Difference messaging protocol that uses prior state information
View Patent ↗A messaging system that reduces communications bandwidth is disclosed. Difference messages are constructed at a sender from a message and prior state information. The difference messages include information describing the difference between the content of the message and a portion of prior state information, such as a prior message. The difference messages, including a prior message identifier, are sent to the receiver in place of the message. The message is reconstructed at the receiver using the corresponding difference message and the prior state information stored at the receiver. If the message reconstruction is unsuccessful, the sender is notified, and further required information is sent to the receiver.
1. A method of sending a message to a recipient, comprising:
obtaining a new message to be transmitted to a recipient;
comparing the new message to at least one message previously transmitted to the recipient;
constructing a difference message that includes identification information identifying an earlier message previously transmitted to the recipient and difference information specifying a difference between the new message and at least a portion of the earlier message; and
transmitting the difference message to the recipient,
wherein the identification information also identifies a second message that was previously transmitted to the recipient.
2. A method according to claim 1 , wherein the difference message further includes message subset information that identifies a subset of the earlier message and wherein the difference information specifies a difference between the new message and the identified subset of the earlier message.
3. A method according to claim 2 , wherein the message subset information includes an identification of a data structure identified in the earlier message.
4. A method according to claim 3 , wherein the difference information sets forth a modification of a data value for an argument of the data structure.
5. A method according to claim 1 , wherein the identification information includes a code that uniquely identifies the earlier message.
6. A method according to claim 1 , wherein the difference information references content that was identified in the second message.
7. A method according to claim 6 , wherein the difference information indicates that the referenced content is to be inserted into an indicated field in the new message.
8. A method according to claim 1 , wherein the comparing step comprises comparing a data format and a corresponding argument of the new message with at least one data format and corresponding argument in the at least one message previously transmitted to the recipient.
9. A method according to claim 1 , wherein the comparing step selects the earlier message upon determining that the new message is similar to the earlier message.
10. A method according to claim 1 , wherein the comparing step selects the earlier message upon determining that the new message has at least a portion of the same data format and some of the same data as the earlier message.