Determining when a low fidelity property value has changed during a SYNC

• US 7,284,021 B2
• Filed: 04/20/2005
• Issued: 10/16/2007
• Est. Priority Date: 06/28/2004
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Starbuck, Bryan T.
• Primary Examiner(s): FLEURANTIN, JEAN B
• Application Number:
  US11/110,230
• Publication Number:
  US 20050289196A1
• Time in Patent Office: 909 Days
• Field of Search: 707 1- 10, 707100-1041, 707200-206, 709/218, 709/248, 709/236, 709/240
• US Class Current: 1/1
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99954 Version management

Abstract

During synchronization of data between a remote device and a local device, it can be determined if a value for a property on a remote device has changed since a last synchronization of the property between the remote device and a local machine. A remote representation of a property value is compared to a local representation associated with the same property value. If the representations are identical, it can be determined that the property value did not change on the remote device. If, however, they are not identical then the property value must have changed after the remote representation was generated.

Claims

1. In a distributed computing system capable of synchronizing data between devices, a method of determining if a value for a property on a low fidelity remote device has changed since a last synchronization of the property between the remote device and a local machine, the method comprising the acts of:

receiving, from said low fidelity remote device, a current value for a remote property and a remote representation, the remote representation having a value which is dependent on a prior value of the remote property;

receiving, from a field of a remote database at the remote device, a remote representation of time-date information that is associated with a change to the value of the remote property, wherein the field of the remote database which includes the remote representation of time-date information is not reserved for storing time-date information;

after receiving the current value for the remote property and the remote representation for a prior value of the remote property, generating, at the local machine, a local representation of the remote property by using the current value for the remote property received from the remote device;

after generating the local representation, comparing the remote representation to the local representation;

determining, based on the comparison, that the prior value of the remote property was changed after the remote representation was generated; and

based on the determination that the prior value of the remote property was changed, determining that the remote representation of time-date information is unreliable.

2. The method of claim 1, wherein the remote representation is a hash of the prior value of the remote property and the local representation is a hash of the current value for the remote property received from the remote device.

3. The method of claim 1, wherein the remote representation of the time-date information is stored down to the seconds.

4. The method of claim 1, wherein a conflict exists between the current value and a local value associated with the remote property, and wherein the remote representation of time-date information is not used for resolving the conflict.

5. The method of claim 1, wherein a local value is used to replace the current value and the remote representation is replaced with an updated remote representation.

6. The method of claim 5, wherein the remote representation is a hash of the prior value of the remote property, the local representation is a hash of the current value for the remote property, and the updated remote representation is a hash of the local value.

7. In a distributed computing system capable of synchronizing data between devices, a method of determining if a value for a property on a low fidelity remote device has changed since a last synchronization of the property between the remote device and a local machine, the method comprising the acts of:

receiving, from said low fidelity remote device, a remote value for a remote property and a remote representation for the remote value of the remote property, the remote representation having a value which is dependent on the remote value for the remote property;

receiving, from a field of a remote database at the remote device, a remote representation of time-date information that is associated with a change to the value of the remote property, wherein the field of the remote database which includes the remote representation of time-date information is not reserved for storing time-date information;

after receiving the remote value for the remote property and the remote representation for the remote value, generating, at the local machine, a local representation of the remote property by using the remote value for the remote property received from the remote device;

after generating the local representation, comparing the remote representation to the local representation;

determining, based on the comparison, that the remote value of the remote property has not changed after the remote representation was generated; and

based on the determination that the remote value of the remote property has not changed, comparing the remote representation of time-time information with a location representation of time-date information, the remote representation of time-date information and the local representation of time-date information indicating when the remote value and local value were generated, respectively.

8. The method of claim 7, wherein the remote representation is a hash of the remote value and the local representation is a hash of the remote value received from the remote device.

9. The method of claim 7, further comprising:

determining that a conflict exists between the remote value and a local value associated with the remote property; and

resolving the conflict based on the results of the comparison of the remote representation of time date to the local representation of time date information.

10. The method of claim 9, wherein the remote representation of the time-date information is stored down only to minutes.

11. The method of claim 9, wherein the local value is used to replace the remote value and the remote representation is replaced with an updated remote representation.

12. The method of claim 11, wherein the remote representation is a hash of the prior value of the remote property, the local representation is a hash of the current value for the remote property, and the updated remote representation is a hash of the local value.

13. In a distributed computing system capable of synchronizing data between devices, a computer program product for implementing a method of determining if a value for a property on a low fidelity remote device has changed since a last synchronization of the property between the remote device and a local machine, the computer program product comprising one or more computer readable media having stored thereon computer executable instructions that, when executed by a processor, can cause the distributed computing system to perform the following:

receive, from said low fidelity remote device, a current value for a remote property and a remote representation, the remote representation having a value which is dependent on a prior value of the remote property;

receive, from a field of a remote database at the remote device, a remote representation of time-date information that is associated with a change to the value of the remote property, wherein the field of the remote database which includes the remote representation of time-date information is not reserved for storing time-date information;

after receiving the current value for the remote property and the remote representation for a prior value of the remote property, generate, at the local machine, a local representation of the remote property by using the current value for the remote property received from the remote device;

after generating the local representation, compare the remote representation to the local representation;

determine, based on the comparison, that the prior value of the remote property was changed after the remote representation was generated; and

based on the determination that the prior value of the remote property was changed, determine that the remote representation of time-date information is unreliable.

14. The computer program product of claim 13, wherein the remote representation is a hash of the prior value of the remote property and the local representation is a hash of the current value for the remote property received from the remote device.

15. The computer program product of claim 13, wherein the remote representation of the time-date information is stored in a time zone independent format.

16. The computer program product of claim 13, wherein a conflict exists between the current value and a local value associated with the remote property, and wherein the remote representation of time-date information is not used for resolving the conflict.

17. The computer program product of claim 13, wherein a local value is used to replace the current value and the remote representation is replaced with an updated remote representation.

18. The computer program product of claim 17, wherein the remote representation is a hash of the prior value of the remote property, the local representation is a hash of the current value for the remote property, and the updated remote representation is a hash of the local value.