Methods and systems for JavaScript parsing

• US 8,984,095 B2
• Filed: 08/15/2013
• Issued: 03/17/2015
• Est. Priority Date: 07/12/2007
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Sebastian, William B.
• Primary Examiner(s): Eskandarnia, Arvin
• Application Number:
  US13/967,924
• Publication Number:
  US 20140082478A1
• Time in Patent Office: 579 Days
• Field of Search: 709/217
• US Class Current: 709/217
• CPC Class Codes: G06F 16/9566 URL specific, e.g. using aliases, detecting broken or misspelled links
• CPC Class Codes: G06F 16/986 Document structures and storage, e.g. HTML extensions
• CPC Class Codes: G06F 40/134 Hyperlinking
• CPC Class Codes: G06F 40/143 Markup, e.g. Standard Generalized Markup Language [SGML] or Document Type Definition [DTD]
• CPC Class Codes: G06F 40/205 Parsing
• CPC Class Codes: G06F 40/211 Syntactic parsing, e.g. based on context-free grammar [CFG] or unification grammars
• CPC Class Codes: G06F 40/221 Parsing markup language streams streaming G06F40/149
• CPC Class Codes: G06F 40/242 Dictionaries
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 9/3213 using tickets or tokens, e.g. Kerberos network architectures or network communication protocols for entities authentication using tickets in a packet data network H04L63/0807

Abstract

The present invention relates to systems, apparatus, and methods of parsing a script within an HTML page. The method includes receiving a script object, where the script object includes text. The method further includes parsing the text of the script object for tokens and comparing the parsed tokens with a valid tokens list to determine locations within the text of the script object that include potential universal resource locators (URLs). The method includes parsing before and after the determined locations until complete URLs are constructed, and forwarding the complete URLs to a detector. The detector then determines whether the complete URLs are valid. The method then sends object retrieval requests to websites associated with the valid complete URLs.

Claims

1. A method of parsing a script within an HTML page, the method comprising:

receiving a script object, wherein the script object includes text;

parsing the text of the script object for tokens without updating a state machine for every byte processed;

comparing the parsed tokens with a valid tokens list to determine locations within the text of the script object that include potential universal resource locators (URLs);

parsing before and after the determined locations until complete URLs are constructed;

forwarding the complete URLs to a detector, wherein the detector determines whether the complete URLs are valid; and

sending object retrieval requests to websites associated with the valid complete URLs.

2. The method for parsing a script within an HTML page as recited in claim 1, wherein the parsing of the text of the script object comprises parsing a subset of the text of the script object.

3. The method for parsing a script within an HTML page as recited in claim 1, wherein the script object is at least one of a Javascript object, an active server page (ASP) object, and a personal hypertext processor (PHP) object.

4. The method for parsing a script within an HTML page as recited in claim 1, further comprising in response to sending an object retrieval request to a website associated with one of the valid complete URLs, receiving a page not found error.

5. The method for parsing a script within an HTML page as recited in claim 4, further comprising in response to receiving the page not found error, discarding the one of the valid complete URLs.

6. The method of claim 5 further comprising:

updating a blacklist with the one of the valid complete URLs.

7. The method for parsing a script within an HTML page as recited in claim 1, further comprising accessing a syntax list associated with the script to facilitate construction of complete URLs.

8. The method for parsing a script within an HTML page as recited in claim 1, further comprising checking the script object to determine if there is additional text to parse.

9. The method for parsing a script within an HTML page as recited in claim 1, wherein the determination of whether a URL is valid comprises comparing the URL to a blacklist of URLs.

10. The method for parsing a script within an HTML page as recited in claim 1, wherein the valid tokens list includes one or more of the following:

a “

.jpg”

token, a “

.gif”

token, an “

.asp”

token, and a “

var”

token.

11. The method of claim 1 wherein each token of the valid tokens list comprises an integer value.

19. The method of claim 11 wherein comparing the parsed tokens with the valid tokens list to determine locations within the text of the script object that include the potential URLs comprises:

converting each of the parsed tokens to a parsed token integer value and performing an integer comparison between each token of the valid tokens list and each of the parsed token 4 byte integer values.

20. The method of claim 19 wherein the integer value for each token is a 4 byte integer value and wherein the parsed token integer value for each parsed token is a 4 byte integer.

12. A system for accelerating network communications, the system comprising:

a client system including a proxy client configured to intercept a content request generated by the client, and to transmit the request;

a proxy server coupled with the client system via the proxy client, the proxy server including a script parser configured to receive a script object, wherein the script object includes text, to parse the text of the script object for tokens without updating a state machine for every byte processed by the script parser, to compare the parsed tokens with a valid tokens list to determine locations within the text of the script object that include potential universal resource locators (URLs), and to parse before and after the determined locations until complete URLs are constructed, wherein the proxy server further includes a detector which is configured to receive the complete URLs to determine whether the complete URLs are valid; and

a content server coupled with the proxy server, the content server configured to receive object retrieval requests associated with the valid complete URLs from the proxy server, and transmit objects associated with the valid completed URLs to the proxy server.

13. A system for accelerating network communications as recited in claim 12, wherein the proxy server further comprises a prefetch scanner configured to scan an attached file associated with one or more of the identified valid URLs to determine candidates for prefetching.

14. A system for accelerating network communications as recited in claim 12, wherein the client and the proxy server are coupled together via a high latency communications link.

15. A system for accelerating network communications as recited in claim 14, wherein the high latency link is one or more of the following:

a satellite link, a wireless link, and a cellular link.

16. A system for accelerating network communications as recited in claim 12, wherein the proxy server and the proxy client are couple together via a low latency link.

17. A system for accelerating network communications as recited in claim 16, wherein the low latency link is one or more of the following:

a digital subscriber line (DSL), a cable modem link, a T1 connection, and a fiber optic connection.

18. A non-transitory machine-readable medium for parsing script files including sets of instructions stored thereon which, when executed by a machine, cause the machine to:

receive a script object, wherein the script object includes text;

parse the text of the script object for tokens without updating a state machine for each byte processed;

compare the parsed tokens with a valid tokens list to determine locations within the text of the script object that include potential URLs;

parse before and after the determined locations until complete URLs are constructed;

forward the complete URLs to a detector, wherein the detector determines whether the complete URLs are valid; and

send object retrieval requests to websites associated with the valid complete URLs.