System for data retrieval by scheduling retrieval if number of units scheduled equals or less than predetermined number and retrieving before or at time elapsed

• US 5,828,904 A
• Filed: 06/03/1997
• Issued: 10/27/1998
• Est. Priority Date: 05/09/1995
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Batson, James D., Hoddie, J. Peter
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Chen, Anderson I.
• Application Number:
  US08/868,025
• Time in Patent Office: 511 Days
• Field of Search: 395/672, 395/849, 395/878
• US Class Current: 710/58
• CPC Class Codes: G06F 16/40 of multimedia data, e.g. slideshows comprising image and additional audio data retrieval of still image data G06F16/50; retrieval of audio data G06F16/60; retrieval of video data G06F16/70
• CPC Class Codes: G06F 16/489 using time information
• CPC Class Codes: G06F 16/70 of video data
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 2220/213 Read-only discs
• CPC Class Codes: G11B 2220/2545 CDs
• CPC Class Codes: G11B 27/10 Indexing; Addressing; Timing or synchronising; Measuring tape travel
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04N 21/21 Server components or server architectures
• CPC Class Codes: H04N 21/23 Processing of content or additional data; Elementary server operations; Server middleware

Abstract

An apparatus for synchronizing data retrieval is described. The apparatus comprises a storage media storing data, a storage control device coupled to the storage media for retrieving the data from the storage media, memory coupled to the storage control device for storing the data; and a scheduling unit coupled to the memory for scheduling retrieval of the data from the storage media before a specified time. A storage media for storing computer instructions is also described. The storage media comprises a first plurality of processor executable instructions for instructing a computer system to schedule retrieval of data from a storage device before a specified time, a second plurality of processor executable instructions for instructing the computer system to retrieve the data from the storage device before the specified time has elapsed, a third plurality of processor executable instructions for instructing the computer system to store the data from the storage device into memory, and a fourth plurality of processor executable instructions for instructing the computer system to process the data from the memory. A method for synchronizing data retrieval in a data processing system is also described. The method comprises determining a specified time for retrieving the data from a storage media, scheduling retrieval of the data from the storage media before the specified time, retrieving the data from the storage media before the specified time has elapsed, and processing the data from the storage media.

Claims

1. A method for synchronizing data retrieval in a data processing system comprising:

determining whether a predetermined number of units of data have been scheduled for retrieval;

determining a specified time for retrieving data from a storage media;

scheduling retrieval of said data from said storage media at or before said specified time, wherein retrieval is scheduled only if a number of units which have been scheduled for retrieval equals or is less than said predetermined number;

retrieving said data from said storage media at or before said specified time has elapsed; and

processing said data from said storage media.

2. The method of claim 1 wherein said data comprises video data and wherein said processing step comprises providing at least a portion of said data to a display device and wherein each of said units represents a display frame.

3. The method of claim 1 wherein said data comprises audio data and wherein said processing step comprises providing at least a portion of said data to a sound transducer.

4. The method of claim 1 wherein scheduling retrieval of said data from said storage media at or before specified time comprises:

retrieving information for locating said data in said storage media; and

storing said information in a memory.

5. The method of claim 1 wherein scheduling retrieval of said data from said storage media at or before said specified time comprises:

creating a retrieval request for retrieving said data from said storage media before said specified time.

6. The method of claim 5 wherein scheduling retrieval of said data from said storage media at or before said specified time further comprises:

sorting pending retrieval requests.

7. The method of claim 1 wherein retrieving said data from said storage media at or before said specified time has elapsed comprises:

reading said data from said storage media; and

notifying a requestor of data availability.

8. A method as in claim 7 wherein said step of reading said data from said storage media comprises reading said data through a computer network.

9. The method of claim 1 wherein processing said data from said storage media comprises:

determining a specified display time for displaying said data; and

scheduling a display interrupt to occur at said specified display time for displaying said data.

10. The method of claim 9 wherein processing said data from said storage media further comprises:

displaying said data when said display interrupt occurs.

11. A method as in claim 1 wherein said data represents musical notes and said processing step comprises providing at least a portion of said data to a sound transducer to produce sound.

12. A method as in claim 11 wherein said data comprises MIDI formatted information.

13. A method as in claim 1 wherein said data comprises text and wherein said processing step comprises providing at least a portion of said data to a display device.

14. A method as in claim 1 wherein said storage media is an optical disk.

15. A method as in claim 14 wherein said optical disk is a CD-ROM.

16. A method as in claim 1 further comprising:

determining a second specified time for retrieving a second set of data from said storage media;

scheduling retrieval of said second set of data from said storage media at or before said second specified time;

retrieving said second set of data from said storage media at or before said second specified time has elapsed;

processing said second set of data from said storage media.

17. A method as in claim 16 wherein said data is located in a first track of a first file and said second set of data is located in a second track of said first file.

18. A method as in claim 16 wherein said data is located in a first track of a first file and said second set of data is located in a second track of a second file.

19. A method as in claim 1 wherein said data comprises SMPTE time codes.

20. A method as in claim 1 wherein said data comprise Sprite based animation information.

21. A method as in claim 1 wherein said predetermined number may be changed based upon said storage media.

30. An apparatus as in claim 10 wherein said data comprises one of text data, data representing musical notes, SMPTE time codes or Sprite based animation information.

31. A method as in claim 2 wherein said predetermined number is determined based upon said storage media.

22. An apparatus for synchronizing data retrieval comprising:

a storage media storing data;

a storage control device coupled to said storage media said storage control device retrieving said data from said storage media;

memory coupled to said storage control device for storing said data; and

a scheduling unit coupled to said memory for determining only one specified time for retrieving data from said storage media and for scheduling retrieval of said data from said storage media at or before said specified time and wherein said scheduling unit determines whether enough units of data have been scheduled for retrieval based upon a comparison between a predetermined number and a number of units of data which have been scheduled and wherein retrieval is scheduled only in response to a result of said comparison.

23. The apparatus of claim 22 wherein said data comprises video data.

24. The apparatus of claim 22 wherein said data comprises audio data.

25. The apparatus of claim 22 wherein said scheduling unit is operable to retrieve information for locating data in said storage media from said storage media and is operable to store said information in said memory.

26. The apparatus of claim 22 wherein said scheduling unit is operable to create a retrieval request for retrieving said data from said storage media at or before said specified time and is operable to sort pending retrieval requests.

27. The apparatus of claim 22 wherein said scheduling unit is operable to determine a specified display time for displaying said data and is operable to schedule a display interrupt to occur at said specified display time for displaying said data.

28. An apparatus as in claim 22 wherein said storage media comprises an optical disk.

29. An apparatus as in claim 22 further comprising a network interface, and wherein said storage media is coupled to said network interface, and wherein said data is retrieved from said storage media through a computer network and said network interface.

32. A storage media for storing executable computer instructions comprising:

a first plurality of processor executable instructions for instructing a computer system to determine only one specified time for retrieving data from said storage device and to schedule retrieval of data from a storage device at or before said specified time and wherein said first plurality of processor executable instructions determines whether enough units of data have been scheduled for retrieval based upon a comparison between a predetermined number and a number of units of data which have been scheduled and wherein retrieval is scheduled only in response to a result of said comparison;

a second plurality of processor executable instructions for instructing said computer system to retrieve said data from said storage device at or before said specified time;

a third plurality of processor executable instructions for instructing said computer system to store said data from said storage device into memory; and

a fourth plurality of processor executable instructions for instructing said computer system to process said data from said memory.

33. The storage media of claim 32 further comprising:

a fifth plurality of processor executable instructions for instructing said computer system to retrieve information for locating said data in said storage device and to store said information in said memory.

34. The storage media of claim 32 further comprising:

a fifth plurality of processor executable instructions for instructing said computer system to create a retrieval request for retrieving said data from said storage device before said specified time and to sort pending retrieval requests.

35. The storage media of claim 32 further comprising:

a fifth plurality of processor executable instructions for instructing said computer system to determine a specified display time for displaying said data and scheduling a display interrupt to occur at said specified display time.

36. A method as in claim 32 wherein said predetermined number is determined based upon said storage media.

37. A computer readable storage medium storing executable computer program instructions which, when executed in a digital processing system causes said system to perform a method comprising:

determining whether enough units of data have been scheduled for retrieval, wherein determining whether enough units have been scheduled comprises a comparison between a number of units which have been scheduled and a predetermined number;

determining a specified time for retrieving data from a storage device media;

scheduling a retrieval of said data from said storage media at or before said specified time, wherein retrieval is scheduled only in response to a result of said comparison;

retrieving said data from said storage media at or before said specified time has elapsed; and

processing said data from said storage media.

38. The method of claim 37 wherein said data comprises video data and wherein said processing step comprises providing at least a portion of said data to a display device and wherein each of said units represents a display frame.

39. The method of claim 37 wherein said data comprises audio data and wherein said processing step comprises providing at least a portion of said data to a sound transducer.

40. The method of claim 37 wherein scheduling retrieval of said data from said storage media at or before said specified time comprises:

retrieving information for locating said data in said storage media; and

storing said information in a memory.

41. The method of claim 37 wherein scheduling retrieval of said data from said storage media at or before said specified time comprises:

creating a retrieval request for retrieving said data from said storage media before said specified time.

42. The method of claim 41 wherein scheduling retrieval of said data from said storage media at or before said specified time further comprises:

sorting pending retrieval requests.

43. The method of claim 37 wherein retrieving said data from said storage media at or before said specified time has elapsed comprises:

reading said data from said storage media; and

notifying a requestor of data availability.

44. The method of claim 37 wherein processing said data from said storage media comprises:

determining a specified display time for displaying said data; and

scheduling a display interrupt to occur at said specified display time for displaying said data.

45. The method of claim 44 wherein processing said data from said storage media further comprises:

displaying said data when said display interrupt occurs.