         FIG. 7  is a schematic structural diagram of yet another data processing apparatus according to an embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following clearly describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. 
     As shown in  FIG. 1A , an embodiment of the present invention provides a data processing method, including the following steps: 
     Step  104 : Receive source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language. 
     Step  105 : Compile the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform. 
     When the source code of the external routine is compiled, first, whether a range of an object, in a database, accessed by the source code is in a preset range of an object accessed in the database is checked; and if the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database, the source code is compiled to obtain the intermediate code. Alternatively, compiling the source code to obtain the intermediate code may further include: checking whether an operation performed by the source code on the object in a database is a preset operation performed on the object in the database, where the operation includes modifying, adding, or deleting the object; and if the operation performed by the source code on the object in the database is the preset operation performed on the object in the database, compiling the source code to obtain the intermediate code, so that the virtual machine on any operating platform can identify the intermediate code. After the source code is successfully compiled to obtain the intermediate code, the intermediate code is stored to the database, and a target name and a target address of the intermediate code are generated, where the target name is used to uniquely identify the intermediate code, and the target address is used to identify an address of the intermediate code in the database. 
     Step  106 : Convert, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform. 
     The instruction set is a hardware program that is stored in a central processor and guides and optimizes an operation of the central processor, and the instruction set may enable the central processor to run more effectively. 
     Step  107 : Store the machine code to a database. 
     A target name and a target address of the machine code are generated, where the target name is used to uniquely identify the machine code, and the target address is used to identify an address of the machine code in the database. 
     In this way, first, source code of an external routine is received, and then, the source code is compiled to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform. In comparison with the prior art, the intermediate code is independent from the operating platform, and is a type of unified code for the operating platform, that is, the virtual machine on any operating platform can identify the intermediate code. Therefore, it is unnecessary to embed different compilers into a database system to compile the source code of the external routine, and convert, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform. Thereby, scalability of the database system is effectively improved. 
     As shown in  FIG. 1B , an embodiment of the present invention provides a data processing method, including the following steps: 
     Step  111 : Receive a database access request sent by a first user equipment that sends source code of an external routine. 
     Step  112 : Determine, according to the database access request, whether the first user equipment has a permission to access a database. 
     Step  113 : If the first user equipment has the permission to access the database, receive the source code of the external routine sent by the first user equipment, so as to convert the source code into machine code and store the machine code to the database. 
     If the first user equipment has the permission to access the database, the source code of the external routine sent by the first user equipment is received, which includes: parsing a data packet of the source code of the external routine to obtain a first identifier of the data packet, where the first identifier is used to identify a source address of the data packet; determining whether the first identifier of the data packet is a preset identifier, where the preset identifier is used to identify an address of the first user equipment; and if the first identifier of the data packet is the preset identifier, receiving a data packet sent by the first user equipment, where the data packet includes the source code of the external routine, where the source code of the external routine is compiled by using an advanced programming language, where the advanced programming language may be a C language, a C++ language, a JAVA language, and so on. 
     Step  114 : Receive the source code of the external routine, where the source code of the external routine is compiled by using an advanced programming language. 
     Step  115 : Compile the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform. 
     Step  116 : Convert, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform. 
     Step  117 : Store the machine code to the database. 
     In this way, before source code of an external routine is received, first, a database access request sent by a first user equipment that sends the source code of the external routine is received, and then after it is determined that the first user equipment has a permission to access a database, the source code of the external routine sent by the first user equipment is received, so that the source code is converted into a machine code and that the machine code is stored to the database. Thereby, security of the database is effectively enhanced, and the user equipment is prevented from unauthorizedly accessing the database. 
     As shown in  FIG. 2 , an embodiment of the present invention provides a data processing method. It is assumed that source code of an external routine is compiled by using a C language, where the method includes the following steps: 
     Step  201 : Receive a database access request sent by a first user equipment. 
     If a first user is a local user, the first user may send the database access request to a database by using the first user equipment, where the database access request sent by the first user equipment includes a user name, a login password, and a permission level. The user name is a login name used by the first user to log in to the database, the login password is a login password used by the first user to log in to the database, and the permission level is a level of an operation that can be performed by the first user on the database when the first user logs in to the database. For example, a permission level such as an administrator, a senior user, an intermediate user, or a junior user has different permissions to operate the database. Exemplarily, the administrator may add or delete a user to or from the database, and perform any compiling operation such as deleting, adding, or modifying on a source program or an object in the database; the senior user may invoke the source program in the database to perform any compiling operation such as deleting, adding, or modifying on the object in the database; the junior user may only access the object in the database. 
     If the first user is not a local user and needs to access the database remotely, the first user may first send, by using the first user equipment, an access request to a server on which the database is located, where the access request includes an Internet Protocol (IP) address and a port number of the server on which the database is located. After successfully accessing the server on which the database is located, the first user may send the database access request to the database again by using the first user equipment, and in this case, the database access request includes the user name, the login name, and the permission level. 
     It should be noted that the user may access the database in a form of command inputting in a disk operating system (DOS) environment, and may add, delete, or modify the source program or data in the database in the form of command inputting; the user may further access the database in a visual window interface. 
     Step  202 : Determine, according to the database access request, whether the first user equipment has a permission to access a database. 
     If the first user equipment does not have the permission to access the database, step  2021  is performed to forbid the first user equipment to access the database. 
     If the first user equipment has the permission to access the database, step  203  is performed. 
     If the first user is not registered with the database, when the first user accesses the database by using the first user equipment, the database determines that the first user is an unauthorized user of the database, and forbids the first user to access the database by using the first user equipment. 
     If the first user equipment has the permission to access the database, that is, the first user is registered with the database by using the first user equipment, when the first user accesses the database by using the first user equipment, the database determines that the first user is an authorized user of the database, and allows the first user to access the database by using the first user equipment. 
     Specifically, if the first user equipment has the permission to access the database, the source code of the external routine sent by the first user equipment is received, which includes: parsing a data packet of the source code of the external routine to obtain a first identifier of the data packet, where the first identifier is used to identify a source address of the data packet, namely, an address of a user equipment sending the data packet; determining whether the first identifier of the data packet is a preset identifier, where the preset identifier is used to identify an address of the first user equipment; and if the first identifier of the data packet is the preset identifier, receiving a data packet sent by the first user equipment, where the data packet includes the source code of the external routine. 
     Step  2021 : Forbid the first user equipment to access the database. 
     In the embodiment of the present invention, it is assumed that the first user equipment has the permission to access the database, and step  203  is performed. 
     Step  203 : Receive source code of an external routine sent by the first user equipment. 
     Step  204 : Check whether a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database. 
     If the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database, step  2041  is performed to stop compiling the source code. 
     For example, it is possible that the object, in the database, accessed by the source code includes an object forbidden to be accessed, causing unauthorized access to the object in the database. It is assumed that the object accessed by the source code is critical business data, leak of a major business secret may be caused, resulting in serious economic losses. If the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database, the source code is compiled to obtain an intermediate code. 
     Specifically, first, a permission level of the object in the database is preset. Objects of different permission levels are of different importance, that is, permission levels of the objects may be set to confidential, high-level, or low-level, and so on. For example, a confidential object cannot be accessed randomly, and can only be accessed by a program or user having a confidential permission. The object may be data in the database. Alternatively, data stored in the database may be classified into different types of objects, where each type of data is a type of object, for example, a data type and an information type. Then, after receiving the source code of the external routine, when compiling the source code, the database checks whether an object, in the database, accessed by the source program is a preset object in the database allowed to be accessed; compiles the source code to obtain the intermediate code if the object, in the database, accessed by the source program is the preset object in the database allowed to be accessed; and stops compiling the source code if the object, in the database, accessed by the source program is a preset object in the database not allowed to be accessed. 
     Further, if the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database, step  205  is performed to check whether an operation performed by the source code on the object in the database is a preset operation performed on the object in the database. 
     Step  2041 : Stop compiling the source code. 
     In the embodiment of the present invention, it is assumed that the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database, and step  205  is performed. 
     Step  205 : Check whether an operation performed by the source code on the object in the database is a preset operation performed on the object in the database. 
     If it is determined that the operation performed by the source code on the object in the database is not the preset operation performed on the object in the database, step  2041  is performed to stop compiling the source code. 
     If it is checked that the operation performed by the source code on the object in the database is the preset operation performed on the object in the database, step  206  is performed. 
     Specifically, first, a permission to operate the object in the database is preset, where the operation includes modifying, adding, or deleting the object. That is, some important objects in the database may be accessed but any operation such as modifying cannot be performed on the objects, where the important objects are objects of a confidential or high permission level; some ordinary objects may be accessed and any operation such as modifying, deleting, or adding may also be performed on the objects, where the ordinary objects are objects of a low permission level. Then, if the object, in the database, accessed by the source code is the preset object in the database allowed to be accessed, it is checked whether the operation performed by the source code on the object in the database is the preset operation performed on the object in the database; if the operation performed by the source code on the object in the database is the preset operation performed on the object in the database, the source code is compiled to obtain the intermediate code; if the operation performed by the source code on the object in the database is not the preset operation performed on the object in the database, compiling of the source code is stopped. 
     Exemplarily, it is assumed that the source code of the external routine is used to calculate actually paid after-tax salaries of company employees whose basic salaries are higher than 3500 Renminbi (RMB). Specifically, it is assumed that the source code can access basic salaries of all employees in the database, where the basic salaries of the employees include 1000 to 5000. However, only data of basic salaries of employees which are higher than 3500 among the basis salaries of all the employees is calculated, and the actually paid after-tax salaries are obtained. If the source code calculates the basic salaries of all the employees to obtain actually paid after-tax salaries, a salary actually received by an employee whose basic salary is lower than 3500 is an actually paid after-tax salary, which does not comply with stipulations of the country, and causes an error in issuing the salary of the employee. 
     In the prior art, when the source code of the external routine is compiled, it is unnecessary to check the range of the object, in the database, accessed by the source code of the external routine, and the operation performed by the source code of the external routine on the object in the database is also not checked; therefore, stability of the object in the database may be affected, or data is inconsistent when another source program in the database makes reference to the source program. 
     In the data processing method according to the embodiment of the present invention, first, a permission level of an object in the database is set, and an operation on the object is set. When the source code of the external routine is compiled, by checking the range of the object, in the database, accessed by the source code of the external routine and checking the operation performed by the source code of the external routine on the object in the database, it is determined whether the range and the operation comply with the preset permission to access the object in the database and the preset operation performed on the object in the database, which effectively enhances operation security of the database and security of data in the database. 
     In the embodiment of the present invention, it is assumed that the operation performed by the source code on the object in the database is the preset operation performed on the object in the database, step  206  is performed to compile the source code to obtain the intermediate code. 
     Step  206 : Compile the source code to obtain intermediate code. 
     Specifically, a language front-end module may be used to compile the source code to obtain the intermediate code, where the language front-end module may be a C language front-end module, a Python language front-end module, or a Fortran language front-end module, and so on. 
     In the embodiment of the present invention, it is assumed that the source code of the external routine is compiled by using the C language, a C language front-end module is used to parse the source code to obtain a parse tree, and then the parse tree is compiled to obtain the intermediate code, so that a virtual machine on any operating platform can identify the intermediate code. The parse tree includes a root node, a root element node, a node, and so on. That is, the source code is analyzed, and the process of generating the parse tree pertains to the prior art, which is not further described herein in the embodiment of the present invention. 
     Particularly, after the source code is compiled to obtain the intermediate code, step  209  is performed to store the intermediate code to the database, or the intermediate code may also be converted into machine code and step  207  is performed. 
     Step  207 : Acquire machine code of the intermediate code. 
     The operating platform includes an integrated circuit chipset using a central processor as a core, where an instruction set on any operating platform is packaged for a virtual machine on the operating platform. The instruction set is a hardware program that is stored in the central processor and guides and optimizes an operation of the central processor, and the instruction set may enable the central processor to run more effectively. The machine code of the intermediate code is acquired by using the operating platform. The operating platform may be an x86 operating platform, a performance optimization with enhanced reduced instruction set computing (RISC)—performance computing (PowerPC) operating platform, an Acorn RISC Machine (ARM) operating platform, and so on. Specifically, the intermediate code of the external routine generated by the language front-end module may be input to the operating platform, and the operating platform may convert the intermediate code of the external routine into machine code that is suitable for running on an operating platform such as the x86 operating platform, the PowerPC operating platform, or the ARM operating platform, that is, machine code run by each operating platform is different. 
     Step  208 : Store the machine code to the database. 
     After the machine code of the intermediate code is acquired, similarly, the database may generate a target name of the machine code, where the target name is used to uniquely identify the machine code, and generate a target address of the machine code, where the target address is used to identify an address of the machine code in the database. The target name and the target address are invisible to the user and are stored in the database. When the machine code of the external routine is invoked, the machine code of the external routine is invoked according to the target name and the target address. 
     Step  209 : Store the intermediate code to the database. 
     Step  2091 : Generate a target name of the intermediate code. 
     The target name is used to uniquely identify the intermediate code. 
     Step  2092 : Generate a target address of the intermediate code. 
     The target address is used to identify an address of the intermediate code in the database. 
     It should be noted that when step  2091  and step  2092  are performed, there may be no sequence for differentiation, that is, the target address of the intermediate code may be generated first, and then the target name of the intermediate code is generated. 
     Particularly, when the database generates the target name and the target address of the intermediate code, to better ensure security of the intermediate code of the external routine, a creator who compiles the external routine may further set an invoking password, that is, only a user who has both the invoking password and a permission to invoke the intermediate code of the external routine may invoke the intermediate code of the external routine. 
     In the prior art, after the source code of the external routine is compiled, the target code of the external routine is obtained; when the target code of the external routine is stored to the database, the target name and the target address set by the user need to be received; the target code of the external routine is stored to the database according to the target name and the target address. Therefore, risks such as deleting, replacing, or tampering the target code of the external routine may exist when the target code of the external routine is managed. 
     In the data processing method according to the embodiment of the present invention, when the intermediate code of the external routine is stored to the database, the database generates the target name of the intermediate code, where the target name is used to uniquely identify the intermediate code, and generates the target address of the intermediate code, where the target address is used to identify the address of the intermediate code in the database. The target name and the target address are invisible to the user and are stored in the database. When the intermediate code of the external routine is invoked, the intermediate code of the external routine is invoked according to the target name and the target address. Therefore, the intermediate code of the external routine is stored and managed by using a method controlled by the database, which may effectively avoid the risks such as deleting, replacing, or tampering the external routine when the intermediate code of the external routine is managed, and not only improve rigorousness of management but also improve security of data in the database. 
     The source code of the external routine in the embodiment of the present invention is only exemplary, and in an actual application, the source code may also be compiled by using another advanced programming language, where a process of compiling source code of an external routine compiled by using the another advanced programming language to obtain intermediate code and then converting the intermediate code into machine code is the same as the method in the embodiment of the present invention, and is not further described herein. 
     In the data processing method according to the embodiment of the present invention, first, a database access request sent by a first user equipment is received; it is determined, according to the database access request, whether the first user equipment has a permission to access a database; if the first user equipment has the permission to access the database, source code of an external routine sent by the first user equipment is received; then, when the source code is compiled, it is checked whether a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database; if the range of the object in the database accessed by the source code is in the preset range of the object accessed in the database, the source code is compiled to obtain intermediate code, and meanwhile, it may also be checked whether an operation performed by the source code on the object in the database is a preset operation performed on the object in the database; if the operation performed by the source code on the object in the database is the preset operation performed on the object in the database, the source code is compiled to obtain the intermediate code; machine code of the intermediate code is acquired; the machine code is stored to the database; and meanwhile, the intermediate code is stored to the database. In comparison with the prior art, the intermediate code is independent from an operating platform, and is a type of unified code for the operating platform, that is, a virtual machine on any operating platform can identify the intermediate code. Therefore, it is unnecessary to embed different compilers into a database system to compile the source code of the external routine, and convert, according to an instruction set on the operating platform, the intermediate code into the machine code capable of running on the operating platform. Thereby, scalability of the database system is effectively improved. Meanwhile, when the source code is compiled, checking the range of the object, in the database, accessed by the source code and checking an operation of accessing the object in the database by the source code effectively enhance operation security of the database and security of data in the database. In addition, the intermediate code and the machine code of the external routine are stored and managed by using a method controlled by the database, which effectively avoids risks such as deleting, replacing, or tampering the external routine when the intermediate code and the machine code of the external routine are managed, and not only improves rigorousness of management but also improves the security of the data in the database. 
     As shown in  FIG. 3 , an embodiment of the present invention provides a data processing method. It is assumed that a database stores intermediate code of an external routine, and the external routine is compiled by using a C language, where the method includes the following steps: 
     Step  301 : Receive a request, which is sent by a second user equipment, for invoking an external routine. 
     It is assumed that a second user is registered with the database by using the second user equipment. When the second user accesses the database by using the second user equipment, the database determines that the second user is an authorized user of the database, and allows the second user to access the database by using the second user equipment. Then, when the second user needs to invoke the external routine, the second user may send, by using the second user equipment, the request for invoking the external routine to the database, and the database receives the request, which is sent by the second user equipment, for invoking the external routine, is received. 
     Step  302 : Determine, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine. 
     An administrator of the database may set a permission of the second user in the database. If the second user equipment does not have the permission to invoke the external routine, the second user who invokes the source program is an unauthorized user, and step  3021  is performed. 
     If the second user equipment has the permission to invoke the external routine, the external routine is invoked from the database. It should be noted that the database stores a function name of the external routine. The external routine may be invoked according to the function name of the external routine. Then, inside the database, according to a target name and a target address of intermediate code or machine code of the stored external routine, the intermediate code or the machine code of the external routine is invoked to run the external routine, so as to return an invoking result to a user. 
     Step  3021 : Forbid the second user equipment to invoke the external routine. 
     A database system may prompt the second user equipment with an operation error, and forbid the second user equipment to invoke the external routine. 
     Exemplarily, it is assumed that the external routine is a program that needs to be used when a financial personnel in a financial department of a company prepares salaries. When the financial personnel in the financial department of the company prepares salaries of company employees in a current month every month, the external routine may be invoked to calculate and modify the salaries of the employees, and then an employee payroll is stored to the database, where the employee payroll includes a salary of every employee in the company in the current month. The administrator of the database specifies that: only the financial personnel who prepares the employee payroll and Chairman of the Board of the company may access the employee payroll in the database by using a user equipment, and may perform an operation such as modifying on the employee payroll by invoking the external routine, and a department leader of the company may access, by using the user equipment, the database to view salaries of employees in the department and a salary of this department leader in the employee payroll, but cannot invoke the external routine to perform an operation such as modifying on the salaries of the employees in the department and the salary of this department leader, and ordinary employees in the company can only access, by using the user equipment, the database to view their own salaries in the employee payroll, and cannot invoke the external routine to perform an operation such as modifying on their own salaries, either. 
     In the embodiment of the present invention, it is assumed that the second user equipment has the permission to invoke the external routine, and step  303  is performed. 
     Step  303 : Acquire a result of the invoking request. 
     Step  304 : Invoke a virtual machine to execute intermediate code of the external routine. 
     When the result of the invoking request is the intermediate code of the external routine, a virtual machine on an operating platform is invoked to execute the intermediate code of the external routine. 
     In the prior art, when the user invokes the external routine by using the user equipment, a user permission to invoke the external routine does not need to be determined, and the external routine is directly invoked, which may affect security or stability of an object in the database. 
     In the data processing method according to the embodiment of the present invention, when the user invokes the external routine by using the user equipment, first, the user permission to invoke the external routine needs to be determined, and only a user who has the permission to invoke the external routine can invoke the external routine by using the user equipment. In comparison with the prior art, before the user equipment invokes the external routine, a step of determining a user invoking permission is added, which effectively improves security or stability of the object in the database. 
     Exemplarily, it is assumed that the database is a structured query language (SQL) database. When a user equipment A needs to access the SQL database, first, a server on which the SQL database is installed checks whether the user equipment A has a permission to connect to the SQL database, and if the user equipment A has the permission to connect to the SQL database, after the user equipment A successfully accesses the SQL database, the SQL database checks again whether the user has a permission to log in to the SQL database; if the user has the permission to log in to the SQL database, the user may operate an object in the SQL database; then, the SQL database determines whether the user has a permission to operate the object. For example, if a table needs to be updated or queried, the SQL database determines a permission of the user to the table, or the user needs to run a stored procedure, and the SQL database determines whether the user has a permission to execute the stored procedure. For example, a permission of the SQL database is shown in Table 1. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Permission of the SQL Server database 
               
            
           
           
               
               
            
               
                 Permission level 
                 Permission 
               
               
                   
               
               
                 Database, table, or index 
                 CREATE (create a database, a table, or an 
               
               
                   
                 index) 
               
               
                 Database or table 
                 DROP(delete a database or a table) 
               
               
                 Database, table, or stored 
                 GRANT OPTION (grant a permission option) 
               
               
                 program 
               
               
                 Table 
                 ALTER (alter a table, such as adding a field 
               
               
                   
                 and an index) 
               
               
                 Table 
                 DELETE (delete data) 
               
               
                 Table 
                 Index (index) 
               
               
                 Table 
                 INSERT (insert) 
               
               
                 Table 
                 SELECT (query) 
               
               
                 Table 
                 UPDATE (update) 
               
               
                 View 
                 CREATE VIEW (create a view) 
               
               
                 View 
                 SHOW VIEW (show a view) 
               
               
                 Stored procedure 
                 ALTER ROUTINE (alter a stored procedure) 
               
               
                 Stored procedure 
                 CREATE ROUTINE (create a stored 
               
               
                   
                 procedure) 
               
               
                 Stored procedure 
                 EXECUTE (execute a stored procedure) 
               
               
                 File access on a server 
                 FILE (file access) 
               
               
                 host 
               
               
                 Server management 
                 CREATE TEMPORARY TABLES (create a 
               
               
                   
                 temporary table) 
               
               
                 Server management 
                 LOCK TABLES (lock a table) 
               
               
                 Server management 
                 CREATE USER (create a user) 
               
               
                 Server management 
                 PROCESS (show a process) 
               
               
                 Server management 
                 RELOAD (execute a reloading command) 
               
               
                 Server management 
                 REPLICATION CLIENT (replicate) 
               
               
                 Server management 
                 REPLICATION SLAVE (replicate) 
               
               
                 Server management 
                 SHOW DATABASES (show a database) 
               
               
                 Server management 
                 SHUTDOWN (shut down a database) 
               
               
                 Server management 
                 SUPER (execute a thread) 
               
               
                   
               
            
           
         
       
     
     In the data processing method according to the embodiment of the present invention, first, a request, which is sent by a second user equipment, for invoking an external routine is received; then, it is determined, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine; if the second user equipment has the permission to invoke the external routine, the external routine is invoked from a database to acquire a result of the invoking request; and a virtual machine is invoked to execute intermediate code of the external routine. In comparison with the prior art, when a user equipment invokes the external routine, a step of determining a user invoking permission is added, which effectively improves security or stability of an object in the database. 
     As shown in  FIG. 4 , an embodiment of the present invention provides a data processing method. It is assumed that a database stores machine code of an external routine, and the external routine is compiled by using a C language, where the method includes the following steps: 
     Step  401 : Receive a request, which is sent by a second user equipment, for invoking an external routine. 
     It is assumed that a second user is registered with the database by using the second user equipment, when the second user accesses the database by using the second user equipment, the database determines that the second user is an authorized user of the database, and allows the second user to access the database by using the second user equipment. Then, when the second user needs to invoke the external routine, the second user may send, by using the second user equipment, the request for invoking the external routine to the database, and the database receives the request, which is sent by the second user equipment, for invoking the external routine, is received. 
     Step  402 : Determine, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine. 
     An administrator of the database may set a permission of the second user in the database. If the second user equipment does not have the permission to invoke the external routine, the second user who invokes the source program is an unauthorized user, and step  4021  is performed. 
     If the second user equipment has the permission to invoke the external routine, the external routine is invoked from the database. It should be noted that the database stores a function name of the external routine. The external routine may be invoked according to the function name of the external routine. Then, inside the database, according to a target name and a target address of intermediate code or machine code of the stored external routine, the intermediate code or the machine code of the external routine is invoked to run the external routine, so as to return an invoking result to a user. 
     Step  4021 : Forbid the second user equipment to invoke the external routine. 
     A database system may prompt the second user equipment with an operation error, and forbid the second user equipment to invoke the external routine. 
     In the embodiment of the present invention, it is assumed that the second user equipment has the permission to invoke the external routine, and step  403  is performed. 
     Step  403 : Acquire a result of the invoking request. 
     Step  404 : Directly execute machine code of the external routine. 
     When the result of the invoking request is the machine code of the external routine, an operating platform corresponding to the machine code is used to run the machine code of the external routine. 
     In the prior art, when the user invokes the external routine by using the user equipment, a user permission to invoke the external routine does not need to be determined, and the external routine is directly invoked, which may affect security or stability of an object in the database. 
     In the data processing method according to the embodiment of the present invention, when the user invokes the external routine by using the user equipment, first, the user permission to invoke the external routine needs to be determined, and only a user who has the permission to invoke the external routine can invoke the external routine by using the user equipment. In comparison with the prior art, before the user equipment invokes the external routine, a step of determining a user invoking permission is added, which effectively improves security or stability of an object in the database. 
     In the data processing method according to the embodiment of the present invention, first, a request, which is sent by a second user equipment, for invoking an external routine is received; then, it is determined, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine; if the second user equipment has the permission to invoke the external routine, the external routine is invoked from a database; a result of the invoking request is acquired; and machine code of the external routine is directly executed. In comparison with the prior art, when a user equipment invokes the external routine, a step of determining a user invoking permission is added, which effectively improves security or stability of an object in the database. 
     Exemplarily, as shown in  FIG. 5 , a process of compiling source code of an external routine to obtain intermediate code or machine code and running the intermediate code or the machine code is described by using a logical frame diagram of the external routine. First, the source code of the external routine is input to a language front-end module  501 ; the language front-end module  501  parses and compiles the source code to obtain a parse tree, and compiles the parse tree; meanwhile, an authenticating module  502  determines whether an operation or access and so on performed by the source code on an object in a database is secure; if the operation or the access and so on performed by the source code on the object in the database is secure, the intermediate code of the source code is obtained; then, the intermediate code is input to an intermediate code module  503 ; the intermediate code module  503  stores, by using a storage management module  504 , the intermediate code of the source code to the database; finally, the intermediate code module  503  inputs the intermediate code of the source code to an operating platform  505 ; the operating platform  505  converts the intermediate code of the source code into the machine code, so as to execute the external routine on the operating platform to obtain an expected result. Alternatively, if the intermediate code of the source code is not converted into the machine code, when the external routine needs to be invoked, the intermediate code of the source code is input to a virtual machine executing module  506 , and the virtual machine executing module  506  executes the machine code when converting the intermediate code of the source code into the machine code. 
     It should be noted that the language front-end module  501  may be a language front-end module such as a C language front-end module, a Python language front-end module, or a Fortran language front-end module, and so on. The operating platform  505  may be an x86 operating platform, a PowerPC operating platform, or an ARM operating platform, and so on, and machine code run on each operating platform is different. 
     As shown in  FIG. 6A , an embodiment of the present invention provides a data processing apparatus  600 , including a first receiving unit  603  configured to receive source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language, a compiling unit  606  configured to compile the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform, a converting unit  607  configured to convert, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform, and a storing unit  608  configured to store the machine code to a database. 
     In this way, first, source code of an external routine is received, and then, the source code is compiled to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform. In comparison with the prior art, the intermediate code is independent from the operating platform, and is a type of unified code for the operating platform, that is, the virtual machine on any operating platform can identify the intermediate code. Therefore, it is unnecessary to embed different compilers into a database system to compile the source code of the external routine, and convert, according to an instruction set on the operating platform, the intermediate code into the machine code capable of running on the operating platform. Thereby, scalability of the database system is effectively improved. 
     As shown in  FIG. 6B , the data processing apparatus  600  further includes a second receiving unit  601  configured to receive a database access request sent by a first user equipment that sends the source code of the external routine, and a first determining unit  602  configured to determine, according to the database access request, whether the first user equipment has a permission to access the database. 
     The first receiving unit  603  is specifically configured to receive, when the first determining unit  602  determines that the first user equipment has the permission to access the database, the source code of the external routine sent by the first user equipment, so that the converting unit  607  converts the source code into the machine code and stores the machine code to the database. 
     The data processing apparatus  600  further includes a first checking unit  604  configured to check whether a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database. 
     The compiling unit  606  is specifically configured to compile the source code to obtain the intermediate code when the first checking unit  604  determines that the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database. 
     The data processing apparatus  600  further includes a second checking unit  605  configured to check whether an operation performed by the source code on an object in the database is a preset operation performed on the object in the database, where the operation includes modifying, adding, or deleting the object. 
     The compiling unit  606  is specifically configured to compile the source code to obtain the intermediate code when the second checking unit  605  determines that the operation performed by the source code on the object in the database is the preset operation performed on the object in the database. 
     The storing unit  608  is further configured to store the intermediate code to the database. 
     The data processing apparatus  600  further includes a first generating unit  609  configured to generate a target name of the intermediate code, where the target name is used to uniquely identify the intermediate code, and a second generating unit  6010  configured to generate a target address of the intermediate code, where the target address is used to identify an address of the intermediate code in the database. 
     It should be noted that after the storing unit  608  stores the intermediate code to the database, at the same time when the first generating unit  609  generates the target name of the intermediate code, where the target name is used to uniquely identify the intermediate code, the second generating unit  6010  may generate the target address of the intermediate code, where the target address is used to identify the address of the intermediate code in the database, without differentiating a sequence of generating the target name and generating the target address. 
     The data processing apparatus  600  further includes an invoking unit  6011 . 
     The second receiving unit  601  is further configured to receive a request, which is sent by a second user equipment, for invoking the external routine. 
     The first determining unit  602  is further configured to determine, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine. 
     The invoking unit  6011  is configured to run the machine code when the first determining unit  602  determines that the second user equipment has the permission to invoke the external routine, so as to invoke the external routine from the database. 
     In the data processing apparatus according to the embodiment of the present invention, first, a database access request sent by a first user equipment is received; it is determined, according to the database access request, that the first user equipment has a permission to access a database, and source code of an external routine is received; then, when the source code is compiled, it is checked that a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database, and the source code is compiled to obtain intermediate code; and meanwhile, it may also be checked that an operation performed by the source code on the object in the database is a preset operation performed on the object in the database; the source code is compiled to obtain the intermediate code; machine code of the intermediate code is acquired; and the machine code is stored to the database; and meanwhile, after the machine code or the intermediate code of the external routine is stored, and when it is determined that a second user equipment has a permission to invoke the external routine, the machine code or the intermediate code is run, so as to invoke the external routine from the database. In comparison with the prior art, the intermediate code is independent from an operating platform, and is a type of unified code for the operating platform, that is, a virtual machine on any operating platform can identify the intermediate code. Therefore, it is unnecessary to embed different compilers into a database system to compile the source code of the external routine, and convert, according to an instruction set on the operating platform, the intermediate code into the machine code capable of running on the operating platform. Thereby, scalability of the database system is effectively improved. Meanwhile, when the source code is compiled, checking the range of the object, in the database, accessed by the source code and checking an operation of accessing the object in the database by the source code effectively enhance operation security of the database and security of data in the database. In addition, the intermediate code and the machine code of the external routine are stored and managed by using a method controlled by the database, which effectively avoids risks such as deleting, replacing, or tampering the external routine when the intermediate code and the machine code of the external routine are managed, and not only improves rigorousness of management but also improves the security of the data in the database. 
     As shown in  FIG. 7 , an embodiment of the present invention provides a data processing apparatus  70 , including a receiver  701  configured to receive source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language, and a processor  702  configured to compile the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform. 
     The processor  702  is further configured to convert, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform. 
     The processor  702  is further configured to store the machine code to a database. 
     In this way, first, source code of an external routine is received, and then, the source code is compiled to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform. In comparison with the prior art, the intermediate code is independent from the operating platform, and is a type of unified code for the operating platform, that is, a virtual machine on any operating platform can identify the intermediate code. Therefore, it is unnecessary to embed different compilers into a database system to compile the source code of the external routine, and convert, according to an instruction set on the operating platform, the intermediate code into the machine code capable of running on the operating platform. Thereby, scalability of the database system is effectively improved. 
     The receiver  701  is further configured to receive a database access request sent by a first user equipment that sends the source code of the external routine. 
     The processor  702  is further configured to determine, according to the database access request, whether the first user equipment has a permission to access the database. 
     The processor  702  is further configured to receive, when the processor  702  determines that the first user equipment has the permission to access the database, the source code of the external routine sent by the first user equipment, so as to convert the source code into the machine code and store the machine code to the database. 
     Specifically, the processor  702  parses a data packet of the source code of the external routine to obtain a first identifier of the data packet, where the first identifier is used to identify a source address of the data packet; and then determines whether the first identifier of the data packet is a preset identifier, where the preset identifier is used to identify an address of the first user equipment. 
     The processor  702  is further configured to check whether a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database. 
     The processor  702  is specifically configured to compile the source code to obtain the intermediate code when the processor  702  determines that the range of the object, in the database, accessed by the source code is in the preset range of the object accessed in the database. 
     The processor  702  is further configured to check whether an operation performed by the source code on the object in the database is a preset operation performed on the object in the database, where the operation includes modifying, adding, or deleting the object. 
     The processor  702  is specifically configured to compile the source code to obtain the intermediate code when the processor  702  determines that the operation performed by the source code on the object in the database is the preset operation performed on the object in the database. 
     The processor  702  is further configured to store the intermediate code to the database. 
     The processor  702  is further configured to generate a target name of the intermediate code, where the target name is used to uniquely identify the intermediate code. 
     The processor  702  is further configured to generate a target address of the intermediate code, where the target address is used to identify an address of the intermediate code in the database. 
     The receiver  701  is further configured to receive a request, which is sent by a second user equipment, for invoking the external routine. 
     The processor  702  is further configured to determine, according to the request for invoking the external routine, whether the second user equipment has a permission to invoke the external routine. 
     The processor  702  is further configured to run the machine code when the processor  702  determines that the second user equipment has the permission to invoke the external routine, so as to invoke the external routine from the database. 
     In the data processing apparatus according to the embodiment of the present invention, first, a database access request sent by a first user equipment is received; it is determined, according to the database access request, that the first user equipment has a permission to access a database, and source code of an external routine is received; then, when the source code is compiled, it is checked that a range of an object, in the database, accessed by the source code is in a preset range of an object accessed in the database; the source code is compiled to obtain intermediate code; and meanwhile, it may also be checked that an operation performed by the source code on the object in the database is a preset operation performed on the object in the database; the source code is compiled to obtain the intermediate code; machine code of the intermediate code is acquired; and the machine code is stored to the database; and meanwhile, after the intermediate code or the machine code of the external routine is stored, and when it is determined that a second user equipment has a permission to invoke the external routine, the machine code or the intermediate code is run, so as to invoke the external routine from the database. In comparison with the prior art, the intermediate code is independent from an operating platform, and is a type of unified code for the operating platform, that is, a virtual machine on any operating platform can identify the intermediate code. Therefore, it is unnecessary to embed different compilers into a database system to compile the source code of the external routine, and convert, according to an instruction set on the operating platform, the intermediate code into the machine code capable of running on the operating platform. Thereby, scalability of the database system is effectively improved. Meanwhile, when the source code is compiled, checking the range of the object, in the database, accessed by the source code and checking an operation of accessing the object in the database by the source code effectively enhance operation security of the database and security of data in the database. In addition, the intermediate code and the machine code of the external routine are stored and managed by using a method controlled by the database, which effectively avoids risks such as deleting, replacing, or tampering the external routine when the intermediate code and the machine code of the external routine are managed, and not only improves rigorousness of management but also improves the security of the data in the database. 
     It may be clearly understood by a person skilled in the art that, for the purpose of convenient and brief description, for a detailed working process of the foregoing apparatus and unit, reference may be made to a corresponding process in the foregoing method embodiments, and details are not described herein again. 
     In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the described apparatus embodiment is merely exemplary. For example, the unit division is merely logical function division and may be other division in an actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. Furthermore, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms. 
     The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. A part or all of the units may be selected according to an actual need to achieve the objectives of the solutions of the embodiments. 
     In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented by hardware in addition to a software functional unit, or by hardware only. 
     A person of ordinary skill in the art may understand that all or a part of the steps of the method embodiments may be implemented by a program instructing relevant hardware. The program may be stored in a computer readable storage medium. When the program runs, the steps of the method embodiments are performed. The foregoing storage medium includes any medium that can store program code, such as a read-only memory (ROM), a random-access memory (RAM), a magnetic disk, or an optical disc. 
     The foregoing descriptions are merely specific implementations of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.