WO2018099107A1

WO2018099107A1 - Hash table management method and device, and computer storage medium

Info

Publication number: WO2018099107A1
Application number: PCT/CN2017/094249
Authority: WO
Inventors: 王晓泾; 陈西; 刘振伟; 包闯; 闫振林
Original assignee: 深圳市中兴微电子技术有限公司
Priority date: 2016-12-02
Filing date: 2017-07-25
Publication date: 2018-06-07
Also published as: CN108153757A; CN108153757B

Abstract

Disclosed is a Hash table management method, comprising: using a chain table to store Hash table entries corresponding to Hash key values where Hash conflicts occur, and using a root table to store a Hash table entry corresponding to each Hash key value and chain table information entries, the chain table information entries being used for indicating whether the chain table has the Hash table entry corresponding to each Hash key value; obtaining the Hash key values and Hash table entries to be stored; reading storage data in the root table according to the obtained Hash key values; storing the Hash table entries to be stored in the root table when the read storage data excludes the chain table information entries; and storing the Hash table entries to be stored in the chain table when the read storage data includes the chain table information entries. Also disclosed is a Hash table management device.

Description

Method and device for managing hash table, computer storage medium

Cross-reference to related applications

The present application is filed on the basis of the Chinese Patent Application Serial No. No. No. No. No. No. No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No No

Technical field

The present invention relates to the field of communications technologies, and in particular, to a method and apparatus for managing a hash table, and a computer storage medium.

Background technique

The network processor is a dedicated instruction processor involved in the field of network applications. It is designed for network packet processing and can make the network system have high performance and high flexibility.

The network processor uses a hash table to establish an index relationship of information when performing information search, thereby realizing quick information search. Here, the hash table uses a hash algorithm to establish an index relationship. The basic idea of this method is to establish a correspondence f between the search key value k and the storage location p of the corresponding information, so that p=f (k), f is a hash algorithm. When the network processor is used for information query, the hash algorithm is used to calculate the storage address of the hash table item information corresponding to the key value, so that the hash table item information corresponding to the key value can be directly found through the storage address.

However, when using a hash table for information query, different key values may be mapped to the same storage address in the hash table, ie k1≠k2, but f(k1)=f(k2). This phenomenon is called ha. Greek conflict, how to solve the hash conflict has become a key issue to improve the performance of network processors.

Summary of the invention

In order to solve the above technical problem, embodiments of the present invention are expected to provide a method and apparatus for hash table management, and a computer storage medium, which improve the number of hash collisions.

The technical solution of the present invention is implemented as follows:

The embodiment of the invention provides a method for managing a hash table, including:

The linked list is used to store the hash table corresponding to the hash key value of the hash conflict, and the root table is used to store the hash table corresponding to each hash key value and the linked list information item, where the linked list information item is used to indicate the linked list. Whether there is a hash table entry corresponding to each hash key value;

Obtaining a hash key value and a hash table item to be stored;

Reading the stored data in the root table according to the obtained hash key value; storing the hash table item to be stored in the root table when the stored storage data does not include the linked list information item; When the stored data includes the linked list information item, the hash table item to be stored is stored in the linked list.

In the above solution, after obtaining the hash key value, the method further includes: performing a hash calculation on the obtained hash key value according to the hash function corresponding to the root table, to obtain a first hash value;

The storing the hash table item to be stored into the root table includes:

The hash table corresponding to the first hash value exists in the root table, and the hash table entry is read according to the first hash value in the root table, and the obtained hash key value and the root table are read. When the hash key value in the extracted hash table item matches, the hash table corresponding to the first hash value in the root table is updated to the hash table item to be stored; the obtained hash key is obtained. If the value does not match the hash key value in the hash table entry read in the root table, and the storage location of the hash table entry still exists in the root table, insert the to-be-stored in the root table. History entry

When the hash table corresponding to the first hash value does not exist in the root table, the hash table entry to be stored is inserted into the root table.

In the above solution, the using the linked list to store the hash table corresponding to the hash key value of the hash conflict, including:

The linked list information item is not included in the read storage data, and the obtained hash key value does not match the hash key value in the hash table entry read in the root table, and the root table does not exist. When the storage location of the hash entry is set, a linked list is created, and the hash table to be stored is inserted in the created linked list.

In the above solution, after the hash table item to be stored is inserted in the linked list, the method further includes: updating the linked list information item in the root table based on the hash table item inserted in the linked list.

In the above solution, the linked list information item is further used to indicate address information of a hash entry existing in the linked list;

The storing the hash table item to be stored into the linked list includes:

Performing a hash calculation on the obtained hash key value according to the hash function corresponding to the linked list to obtain a second hash value; and hashing the hash table key corresponding to the obtained hash key value in the linked list information item The address information is recorded as a third hash value;

When the third hash value is the same as the second hash value, the hash table entry is read according to the second hash value in the linked list, and the obtained hash key value and the linked list are read out. When the hash key value in the hash table matches, the hash table corresponding to the second hash value in the linked list is updated to the hash table to be stored; the hash key value and the read are obtained. When the hash key values in the hash table entries do not match, the hash table entries to be stored are inserted into the linked list;

When the third hash value is different from the second hash value, a hash table entry to be stored is inserted in the linked list.

In the above solution, after the hash table item to be stored is inserted in the linked list, the method includes: updating the linked list information item based on the inserted hash table item.

In the above solution, the method further includes:

Get the lookup key value used to perform the hash lookup;

The hash table entry is searched in the root table according to the search key value, and the hash table entry search result is obtained;

When the hash table entry search result indicates that the hash table corresponding to the search key value exists in the root table, determining a hash table corresponding to the search key value in the root table in the hash table entry search result item;

When the hash table entry search result indicates that the hash table corresponding to the search key value does not exist in the root table, the hash table entry is searched in the linked list according to the search key value, and the linked list is matched with the search key value. Hash table entry.

In the above solution, the method further includes: presetting a first storage space and a second storage space, where the capacity of the second storage space is greater than the capacity of the first storage space;

The hash table entries in the root table are stored in the first storage space or the second storage space, and the hash table entries in the linked list are stored in the second storage space.

The embodiment of the invention further provides a device for managing a hash table, the device comprising: a linked list and a root table, wherein:

a linked list configured to store a hash table entry corresponding to a hash key value in which a hash conflict occurs;

The root table is configured to store a linked list information item and a hash table entry corresponding to each hash key value, where the linked list information item is used to indicate whether a hash table entry corresponding to each hash key value exists in the linked list;

The device further includes: an obtaining module and a processing module; wherein

Obtaining a module, configured to obtain a hash key value and a hash table item to be stored;

The processing module is configured to: read the stored data in the root table according to the obtained hash key value; and store the hash table item to be stored to the root table when the stored storage data does not include the linked list information item The hash table item to be stored is stored in the linked list when the linked list information item is included in the read storage data.

In the above solution, the processing module is further configured to perform hash calculation on the obtained hash key value according to a hash function corresponding to the root table, to obtain a first hash value;

Correspondingly, the processing module is further configured to: in the root table, a hash table entry corresponding to the first hash value, where the hash table entry is read according to the first hash value, When the obtained hash key value matches the hash key value in the hash table entry read in the root table, the hash table corresponding to the first hash value in the root table is updated to be stored. Hash table entry; the hash key value obtained If the hash key value in the hash table entry read in the root table does not match, and the storage location of the hash table entry still exists in the root table, insert the hash to be stored in the root table. An entry of the hash table to be stored in the root table when the hash table corresponding to the first hash value does not exist in the root table.

In the above solution, the processing module is further configured to not include the linked list information item in the read storage data, and the obtained hash key value and the hash key in the hash table item read in the root table If the value does not match, and the storage location of the hash table entry does not exist in the root table, the linked list is created, and the hash table to be stored is inserted in the established linked list.

In the above solution, the processing module is further configured to: after inserting the hash table item to be stored in the linked list, update the linked list information item in the root table based on the hash table item inserted in the linked list.

The processing module is further configured to perform a hash calculation on the obtained hash key value according to the hash function corresponding to the linked list, to obtain a second hash value, and obtain the hash in the linked list information item. The address information of the hash table corresponding to the key value is recorded as a third hash value;

The processing module is further configured to: when the third hash value and the second hash value are the same, read the hash table entry according to the second hash value in the linked list, and obtain the hash key When the value matches the hash key value in the hash table entry in the linked list, the hash table corresponding to the second hash value in the linked list is updated to the hash table to be stored; When the hash key value does not match the hash key value in the read hash table entry, the hash table entry to be stored is inserted in the linked list; the third hash value and the second hash value are When the hash values are different, the hash table entry to be stored is inserted in the linked list.

In the above solution, the processing module is further configured to: after inserting the hash table item to be stored in the linked list, update the linked list information item based on the inserted hash table item.

In the above solution, the device further includes: a lookup module;

The search module is further configured to obtain a lookup key value for performing a hash search; perform a hash table item search in the root table according to the search key value, and obtain a hash table item search result; and search results in the hash table item. When the hash table entry corresponding to the search key value exists in the root table, the hash table entry corresponding to the search key value in the root table is determined in the hash table entry search result; in the hash table entry If the search result indicates that the hash table corresponding to the search key value does not exist in the root table, the hash table entry is searched in the linked list according to the search key value, and the hash table corresponding to the search key value in the linked list is obtained. .

In the above solution, the device further includes: a first storage space and a second storage space, where the capacity of the second storage space is greater than the capacity of the first storage space;

The storage location of the hash table entry in the root table is the first storage space or the second storage space, and the storage location of the hash table entry in the linked list is the second storage space.

Embodiments of the present invention also provide a computer storage medium storing a computer program configured to perform the method of hash table management described above.

A method and device for managing hash table according to an embodiment of the present invention, and a computer storage medium, use a linked list to store a hash table entry corresponding to a hash key value in which a hash conflict occurs, and use a root table to store each hash key value corresponding to the hash table. a hash table entry, and a linked list information item, the linked list information item is used to indicate whether there is a hash table entry corresponding to each hash key value in the linked list; obtaining a hash key value and a hash table entry to be stored; Reading the stored data in the root table according to the obtained hash key value; storing the hash table item to be stored in the root table when the stored storage data does not include the linked list information item; When the stored data includes the linked list information item, the hash table item to be stored is stored in the linked list. In this way, the number of hash collisions is increased.

DRAWINGS

1 is a flow chart of a first embodiment of a method for managing hash table according to the present invention;

2 is a schematic structural diagram of a hash entry in an embodiment of the present invention;

3 is a schematic structural diagram of a linked list information item according to an embodiment of the present invention;

4 is a flowchart of a second embodiment of a method for managing a hash table according to the present invention;

FIG. 5 is a schematic diagram of a first component structure of an apparatus for managing a hash table according to an embodiment of the present invention; FIG.

6 is a schematic diagram of a second component structure of an apparatus for managing a hash table according to an embodiment of the present invention;

7 is a schematic diagram of an internal structure of a root table lookup module according to an embodiment of the present invention;

8 is a schematic diagram of an internal structure of a linked list lookup module according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of an internal structure of a lookup request scheduling module according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of an internal structure of a lookup return scheduling module according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of an internal structure of a software entry management module according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings.

1 is a flowchart of a first embodiment of a method for managing a hash table according to the present invention. As shown in FIG. 1, the method includes:

Step 10: The hash table corresponding to the hash key value in which the hash conflict occurs is stored by using the linked list, and the hash table corresponding to each hash key value and the linked list information item are stored by using the root table, and the linked list information item is used. Indicates whether there is a hash table entry corresponding to each hash key value in the linked list.

2 is a schematic structural diagram of a hash entry in the embodiment of the present invention. As shown in FIG. 2, the hash entry includes: a hash table entry identifier, a hash table header information n, and a hash table entry n, n. Take an integer greater than 0. The hash table entry identifier is used to identify that the current data is a hash table entry, the hash table entry header information n is used to determine the location of the hash table entry n, and the hash table entry n is a hash corresponding to the hash key value n. Entry. It should be noted that, when the hash table item information is read, the size of the read data is determined by the bit width of the transmitted data, and the larger the bit width, the more the hash table information obtained, that is, the more the n value is. Big. On the contrary, the smaller the value of n.

FIG. 3 is a schematic structural diagram of a linked list information item according to an embodiment of the present invention. As shown in FIG. 3, the linked list information item includes: a linked list information item representation identifier, a linked list comparison information, and a linked list address information. The linked list information item identifier is used to identify the linked list information item, and the linked list comparison information is used to indicate Whether the hash table corresponding to the hash key value is stored in the linked list, and the linked list address information is used to indicate the storage location of the hash table corresponding to the hash key value in the linked list. For example, the linked list information includes: A, B, and C; the linked list address information includes: a, b. The actual storage address of the hash entry corresponding to A and B is a, and the actual storage address of the hash entry corresponding to C is b. After the hash table entry information to be stored is calculated, A' is obtained. One of C is equal to A', indicating that there is a corresponding hash table entry in the linked list, and the storage location can be determined; otherwise, the corresponding hash table entry does not exist in the linked list.

Step 11: Obtain a hash key value and a hash table entry to be stored.

Step 12: The stored data in the root table is read according to the obtained hash key value; when the linked data item is not included in the read stored data, the hash table item to be stored is stored in the root table; When the linked list information item is included in the read storage data, the hash table item to be stored is stored in the linked list.

In this step, the stored data in the root table is read according to the obtained hash key value, and the stored data included includes: hash table entry information corresponding to the hash key value stored in the root table, or the root table Linked information items. Exemplarily, it may be determined whether the linked list information item indicates whether the identifier is 1, and if yes, determining that the stored data includes a linked list information item, and if not, determining that the stored data does not include the linked list information item.

In an actual implementation, after obtaining the hash key value, the method further includes: performing hash calculation on the obtained hash key value according to the hash function corresponding to the root table, to obtain a first hash value. The first hash value is used to determine whether the hash table corresponding to the hash key value is stored in the root table.

Here, the corresponding hash function in the root table may be: p=f(k), where k is a hash key value, p corresponds to the storage address p of the hash table entry, and f is established between k and p. The hash function. f can be a remainder remainder method kmodA (A ≤ m), a random number method random (k), and the like.

In this step, the hash table entry to be stored is stored in the root table, and the hash table corresponding to the first hash value exists in the root table, and the first hash value is used in the root table. Read hash table And updating, when the obtained hash key value matches the hash key value in the hash table item read in the root table, the hash table item corresponding to the first hash value in the root table is updated to The hash table entry to be stored; the obtained hash key value does not match the hash key value in the hash table entry read in the root table, and the hash table entry still exists in the root table. When the location is stored, a hash table entry to be stored is inserted in the root table.

When the hash table corresponding to the first hash value does not exist in the root table, the hash table to be stored is inserted into the root table.

In the actual implementation, before using the linked list to store the hash table corresponding to the hash key value of the hash conflict, the method further includes: establishing the linked list.

Here, the linked list information item is not included in the read storage data, and the obtained hash key value does not match the hash key value in the hash table entry read in the root table, and the root table is in the root table. When there is no storage location of the hash table entry, a linked list is created, and the hash table to be stored is inserted in the established linked list.

After the hash table item to be stored is inserted in the linked list, the method further includes: updating the linked list information item in the root table based on the hash table item inserted in the linked list.

In this step, the linked list information item is further used to indicate address information of a hash entry existing in the linked list;

Preferably, storing the hash table item to be stored in the linked list may include: performing hash calculation on the obtained hash key value according to the hash function corresponding to the linked list, to obtain a second hash value; The address information of the hash table entry corresponding to the obtained hash key value in the linked list information item is recorded as the third hash value.

It should be noted that the hash function corresponding to the linked list is another hash function different from the root table hash function. The second hash value and the third hash value are both obtained by calculating a hash key value through a hash function corresponding to the linked list.

When the third hash value is the same as the second hash value, the hash table entry is read according to the second hash value in the linked list, and the obtained hash key value and the linked list are read out. Haha in the hash table entry When the hash key value is matched, the hash table corresponding to the second hash value in the linked list is updated to the hash table to be stored; in the obtained hash key value and the read hash table entry When the hash key values do not match, the hash table entry to be stored is inserted in the linked list.

After the hash table item to be stored is inserted in the linked list, the method further includes: updating the linked list information item based on the inserted hash table item.

Preferably, when storing the hash table to be stored, the method further includes: presetting a first storage space and a second storage space, where the capacity of the second storage space is greater than a capacity of the first storage space; The hash table entries in the table are stored in the first storage space or the second storage space, and the hash table entries in the linked list are stored in the second storage space.

Here, the second storage space may be of any size, so that a large-capacity hash table entry or a hash table entry that generates a hash conflict is stored in the second storage space, and the storage location of the hash table entry is implemented. Flexible management increases the number of hash collisions.

It should be noted that if a hash conflict occurs when the hash table entry is stored in the root table, the conflicted hash table entry needs to be stored in the linked list, and the linked list information item may be in the format shown in FIG. Stored in the storage unit where the hash conflict exists in the root table, so that when the hash table item with the hash conflict is searched, the linked list information item can be returned, thereby further searching for the conflict hash table item saved in the linked list. .

In actual implementation, after the hash table item to be stored is stored, the method may further include searching for a corresponding hash table entry according to the input key value.

Optionally, the method for finding a hash entry may include:

Get the lookup key value used to perform the hash lookup;

The hash table entry corresponding to the lookup key value does not exist in the hash table entry search result indicating list. Determining, in the hash table entry search result, a hash table entry corresponding to the lookup key value in the root table;

When the hash table item corresponding to the search key value exists in the hash table item search result indication link table, the hash table item search is performed in the linked list according to the search key value, and the hash table corresponding to the search key value is obtained. Histology item.

In the embodiment of the present invention, a linked list is used to store a hash table entry corresponding to a hash key value in which a hash conflict occurs, and a root table is used to store a hash table entry corresponding to each hash key value and a linked list information item, where the linked list information is used. The item is used to indicate whether there is a hash table entry corresponding to each hash key value in the linked list; obtaining a hash key value and a hash table item to be stored; and reading the storage in the root table according to the obtained hash key value Data; storing the hash table item to be stored in the root table when the stored data is not included in the stored data; and storing the stored information in the stored data includes the linked list information item The hash table entries are stored in the linked list. In this way, the number of hash collisions is increased.

Second embodiment

In order to further embodies the object of the present invention, further exemplification will be made on the basis of the first embodiment of the present invention.

4 is a flowchart of a second embodiment of a method for managing a hash table according to the present invention, the method includes:

Step 40: Enter the hash entry information to be stored.

Here, the hash entry information to be stored may include: a hash table to be stored, a key value corresponding to the hash table to be stored, a key type and size, and the like.

Step 41: The storage address obtained according to the hash table entry information accesses the root table to read the stored data.

In this step, the first hash value is obtained by using the first hash function to calculate the key value in the hash table item information, where the first hash value may be the corresponding hash table item in the root table. The storage address can also be an offset address, plus the base address to get the final storage address. The stored data in the root table is accessed through the obtained storage address.

Here, the obtained storage data may be: hash table item information stored in the root table, or root The linked list information item in the table. When the hash table entry of the same key value can be found in the root table according to the key value corresponding to the hash table to be stored, the hash table entry is directly obtained, and when the hash table entry of the same key value is not found, , get the linked list information item.

It should be noted that the purpose of accessing the data in the storage address is to determine whether the currently input hash table item information is used to update the existing item information in the root table or the linked list, or as a new hash table. The item information is inserted into the root or linked list.

Step 42: Determine whether the obtained data is a linked list information item. If yes, go to step 43; if no, go to step 44.

In this step, the purpose of determining whether the obtained data is a linked list information item is: determining whether the input storage information is stored in the root table or in the linked list.

Preferably, whether the obtained data is a linked list information item can be determined by determining whether there is a linked list information item representation identifier in the read data.

Step 43: Obtain a second hash value corresponding to the key value, determine whether a third hash value equal to the second hash value is stored in the linked list information item, and if yes, execute step 431; if no, execute step 432.

In this step, the second hash function is used to calculate the key value in the stored information to obtain the second hash value, and the second hash value is compared with all the third hashes stored in the linked list comparison information in the linked list information item. Value comparison, when there is a third hash value equal to the second hash value, indicating that the storage information at this time is used to update the hash table entry in the linked list; when there is no equal value to the second hash value The third hash value indicates that the storage information at this time is inserted into the linked list as a new hash table entry.

Step 431: Determine, according to the entry information corresponding to the second hash value in the linked list, whether the key value corresponding to the hash entry is equal to the input key value. If yes, go to step 45; if no, go to step 432.

Step 432: Determine whether the linked list is full. If yes, go to step 46; if no, go to step 433.

Step 433: Insert the information of the hash table item to be stored into the linked list, and update the linked list information item in the root table.

In this step, after the stored information is inserted into the linked list as a new hash table entry, the second hash value corresponding to the key value in the stored information needs to be stored in the linked list comparison information of the linked list information item. The linked list address information is updated at the same time, and the storage address is allocated for the hash table corresponding to the second hash value.

It can be understood that, after the execution of this step is completed, the current storage information has been successfully saved in the linked list, and the hash table entry management ends, and step 47 is performed.

Step 44: Determine whether the hash table entry read from the root table is valid. If yes, go to step 442; if no, go to step 441.

In this step, the method for determining whether the hash entry is valid may be: determining whether the valid identifier of the hash entry in the header information of the hash table entry is 1 by using the stored data, and if yes, indicating that the current read is The hashed entry is valid; if not, it means that no data is included in the read data. In this case, you need to insert the information to be stored into the root table.

Step 441: After the hash table item information to be stored is inserted into the root table, step 47 is performed.

Step 442: Determine whether the key value corresponding to the hash entry is equal to the input key value. If yes, go to step 45; if no, go to step 443.

Step 443: Determine whether the root table is full. If yes, go to step 444; if no, go to step 441.

Step 444: Apply to establish a linked list for storing input information, and determine whether the application is successful. If yes, go to step 445; if no, go to step 46.

Step 445: The input information is stored in the linked list, and the linked list information item in the root table is updated, and step 47 is performed.

Step 45: Update the corresponding hash table item information in the table by using the input hash table item information.

Here, in determining the input key value and the corresponding hash table item in the current root table or linked list When present, it indicates that the currently input information is used to update the corresponding information in the root table or the linked list. After the update operation is performed, step 47 is performed.

Step 46: The storage fails.

Step 47: The storage ends.

According to the foregoing table entry management method, the hash table entry information to be stored is the same as the root table update and insertion process. When the hash table entry information to be stored is inserted into the linked list, the linked list information item in the root table needs to be performed. Update, and when updating the linked list, only need to replace the corresponding hash table item information does not need to update the linked list information item.

In actual implementation, when the information of the hash table item needs to be queried, the user only needs to input the query information, where the query information includes: the key value, the key type and the size of the hash table item to be queried. It should be noted that the query process and the storage process are the same in the process of reading the data and comparing the key values, but deleting the steps of inserting or updating the hash table entries.

Third embodiment

For the method of the embodiment of the present invention, the embodiment of the present invention further provides a device for managing a hash table, and FIG. 5 is a schematic diagram of a first component structure of the device for managing a hash table according to an embodiment of the present invention, as shown in FIG. The device includes: a linked list and a root table; wherein

The device further includes: an obtaining module 50 and a processing module 51; wherein

The obtaining module 50 is configured to obtain a hash key value and a hash table item to be stored.

The processing module 51 is configured to: read the stored data in the root table according to the obtained hash key value; and store the hash table item to be stored to the root when the stored storage data does not include the linked list information item In the table, when the linked data item is included in the read storage data, the hash table item to be stored is stored in the linked list.

Preferably, the processing module 51 is further configured to perform a hash calculation on the obtained hash key value according to a hash function corresponding to the root table, to obtain a first hash value;

Correspondingly, the processing module 51 is further configured to: in the root table, a hash table entry corresponding to the first hash value, where the hash table entry is read according to the first hash value, When the obtained hash key value matches the hash key value in the hash table entry read in the root table, the hash table corresponding to the first hash value in the root table is updated to be stored. Hash table entry; the obtained hash key value does not match the hash key value in the hash table entry read in the root table, and the storage location of the hash table entry still exists in the root table Inserting a hash table entry to be stored in the root table; when there is no hash table entry corresponding to the first hash value in the root table, inserting a hash to be stored in the root table Entry.

Preferably, the processing module 51 is further configured to not include the linked list information item in the read storage data, and the obtained hash key value and the hash key in the hash table item read in the root table If the value does not match, and the storage location of the hash table entry does not exist in the root table, the linked list is created, and the hash table to be stored is inserted in the established linked list.

Preferably, the processing module 51 is further configured to: after inserting the hash table item to be stored in the linked list, update the linked list information item in the root table based on the hash table item inserted in the linked list.

Preferably, the linked list information item is further used to indicate address information of a hash entry existing in the linked list;

The processing module 51 is further configured to perform hash calculation on the obtained hash key value according to the hash function corresponding to the linked list, to obtain a second hash value, and obtain the hash information information item and the obtained hash value. The address information of the hash table corresponding to the hash key value is recorded as a third hash value;

The processing module 51 is further configured to: when the third hash value and the second hash value are the same, read the hash table entry according to the second hash value in the linked list, and obtain the hash When the key value matches the hash key value in the hash table entry read in the linked list, the hash table corresponding to the second hash value in the linked list is updated to the hash table to be stored; Get the hash key value and read it out When the hash key value in the hash table item does not match, the hash table item to be stored is inserted in the linked list; when the third hash value is different from the second hash value, in the linked list Insert the hash table entry to be stored.

Preferably, the processing module 51 is further configured to: after inserting the hash table item to be stored in the linked list, update the linked list information item based on the inserted hash table item.

Preferably, the device further includes: a lookup module;

Preferably, the device further includes: a first storage space and a second storage space, wherein the capacity of the second storage space is greater than the capacity of the first storage space;

In actual implementation, the first storage space may be an on-chip storage unit inside the device, the second storage space may be an off-chip storage unit outside the device, and the storage space of the off-chip storage unit is large and the on-chip storage unit may be All or part of the root table, and all the linked lists are stored in the off-chip storage unit, improving the working efficiency of the device.

In an actual application, the obtaining module 50 and the processing module 51 may each be a Central Processing Unit (CPU), a Micro Processor Unit (MPU), and a Digital Signal Processor (Digital Signal Processor) located in the terminal device. DSP), or Field Programmable Gate Array (FPGA) implementation.

Fourth embodiment

FIG. 6 is a schematic diagram of a second component structure of an apparatus for managing a hash table according to an embodiment of the present invention. The apparatus may include: a user interface 101, a root table lookup module 102, a linked list lookup module 103, a lookup request scheduling module 104, and an external storage management module. 105. An external storage module 106, a lookup return scheduling module 107, a software entry management module 108, and an internal storage module 109.

The user interface 101, the root table lookup module 102, the linked list lookup module 103, the lookup request scheduling module 104, the external storage management module 105, and the lookup return scheduling module 107 are used for lookup management of the hash table entries.

The software entry management module 108 manages the storage of the hash entries.

The external storage module 106 and the internal storage module 109 are configured to implement flexible storage of hash entries.

The specific operation process of each module in the hash table item management apparatus provided by the embodiment of the present invention is as follows:

FIG. 7 is a schematic diagram of an internal structure of a root table lookup module according to an embodiment of the present invention. As shown in FIG. 7, the root table lookup module includes: a root table cache unit 201, a root table parsing unit 202, and a root table processing unit 203. The root table lookup module 102 receives the lookup information transmitted by the user interface 101, and the search information includes: a key value, a key type and a size, etc.; the lookup information is placed in the root table cache unit 201, and the key value is sent to the inside of the device. In the storage module 109, the internal storage module 109 calculates a first hash value according to the key value, and the return data corresponding to the first hash value is sent to the root table processing unit 203; and the root table parsing unit 202 also calculates the key value according to the key value. The first hash value is generated and sent to the lookup request scheduling module 104. The lookup request may include: all the search information, a trigger signal indicating the search for the external storage module 106, and the like. The lookup request scheduling module 104 requests the external storage module to search for the corresponding hash table entry, and sends the return data corresponding to the first hash value to the root table processing unit 203; the root table processing unit 203 reads the lookup from the cache unit 201. The information is matched with the obtained return data. If it matches, indicating that the returned data contains the hash table corresponding to the key value, the return data is directly sent to the lookup return scheduling module 107, and the structure of the returned data is as shown in the figure. 2; if it does not match, it means that the returned data does not contain the hash table corresponding to the key value, and needs to perform the linked list lookup. At this time, the lookup request is initiated to the linked list lookup module 103, and the structure of the linked list information item in the returned data is as shown in FIG. 3 is shown.

Here, when the root table lookup module does not obtain the hash table item to be searched, and obtains the linked list information item, the list lookup is automatically performed by parsing the linked list information item, thereby improving the search efficiency of the entry.

Optionally, the root table processing unit 203 reads the lookup information from the root table cache unit 201 and matches the obtained return data, including: the key value, the key type and the size in the search information, and the returned data. The information such as the key value, the key type, and the size of the hash table item are compared one by one. When all the information is the same, it is determined that the data matches, and the returned data includes the hash table item to be searched; if at least one item is not The same, to determine the data does not match, the returned data does not contain the hash table item to be found.

FIG. 8 is a schematic diagram of an internal structure of a linked list lookup module according to an embodiment of the present invention. As shown in FIG. 8, the linked list lookup module includes: a linked list cache unit 301, a linked list parsing unit 302, and a linked list processing unit 303. After the root table lookup module 102 initiates the lookup request to the linked list lookup module 103, the lookup request is stored in the linked list cache unit 301 and the linked list parsing unit 302. The linked list parsing unit 302 parses the lookup request and sends it to the lookup request scheduling module 104 for a lookup request. The scheduling module 104 applies to the external storage management module 105 for a corresponding query operation, and the external storage management module 105 completes the query to the external storage module 106 and returns the query result to the linked list processing unit 303; the linked list processing unit 303 reads from the linked list cache unit 301. The lookup information contained in the lookup request is compared and compared with the obtained query result, and the comparison result is sent to the lookup return scheduling module 107. Here, when the hash table corresponding to the key value is found in the linked list, the obtained hash table entry is returned; when the hash table corresponding to the key value is not found in the linked list, the prompt information may be returned Find the corresponding hash table entry.

FIG. 9 is a schematic diagram of an internal structure of a lookup request scheduling module according to an embodiment of the present invention, as shown in FIG. The lookup request scheduling module 104 includes a root table lookup cache unit 401, a linked list lookup cache unit 402, and a lookup request scheduling unit 403. The root table lookup cache unit 401 and the linked list lookup cache unit 402 cache the lookup requests generated by the root table parsing unit 202 and the linked list parsing unit 302, respectively. The lookup request scheduling unit 403, after reading the lookup request in the two cache units, adds a lookup type flag to the lookup request and sends it to the external storage management module 105. Here, the search type identifier can identify whether the current table content or the linked list content needs to be searched. Optionally, a search type flag bit can be set to distinguish the current search object. When the search type flag bit is 1, the search object is The entry information in the root table; when the lookup type flag is 0, it indicates that the search object is the entry information in the linked list. You can improve the efficiency of finding hash entries by setting the lookup type identifier.

10 is a schematic diagram of an internal structure of a lookup return scheduling module according to an embodiment of the present invention. As shown in FIG. 10, the lookup return scheduling module 107 includes a root table lookup result buffering unit 701, a linked list lookup result buffering unit 702, and a lookup returning scheduling unit 703. The root table search result buffer unit 701 and the linked list search result buffer unit 702 respectively cache the lookup return results generated by the root table processing unit 303 and the linked list processing unit 403, and the lookup return scheduling unit 703 reads the search results in the two cache units, and It is returned to the user via the user interface 101.

FIG. 11 is a schematic diagram of an internal structure of a software entry management module according to an embodiment of the present invention. As shown in FIG. 11, the software entry management module 108 may include: a master device 801, a software management unit 802, and a software cache unit 803.

When storing the hash table entry, the master device 801 first determines whether the hash table entry is stored in the root table or the linked list by the software management unit 802. After determining the storage location of the hash table entry storage, the software management unit 802 The hash table entry is first cached into the software cache unit 803, and the software cache is interconnected by a peripheral component (Peripheral Component Interconnect Express, The PCIE) interface is written to the external storage module 106. It should be noted that, in order to reduce the operation efficiency of the internal storage module of the device, the root table and the linked list may be stored in the external storage module; or the smaller hash entries in the root table may be stored in the internal storage module. , store the large hash table entries in the external storage module.

Here, the hash table entry management device may adopt a pipeline method when performing hash table item search, for an entry of the same level entry, that is, an entry of the same root table or a linked list. Because the storage location and the discovery process are consistent, the lookup interface can perform sequential lookups for the same level of lookup. For different levels of lookup, that is, the searched entries are in the root table and the linked list, and the lookup interface can also be searched according to the order in which the lookup requests are obtained.

In the process of searching for a hash entry, the storage management of the hash entry may be implemented at the same time. If an error occurs in the process of storing the entry, the error identifier may be returned to the hash table item management device, and then The error condition is handled by the management device, for example, re-storing the entry or blocking the lookup of the error entry.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention can take the form of a hardware embodiment, a software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. The work specified in one or more blocks of a flow or a flow and/or a block diagram of a flowchart Able device.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

Correspondingly, an embodiment of the present invention further provides a computer storage medium, wherein a computer program is configured, and the computer program is configured to perform a hash table management method according to an embodiment of the present invention.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Industrial applicability

The technical solution of the embodiment of the present invention uses a linked list to store a hash table entry corresponding to a hash key value in which a hash conflict occurs, and uses a root table to store a hash table entry corresponding to each hash key value, and a linked list information item. The linked list information item is used to indicate whether there is a hash table corresponding to each hash key value in the linked list; obtaining a hash key value and a hash table item to be stored; and reading the root table according to the obtained hash key value; Storage data; when the stored data is not included in the stored data, the hash table item to be stored is stored in the root table; when the stored data includes the linked list information item, the The hash table items to be stored are stored in the linked list. In this way, the number of hash collisions is increased.

Claims

A method of hash table management, the method comprising:

The linked list is used to store the hash table corresponding to the hash key value of the hash conflict, and the root table is used to store the hash table corresponding to each hash key value and the linked list information item, where the linked list information item is used to indicate the linked list. Whether there is a hash table entry corresponding to each hash key value;

Obtaining a hash key value and a hash table item to be stored;

Reading the stored data in the root table according to the obtained hash key value; storing the hash table item to be stored in the root table when the stored storage data does not include the linked list information item; When the stored data includes the linked list information item, the hash table item to be stored is stored in the linked list.
The method according to claim 1, wherein after obtaining the hash key value, the method further comprises: performing a hash calculation on the obtained hash key value according to the hash function corresponding to the root table, First hash value;

The storing the hash table item to be stored into the root table includes:

The hash table corresponding to the first hash value exists in the root table, and the hash table entry is read according to the first hash value in the root table, and the obtained hash key value and the root table are read. When the hash key value in the extracted hash table item matches, the hash table corresponding to the first hash value in the root table is updated to the hash table item to be stored; the obtained hash key is obtained. If the value does not match the hash key value in the hash table entry read in the root table, and the storage location of the hash table entry still exists in the root table, insert the to-be-stored in the root table. History entry

When the hash table corresponding to the first hash value does not exist in the root table, the hash table entry to be stored is inserted into the root table.
The method of claim 1, wherein the using the linked list to store the hash table entry corresponding to the hash key value in which the hash collision occurs includes:

The linked list information item is not included in the read stored data, and the obtained hash key value and root are obtained. If the hash key values in the hash table entries in the table do not match, and the storage location of the hash table entries does not exist in the root table, the linked list is created, and the hash to be stored is inserted in the established linked list. Entry.
The method according to claim 3, wherein after inserting the hash table entry to be stored in the linked list, the method further comprises: updating the linked list in the root table based on the hash table entry inserted in the linked list Information item.
The method according to claim 1, wherein the linked list information item is further used to indicate address information of a hash entry existing in the linked list;

The storing the hash table item to be stored into the linked list includes:

Performing a hash calculation on the obtained hash key value according to the hash function corresponding to the linked list to obtain a second hash value; and hashing the hash table key corresponding to the obtained hash key value in the linked list information item The address information is recorded as a third hash value;

When the third hash value is the same as the second hash value, the hash table entry is read according to the second hash value in the linked list, and the obtained hash key value and the linked list are read out. When the hash key value in the hash table matches, the hash table corresponding to the second hash value in the linked list is updated to the hash table to be stored; the hash key value and the read are obtained. When the hash key values in the hash table entries do not match, the hash table entries to be stored are inserted into the linked list;

When the third hash value is different from the second hash value, a hash table entry to be stored is inserted in the linked list.
The method according to claim 5, wherein after inserting the hash table entry to be stored in the linked list, the method comprises: updating the linked list information item based on the inserted hash table entry.
The method of claim 1 wherein the method further comprises:

Get the lookup key value used to perform the hash lookup;

The hash table entry is searched in the root table according to the search key value, and the hash table entry search result is obtained;

When the hash table entry search result indicates that the hash table corresponding to the search key value exists in the root table, determining, in the hash table entry search result, a hash corresponding to the search key value in the root table Entry

When the hash table entry search result indicates that the hash table corresponding to the search key value does not exist in the root table, the hash table entry is searched in the linked list according to the search key value, and the linked list is matched with the search key value. Hash table entry.
The method according to claim 1, wherein the method further comprises: presetting a first storage space and a second storage space, wherein the capacity of the second storage space is greater than the capacity of the first storage space;

The hash table entries in the root table are stored in the first storage space or the second storage space, and the hash table entries in the linked list are stored in the second storage space.
A device for managing a hash table, the device comprising: a linked list and a root table, wherein:

a linked list configured to store a hash table entry corresponding to a hash key value in which a hash conflict occurs;

The root table is configured to store a linked list information item and a hash table entry corresponding to each hash key value, where the linked list information item is used to indicate whether a hash table entry corresponding to each hash key value exists in the linked list;

The device further includes: an obtaining module and a processing module; wherein

Obtaining a module, configured to obtain a hash key value and a hash table item to be stored;

The processing module is configured to: read the stored data in the root table according to the obtained hash key value; and store the hash table item to be stored to the root table when the stored storage data does not include the linked list information item The hash table item to be stored is stored in the linked list when the linked list information item is included in the read storage data.
The apparatus according to claim 9, wherein the processing module is further configured to perform a hash calculation on the obtained hash key value according to a hash function corresponding to the root table to obtain a first hash value;

Correspondingly, the processing module is further configured to: in the root table, a hash table entry corresponding to the first hash value, where the hash table entry is read according to the first hash value, The root is obtained when the obtained hash key value matches the hash key value in the hash table entry read in the root table. The hash table corresponding to the first hash value in the table is updated to the hash table entry to be stored; the hash key value in the hash key value read from the hash table and the hash table read in the root table is not If the storage location of the hash table entry exists in the root table, the hash table entry to be stored is inserted in the root table; the first hash value does not exist in the root table. When a table entry is selected, a hash table entry to be stored is inserted in the root table.
The apparatus according to claim 9, wherein the processing module is further configured to not include the linked list information item in the read stored data, and the obtained hash key value and the hash read in the root table If the hash key in the entry does not match, and the storage location of the hash entry does not exist in the root table, the linked list is created, and the hash table to be stored is inserted in the established linked list.
The device according to claim 11, wherein the processing module is further configured to: after inserting a hash table entry to be stored in the linked list, based on a hash table entry inserted in the linked list, in the root table Update the linked list information item.
The apparatus according to claim 9, wherein the linked list information item is further used to indicate address information of a hash entry existing in the linked list;

The processing module is further configured to perform a hash calculation on the obtained hash key value according to the hash function corresponding to the linked list, to obtain a second hash value, and obtain the hash in the linked list information item. The address information of the hash table corresponding to the key value is recorded as a third hash value;

The processing module is further configured to: when the third hash value and the second hash value are the same, read the hash table entry according to the second hash value in the linked list, and obtain the hash key When the value matches the hash key value in the hash table entry in the linked list, the hash table corresponding to the second hash value in the linked list is updated to the hash table to be stored; When the hash key value does not match the hash key value in the read hash table entry, the hash table entry to be stored is inserted in the linked list; the third hash value and the second hash value are When the hash values are different, the hash table entry to be stored is inserted in the linked list.
The apparatus of claim 13, wherein the processing module is further configured to After the hash table entry to be stored is inserted in the linked list, the linked list information item is updated based on the inserted hash table entry.
The apparatus of claim 9, wherein the apparatus further comprises: a lookup module;

The search module is further configured to obtain a lookup key value for performing a hash search; perform a hash table item search in the root table according to the search key value, and obtain a hash table item search result; and search results in the hash table item. When the hash table entry corresponding to the search key value exists in the root table, the hash table entry corresponding to the search key value in the root table is determined in the hash table entry search result; in the hash table entry If the search result indicates that the hash table corresponding to the search key value does not exist in the root table, the hash table entry is searched in the linked list according to the search key value, and the hash table corresponding to the search key value in the linked list is obtained. .
The device according to claim 9, wherein the device further comprises: a first storage space and a second storage space, the capacity of the second storage space being greater than the capacity of the first storage space;

The storage location of the hash table entry in the root table is the first storage space or the second storage space, and the storage location of the hash table entry in the linked list is the second storage space.
A computer storage medium having computer executable instructions stored thereon, the computer executable instructions being configured to perform the method of hash table management of any of claims 1-8.