CN107870925A

CN107870925A - A kind of character string filter method and relevant apparatus

Info

Publication number: CN107870925A
Application number: CN201610850786.5A
Authority: CN
Inventors: 武昊; 刘斌; 林栋�
Original assignee: Tsinghua University; Huawei Technologies Co Ltd
Current assignee: Tsinghua University; Huawei Technologies Co Ltd
Priority date: 2016-09-26
Filing date: 2016-09-26
Publication date: 2018-04-03
Anticipated expiration: 2036-09-26
Also published as: CN107870925B

Abstract

The embodiment of the invention discloses a kind of character string filter method and relevant apparatus,For network node, interface filter device is set,Interface filter device includes saving the first filter assemblies and the second filter assemblies with the character string of the network node related data and string prefix,Interface filter device can receive the acquisition request of request of data side's transmission prior to network node,Character string and string prefix according to being preserved match the character string to be identified carried in acquisition request,If character string to be identified can match any one character string or string prefix in interface filter device,It can then determine that the data that the acquisition is asked in asking are related to the network node,It can be seen that,Effectively the acquisition request of acquisition request and network node extraneous data can be filtered by interface filter device,It is related to the network node to ensure network node as far as possible to need request the asked data to be processed that obtain,So as to improve the utilization rate of network node process resource.

Description

A kind of character string filter method and relevant apparatus

Technical field

The present invention relates to data processing field, more particularly to a kind of character string filter method and relevant apparatus.

Background technology

In a communication network, data can be identified by character string, preserved the network node of data and can be recorded Character string corresponding to stored data.When request of data side wishes to obtain a data, it can send and carry to network node There is the acquisition request for the character string for identifying this data.Receiving the network node of acquisition request will can take in acquisition request The character string that the string matching of band is recorded itself, if the match is successful, then it represents that the network node has to the request of data Side provides the ability of this data.

However, under most of request, request of data side is not to send to obtain request to specified network node, but with example Mode such as broadcast propagates acquisition request, and any one network node for preserving data can receive acquisition request. But be not that each network node has the preservation acquisition to ask asked data, in fact, a network node institute The data greatly asked in the acquisition request received are all uncorrelated to the data that this network node itself preserves. If network node carries out matching treatment to each the acquisition request received, network node is caused to waste a large amount of systems Resource handles these incoherent obtain and asked, and reduces efficiency.

Therefore network node has the demand filtered to the acquisition request received, to wish that number will be preserved with itself Ask to filter out before treatment according to incoherent obtain, to improve system effectiveness.But not effective at present is network section Point filtering obtains the scheme of request.

The content of the invention

In order to solve the above-mentioned technical problem, the embodiments of the invention provide one kind

In a first aspect, the invention provides a kind of character string filter method, applied to the interface filter device of network node, The interface filter device comprises at least the first filter assemblies and the second filter assemblies, and use is saved in first filter assemblies Saved in the character string for identifying data related to the network node, second filter assemblies be used for mark with it is described The string prefix of the related data of network node, methods described include：

The interface filter device receives acquisition request, described to obtain the word to be identified for asking to include requested data Symbol string；

The interface filter device judge the character string to be identified whether with first filter assemblies preserve character The string prefix matching that string and the second filter assemblies preserve；

If any one in the character string that the character string to be identified preserves with first filter assemblies matches or described Any one in the string prefix that second filter assemblies preserve matches, and the interface filter device identifies the requested data For the data related to the network node；

The interface filter device uploads described obtain to the network node and asked.

Optionally, the interface filter device judges whether the character string to be identified preserves with first filter assemblies Character string and the second filter assemblies preserve string prefix matching, including：

If character string and second filter assemblies that the character string to be identified preserves with first filter assemblies are protected Deposit string prefix to mismatch, the interface filter device identifies that the requested data is uncorrelated to the network node Data；

The interface filter device obtains request discarding by described, please without uploading the acquisition to the network node Ask.

Optionally, the network node is in NDN.

Second aspect, the invention provides a kind of interface filter device for character cascade filter, the interface filter dress Put for obtaining request for corresponding network node filtering, the interface filter device comprises at least the first filter assemblies and second Filter assemblies, first filter assemblies include character string BF, and second filter assemblies include prefix BF；

The character string BF is used to preserve the character string for being used for identifying the data related to the network node；

The prefix BF is used to preserve the string prefix for being used for identifying the data related to the network node；

The interface filter device, which is used to receive, to be asked by the acquisition that the network node receives, described to obtain in request Character string to be identified including requested data；

The character string BF and prefix BF is used to wait to know according to the matching of the character string and string prefix of preservation Other character string, if any one in the character string that the character string to be identified preserves with the character string BF match or with it is described before Sew any one in the string prefix of BF preservations to match, the interface filter device is additionally operable to identify that the requested data is The data related to the network node；And upload described obtain to the network node and ask.

Optionally, if the character string to be identified preserves word with the character string BF character strings preserved and the prefix BF Symbol string prefix mismatches, and the interface filter device is additionally operable to identify that the requested data is and the network node not phase The data of pass；And request discarding is obtained by described, asked without uploading described obtain to the network node.

Optionally, first filter assemblies also include corresponding character string BF character string and count CBF, and described second Filter assemblies also include corresponding prefix BF prefix CBF：

The character string CBF is used for the service condition for recording the first Hash table, and first Hash table is first mistake Hash table corresponding to component is filtered, first Hash table is used for the cryptographic Hash for recording the character string that the character string BF is preserved；

The prefix CBF is used for the service condition for recording the second Hash table, and second Hash table is the described second filtering Hash table corresponding to component, second Hash table are used for the cryptographic Hash for recording the string prefix that the prefix BF is preserved.

Optionally, when changing the character string preserved in the character string BF, the character string CBF is additionally operable to according to change The service condition of first Hash table described in content update；

When changing the string prefix preserved in the prefix BF, the prefix CBF is additionally operable to according to change content more The service condition of new second Hash table.

The third aspect, the invention provides a kind of regulation and control method for interface filter device, is filled applied to interface filter Put, the interface filter device comprises at least the first filter assemblies and the second filter assemblies, and first filter assemblies include word Symbol string BF, second filter assemblies include prefix BF；The character string BF, which is used to preserve, to be used to identify and the network node The character string of related data；The prefix BF is used to preserve the character string for being used for identifying the data related to the network node Prefix；The interface filter device records the character string preserved in the character string BF and the string prefix preserved in the former BF Between incidence relation, methods described includes：

According to the quantity that character string is preserved in the character string BF, calculate the character string BF and character string false positive occur Degree, the character string false positive mismatch the character string preserved with the character string BF for identifying the character string BF Character-string error to be identified be defined as matching probability numbers；

If the character string false positive is more than the first predetermined threshold value, by the first character string of the first length condition that meets from institute State and deleted in character string BF, first character string is the character string preserved in the character string BF；

It is saved in first character string as string prefix in the prefix BF.

Optionally, it is described according to the quantity that character string is preserved in the character string BF, calculate the character string BF and word occur The degree of symbol string false positive, including：

If the character string false positive is less than the second predetermined threshold value, the first string prefix of the second length condition will be met Deleted from the prefix BF, first string prefix is the string prefix preserved in the prefix BF；

It is saved in first string prefix as character string in the character string BF.

Optionally, the first string prefix for meeting the second length condition from the prefix BF is deleted it described Afterwards, in addition to：

According to associating between the character string preserved in the character string BF and the string prefix preserved in the former BF System, the string prefix of the first string prefix described in subordinate is preserved into the prefix BF.

Optionally, in addition to：

According to the quantity that string prefix is preserved in the prefix BF, calculate the prefix BF and the journey of prefix false positive occur Degree, the prefix false positive, which is used to identifying the prefix BF, to be treated the string prefix preserved with the prefix BF is unmatched Identification string mistake is defined as the probability numbers of matching；

If the prefix false positive is determined before meeting multiple character strings of the first length condition more than the 3rd predetermined threshold value Sew, the multiple string prefix is subordinated to identical common prefix；

The multiple string prefix is merged into the common prefix, and by the multiple string prefix before described Sew in BF and delete.

Optionally, the quantity according to preservation string prefix in the prefix BF, before calculating the prefix BF appearance Sew the degree of false positive, including：

If the prefix false positive is less than the 4th predetermined threshold value, by the second string prefix of the second length condition that meets from Deleted in the prefix BF, second string prefix is the string prefix preserved in the prefix BF；

It is saved in second string prefix as character string in the character string BF.

Optionally, the second string prefix for meeting the second length condition from the prefix BF is deleted it described Afterwards, in addition to：

According to associating between the character string preserved in the character string BF and the string prefix preserved in the former BF System, the string prefix of the second string prefix described in subordinate is preserved into the prefix BF.

Optionally, the first length condition is that the maximum of string length is preserved in the character string BF.

Optionally, the second length condition is that the minimum value of string prefix length is preserved in the prefix BF.

Fourth aspect, the invention provides a kind of character string filter, applied to the interface filter device of network node, The interface filter device comprises at least the first filter assemblies and the second filter assemblies, and use is saved in first filter assemblies Saved in the character string for identifying data related to the network node, second filter assemblies be used for mark with it is described The string prefix of the related data of network node, the character string filter include receiving unit, judging unit, the first knowledge Other unit, transmitting element：

The receiving unit, request is obtained for receiving, described obtain asks to include the to be identified of requested data Character string；

The judging unit, for judge the character string to be identified whether with first filter assemblies preserve character The string prefix matching that string and the second filter assemblies preserve；If the character string to be identified preserves with first filter assemblies Character string in any one matching or second filter assemblies preserve string prefix in any one match, trigger institute State the first recognition unit；

First recognition unit, for identifying that the requested data is the data related to the network node；

The transmitting element, asked for uploading described obtain to the network node.

Optionally, in addition to the second recognition unit and discarding unit：

If character string and second filter assemblies that the character string to be identified preserves with first filter assemblies are protected Deposit string prefix to mismatch, the judging unit triggers the second recognition unit；

Second recognition unit, for identify the requested data be and the incoherent data of the network node；

The discarding unit, please without uploading the acquisition to the network node for obtaining request discarding by described Ask.

Optionally, the network node is in NDN.

5th aspect, the invention provides a kind of regulation device for interface filter device, is filled applied to interface filter Put, the interface filter device comprises at least the first filter assemblies and the second filter assemblies, and first filter assemblies include word Symbol string BF, second filter assemblies include prefix BF；The character string BF, which is used to preserve, to be used to identify and the network node The character string of related data；The prefix BF is used to preserve the character string for being used for identifying the data related to the network node Prefix；The interface filter device records the character string preserved in the character string BF and the string prefix preserved in the former BF Between incidence relation, the regulation device includes computing unit, deletes unit and storage unit：

The computing unit, for according to the quantity that character string is preserved in the character string BF, calculating the character string BF There is the degree of character string false positive, the character string false positive will protect for identifying the character string BF with the character string BF The unmatched character-string error to be identified of the character string deposited is defined as the probability numbers of matching；If the character string false positive surpasses The first predetermined threshold value is crossed, triggers the deletion unit；

The deletion unit, for the first character string of the first length condition that meets to be deleted from the character string BF, First character string is the character string preserved in the character string BF；

The storage unit, for being saved in first character string as string prefix in the prefix BF.

Optionally, if the character string false positive is less than the second predetermined threshold value, the computing unit triggering is described to delete list Member, the deletion unit are additionally operable to delete the first string prefix of the second length condition that meets from the prefix BF, institute A string prefix for stating the first string prefix to preserve in the prefix BF；

The storage unit is additionally operable to be saved in first string prefix as character string in the character string BF.

Optionally, the storage unit is additionally operable to according to the character string preserved in the character string BF with being preserved in the former BF String prefix between incidence relation, the string prefix of the first string prefix described in subordinate is preserved to the prefix In BF.

Optionally, in addition to determining unit and combining unit：

The computing unit is additionally operable to, according to the quantity for preserving string prefix in the prefix BF, calculate the prefix BF There is the degree of prefix false positive, the prefix false positive is used to identify the character that the prefix BF will preserve with the prefix BF The string unmatched character-string error to be identified of prefix is defined as the probability numbers of matching；If the prefix false positive is more than the 3rd Predetermined threshold value, trigger the determining unit；

The determining unit, for the multiple string prefix for determining to meet the first length condition, the multiple character String prefix is subordinated to identical common prefix；

The combining unit, for the multiple string prefix to be merged into the common prefix, and will be the multiple String prefix is deleted from the prefix BF.

Optionally, if the prefix false positive is less than the 4th predetermined threshold value, the computing unit triggers the deletion unit, The deletion unit is additionally operable to delete the second string prefix of the second length condition that meets from the prefix BF, and described the Two string prefix are the string prefix preserved in the prefix BF；

The storage unit is additionally operable to be saved in second string prefix as character string in the character string BF.

Optionally, the storage unit is additionally operable to according to the character string preserved in the character string BF with being preserved in the former BF String prefix between incidence relation, the string prefix of the second string prefix described in subordinate is preserved to the prefix In BF.

Interface filter device is set for network node it can be seen from above-mentioned technical proposal, interface filter device includes The first filter assemblies and the second filter assemblies with the character string of the network node related data and string prefix are saved, are connect Mouthful filter can receive the acquisition request of request of data side's transmission prior to network node, according to the character string preserved and String prefix matches the character string to be identified carried in acquisition request, if character string to be identified can match interface filter Any one character string or string prefix in device, then it can determine data and the network section asked in acquisition request Point is related, can ask the acquisition be uploaded to network node processing, it is seen then that by interface filter device can effectively by The acquisition request of acquisition request and network node extraneous data is filtered, and ensures that network node needs acquisition to be processed please as far as possible It is related to the network node to seek asked data, so as to improve the utilization rate of network node process resource, is improved The treatment effeciency of network node.

Brief description of the drawings

In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing There is the required accompanying drawing used in technology description to be briefly described, it should be apparent that, drawings in the following description are only this Some embodiments of invention, for those of ordinary skill in the art, without having to pay creative labor, may be used also To obtain other accompanying drawings according to these accompanying drawings.

Fig. 1 is a kind of method flow diagram of character string filter method provided in an embodiment of the present invention；

Fig. 2 is a kind of structure drawing of device of interface filter device for character cascade filter provided in an embodiment of the present invention；

Fig. 3 is a kind of hardware structure diagram of NDN-NIC frameworks provided in an embodiment of the present invention；

Fig. 4 is a kind of method flow diagram of regulation and control method for interface filter device provided in an embodiment of the present invention；

Fig. 5 is the regulation and control schematic diagram that interface filter device is directed in a kind of NDN scenes provided in an embodiment of the present invention；

Fig. 6 is the regulation and control schematic diagram that interface filter device is directed in a kind of NDN scenes provided in an embodiment of the present invention；

Fig. 7 is a kind of method flow diagram of regulation and control method for interface filter device provided in an embodiment of the present invention；

Fig. 8 is the regulation and control schematic diagram that interface filter device is directed in a kind of NDN scenes provided in an embodiment of the present invention；

Fig. 9 a are to regulate and control schematic diagram between BF-CS and BF-FIB in a kind of NDN scenes provided in an embodiment of the present invention；

Fig. 9 b are to regulate and control schematic diagram between BF-CS and BF-FIB in a kind of NDN scenes provided in an embodiment of the present invention；

Fig. 9 c are to regulate and control schematic diagram between BF-CS and BF-FIB in a kind of NDN scenes provided in an embodiment of the present invention；

Fig. 9 d are to regulate and control schematic diagram between BF-CS and BF-FIB in a kind of NDN scenes provided in an embodiment of the present invention；

Figure 10 is a kind of structure drawing of device of character string filter provided in an embodiment of the present invention

Figure 11 is a kind of structure drawing of device of regulation device for interface filter device provided in an embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Whole description, it is clear that described embodiment is only part of the embodiment of the present invention, rather than whole embodiments.It is based on Embodiment in the present invention, those of ordinary skill in the art are obtained every other under the premise of creative work is not made Embodiment, belong to the scope of protection of the invention.

In a communication network, data can be identified by character string, such as content-label network (Named Data Networking, NDN) in, content (data) is identified by name (namely a kind of character string or interest) , rather than the address of the network node of storage content i.e. destination host.When request of data side, (Consumer) wishes to obtain When taking a data, the acquisition request for carrying the character string for identifying this data can be sent to network node, the acquisition please The recipient not specified is asked, such as in NDN, the acquisition request (Interest) transmitted by content requests side is in shared media Propagated in (shared media, such as Wi-Fi environment), be not required to specify specific receiving terminal.Network node in shared media Such as the terminal (host) of data storage can receive acquisition request.But each acquisition request institute received is not it The data of request are all the data related to network node.In some scenes, or even the acquisition that a network node receives please In asking, the acquisition for having more than ninety percent asks that asked data are unrelated with this network node, i.e., this network node can carry The data of confession are not that these obtain the asked data of request.Handle these unrelated acquisition requests and waste network node A large amount of system resources (CPU calculating, memory access of tabling look-up etc.), are unfavorable for pushing away for this communication network by character string identification data Extensively.

Therefore, the embodiments of the invention provide a kind of character string filter method and relevant apparatus, set and connect for network node Mouthful filter, interface filter device include saving and the character string of the network node related data and string prefix First filter assemblies and the second filter assemblies, interface filter device can receive the transmission of request of data side prior to network node Request is obtained, the character string to be identified carried in acquisition request is matched according to the character string and string prefix that are preserved, if Character string to be identified can match any one character string or string prefix in interface filter device, then can determine that this is obtained Take the data asked in request related to the network node, the acquisition can be asked to be uploaded to network node processing, can See, effectively can be filtered the acquisition request of acquisition request and network node extraneous data by interface filter device, It is related to the network node to ensure network node as far as possible to need request the asked data to be processed that obtain, so as to improve The utilization rate of network node process resource, improve the treatment effeciency of network node.

The interface filter device that the embodiment of the present invention is provided can correspond with network node, be arranged on network node The interface between network on, above-mentioned acquisition can be received prior to network node with this and asked, pass through interface filter device Filtering to obtaining request, the data of request can substantially be screened out with the incoherent acquisition request of the network node, without carrying Supply the network node to be handled, to avoid wasting the system resource of the network node.Under NDN scene, the interface mistake Filter device can be arranged on the NIC (Network Interface Card, NIC) of terminal in NDN, so as to be formed A kind of interface filter device of NDN-NIC frameworks.The work of identification and filtering acquisition request is retained on NIC hardware and completed, The request that obtains being delivered in the Software Protocol Stack of network node is enabled all to be the acquisition that present networks node is handled as far as possible Request.

Next how receive first using the interface filter device set for network node, the network section is reduced to realize The unrelated implementation for obtaining request of point processing.

Before filter method flow is introduced, the interface filter device that the embodiment of the present invention is provided is introduced first, this connects Mouth filter network node for corresponding to provides the filtering function for obtaining request.The interface filter device comprises at least the first mistake Component and the second filter assemblies are filtered, are saved in first filter assemblies for identifying the data related to the network node Character string, before the character string for identifying the data related to the network node is saved in second filter assemblies Sew.

For example, the character string related to network node can be understood as the character of the data related with the network node String.In the present invention, character string can have the function of mark data, such as can be the title of a file or content, Can be ID, mark of data etc..The data related to network node can not only include the data preserved in the network node, It can also include being not held on the network node, but the network node can be with the data of quick obtaining, such as it is stored in this Data in the neighbor node of network node etc..Character string so related to network node can identify the word of this kind of data Symbol string, the string prefix related to network node can be opened in the character string for identify this kind of data from the starting point of character string The part of beginning.Such as the character string of a data for "/A/b/3 ", the starting point of this character string is leftmost "/", this The string prefix of individual character string can include "/", "/A ", "/A/b " etc..Such as string prefix "/" can include it is all with The character string of "/" starting, such as "/a ", "/b/1 " etc. can match with string prefix "/".

As can be seen that complete name of the character string equivalent to data, and string prefix is equivalent to the division name of data.

Under NDN scene, the character string preserved in the first filter assemblies can be the content storage of NDN network node The content name (character strings of data) preserved in storehouse (Content Store, CS).And the character preserved in the second filter assemblies Prefix of going here and there can be the forwarding information storehouse (Forwarding Information Base, FIB) of network node or interest table undetermined The name prefix (string prefix) preserved in (Pending Interest Table, PIT).

In interface filter device in addition to it can include the first filter assemblies and the second filter assemblies, other can also be included Filter assemblies, such as the filter assemblies of other preservation string prefix can also be included.

Fig. 1 is a kind of method flow diagram of character string filter method provided in an embodiment of the present invention, applied to network node Interface filter device, in a kind of optional application scenarios, the network node is the network node in NDN, methods described bag Include：

S101：The interface filter device receives acquisition request, and described obtain asks to include treating for requested data Identification string.

For example, interface filter device can receive the acquisition request in network, the acquisition prior to the network node Ask to be used for acquisition request data, the data include the character string for identifying.For the interface filter device, due to Not yet determine whether the data are the data related to the network node, therefore for judging whether the foundation of correlation：The data Character string is referred to as character string to be identified.

S102：The interface filter device judges what whether the character string to be identified preserved with first filter assemblies The string prefix matching that character string and the second filter assemblies preserve.If the character string to be identified and first filter assemblies Any one in the string prefix that any one matching or second filter assemblies preserve in the character string of preservation matches, and holds Row S103.

For example, the character string to be identified can be carried out with the first filter assemblies and the second filter assemblies successively Match somebody with somebody, can also be matched simultaneously.By character string to be identified " exemplified by/A/b/3 ", if the character string preserved in the first filter assemblies Including "/A/b/3 ", then it is considered that should "/A/b/3 " and the string matching in the first filter assemblies.If the second filtering group The string prefix preserved in part is including "/A/b ", " one in/A ", "/", it is also assumed that being somebody's turn to do, "/A/b/3 " filters with second The string prefix matching preserved in device.

S103：The interface filter device identifies that the requested data is the data related to the network node.

S104：The interface filter device uploads described obtain to the network node and asked.

When confirming the data corresponding to the character string to be identified to be related to the network node by character string to be identified Data when, can by obtain request be uploaded to the network node, by the network node to the acquisition ask carry out subsequent treatment.

It should be noted that when carrying out S102 matching, if the character string to be identified and first filter assemblies The character string of preservation and second filter assemblies preserve string prefix and mismatched, described in the interface filter device identification Requested data be and the incoherent data of the network node, that is to say, that even if by the acquisition request be supplied to the network Node, the network node can not be supplied to the data of the sender of acquisition request.Therefore in this case, the interface filter dress Request discarding can be obtained by described by putting, and be asked without uploading described obtain to the network node.

As can be seen that setting interface filter device for network node, interface filter device includes saving and the network The character string of node related data and the first filter assemblies of string prefix and the second filter assemblies, interface filter device can be with Prior to the acquisition request that network node receives the transmission of request of data side, matched according to the character string and string prefix preserved The character string to be identified carried in acquisition request, if character string to be identified can match any one in interface filter device Character string or string prefix, then it can determine that the data that the acquisition is asked in asking are related to the network node, can incite somebody to action Acquisition request is uploaded to network node processing, it is seen then that can be effectively by acquisition request and net by interface filter device The acquisition request of network node extraneous data is filtered, and ensures that network node needs to be processed obtain to ask asked number as far as possible According to being related to the network node, so as to improve the utilization rate of network node process resource, the place of network node is improved Manage efficiency.

Next docking port filter will be carried out from the angle of device to illustrate.As shown in Fig. 2 the interface filter dress Put 200 and be used to be corresponding network node filtering acquisition request, interface filter device 200 comprises at least the first filter assemblies 210 With the second filter assemblies 220, the first filter assemblies 210 include character string Bloom filter (Bloom Filter, BF) 211, the Two filter assemblies 220 include prefix BF221.

BF is a kind of data structure for being used for Detection of Existence (membership query), the stream being widely used in network Classification and lookup structure.The data being stored in BF will carry out set by BF Hash table.Word in embodiments of the present invention Symbol string BF and prefix BF is a kind of BF.

Character string BF211 is used to preserve the character string for being used for identifying the data related to the network node.

Prefix BF221 is used to preserve the string prefix for being used for identifying the data related to the network node.

Interface filter device 200, which is used to receive, to be asked by the acquisition that the network node receives, described to obtain in request Character string to be identified including requested data.

The character string BF211 and prefix BF221 is used to treat according to the matching of the character string and string prefix of preservation Identification string, if any one in the character string that the character string to be identified preserves with the character string BF match or with it is described Any one in the string prefix that prefix BF is preserved matches, and the interface filter device is additionally operable to identify the requested data For the data related to the network node；And upload described obtain to the network node and ask.

Optionally, the first filter assemblies 210 also include corresponding character string BF211 character string counting bloom filter (Counting Bloom Filter, CBF) 212, the second filter assemblies 220 also include corresponding prefix BF221 prefix CBF222。

Character string CBF212 is used for the service condition for recording the first Hash table, and first Hash table is the described first filtering Hash table corresponding to component, first Hash table are used for the cryptographic Hash for recording the character string that character string BF211 is preserved.

Prefix CBF222 is used for the service condition for recording the second Hash table, and second Hash table is the second filtering group Hash table corresponding to part, second Hash table are used for the cryptographic Hash for recording the string prefix that prefix BF221 is preserved.

For example, CBF falls within a kind of BF.

In BF, the character string that the BF is preserved can be recorded by Hash table (hash table), with character string Exemplified by BF211, if character string BF211 saves a character string, cryptographic Hash can be stored in the first Kazakhstan corresponding to the character string Several positions in uncommon table, when character string BF211 needs to match character string to be identified, can treat identification string and be breathed out It is uncommon to calculate, by obtained cryptographic Hash come compared with the first Hash table, if the cryptographic Hash of character string to be identified is breathed out first There is record corresponding position in uncommon table, and character string BF211 can consider the string matching that character string to be identified preserves with itself, If the cryptographic Hash of character string to be identified have in the first Hash table in corresponding position it is one or several do not record, character string BF211 can consider that character string to be identified mismatches with the character string itself preserved.Character string corresponding to character string BF211 CBF212 can be used for the service condition for recording the first Hash table, such as there are record, Yi Jiji in which position in the first Hash table Record several times.Such as positions of the cryptographic Hash in the first Hash table of character string 1 that preserves of character string BF211 is a1, b2, c2, Position of the cryptographic Hash of character string 2 in the first Hash table is a1, b5, c8, then the first Kazakhstan that character string CBF212 is recorded The service condition of uncommon table can be that position a1 have recorded twice, and position b2, c2, b5, c8 respectively have recorded once.

Prefix BF221 can also equally carry out Hash calculation, and the cryptographic Hash that will be obtained to the string prefix preserved It is recorded in the second Hash table, similarly, prefix CBF222 is to the record of the second Hash table with character string CBF to the first Hash table Record similar, repeat no more here.

Optionally, when changing the character string preserved in character string BF211, character string CBF212 is additionally operable to according in change Hold the service condition for updating first Hash table.

When changing the string prefix preserved in prefix BF221, prefix CBF222 is additionally operable to according to change content update The service condition of second Hash table.

For example, the character string preserved in change character string BF211 can include deleting the character string deposited, can also Including preserving new character string, can also include modifying to having deposited character string.To the character string preserved in character string BF211 It can actively be modified, can also be changed according to the change progress of the data related with network node is corresponding, such as network Node deletes the data a that script preserves, and character string BF211 is also required to the data a originally preserved character string accordingly Delete, to improve filtering accuracy.

When the character string preserved in character string BF211 is changed, character string CBF212 is additionally operable to according to change content Update the service condition of first Hash table, such as the cryptographic Hash of character string 1 that character string BF211 is preserved is in the first Hash table In position be a1, b2, c2, the position of the cryptographic Hash of character string 2 in the first Hash table is a1, b5, c8, then character string The service condition for the first Hash table that CBF212 is recorded can be that position a1 have recorded twice, and position b2, c2, b5, c8 respectively remember Record once.If now deleting character string 2, character string CBF212 can be by position a1 in the first Hash table, corresponding to b5, c8 Record numerical value respectively subtract 1, now the service condition of the first Hash table can be position a1, and b2, c2 respectively have recorded once.

Illustrated with reference to concrete application scene, in the case where network node is in NDN, interface filter device can be with It is NDN-NIC frameworks, the apparatus structure of the framework may refer to Fig. 3, in the NDN-NIC frameworks, by software section NDN-NIC Driver and hardware components NDN-NIC hardware is formed.Wherein, Counting Bloom are used in NDN-NIC driver Filter builds three filters, is realized with software；NDN-NIC hardware realized on hardware corresponding to three be based on Bloom Filter filter, corresponded with three CBF contents in driver.That is BF-CS includes corresponding CBF-CS, BF-FIB includes corresponding CBF-FIB, and BF-PIT includes corresponding CBF-PIT.

When NDN-NIC updates, the CBF on software is first updated.Which position changes in Hash table corresponding to CBF records (such as 0->1 and 1->0).Then, in BF, 0- in CBF is updated first>1 position, then updates 1- again>0 position.Therefore, firmly Part can continue with the acquisition request received at no point in the update process.

After NDN-NIC receives acquisition request, matching operation can be directly carried out in hardware BF, without passing through CBF in driver.

It can be seen that for network node set interface filter device, the interface filter device comprise at least the first filter assemblies and Second filter assemblies, the first filter assemblies include character string BF, and the second filter assemblies include prefix BF, pass through character string BF The character string for identifying the data related to the network node is preserved, prefix BF is preserved for identifying and the network node The string prefix of related data.Interface filter device can receive the acquisition of request of data side's transmission prior to network node Request, according to the character string and string prefix that are preserved in character string BF and prefix BF match the acquisition request in carry treat Identification string, so as to effectively be filtered the acquisition request of acquisition request and network node extraneous data, as far as possible It is related to the network node to ensure network node to need request the asked data to be processed that obtain, so as to improve network The utilization rate of node processing resource, improve the treatment effeciency of network node.

The filtering for obtaining request is realized in the interface filter device set for network node by BF, because BF storage is empty Between it is limited, when the data bulk of preservation is more, by script matching less than character-string error to be identified be defined as matching To situation can roll up, such case is properly termed as false positive (false positive).The appearance of false positive causes very The acquisition of multi-request and the network node extraneous data asks to filter all without by interface filter device, and is uploaded to the network Node processing so that interface filter device cisco unity malfunction.

After the substantial amounts of character string preserved in the situation of false positive such as character string BF, the position in the first Hash table may It is substantially all and is recorded, in this case, if character string BF matches a character string to be identified, the Kazakhstan of the character string to be identified Uncommon value corresponding position in the first Hash table is very possible all by the cryptographic Hash of character string BF other character strings preserved It has recorded, in this case, even if the character string that the character string to be identified is preserved with character string BF mismatches, but by There is record in corresponding position in the first Hash table in the cryptographic Hash of the character string to be identified, therefore character string BF still can determine whether The character string to be identified is that the conclusion of string matching is preserved with itself.

The degree of one BF false positive increases and exponential increase with the quantity of stored data in this BF, can See, it is very big that influence of the quantity of data to false positive is preserved in BF.

Following formula can be used by calculating false positive degree in a BF：

False positive degree=(1-e^-kn/m)^k

Wherein, k is the quantity of cryptographic Hash position recorded in Hash table of a data, and m is position in Hash table Quantity, n are the quantity that data are preserved in BF.

Generally, the character string BF in interface filter device is due to needing the character string quantity that preserves far more than prefix The string prefix preserved needed for BF, therefore character string BF is easier the character string false positive issue for occurring for character string, i.e. word The possibility that the unmatched character-string error to be identified of the character string preserved with the character string BF is defined as matching by symbol string BF Property is bigger.

In order to solve the too high caused problem of BF false positives, especially on influence caused by character string BF, the present invention Embodiment provides a kind of regulation and control method for interface filter device, and this method is applied to interface filter device, the interface mistake Filter device can be the interface filter device mentioned in the embodiment as corresponding to Fig. 1 and Fig. 2.And for the tune of interface filter device Three kinds of modes, respectively moving operation (Transform), union operation are mainly proposed in the prosecutor method embodiment of the present invention (Aggregation) and rolling back action (Reversion), aforesaid operations next will be introduced one by one.

The interface filter device comprises at least the first filter assemblies and the second filter assemblies, the first filter assemblies bag Character string BF is included, second filter assemblies include prefix BF；The character string BF, which is used to preserve, to be used to identify and the network The character string of the related data of node；The prefix BF is used to preserve the word for being used for identifying the data related to the network node Symbol string prefix.

The interface filter device records the character string preserved in the character string BF and the character string preserved in prefix BF Incidence relation between prefix.Such as the incidence relation can be recorded by tree, the node in tree construction can be word Character in symbol string.

Fig. 4 be a kind of regulation and control method for interface filter device provided in an embodiment of the present invention method flow diagram, institute The method of stating includes：

S401：According to the quantity that character string is preserved in the character string BF, calculate the character string BF and character string vacation occur Positive degree, the character string false positive are equal by the character string preserved with the character string BF for identifying the character string BF Unmatched character-string error to be identified is defined as the probability numbers of matching；If the character string false positive is more than the first default threshold Value, perform S402.

For example, the character string false positive and prefix false positive mentioned in the present embodiment are the vacation sun of BF a kind of Property, i.e. character string false positive is the false positive for character string BF, and prefix false positive is the false positive for prefix BF.

Due to specify that the degree of false positive is related to the quantity that data are preserved in BF, therefore word in character string BF can be passed through The quantity of symbol string calculates the degree of character string false positive.If character string false positive is higher, such as beyond the first default threshold It is worth (such as 25%), can will be much incoherent with network node at this moment using the poor effect of character string BF matched character strings The character-string error to be identified of data is defined as matching, and causes a large amount of uncorrelated acquisition requests to upload to network node, to net Network node causes processing load.

In order to reduce character string false positive, most direct mode is exactly to reduce the number that character string is preserved in character string BF Amount, therefore need to determine suitable character string from character string BF.

S402：The first character string for meeting the first length condition is deleted from the character string BF, first character The character string gone here and there to be preserved in the character string BF.

S403：It is saved in first character string as string prefix in the prefix BF.

For example, determine that the character string for deletion needs to consider that character string BF filtering accuracy will not be influenceed Excessive, being additionally, since the character string of deletion can be saved in prefix BF as string prefix, it is contemplated that working as this character Conspire to create for string prefix when, prefix BF filtering accuracy will not be influenceed excessive.So the embodiment of the present invention is grown from character string Degree is used as Rule of judgment, when a character string is longer, even if as string prefix, what the string prefix can match Character string scope is also not too large, prefix BF filtering accuracy is influenceed little.

Character string in character string BF is deleted, and the behaviour in prefix BF is saved in using the character string as string prefix It is properly termed as moving operation (Transform).Moving operation is mainly used in character string BF.It is this to be converted to from character string String prefix causes prefix BF filtering accuracy is influenceed to be properly termed as prefix matching false positive (prefix match false positive).Such as " when/A/b/3 " is used as character string, "/A/b/3/1 " is can not be with character string "/A/b/ for character string to be identified 3 " matchings, still, when " when/A/b/3 " is used as string prefix, the character string "/A/b/3/1 " to be identified that can not match originally Can be with string prefix "/A/b/3 ", it is seen then that this operation using character string as string prefix, can make it that some are former Originally the string matching to be identified that can not be matched, and the data corresponding to the character string to be identified that these can not be matched originally are With the incoherent data of network node, therefore carry the character string to be identified acquisition request this should not be uploaded to network node, But when using character string, "/A/b/3 " as character string to be identified after string prefix, is carried, " ask by/A/b/3/1 " acquisition Network node can be uploaded to, unnecessary processing load is caused for network node.It can be seen that when performing moving operation, Need to consider prefix matching false positive.

So it can determine that a string length meets the character string conduct of the first length condition from character string BF The character string removed from character string BF.

String length described here can determine according to the quantity of included character in character string.The character of character string Quantity is more, and length is relatively longer.

Optionally, the first length condition is that the maximum of string length is preserved in the character string BF.Namely First character string can be that character string most long in character string BF.So as to the influence of the prefix matching false positive to wherein BF It is minimum.

Illustrate with reference to specific NDN application scenarios, as shown in figure 5, wherein, CS controllers (CS-controller) are first sent out LGT_CS is sent, the most long list item x (i.e. most long character string) deposited in query name tree (name tree), name tree is namely Incidence relation between the string prefix preserved in the character string and BF-FIB that are preserved in BF-CS.

Then DEL_CS is sent, the x that Delete query arrives in BF-CS；Then to FIB controllers (FIB-controller) The information ADD_FIB, FIB-controller for sending addition x send LBL_FIB immediately, update the shape of x nodes in name tree State：CS->FIB, ADD_BF_FIB is then sent into BF-FIB, add x, complete the Transform operations of a list item.

It can be seen that quantity calculating and character string BF character string false positive degree by preserving character string in character string BF, When character string false positive is more than the first predetermined threshold value, by the first character string for meeting the first length condition in character string BF from institute State and deleted in character string BF, so as to reduce the quantity that character string is preserved in character string BF, thus effectively reduce character string The degree of false positive in BF, character string BF filter efficiency is improved, while in order to improve filtering accuracy, can also be by first Character string is saved in prefix BF as string prefix, and pin is realized by the prefix formed with the first character string by prefix BF To the matching feature of the first character string.

Optionally, for S401, if the character string false positive is less than the second predetermined threshold value, the second length will can also be met First string prefix of degree condition is deleted from the prefix BF, and first string prefix is to be preserved in the prefix BF A string prefix.

For example, when character string BF character string false positive is relatively low (such as 10%), character can be accordingly increased Character string quantity in string BF, efficiently to use character string BF.

In order to determine first string prefix from prefix BF, determined the invention provides one kind from prefix BF String prefix is moved to character string BF as character string, and increase is subordinated to the more of the string prefix of removal in prefix BF The rolling back action (Reversion) of individual string prefix.Rolling back action is mainly used in prefix BF.

Prefix BF group matches false positive is considered that when determining the first string prefix from prefix BF, is selected Prefix matching false positive in prefix BF can effectively be reduced by selecting shorter string prefix.Therefore the second length condition can compare Small, optionally, the second length condition is that the minimum value of string prefix length is preserved in the prefix BF.

Further, the first string prefix for meeting the second length condition from the prefix BF is deleted it described Afterwards, in addition to：

For example, the first string prefix is deleted, and increase the multiple character strings for being subordinated to the first string prefix Prefix, can reduce delete filtering accuracy of first string prefix to prefix BF influence,

Such as string prefix " the word that/A/b/3 " after the removal from prefix BF, can be preserved from the character string BF Accord with and determine to be subordinated to "/A/b/3 " other possibility in the incidence relation between the string prefix preserved in string and the former BF Combination, such as "/A/b/3/1 " and "/A/b/3/b ", so as to addition "/A/b/3/1 " and the "/A/b/3/ in prefix BF B ", which is used to offset to a certain extent, deletes the string prefix " influences of/A/b/3 " to prefix BF filtering accuracys.

Illustrate with reference to specific NDN application scenarios, as shown in Figure 6.Due to introducing the concept of prefix matching false positive, lead Cause NDN-NIC to must be balanced against both sides false positive, ensure that overall false positive is minimum.NDN-NIC is set to BF false positive Lower and upper bounds threshold value.When BF false positive is less than lower bound threshold value, rolling back action is taken to extend a part of BF-FIB elements, with drop Low prefix matching false positive.Rolling back action can once select the string prefix that some BF-FIB is kept, and be translated into BF- Character string is corresponded in CS, then other string prefix for the string prefix for being subordinated to the selection are added in BF-FIB.

Rolling back action implementation procedure is as shown in Figure 6.It is most short that FIB-controller sends SRT_FIB information queries first There is the prefix x of multiple descendant nodes (x1, x2)；Then ADD_CS message addition character string x is sent to CS-controller；CS- Controller adds character string x with ADD_BF_CS orders in BF_CS, while with LBL_CS information updating name tree X state (now if it find that x is not present in original CS, then deleting the x added originally)；The other end, BF- Controller deletes x with DEL_BF_FIB orders in BF-FIB, and is added with ADD_BF_FIB in x1 and x2 to BF-FIB, The new state for finally adding x1 and x2 in name tree with RMV_LBL message be BF-FIB in string prefix.

In addition to it should be noted character string BF false positive, it is also necessary to the quantity of string prefix in prefix BF is paid close attention to, If the quantity of string prefix is excessive, prefix BF equally also occurs such as character string BF false positive issue, in order to Distinguish, be referred to as prefix false positive in embodiments of the present invention for prefix BF false positive.

On the basis of embodiment corresponding to Fig. 4, Fig. 7 is that one kind provided in an embodiment of the present invention is directed to interface filter device Regulation and control method method flow diagram, methods described includes：

S701：According to the quantity that string prefix is preserved in the prefix BF, calculate the prefix BF and the false sun of prefix occur Property degree, the prefix false positive is used to identify the prefix BF by the string prefix preserved with the prefix BF not The character-string error to be identified matched somebody with somebody is defined as the probability numbers of matching.If the prefix false positive is held more than the 3rd predetermined threshold value Row S702；If the prefix false positive is less than the 4th predetermined threshold value, S704 is performed.

For example, the false positive mode for calculating the mode traditional calculations BF of prefix false positive is consistent, repeat no more here. By the 3rd predetermined threshold value and the 4th predetermined threshold value, can be avoided by prefix BF prefix false positive control within the specific limits The too high influence that accuracy is filtered to prefix BF of prefix false positive, also avoids prefix false positive is too low from making to the poorly efficient of prefix BF With.For the ease of calculating, the 3rd predetermined threshold value can be with identical with the first predetermined threshold value, the 4th predetermined threshold value and the second predetermined threshold value Can be with identical.

S702：The multiple string prefix for meeting the first length condition are determined, the multiple string prefix is subordinated to Identical common prefix.

For example, the first length condition can set longer, can to cover due to longer string prefix word The character string quantity that is covered relative to shorter string prefix of symbol string quantity is smaller, therefore by the conjunction of longer string prefix And to the smaller of prefix BF prefix matching false positive,

S703：The multiple string prefix is merged into the common prefix, and by the multiple string prefix from Deleted in the prefix BF.

It is this that two string prefix are merged into its shared common prefix, and the two string prefix are deleted Operate as union operation (Aggregation).Union operation is mainly used in prefix BF.

By taking the union operation of two string prefix as an example, string prefix "/a/c/3 " and "/a/c/b " is subordinated to phase "/a/c ", common prefix described here are identical prefix in multiple string prefix to same common prefix.Grasped by merging Make, can by string prefix "/a/c/3 " and "/a/c/b " merge into string prefix "/a/c ", prefix BF delete originally protect String prefix "/a/c/3 " and the "/a/c/b ", and preserve string prefix " in/a/c " to prefix BF deposited.

By union operation, the quantity of string prefix in prefix BF can be effectively reduced, reduces prefix BF prefix False positive.

It should be noted that rolling back action triggering except can be relatively low by character string BF character string false positive when is outer, and also Triggered when can be relatively low by prefix BF prefix false positive.

S704：The second string prefix for meeting the second length condition is deleted from the prefix BF, second word Symbol string prefix is the string prefix preserved in the prefix BF.

S705：It is saved in second string prefix as character string in the character string BF.

S706：According to the pass between the string prefix preserved in the character string and the former BF preserved in the character string BF Connection relation, the string prefix of the second string prefix described in subordinate is preserved into the prefix BF.

Illustrate with reference to specific NDN application scenarios, as shown in Figure 8.FIB-controller sends LGT_ADD_SET first Message, inquire about in name tree, there is the BF-FIB string prefix set (x1, x2) of most long common prefix (x)；Then in BF- X1, x2 are deleted with DEL_BF_FIB message in FIB, while x is added with ADD_BF_FIB；Finally send RMV_LBL and LBL_FIB Update x on name tree, x1, x2 state.

Realized followed by a concrete scheme in NDN scenes how further illustrate three kinds of operations described above R. concomitans, as illustrated in fig. 9 to preserve the string prefix preserved in character string and BF-FIB in BF-CS.

When BF-CS increases character string newly, " after/A/a/2 ", character string is changed into 7 in BF-CS, and now character string false positive is more than First predetermined threshold value is, it is necessary to move operation."/A/b/2 " is used as character to most long character string in selection BF-CS from BF-CS String prefix is saved in BF-FIB.BF-CS and BF-FIB after moving operation can be as shown in figure 9b.

Now cause BF-FIB prefix false positive to be more than the 3rd predetermined threshold value, select to have in BF-FIB it is identical it is public before Two most long character string prefixes "/A/c/1 " and "/A/c/2 " merges operation sewed.BF-CS and BF- after moving operation FIB can be as is shown in fig. 9 c.

Two character strings "/A/a/1 " and " after/A/b/1 ", it is default that character string false positive is less than second is being deleted in BF-CS Threshold value, string prefix in BF-FIB being now present, "/A/c " (for string prefix most short in BF-FIB) is as character string It is moved in BF-CS, while "/A/c " two subsequent character string prefixes "/A/c/1 " and "/A/c/2 " is substituted into BF-FIB In, complete the BF-CS after rolling back action and BF-FIB can be as shown in figure 9d.

Figure 10 is a kind of structure drawing of device of character string filter provided in an embodiment of the present invention, applied to network node Interface filter device, the interface filter device comprises at least the first filter assemblies and the second filter assemblies, first mistake The character string for identifying the data related to the network node is saved in filter component, is preserved in second filter assemblies It is used for the string prefix for identifying the data related to the network node, the character string filter 1000 includes reception Unit 1001, judging unit 1002, the first recognition unit 1003, transmitting element 1004：

The receiving unit 1001, request is obtained for receiving, described obtain asks to include treating for requested data Identification string；

The judging unit 1002, for judge the character string to be identified whether with first filter assemblies preserve The string prefix matching that character string and the second filter assemblies preserve；If the character string to be identified and first filter assemblies Any one in the string prefix that any one matching or second filter assemblies preserve in the character string of preservation matches, and touches Send out the first recognition unit 1003 described；

First recognition unit 1003, for identifying that the requested data is the number related to the network node According to；

The transmitting element 1004, asked for uploading described obtain to the network node.

Optionally, in addition to the second recognition unit and discarding unit：

Optionally, the network node is in content-label network N DN.

It can be seen that setting interface filter device for network node, interface filter device includes saving and the network node The character string of related data and the first filter assemblies of string prefix and the second filter assemblies, interface filter device can be prior to Network node receives the acquisition request of request of data side's transmission, matches this according to the character string and string prefix that are preserved and obtains The character string to be identified carried in request is taken, if character string to be identified can match any one character in interface filter device String or string prefix, then it can determine that the data that the acquisition is asked in asking are related to the network node, this can be obtained Request is taken to be uploaded to network node processing, it is seen then that can be effectively by acquisition request and network section by interface filter device The acquisition request of independence number evidence is filtered, and the data that ensureing network node as far as possible needs acquisition request to be processed asked are It is related to the network node, so as to improve the utilization rate of network node process resource, improve the processing effect of network node Rate.

Figure 11 is a kind of structure drawing of device of regulation device for interface filter device provided in an embodiment of the present invention, should For interface filter device, the interface filter device comprises at least the first filter assemblies and the second filter assemblies, and described first Filter assemblies include character string BF, and second filter assemblies include prefix BF；The character string BF, which is used to preserve, to be used to identify The character string of the data related to the network node；It is related to the network node for identifying that the prefix BF is used for preservation Data string prefix；The interface filter device records the character string preserved in the character string BF with being protected in the former BF Incidence relation between the string prefix deposited, the regulation device 1100 include computing unit 1101, delete the and of unit 1102 Storage unit 1103：

The computing unit 1101, for according to the quantity that character string is preserved in the character string BF, calculating the character There is the degree of character string false positive in string BF, and the character string false positive will be with the character string for identifying the character string BF The unmatched character-string error to be identified of character string that BF is preserved is defined as the probability numbers of matching；If the false sun of the character string Property more than the first predetermined threshold value, trigger the deletion unit 1102；

The deletion unit 1102, for the first character string of the first length condition that meets to be deleted from the character string BF Remove, first character string is the character string preserved in the character string BF；

The storage unit 1103, for being saved in the prefix BF using first character string as string prefix In.

Optionally, in addition to determining unit and combining unit：

The first filter assemblies, the first Hash table, the first predetermined threshold value, the first length bar mentioned in the embodiment of the present invention Part, the first character string, " first " of the first string prefix are used only to do name mark, do not represent first sequentially. The rule is equally applicable to " second ", " the 3rd ", " the 4th ".

One of ordinary skill in the art will appreciate that：Realizing all or part of step of above method embodiment can pass through Programmed instruction related hardware is completed, and foregoing routine can be stored in a computer read/write memory medium, and the program exists During execution, execution the step of including above method embodiment；And foregoing storage medium can be in following media at least one Kind：Read-only storage (English：Read-only memory, abbreviation：ROM), RAM, magnetic disc or CD etc. are various to store The medium of program code.

It should be noted that each embodiment in this specification is described by the way of progressive, each embodiment it Between identical similar part mutually referring to what each embodiment stressed is the difference with other embodiment. For equipment and system embodiment, because it is substantially similar to embodiment of the method, so describe fairly simple, The relevent part can refer to the partial explaination of embodiments of method.Equipment and system embodiment described above is only schematic , wherein as the unit that separating component illustrates can be or may not be physically separate, be shown as unit Part can be or may not be physical location, you can with positioned at a place, or can also be distributed to multiple networks On unit.Some or all of module therein can be selected to realize the purpose of this embodiment scheme according to the actual needs. Those of ordinary skill in the art are without creative efforts, you can to understand and implement.

The foregoing is only a preferred embodiment of the present invention, but protection scope of the present invention be not limited thereto, Any one skilled in the art the invention discloses technical scope in, the change or replacement that can readily occur in, It should all be included within the scope of the present invention.Therefore, protection scope of the present invention should be with scope of the claims It is defined.

Claims

1. a kind of character string filter method, it is characterised in that applied to the interface filter device of network node, the interface filter Device comprises at least the first filter assemblies and the second filter assemblies, saved in first filter assemblies for identify with it is described The character string of the related data of network node, save in second filter assemblies related to the network node for identifying Data string prefix, methods described includes：

The interface filter device receives acquisition request, described to obtain the character to be identified for asking to include requested data String；

The interface filter device judge the character string to be identified whether with first filter assemblies preserve character string and The string prefix matching that second filter assemblies preserve；

If any one in the character string that the character string to be identified preserves with first filter assemblies matches or described second Any one in the string prefix that filter assemblies preserve matches, the interface filter device identify the requested data be with The related data of the network node；

2. according to the method for claim 1, it is characterised in that the interface filter device judges the character string to be identified The string prefix that the character string and the second filter assemblies whether preserved with first filter assemblies preserves matches, including：

If character string and second filter assemblies that the character string to be identified preserves with first filter assemblies preserve word Symbol string prefix mismatches, and the interface filter device identifies that the requested data is and the incoherent number of the network node According to；

The interface filter device obtains request discarding by described, is asked without uploading described obtain to the network node.

3. according to the method for claim 1 or 2, it is characterised in that the network node is in content-label network N DN.

4. a kind of interface filter device for character cascade filter, it is characterised in that the interface filter device is used for be right Network node filtering is answered to obtain request, the interface filter device comprises at least the first filter assemblies and the second filter assemblies, institute Stating the first filter assemblies includes character string Bloom filter BF, and second filter assemblies include prefix BF；

The interface filter device, which is used to receive, to be asked by the acquisition that the network node receives, and described obtain asks to include The character string to be identified of requested data；

The character string BF and prefix BF is used to match the word to be identified according to the character string and string prefix of preservation Symbol string, if any one in the character string that the character string to be identified preserves with the character string BF match or with the prefix BF Any one in the string prefix of preservation matches, the interface filter device be additionally operable to identify the requested data for institute State the related data of network node；And upload described obtain to the network node and ask.

5. interface filter device according to claim 4, it is characterised in that if the character string to be identified and the character The character string and the prefix BF that string BF is preserved preserve string prefix and mismatched, and the interface filter device is additionally operable to identify The requested data be and the incoherent data of the network node；And obtain request by described and abandon, without to the net Network node uploads described obtain and asked.

6. interface filter device according to claim 4, it is characterised in that first filter assemblies also include corresponding institute The character string for stating character string BF counts the grand filter element CBF of cloth, and second filter assemblies also include the corresponding prefix BF's Prefix CBF：

The character string CBF is used for the service condition for recording the first Hash table, and first Hash table is the first filtering group Hash table corresponding to part, first Hash table are used for the cryptographic Hash for recording the character string that the character string BF is preserved；

The prefix CBF is used for the service condition for recording the second Hash table, and second Hash table is second filter assemblies Corresponding Hash table, second Hash table are used for the cryptographic Hash for recording the string prefix that the prefix BF is preserved.

7. interface filter device according to claim 6, it is characterised in that when the word preserved in the change character string BF During symbol string, the character string CBF is additionally operable to the service condition of the first Hash table according to change content update；

When changing the string prefix preserved in the prefix BF, the prefix CBF is additionally operable to according to change content update institute State the service condition of the second Hash table.

A kind of 8. regulation and control method for interface filter device, it is characterised in that applied to interface filter device, the interface mistake Filter device comprises at least the first filter assemblies and the second filter assemblies, and first filter assemblies include character string Bloom filter BF, second filter assemblies include prefix BF；It is related to the network node for identifying that the character string BF is used for preservation Data character string；The prefix BF is used for before preserving the character string for being used for identifying the data related to the network node Sew；The interface filter device record the character string that is preserved in the character string BF and the string prefix that is preserved in the former BF it Between incidence relation, methods described includes：

According to the quantity that character string is preserved in the character string BF, calculate the character string BF and the journey of character string false positive occur Degree, the character string false positive are unmatched by the character string preserved with the character string BF for identifying the character string BF Character-string error to be identified is defined as the probability numbers of matching；

If the character string false positive is more than the first predetermined threshold value, by the first character string of the first length condition that meets from the word Deleted in symbol string BF, first character string is the character string preserved in the character string BF；

It is saved in first character string as string prefix in the prefix BF.

9. regulation and control method according to claim 8, it is characterised in that described to preserve character string according in the character string BF Quantity, calculate the character string BF and the degree of character string false positive occur, including：

If the character string false positive is less than the second predetermined threshold value, by the first string prefix of the second length condition that meets from institute State and deleted in prefix BF, first string prefix is the string prefix preserved in the prefix BF；

10. regulation and control method according to claim 9, it is characterised in that will meet the first of the second length condition described After string prefix is deleted from the prefix BF, in addition to：

, will according to the incidence relation between the string prefix preserved in the character string and the former BF preserved in the character string BF The string prefix of first string prefix described in subordinate is preserved into the prefix BF.

11. regulation and control method according to claim 8, it is characterised in that also include：

According to the quantity that string prefix is preserved in the prefix BF, calculate the prefix BF and the degree of prefix false positive occur, The prefix false positive, which is used to identifying the prefix BF, to be waited to know by the string prefix preserved with the prefix BF is unmatched Other character-string error is defined as the probability numbers of matching；

If the prefix false positive more than the 3rd predetermined threshold value, determines the multiple string prefix for meeting the first length condition, The multiple string prefix is subordinated to identical common prefix；

The multiple string prefix is merged into the common prefix, and by the multiple string prefix from the prefix BF Middle deletion.

12. regulation and control method according to claim 11, it is characterised in that described to preserve character string according in the prefix BF The quantity of prefix, calculate the prefix BF and the degree of prefix false positive occur, including：

If the prefix false positive is less than the 4th predetermined threshold value, by the second string prefix of the second length condition that meets from described Deleted in prefix BF, second string prefix is the string prefix preserved in the prefix BF；

13. regulation and control method according to claim 12, it is characterised in that will meet the second of the second length condition described After string prefix is deleted from the prefix BF, in addition to：

, will according to the incidence relation between the string prefix preserved in the character string and the former BF preserved in the character string BF The string prefix of second string prefix described in subordinate is preserved into the prefix BF.

14. regulation and control method according to claim 8, it is characterised in that the first length condition is the character string BF The middle maximum for preserving string length.

15. regulation and control method according to claim 9, it is characterised in that the second length condition is in the prefix BF Preserve the minimum value of string prefix length.

A kind of 16. character string filter, it is characterised in that applied to the interface filter device of network node, the interface mistake Filter device comprises at least the first filter assemblies and the second filter assemblies, is saved in first filter assemblies for mark and institute The character string of the related data of network node is stated, is saved in second filter assemblies for identifying and the network node phase The string prefix of the data of pass, the character string filter include receiving unit, judging unit, the first recognition unit, hair Send unit：

The receiving unit, request is obtained for receiving, it is described to obtain the character to be identified for asking to include requested data String；

The judging unit, for judge the character string to be identified whether with first filter assemblies preserve character string and The string prefix matching that second filter assemblies preserve；If the word that the character string to be identified preserves with first filter assemblies Any one in the string prefix that any one matching or second filter assemblies preserve in symbol string matches, triggering described the One recognition unit；

17. character string filter according to claim 16, it is characterised in that also including the second recognition unit and discarding Unit：

If character string and second filter assemblies that the character string to be identified preserves with first filter assemblies preserve word Symbol string prefix mismatches, and the judging unit triggers the second recognition unit；

The discarding unit, for obtaining request discarding by described, asked without uploading described obtain to the network node.

18. according to the character string filter of claim 16 or 17, it is characterised in that the network node is in content-label In network N DN.

A kind of 19. regulation device for interface filter device, it is characterised in that applied to interface filter device, the interface Filter comprises at least the first filter assemblies and the second filter assemblies, and first filter assemblies include the grand filtering of character string cloth Device BF, second filter assemblies include prefix BF；The character string BF, which is used to preserve, to be used to identify and the network node phase The character string of the data of pass；The prefix BF is used for before preserving the character string for being used for identifying the data related to the network node Sew；The interface filter device record the character string that is preserved in the character string BF and the string prefix that is preserved in the former BF it Between incidence relation, the regulation device includes computing unit, deletes unit and storage unit：

The computing unit, for according to the quantity that character string is preserved in the character string BF, calculating the character string BF and occurring The degree of character string false positive, the character string false positive are used to identifying the character string BF and will preserved with the character string BF The unmatched character-string error to be identified of character string is defined as the probability numbers of matching；If the character string false positive is more than One predetermined threshold value, trigger the deletion unit；

The deletion unit, it is described for the first character string of the first length condition that meets to be deleted from the character string BF First character string is the character string preserved in the character string BF；

20. regulation device according to claim 19, it is characterised in that if the character string false positive is default less than second Threshold value, the computing unit trigger the deletion unit, and the deletion unit is additionally operable to that the first of the second length condition will be met String prefix is deleted from the prefix BF, and first string prefix is the character string preserved in the prefix BF Prefix；

21. regulation device according to claim 20, it is characterised in that the storage unit is additionally operable to according to the character Incidence relation between the character string preserved in string BF and the string prefix preserved in the former BF, by the first character described in subordinate The string prefix of string prefix is preserved into the prefix BF.

22. regulation device according to claim 19, it is characterised in that also including determining unit and combining unit：

The computing unit is additionally operable to, according to the quantity for preserving string prefix in the prefix BF, calculate the prefix BF and occur The degree of prefix false positive, the prefix false positive are used for before identifying the character string that the prefix BF will preserve with the prefix BF Sew the probability numbers that unmatched character-string error to be identified is defined as matching；If the prefix false positive is default more than the 3rd Threshold value, trigger the determining unit；

The determining unit, for the multiple string prefix for determining to meet the first length condition, before the multiple character string Sew and be subordinated to identical common prefix；

The combining unit, for the multiple string prefix to be merged into the common prefix, and by the multiple character String prefix is deleted from the prefix BF.

23. regulation device according to claim 22, it is characterised in that if the prefix false positive is less than the 4th default threshold Value, the computing unit trigger the deletion unit, and the deletion unit is additionally operable to that the second word of the second length condition will be met Symbol string prefix is deleted from the prefix BF, and second string prefix is in the prefix BF before a character string preserving Sew；

24. regulation device according to claim 23, it is characterised in that the storage unit is additionally operable to according to the character Incidence relation between the character string preserved in string BF and the string prefix preserved in the former BF, by the second character described in subordinate The string prefix of string prefix is preserved into the prefix BF.

25. regulation device according to claim 19, it is characterised in that the first length condition is the character string BF The middle maximum for preserving string length.

26. regulation device according to claim 20, it is characterised in that the second length condition is in the prefix BF Preserve the minimum value of string prefix length.