Compression of structured documents

• US 7,593,949 B2
• Filed: 01/09/2006
• Issued: 09/22/2009
• Est. Priority Date: 01/09/2006
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Begun, Andrew P, Lawrence, Thomas R
• Primary Examiner(s): To; Baoquoc N
• Application Number:
  US11/328,300
• Publication Number:
  US 20070162479A1
• Time in Patent Office: 1,352 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 40/123 Storage facilities
• CPC Class Codes: G06F 40/131 Fragmentation of text files, e.g. creating reusable text-blocks; Linking to fragments, e.g. using XInclude; Namespaces
• 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

Abstract

Various embodiments are disclosed relating to a compression of documents. According to an example embodiment, a document may be compressed by replacing one or more language constructs in the document with a language-based replacement code. In addition, the document may be compressed by replacing one or more text strings in the document with a schema-based replacement code.

Claims

1. A method to be performed on a computing device, the computing device comprising a processor and a memory, the method comprising:

determining a schema for use with a structured document, wherein the structured document is based upon a language, wherein the structured document comprises an XML document;

generating a value replacement table based on the schema according to a set of rules;

compressing the structured document based on the value replacement table and based on a structure of the language, wherein the compressing the structured document based on the structure of the language comprises replacing one or more language constructs in the structured document with a language-based replacement code, including performing at least one of the following;

replacing a language construct of an element-with-a-prefix with a replacement code;

replacing a language construct of element-with-same-prefix-as-last-element with a replacement code;

replacing a language construct of an end-element or end-tag with a replacement code;

replacing a language construct of a name-space-declaration with a replacement code; and

replacing a language construct of an attribute-with-same-prefix-as-last-element with a replacement code,

wherein the language constructs that are replaced are based on either a required structure of the language or a common usage pattern for the language; and

transmitting the compressed structured document without transmitting the value replacement table, the compressed structured document comprises a compressed XML document.

2. The method of claim 1 wherein the schema comprises an XML schema, and wherein the generating a value replacement table comprises:

creating a list of one or more text strings or other values from the XML schema; and

assigning a schema-based replacement code to each text string or value according to the set of rules.

3. The method of claim 2 wherein the assigning a schema-based replacement code comprises assigning a replacement code for one or more of each of the following present in the XML schema:

element names;

attribute names;

enumeration, default and/or fixed values; and

values of namespace declarations.

4. The method of claim 1 wherein the structured document comprises an XML document, the compressing comprises replacing one or more text strings or other values in the XML document with a schema-based replacement code according to the generated value replacement table.

5. The method of claim 1, wherein the structured document comprises an XML document, and further comprising compressing the XML document by removing some recoverable information in the XML document based on a well-formed nature or required structure of the XML document.

6. The method of claim 1 and further comprising:

receiving the compressed document at a receiving computing device; and

performing the following at the receiving computing device;

determining the schema to be used for the received document;

generating the value replacement table based on the schema according to the set of rules; and

decompressing the compressed document based on the value replacement table.

7. An apparatus comprising:

a processing device adapted to;

determine a schema for use with a structured document, wherein the structured document is based upon a language, wherein the structured document comprises an XML document;

generate a value replacement table based on the schema according to a set of rules;

compress the structured document based on the value replacement table and based on a structure of the language, wherein the compressing the structured document based on the structure of the language comprises replacing one or more language constructs in the structured document with a language-based replacement code, including performing at least one of the following;

replacing a language construct of an element-with-a-prefix with a replacement code;

replacing a language construct of element-with-same-prefix-as-last-element with a replacement code;

replacing a language construct of an end-element or end-tag with a replacement code;

replacing a language construct of a name-space-declaration with a replacement code; and

replacing a language construct of an attribute-with-same-prefix-as-last-element with a replacement code; and

transmit the compressed structured document without transmitting the value replacement table, the compressed structured document comprises a compressed XML document.

8. The apparatus of claim 7 wherein the schema comprises an XML schema, the processing device adapted to generate comprises a processing device adapted to:

create a list of one or more text strings or other values in the XML schema; and

assign a schema-based replacement code to each text string or value in the XML schema according to the set of rules.

9. The apparatus of claim 7 wherein the processing device adapted to compress comprises a processing device adapted to replace one or more text strings or other values in the document with a schema-based replacement code according to the generated value replacement table.

10. The apparatus of claim 7 wherein the language constructs that are replaced are based on either a required structure of the language or a common usage pattern for the language.

11. A method to be performed on a computing device, the computing device comprising a processor and a memory, the method comprising:

receiving a compressed structured document without receiving a value replacement table, wherein the structured document is based upon a language, wherein the structured document comprises an XML document;

determining a schema for use with the received compressed structured document;

generating a value replacement table based on the schema according to a set of rules, wherein the generating comprises;

creating a list of one or more text strings or other values in the schema; and

assigning a schema-based replacement code to each text string or value in the schema according to the set of rules; and

decompressing the compressed structured document based on a structure of the language and based on the value replacement table, wherein the decompressing comprises;

replacing each of one or more language-based replacement codes in the compressed structured document with a language construct, wherein the compressed structured document comprises a compressed XML document.

12. The method of claim 11 wherein the language construct comprises an XML tag.