CN103684718B - Error-tolerant network redundancy elimination implementation method - Google Patents

The invention provides an error-tolerant network redundancy elimination implementation method to solve the problem that error codes are easily generated in the redundancy elimination process, and belongs to the technical field of networks. The method includes the steps of firstly, conducting fingerprint coding on redundant data segments in a data packet to be sent; secondly, enabling a sending end to transmit the data packet where the fingerprint coding is conducted to a receiving end or a downstream node; finally, conducting decoding on the data packet through the receiving end or the downstream node. According to the method, under the condition that network transmission errors exist, the downstream node can timely and accurately extract fingerprint information and correctly decode and restore original grouped data.

A kind of network redundancy of mistake tolerance eliminates implementation method

Technical field

The present invention relates to networking technology area, the network redundancy elimination implementation method of more particularly, to a kind of mistake tolerance.

Background technology

Due on internet in a large number same or analogous content repeatedly asked by the user of network edge, cause data and exist Repeating on network is transmitted, and result in substantial amounts of redundant flow, not only consumption network bandwidth, and reduces the effect of internet Rate.Constantly expand with capacity of memory device, arithmetic facility performance improves constantly, price constantly reduces, introduce net in internet Memory storage facility, makes network have memory function and has become as possibility, and having the internet of store function, to be capable of network superfluous Residual current amount technology for eliminating, it records the data of transmission over networks, identifies the data being repeatedly transmitted, thus eliminating redundant transmission, Play the effect reducing network traffics, improving network performance.But, eliminate (data redundancy in data redundancy Elimination, dre) during, the finger print information of coding can produce the phenomenons such as error code, time-out, network rings in transmitting procedure Border is complicated, and this phenomenon is obvious, causes receiving terminal or downstream node receives the finger print information of mistake it is impossible to normal Decoding.

Easily produce error code for solving existing data redundancy technology for eliminating, lead to what downstream node cannot normally decode to ask Topic, mainly has following several settlement mechanism in prior art:

1st, based on the settlement mechanism retransmitting: downstream node detection receiving data situation, find that mistake then requires transmitting terminal weight New transmission packet.The problem that the method exists: serious waste Internet resources, particularly with wireless transmission environments, repeat to transmit Number of times can be very many, had a strong impact on network transmission efficiency.

2nd, ack intercepts: whether normal for packet situation is fed back to transmitting terminal after receiving packet by downstream node. If data message is normal, transmitting terminal can normally be sent to downstream node really according to this packet of this validation of information.If data Package informatin is abnormal, then this information cache then (transmission should once by " blacklist " record in " blacklist " by transmitting terminal The information of the packet of mistake), therefore, if same packet makes a mistake again, transmitting terminal is permissible by being somebody's turn to do " blacklist " Quickly find the packet that mistake occurs.There are 2 points of problems in the method: first, receiving terminal or downstream node just receive Normal packet and have sent confirmation, but due to due to network delay, transmitting terminal does not receive confirmation and mistake Think that receiving terminal or downstream node do not have successful data reception, transmitting terminal can send the data being already properly received again Information and cause information misinformate, thus wasting Internet resources.Second, the method cannot be applied to the association not having feedback acknowledgment mechanism In view, such as udp agreement (User Datagram Protocol).

In sum, existing data redundancy technology for eliminating presence easy error code that produces in transmitting procedure leads to receiving terminal Or downstream node cannot correct decoding, network transmission efficiency is slow, the serious problem of network resources waste.

Content of the invention

It is an object of the invention to provide a kind of network redundancy of mistake tolerance eliminates implementation method, to solve prior art When the finger print information solving the problems, such as to encode produces error code in transmitting procedure, using wrong based on the settlement mechanism detection retransmitting By mistake transmitting terminal is then required to resend packet, serious waste Internet resources are it is also difficult to ensure the real-time transmission of message Problem；And the method intercepted using ack needs feedback acknowledgment information it is impossible to be applied to the transmission association that there is not feedback acknowledgment mechanism View, and if feedback acknowledgment information leads to transmitting terminal to repeat to send out because the reasons such as network delay can not be transferred to transmitting terminal in time The phenomenon sending packet can cause serious problem of resource waste.

For solving above-mentioned technical problem, a kind of network redundancy of mistake tolerance that the present invention provides eliminates implementation method, bag Include: carry out finger-print codes to sent the redundant data fragment in packet；Packet after finger-print codes is passed by transmitting terminal It is defeated by receiving terminal or downstream node；Receiving terminal or downstream node enter row decoding to packet.

Preferably, described carry out finger-print codes to sent the redundant data fragment in packet, it concretely comprises the following steps:

Redundant data fragment is selected from packet currently to be sent；

First redundant data fragment is calculated to hash value h of m-th redundant data fragment by hash function₁To h_m；Its In, m is the sum of the redundant data fragment selected in packet currently to be sent, and m > 1；

Currently select first redundant data fragment finger-print codes is h_mh₁h₂, by m-th currently selected redundant digit It is h according to fragment finger-print codes_m-1h_mh₁, n-th currently selected redundant data fragment finger-print codes are h_n-1h_nh_n+1, wherein, n It is the positive integer being less than m more than 1；

Redundant data fragment in currently packet to be sent is replaced with its corresponding finger-print codes.

Preferably, before described receiving terminal or downstream node enter row decoding to packet, described receiving terminal or under Trip node caches hash value table corresponding with redundant data fragment in advance.

Preferably, described receiving terminal or downstream node enter row decoding to packet, concretely comprise the following steps: extract number in order According to all finger-print codes in bag；Determine the correct hash value of each finger-print codes corresponding redundant data fragment；According to each redundancy The hash value of data slot, extracts corresponding data slot in hash value table corresponding with data slot from caching；By number Replaced with its corresponding data slot according to each finger-print codes in bag, the work decoding of complete paired data bag.

Preferably, the concrete grammar of the described correct hash value determining each finger-print codes corresponding redundant data fragment For:

S1: extract second hash value in current finger print coding, be designated as h；

S2: judge whether to find h in hash value table corresponding with redundant data fragment in described caching corresponding superfluous Remaining data slot, is the correct hash value that h then encodes as current finger print corresponding redundancy redundant data fragment, terminates data Bag decoding flow process；Otherwise continue executing with s3；

S3: extract current finger print respectively in the previous finger-print codes and rear finger-print codes of current finger print coding and compile The hash of the corresponding redundant data fragment of code, is designated as hf, hl respectively, subsequently executes s4；Wherein, if current finger print is encoded to currently First finger-print codes sequentially extracting in packet, then compile last fingerprint sequentially extracting in current data packet Code is as the previous finger-print codes of described first finger-print codes；If current finger print is encoded in current data packet and sequentially extracts Last finger-print codes going out, then using sequentially extract in current data packet first finger-print codes as described last Rear finger-print codes of individual finger-print codes；

S4: judge whether can find the corresponding data slice of hf or hl in described hash value table corresponding with data slot Section, is the correct hash that the hash value corresponding to this data slot then encodes corresponding redundant data fragment as current finger print Value, otherwise end data packet decoding flow process is it is desirable to transmitting terminal resends this packet.

The having the beneficial effect that of the technique scheme of the present invention:

1st, the method that the present invention provides passes through the hash using Current redundant data slot and its redundant data fragment in front and back Value combine finger-print codes are carried out to each redundant data fragment so that due to error of transmission lead to receiving terminal or downstream node or It is only necessary to pass through to be currently needed for the previous redundant data fragment of the redundant data fragment of decoding when downstream node cannot normally decode Or the finger-print codes of a rear redundant data fragment can obtain being currently needed for the correct hash value of the redundant data fragment of decoding, Thus getting the corresponding data slot of this hash, therefore typically sending data again without requiring transmitting terminal, improve network Efficiency of transmission, save the network bandwidth.

2nd, for the network environment that transmission conditions are more severe, the likelihood ratio of transmission error code is larger, the side that the present invention provides When in method, receiving terminal or downstream node can normally decode, just can be according in front and back's fingerprint letter in receiving terminal or downstream node Breath confirms in time to the information being received, and the method solving existing feedback acknowledgment is because confirmation postpones so that sending out Sending end is also possible to normally receive the confirmation of receiving terminal or downstream node and causes packet to repeat to send Problem.

Brief description

Fig. 1 is that a kind of network redundancy of mistake tolerance provided in an embodiment of the present invention eliminates implementation method schematic flow sheet；

Fig. 2 is the schematic flow sheet carrying out finger-print codes in Fig. 1 to sent the redundant data fragment in packet；

Fig. 3 is the current redundant data fragment finger-print codes schematic diagram in packet to be sent；

Fig. 4 represents intention for hash value is corresponding with redundant data fragment；

Fig. 5 is the schematic flow sheet of step s13 in Fig. 1；

Fig. 6 is the schematic flow sheet of the correct hash value obtaining each finger-print codes corresponding redundant data fragment.

Specific embodiment

For making the technical problem to be solved in the present invention, technical scheme and advantage clearer, below in conjunction with accompanying drawing and tool Body embodiment is described in detail.

The network redundancy that Fig. 1 show a kind of mistake tolerance provided in an embodiment of the present invention eliminates implementation method, comprising:

S11: carry out finger-print codes to sent the redundant data fragment in packet；

Packet after finger-print codes is transferred to receiving terminal or downstream node by s12: transmitting terminal；

S13: receiving terminal or downstream node enter row decoding to packet.

Fig. 2 is the schematic flow sheet carrying out finger-print codes in Fig. 1 to sent the redundant data fragment in packet, that is, S11 specifically includes following steps:

S21: select redundant data fragment from packet currently to be sent.

S22: calculate the first redundant data fragment currently selected by hash function to m-th redundant data fragment Hash value h₁To h_m；Wherein, m is the sum of the redundant data fragment selected in packet currently to be sent, while m > 1.

S23: redundant data fragment is carried out with finger-print codes: by currently select first redundant data fragment finger-print codes For h_mh₁h₂, m-th currently selected redundant data fragment finger-print codes are h_m-1h_mh₁, by n-th currently selected redundant digit It is h according to fragment finger-print codes_n-1h_nh_n+1, wherein, n is the positive integer being less than m more than 1.

S24: the redundant data fragment in currently packet to be sent is replaced with its corresponding finger-print codes, completes to working as The finger-print codes work of front packet to be sent.

Fig. 3 is the current redundant data fragment finger-print codes schematic diagram in packet to be sent, and wherein m is data redundancy piece Disconnected sum, n is the positive integer being less than m more than 1；" hash value " corresponding row shows that each redundant data fragment is corresponding Hash value；The row of " finger-print codes " shows the hash value according to each data redundancy segment and its redundancy segment in front and back The finger-print codes that hash value generates.

Preferably, before step s13 in Fig. 1, further comprise the steps of: and cache one in advance in receiving terminal or downstream node Hash value table corresponding with redundant data fragment, is illustrated in figure 4 hash value table corresponding with data slot.

Preferably, as shown in figure 5, step s13 in Fig. 1 specifically includes following steps:

S51: extract all finger-print codes in packet；

S52: according to all finger-print codes being extracted, determine the correct of each finger-print codes corresponding redundant data fragment Hash value；

S53: according to the hash value of each redundant data fragment, extract in hash value table corresponding with data slot from caching Go out corresponding data slot；

S54: each finger-print codes in packet are replaced with its corresponding data slot, the decoding work of complete paired data bag Make.

Preferably, determine concrete grammar such as Fig. 6 of the correct hash value of each finger-print codes corresponding redundant data fragment Shown:

S61: extract second hash value in current finger print coding, be designated as h；

S62: judge whether to find h corresponding redundant data fragment in hash value table corresponding with data slot, be Then execute s67；Otherwise continue executing with s63；

S63: extract current finger print respectively in the previous finger-print codes and rear finger-print codes of current finger print coding Encode the hash value of corresponding redundant data fragment, be designated as hf, hl respectively, subsequently execute s64；Wherein, if current finger print coding For first finger-print codes sequentially extracting in current data packet, then by sequentially extract in current data packet last Finger-print codes are as the previous finger-print codes of described first finger-print codes；If current finger print is encoded to suitable in current data packet Last finger-print codes that sequence extracts, then using sequentially extract in current data packet first finger-print codes as described A rear fingerprint of last finger-print codes is compiled；

S64: judge whether can find the corresponding data slot of hf or hl in hash value table corresponding with data slot, be Then execute s66；Otherwise execute s65；

S65: end data packet decodes flow process, and sends information to transmitting terminal, informs its receiving terminal or downstream joint Point cannot normally decode it is desirable to transmitting terminal resends this packet；

S66: the hash value corresponding to this data slot is just being encoded corresponding redundant data fragment as current finger print Really hash value returns；

S67: the correct hash value that h is encoded corresponding redundant data fragment as current finger print returns.

For example, it is assumed that current receiving terminal will be to second finger-print codes h in currently received packet₁h₂h₃Translated Code, its previous finger-print codes is h₁₀h₁h₂, finger-print codes are to compile h thereafter₂h₃h₄, then first from finger-print codes h₁h₂h₃Middle extraction Go out hash value h₂, then in the hsah value table corresponding with data slot of Fig. 4, find h₂Corresponding data slot, that is, complete this The correct decoding process of finger-print codes.If second hash value code in second finger-print codes in currently received packet Word makes a mistake, and can not find from currently received packet in the hsah value table corresponding with data slot of Fig. 4 The second hash value extracting in two finger-print codes, then extract the 3rd hash value in its previous finger-print codes, and Extract first hash value in finger-print codes thereafter, if can be found it in hsah value table corresponding with data slot Any one of first hash value in the 3rd hash value in previous finger-print codes and thereafter finger-print codes hash value, The h that then current receiving terminal can directly according to first finger-print codes and the 3rd finger-print codes₂Section enter row decoding, without will Sender is asked again to transmit.

To sum up, the present invention is in the case of network transmission error, and downstream node also can promptly and accurately take the fingerprint information, And correct decoded back original packet data.Specifically, the method that the present invention provides is passed through using Current redundant data slot And its hash value of redundant data fragment in front and back combines and carries out finger-print codes to each redundant data fragment so that because transmission misleads It is only necessary to pass through to be currently needed for the previous of the redundant data fragment of decoding when causing receiving terminal or downstream node cannot normally decode The finger-print codes of redundant data fragment or a rear redundant data fragment can obtain the redundant data fragment being currently needed for decoding Correct hash value, thus getting the corresponding data slot of this hash, therefore typically send number again without requiring transmitting terminal According to improve network transmission efficiency, save the network bandwidth.Additionally, for the more severe network environment of transmission conditions, transmitting The likelihood ratio of error code is larger, when in the method that the present invention provides, receiving terminal or downstream node can normally decode, in receiving terminal Or downstream node just can confirm to the information being received according in front and back's finger print information in time, solves existing feedback The method confirming postpones to make transmitting terminal be also possible to normally receive receiving terminal or downstream node due to confirmation Confirmation and cause packet repeat send problem.

It is more than the preferred embodiment of the present invention it is noted that for those skilled in the art, On the premise of without departing from principle of the present invention, some improvements and modifications can also be made, these improvements and modifications also should regard For protection scope of the present invention.