Computer-readable recording medium, encoding apparatus, encoding method, comparison apparatus, and comparison method

Patent metadata

Field	Value
Publication number	US-9628110-B2
Application number	US-201615209978-A
Country	US
Kind code	B2
Filing date	Jul 14, 2016
Priority date	Jul 16, 2015
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

The encoding apparatus registers, in a dynamic dictionary, strings in input text data that are not contained in a static dictionary. The encoding apparatus adds, to first hashed data obtained by individually N-dimensionally hashing words contained as registered items in the static dictionary, hashed data obtained by individually hashing strings registered in the dynamic dictionary. The encoding apparatus 100 determines, by using the first hashed data, whether each input string has been registered in the static dictionary 124 and whether the string has been registered in the dynamic dictionary 122 . In accordance with the result of the determination, the encoding apparatus 100 performs encoding based on a content registered in the static dictionary or the dynamic dictionary.

First claim

What is claimed is:

1. A non-transitory computer-readable recording medium storing therein an encoding program that causes a computer to execute a process comprising:
registering, in a dynamic dictionary, strings in input text data that are not contained in a static dictionary;
adding, to first hashed data obtained by individually N-dimensionally hashing words contained as registered items in the static dictionary, hashed data obtained by individually hashing strings registered in the dynamic dictionary;
determining, by using the first hashed data, whether each input string has been registered in the static dictionary and whether the string has been registered in the dynamic dictionary; and
in accordance with a result of the determining, performing encoding based on a content registered in the static dictionary or the dynamic dictionary.

2. The computer-readable recording medium according to claim 1 , wherein the adding includes, when a piece of the first hashed data obtained by N-dimensionally hashing words collides with another, registering the piece of the first hashed data in an overlap table.

3. The computer-readable recording medium according to claim 2 , wherein, the adding includes, when the overlap table is full, transferring the first hashed data to another overlap table having a larger capacity.

4. The computer-readable recording medium according to claim 1 , wherein the first hashed data is hashed data obtained by N-dimensionally hashing words, where N is at least 2.

5. The computer-readable recording medium according to claim 2 , wherein, the adding includes securing, in the overlap table, a region to be used for managing data with respect to each piece of the first hashed data.

6. An encoding apparatus comprising:
a processor; and
a memory, wherein the processor executes:
registering, in a dynamic dictionary, strings in input text data that are not contained in a static dictionary;
adding, to first hashed data obtained by individually N-dimensionally hashing words contained as registered items in the static dictionary, hashed data obtained by individually hashing strings registered in the dynamic dictionary;
determining, by using the first hashed data, whether each input string has been registered in the static dictionary and whether the string has been registered in the dynamic dictionary; and
in accordance with a result of the determining, performing encoding based on a content registered in the static dictionary or the dynamic dictionary.

7. An encoding method to be performed by a computer, the method comprising:
registering, in a dynamic dictionary, strings in input text data that are not contained in a static dictionary using a processor;
adding, to first hashed data obtained by individually N-dimensionally hashing words contained as registered items in the static dictionary, hashed data obtained by individually hashing strings registered in the dynamic dictionary using the processor;
determining, by using the first hashed data, whether each input string has been registered in the static dictionary and whether the string has been registered in the dynamic dictionary using the processor; and
in accordance with a result of the determining, performing encoding based on a content registered in the static dictionary or the dynamic dictionary using the processor.

8. A non-transitory computer-readable recording medium storing therein a comparison program that causes a computer to execute a process comprising:
calculating hashed data into which an input word is hashed; and
by using the calculated hashed data as a comparison key and using first hashed data obtained by individually N-dimensionally hashing words contained as registered items in a static dictionary and in a dynamic dictionary in which strings not contained in the static dictionary are registered, determining whether the input word has been registered in the static dictionary and whether the input word has been registered in the dynamic dictionary.

9. A comparison apparatus comprising:
a processor; and
a memory; and wherein the processor executes:
calculating hashed data into which an input word is hashed; and
by using the calculated hashed data as a comparison key and using first hashed data obtained by individually N-dimensionally hashing words contained as registered items in a static dictionary and in a dynamic dictionary in which strings not contained in the static dictionary are registered, determining whether the input word has been registered in the static dictionary and whether the input word has been registered in the dynamic dictionary.

10. A comparison method to be performed by a computer, the method comprising:
calculating hashed data into which an input word is hashed using a processor; and
by using the calculated hashed data as a comparison key and using first hashed data obtained by individually N-dimensionally hashing words contained as registered items in a static dictionary and in a dynamic dictionary in which strings not contained in the static dictionary are registered, determining whether the input word has been registered in the static dictionary and whether the input word has been registered in the dynamic dictionary using the processor.

Assignees

• Fujitsu Ltd

Inventors

• Kataoka Masahiro
• Matsumura Ryo
• Ozawa Takaki

Classifications

• G06F40/242

  Dictionaries · CPC title

• G06F16/325

  Hash tables · CPC title

• H03M7/3086 Primary

  employing a sliding window, e.g. LZ77 · CPC title

• G06F40/126

  Character encoding · CPC title

• H03M7/3084 Primary

  using adaptive string matching, e.g. the Lempel-Ziv method · CPC title