Compression/decompression of tags in markup documents by creating a tag code/decode table based on the encoding of tags in a DTD included in the documents

• US 6,330,574 B1
• Filed: 03/30/1998
• Issued: 12/11/2001
• Est. Priority Date: 08/05/1997
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Murashita, Kimitaka
• Primary Examiner(s): Hong, Stephen S.
• Assistant Examiner(s): Paula, Cesar B
• Application Number:
  US09/050,104
• Time in Patent Office: 1,352 Days
• Field of Search: 707/501, 707/513, 707/101, 707/532
• US Class Current: 715/236
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

In a tag document compressing/decompressing technique, a tag document compressing apparatus, for example, has a tag extracting unit for scanning document type definition of an inputted tag document to extract a tag, a tag code table creating unit for assigning a predetermined code to the tag in the document type definition on the basis of the tag extracted by the tag extracting unit to create a tag code table, and a tag coding unit for coding the tag in document instance on the basis of the tag code table created by the tag code table creating unit so as to compress the document in consideration of the tag in the tag document, thereby improving a compression rate of the tag document and decreasing a quantity of data of the same.

Claims

1. A tag document compressing apparatus to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document comprising:

a tag extracting unit to scan a DTD of an inputted tag documents, which is object of compressing, to extract said tag;

a tag code table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code table dedicated to tag encoding to compress said tag document; and

a tag coding unit to encode said tag in said document instance corresponding to said DTD of said tag document on the basis of said tag code table created by said tag code table creating unit.

2. The tag document compressing apparatus according to claim 1, wherein when a plurality of tag documents having the same DTD are encoded, said tag coding unit encodes tags in the document instances of all of the tag documents on the basis of a single tag code table created with respect to the first tag document by said tag extracted unit and said tag code table creating unit.

3. A tag document compressing apparatus to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document comprising:

a tag extracting unit to scan the DTD of an inputted tag document, to be compressed, to extract said tag;

a tag code creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code table dedicated to tag encoding to compress said tag document;

a tag discriminating unit to determine whether data in said inputted document instance is said tag extracted by said tag extracting unit;

a coding process unit to encode said inputted data of said document instance corresponding to said DTD on the basis of said tag code table when said tag discriminating unit determines that said inputted data is said tag, whereas encoding said inputted data in a predetermined encoding system when said tag discriminating unit determines that said inputted data is not said tag; and

a special code outputting unit to output a special code showing encoding of a tag to a decoding side of said tag before said inputted data is encoded when said tag discriminating unit discriminates that said inputted data is said tag.

4. The tag document compressing apparatus according to claim 3, wherein said coding process unit comprises:

a first coding unit to encode said inputted data on the basis of said tag code table;

a second coding unit to encode said inputted data in a predetermined encoding system; and

a switching control unit to output said inputted data to said first coding unit when said tag discriminating unit determines that said inputted data is said tag, whereas outputting said inputted data to said second coding unit when said tag discriminating unit determines that said inputted data is not said tag.

5. The tag document compressing apparatus according to claim 3, wherein said tag code table creating unit has a tag storing unit to store said tag extracted by said tag extracting unit, and assigns information on a position in which said tag is stored in said tag storing unit as a code of said tag to create said tag code table.

6. The tag document compressing apparatus according to claim 5, wherein said information on a storing position is information including address information of said tag storing unit.

7. The tag document compressing apparatus according to claim 6, wherein said information on a storing position is said address information and information on a length of a relevant tag.

8. The tag document compressing apparatus according to claim 3, wherein said tag code table creating unit comprises:

a first coding dictionary creating unit to assign an initial code to said tag extracted by said tag extracting unit to create a first coding dictionary of said tag as said tag code table; and

a coding dictionary updating unit to update said code in said first coding dictionary created by said first coding dictionary creating unit according to the frequency of occurrence of a corresponding tag when said coding process unit encodes said tag.

9. The tag document compressing apparatus according to claim 3, wherein said tag code table creating unit comprises:

a second coding dictionary creating unit to count the frequency of occurrence of said tag in said document instance on the basis of said tag extracted by said tag extracting unit, and assigning a code according to a result of the counting to said tag to create a second coding dictionary of said tag as said tag code table.

10. The tag document compressing apparatus according to claim 9, further comprising an occurrence frequency information outputting unit to output information on the frequency of occurrence of said tag to said decoding side of said tags.

11. The tag document compressing apparatus according to claim 9, wherein said second coding dictionary creating unit comprises:

a tag counting unit to determine whether said tag extracted by said tag extracting unit coincides with said tag in said document instance to count the frequency of occurrence of said tag in said document instance;

a code generating unit to generate a code according to a result of the counting by said tag counting unit; and

a code holding unit to hold said code generated by said code generating unit to create said second coding dictionary.

12. A tag document compressing apparatus to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document comprising:

a tag extracting unit to scan said DTD of an inputted tag document, to be compressed, to extract said tag;

a tag code table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code table dedicated to tag encoding to compress said tag document;

a tag discriminating unit to determine whether inputted data in said document instance is said tag extracted by said tag extracting unit; and

a coding process unit to encode said inputted data of said document instance corresponding to said DTD on the basis of said tag code table when said tag discriminating unit determines that said inputted data is said tag, whereas encoding said inputted data in a predetermined encoding system when said tag discriminating unit determines that said inputted data is not said tag.

13. The tag document compressing apparatus according to claim 12, wherein said tag discriminating unit detects a start-tag showing a start of a tag on the basis of said tag extracted by said tag extracting unit to determine that said inputted data is said tag.

14. A tag document decompressing apparatus to decode an encoded tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said encoded tag document comprising:

a tag extracting unit to scan said DTD of an inputted tag document, to be decompressed, to extract said tag;

a tag decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag decode table dedicated to tag decoding to decompress said encoded tag document; and

a tag decoding unit to decode said tag in said encoded document instance corresponding to said DTD on the basis of said tag decode table created by said tag decode table creating unit.

15. The tag document decompressing apparatus according to claim 14, wherein when a plurality of tag document having the same DTD are decoded, said tag decoding unit decodes tags in document instances of all of said tag documents on the basis of said single tag decode table created with respect to the first tag document by said tag extracting unit and said tag decode table creating unit.

16. A tag document decompressing apparatus to decode an encoded tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said encoded tag document comprising:

a tag extracting unit to scan the DTD of an inputted tag document, to be decompressed, to extract said tag;

a tag decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag decode table dedicated to tag decoding to decompress said encoded tag document;

a special code discriminating unit to determine whether inputted encoded data is a special code showing inputting of encoded data of a tag; and

a decoding process unit to decode encoded data, following said special code, of said document instance corresponding to said DTD on the basis of said tag decode table when said special code discriminating unit determines that said encoded data is said special code, whereas decoding said encoded data in a predetermined decoding system when said special code discriminating unit determines that said encoded data is not said special code.

17. The tag document decompressing apparatus according to claim 16, wherein said decoding process unit comprises:

a first decoding unit to decode said inputted encoded data on the basis of said tag decode table;

a second decoding unit to decode said inputted encoded data in a predetermined decoding system; and

a switching control unit to output encoded data following said special code to said first decoding unit when said special code discriminating unit determines that said encoded data is said special code, whereas outputting said encoded data to said second decoding unit when said special code discriminating unit determines that said encoded data is not said special code.

18. The tag document decompressing apparatus according to claim 16, wherein said tag decode table creating unit has a tag storing unit to store said tag extracted by said tag extracting unit, and assigns information on a position in which said tag is stored in said tag storing unit as a code of said tag to create said tag decode table.

19. The tag document decompressing apparatus according to claim 18, wherein said information on the position is information including address information of said tag storing unit.

20. The tag document decompressing apparatus according to claim 19, wherein said information on the position is said address information and information on a length of a relevant tag.

21. The tag document decompressing apparatus according to claim 16, wherein said tag decode table creating unit comprises:

a first decoding dictionary creating unit to assign an initial code to each of said tag extracted by said tag extracting unit to create a first decoding dictionary of said tag as said tag decode table; and

a decoding dictionary updating unit to update said code in said first decoding dictionary created by said first decoding dictionary creating unit according to the frequency of occurrence of a corresponding tag when said decoding process unit decodes said tag.

22. The tag document decompressing apparatus according to claim 16, wherein said tag decode table creating unit comprises:

a second decoding dictionary creating unit to create a second decoding dictionary of said tag on the basis of said tag extracted by said tag extracting unit and information on the frequency of occurrence of said tag.

23. A tag document decompressing apparatus to decode an encoded tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said encoded tag document comprising:

a tag extracting unit to scan the DTD of an inputted tag document, to be decompressed, to extract said tag;

a tag decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag decode table dedicated to tag decoding to decompress said encoded tag document;

a tag code discriminating unit to determine whether inputted encoded data is encoded data of said tag; and

a decoding process unit to decode said encoded data of said document instance corresponding to said DTD on the basis of said tag decode table when said tag code discriminating unit determines that said encoded data is said tag, whereas decoding said encoded data in a predetermined decoding system when said code discriminating unit determines that said encoded data is not said tag.

24. The tag document decompressing apparatus according to claim 23, wherein said tag code discriminating unit detects a start-tag showing a start of a tag on the basis of said tag extracted by said tag extracting unit to determine that said encoded data is said tag.

25. A tag document compressing/decompressing apparatus to encode a tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, and decoding said encoded tag document to decompress the same comprising:

a tag extracting unit to scan said DTD of an inputted tag document to extract said tag;

a tag code/decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code/decode table dedicated to tag coding and tag decoding to compress said tag document and decompress said encoded tag document;

a tag coding unit to encode said tag in said document instance corresponding to said DTD on the basis of said tag code/decode table created by said tag code/decode table creating unit; and

a tag decoding unit to decode said tag in said document instance encoded by said tag coding unit on the basis of said tag code/decode table created by said tag code/decode table creating unit.

26. A tag document compressing/decompressing apparatus to encode a tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, and decoding said encoded tag document to decompress the same comprising:

a tag extracting unit to scan said DTD of an inputted tag document to extract said tag;

a tag code/decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code/decode table dedicated to tag coding and tag decoding to compress said tag document and decompress said encoded tag document;

a tag discriminating unit to determine whether inputted data in said document instance is said tag extracted by said tag extracting unit;

a coding process unit to encode said inputted data of said document instance corresponding to said DTD on the basis said tag code/decode table when said tag discriminating unit determines that said inputted data is said tag, whereas encoding said inputted data in a predetermined encoding system when said tag discriminating unit determines that said inputted data is not said tag;

a special code outputting unit to output a special code showing encoding of a tag before said inputted data is encoded when said tag discriminating unit determines that said inputted data is said tag;

a special code discriminating unit to determine whether encoded data outputted from said encoding process unit is said special code; and

a decoding process unit to decode encoded data following said special code outputted from said coding process unit on the basis of said tag code/decode table when said special code discriminating unit determines that said encoded data is said special code, whereas decoding said encoded data outputted from said encoding process unit in a predetermined decoding system when said special code discriminating unit determines that said encoded data is not said special code.

27. A tag document compressing method to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in the DTD to compress said tag document, comprising:

assigning a code to said tag in the same DTD to create a tag code table dedicated to tag coding to compress said tag document, and encoding said tag in said document instance corresponding to said DTD on the basis of said tag code table.

28. The tag document compressing method according to claim 27, wherein when a plurality of tag documents having the same DTD are encoded, tags in the document instances of all of said tag documents are encoded on the basis of a single tag code table created with respect to the first tag document.

29. A tag document compressing method to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, comprising:

assigning a code to said tag in the same DTD to create a tag code table dedicated to tag coding to compress said tag document;

outputting a special code showing encoding of a tag to a decoding side of said tag when inputted data of said document instance is said tag and encoding said inputted data of said document instance corresponding to said DTD on the basis of said tag code table, whereas encoding said inputted data in a predetermined encoding system when said inputted data is not said tag.

30. A tag document compressing method to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, comprising the steps of:

assigning a code to said tag in the same DTD to create a tag code table dedicated to tag coding to compress said tag document;

encoding inputted data in said document instance corresponding to said DTD on the basis of said tag code table when said inputted data is said tag, whereas encoding said inputted data in a predetermined encoding system when said inputted data is not said tag.

31. A tag document decompressing method to decode an encoded tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said encoded tag document, comprising:

assigning a code to said tag in the same DTD to create a tag decode table dedicated to tag decoding to decode to decompress said encoded tag document; and

decoding said tag in said encoded document instance corresponding to said DTD on the basis of said tag decode table.

32. The tag document decompressing method according to claim 31, wherein when a plurality of tag documents having the same DTD are decoded, tags in the document instances of all of said tag documents are decoded on the basis of a single tag decode table created with respect to the first tag document.

33. A tag document decompressing method to decode an encoded tag document having a document type definition (DTD) type defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said encoded tag document, comprising:

assigning a code to said tag in the same DTD to create a tag decode table dedicated to tag decoding to decompress said encoded tag document; and

decoding encoded data of said document instance corresponding to said DTD inputted following a special code showing that encoded data is said tag on the basis of said tag decode table when said inputted encoded data is said special code, whereas decoding said encoded data in a predetermined decoding system when said inputted encoded data is not said special code.

34. A tag document decompressing method to decode an encoded tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said encoded tag document, comprising:

assigning a code to said tag in the same DTD to create a tag decode table dedicated to tag decoding to decompress said encoded tag document; and

decoding inputted encoded data of said document instance corresponding to said DTD on the basis of said tag decode table when said inputted encoded data is encoded data of said tag, whereas decoding said inputted encoded data in a predetermined decoding system when said inputted encoded data is not encoded data of said tag.

35. A tag document compressing/decompressing method to encode a tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, and decoding said encoded tag document to decompress the same, comprising:

assigning a code to said tag in the same DTD to create a tag code/decode table dedicated to tag coding and tag decoding to compress said tag document and decompress said encoded tag document; and

encoding said tag in said document instance corresponding to said DTD on the basis of said tag code/decode table, and decoding said encoded tag on the basis of said tag code/decode table.

36. A tag document compressing/decompressing method to encode a tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, and decoding said encoded tag document to decompress the same, comprising:

assigning a code to said tag in the same DTD to create a tag code/decode table dedicated to tag coding and tag decoding to compress said tag document and decompress said encoded tag document;

outputting a special code showing encoding of a tag when inputted data in said document instance is said tag and encoding said inputted data of said document instance corresponding to said DTD on the basis of said tag code/decode table, whereas encoding said inputted data in a predetermined encoding system when said inputted data is not said tag; and

when encoded data is decoded, decoding encoded data following said special code on the basis of said tag code/decode table when said encoded data is said special code, whereas decoding said encoded data in a predetermined decoding system when said encoded data is not said special code.

37. A recording medium readable by a computer storing a tag document compressing program to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, characterized by that said tag document compressing program makes said computer function as a tag extracting unit to scan said DTD of an inputted tag document, to be compressed, to extract said tag, a tag code table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code table dedicated to tag coding to compress said tag document, and a tag coding unit to encode said tag in said document instance corresponding to said DTD on the basis of said tag code table created by said tag code table creating unit.

38. A recording medium readable by a computer storing a tag document compressing program to encode a tag document including a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document, characterized by that said tag document compressing program makes said computer function as a tag extracting unit to scan said DTD of an inputted tag document, to be compressed, to extract said tag, a tag code table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code table dedicated to tag coding to compress said tag document, a tag discriminating unit to determine whether inputted data in said document instance is said tag extracted by said tag extracting unit, a coding process unit to encode said inputted data of said document instance corresponding to said DTD on the basis of said tag code table when said tag discriminating unit determines that said inputted data is said tag, whereas encoding said inputted data in a predetermined encoding system when said tag discriminating unit determines that said inputted data is not said tag, and a special code outputting unit to output a special code showing encoding of a tag to a decoding side of said tag before said inputted data is encoded when said tag discriminating unit determines that said inputted data is said tag.

39. A recording medium readable by a computer storing a tag document decompressing program to decode an encoded tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said encoded tag document, characterized by that said tag document decompressing program makes said computer function as a tag extracting unit to scan said DTD of an inputted tag document, to be decompressed, to extract said tag, a tag decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag decode table dedicated to tag decoding to compress said tag document and decompress said encoded tag document, and a tag decoding unit to decode said tag in said encoded document instance corresponding to said DTD on the basis of said tag decode table created by said tag decode table creating unit.

40. A recording medium readable by a computer storing a tag document decompressing program to decode an encoded tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to decompress said tag document, characterized by that said tag document decompressing program makes said computer function as a tag extracting unit to scan said DTD of an inputted tag document to extract said tag, a tag decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag decode table dedicated to tag decoding to decompress said encoded tag document, a special code discriminating unit to determine whether inputted encoded data is a special code showing that encoded data of a tag is inputted, and a decoding process unit to decode encoded data of said document instance corresponding to said DTD inputted following said special code on the basis of said tag decode table when said special code discriminating unit determines that said encoded data is said special code, whereas decoding said encoded data in a predetermined decoding system when said special code discriminating unit determines that said encoded data is not said special code.

41. A recording medium readable by a computer storing a tag document compressing/decompressing program to encode a tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document and decoding said encoded tag document to decompress the same, characterized by that said tag document compressing/decompressing program makes said computer function as a tag extracting unit to scan said DTD of an inputted tag document to extract said tag, a tag code/decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code/decode table dedicated to tag coding and tag decoding to compress said tag document and decompress said encoded tag document, a tag coding unit to encode said tag in said document instance corresponding to said DTD on the basis of said tag code/decode table created by said tag code/decode table creating unit, and a tag decoding unit to decode said tag in said document instance encoded by said tag coding unit on the basis of said tag code/decode table created by said tag code/decode table creating unit.

42. A recording medium readable by a computer storing a tag document compressing/decompressing program to code a tag document having a document type definition (DTD) defining a tag showing a document structure and a document instance described using said tag defined in said DTD to compress said tag document and decoding said encoded tag document to decompress the same, characterized by that said tag document compressing/decompressing program makes said computer function as a tag extracting unit to scan said DTD of an inputted tag document to extract said tag, a tag code/decode table creating unit to assign a code to said tag, in the same DTD, extracted by said tag extracting unit to create a tag code/decode table dedicated to tag coding and tag decoding to compress said tag document and decompress said encoded tag document, a tag discriminating unit to determine whether inputted data in said document instance is said tag extracted by said tag extracting unit, a coding process unit to encode said inputted data of said document instance corresponding to said DTD on the basis of said tag code/decode table when said tag discriminating unit determines that said inputted data is said tag, whereas encoding said inputted data in a predetermined system when said tag discriminating unit determines that said inputted data is not said tag, a special code outputting unit to output a special code showing encoding of a tag before said inputted data is encoded when said tag discriminating unit determines that said inputted is said tag, and a decoding process unit to decode encoded data following said special code outputted from said coding process unit on the basis of said tag code/decode table when said special code discriminating unit determines that said encoded data is said special code, whereas decoding said encoded data in a predetermined decoding system when said special code discriminating unit determines that said encoded data is not said special code.