Table entry adding, deleting and searching method of hash table and hash table storage device

A technology for storing locations and table items, applied in the field of communication, can solve problems such as occupation, unfavorable hardware implementation, and affecting table lookup speed

Active Publication Date: 2011-09-21
SANECHIPS TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This will cause multiple visits to the same table. Since there is only one table, the search can only be performed sequentially, which will seriously affect the speed of table lookup; If you find a storage space, you must ensure that the storage space is large enough, and the space utilization rate will be greatly reduced
If you use multiple hash tables to search in parallel, you need to occupy multiple memory interfaces, which is not conducive to hardware implementation

Method used

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  • Table entry adding, deleting and searching method of hash table and hash table storage device
  • Table entry adding, deleting and searching method of hash table and hash table storage device
  • Table entry adding, deleting and searching method of hash table and hash table storage device

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Experimental program
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Embodiment 1

[0088] Please refer to image 3 , is a schematic structural diagram of an embodiment of the hash table storage device in this embodiment. The hash table storage and search system in this embodiment includes a main control logic module 505, a plurality of calculation modules 502a-502n, a plurality of search modules 503a-503n, a table entry adding module 504, a statistics module 505, and a table entry splitting module 506, A plurality of bitmap modules 507a-507n, a plurality of entry storage modules 508a-508n, a data judgment module 509 and an exception processing module 550. The internal connection of the hash table storage device in this embodiment is divided into a data line and a control line. On the data line, the main control logic module 501 is coupled to a plurality of calculation modules 502a-502n, a data judgment module 509; a plurality of calculation modules 502a-502n 502n is respectively coupled to multiple search modules 503a-503n; multiple search modules 503a-503n...

Embodiment 2

[0157] see Figure 9 , this figure is a logical structure diagram of an embodiment of the hash table of the present embodiment, each hash sub-table corresponds to a bitmap and a hash function, wherein the input key value is input to the hash table of the present embodiment through the input interface In the sub-table, the hash value of the input key value is calculated by the hash table storage device, and the hash value is used as an index to find and fill in the vacancy in the bitmap and the hash sub-table; among them, bitmap0~9 are 10 of the same size, A state table with a storage depth of m, hash sub-tables 0 to 9 are 10 memories with the same size and a storage depth of m.

[0158] The hash table storage device in this embodiment is used to complete all operations on input key values ​​according to user requests, including adding, searching, monitoring, exception handling, and the like. Please refer to image 3 , when the hash key value is input into the main control lo...

Embodiment 3

[0176] see Figure 9 , which is a logical structure diagram of an embodiment of the hash table in this embodiment, wherein the input key value is input into the hash sub-table of this embodiment through the input interface, and the input key value is calculated by the hash table controller Hash value, use the hash value as an index to find and fill in the vacancy in the hash subtable; among them, hash subtable 0~9 are 10 memories, representing 10 hash subtables, bitmap0~9 are 10 state tables, However, the storage depth of the first 4 of the 10 memories in this embodiment is m, and the storage depth of the last 6 is m / 2.

[0177] The logical structure of the hash table controller in this embodiment, the storage and search process of the hash table, and the logical structure of the lookup table items are completely consistent with those in the second embodiment.

[0178] Compared with the second embodiment, the space utilization rate of the third embodiment is higher.

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Abstract

The invention discloses a table entry adding, deleting and searching method of a hash table and a hash table storage device. The table entry searching method of the hash table comprises the following steps of: calculating hash values of table entry key values to be searched in parallel, searching the corresponding bitmaps according to the hash values, comparing the search results, and taking out the table entry corresponding to the address of the bitmap in the hash table when the conflict bit is invalid for the first time; and comparing the table entry with the table entry to be searched, if matching, determining that the table entry is the table entry to be searched, namely the table entry to be searched is found. According to the table entry searching method of the hash table, storage of all table entries and no table entry leave are realized with least search time and high table space utilization rate, the required table entry can be accurately searched by accessing the memory for one time, meanwhile, the interface between the hardware and a memory is conveniently realized, and table space size, search efficiency and hardware implementation can be well balanced.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a method for adding, deleting and searching entries of a hash table and a storage device thereof. Background technique [0002] In the communication field, there are various matching algorithms, for example, for exact matching search, a hash algorithm can be used. The process of the hash search is to use the hash function to perform the abbreviation operation on the input search key (Key), then use the calculated hash value to address in the hash index table, and read out after finding the matching item. The hash index (Hash Index) stored in the corresponding item is finally used to address the direct address mapping table to obtain the required search result. [0003] The hash algorithm is a common fast search algorithm, and its basic idea is to use the keyword k of each element in the linear table as an independent variable. Through a certain functional relationship H(k...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F17/30
CPCG06F17/3033G06F17/30G06F16/2255
Inventor 李彧张炜孙远航崔玉姣郑永梅
Owner SANECHIPS TECH CO LTD
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