Method and apparatus for reducing network resource transmission size using delta compression

A method in a far end network optimizer that participates in reducing network resource transmission size through use of delta compression, wherein the far end network optimizer is coupled with a plurality of near end network optimizers that each are coupled with a plurality of client devices, the method comprising:

• receiving, from a first one of the plurality of near end network optimizers, a first request for a network resource on behalf of one of the plurality of client devices;
• in response to receiving the first request,
• retrieving the requested network resource from an origin server that hosts the requested network resource,
• transmitting the retrieved network resource to the first near end network optimizer, and
• storing the retrieved network resource as a first version of the requested network resource in a dynamic dictionary of the far end network optimizer;
• receiving, from a second one of the plurality of near end network optimizers, a second request for a network resource on behalf of one of the plurality of client devices, the second request including a version identifier that identifies a second version of the network resource stored in the second near end network optimizer;
• responsive to determining that the second version of the network resource is not stored in the dynamic dictionary of the far end network optimizer, performing the following:
• retrieving a third version that is a most current version of the network resource from the origin server that hosts the network resource,
• transmitting a response to the first near end network optimizer that includes the third version of the network resource, and
• storing the third version of the requested network resource in the dynamic dictionary of the far end network optimizer;
• receiving, from a third one of the plurality of near end network optimizers, a third request for the network resource on behalf of one of the plurality of client devices, the third request including a version identifier that identifies the first version of the network resource and indicates that the first version of the network resource is stored in the third near end network optimizer;
• and
• in response to the third request and responsive to determining that the first version of the network resource is stored in the dynamic dictionary of the far end network optimizer, performing the following:
• retrieving a fourth version of the network resource that is a most current version of the network resource from the origin server that hosts the network resource,
• determining a set of one or more differences between the first version and the fourth version of the network resource,
• transmitting the set of differences to the third near end network optimizer, and
• storing the fourth version of the network resource in the dynamic dictionary of the far end network optimizer.

A non-transitory machine-readable storage medium that provides instructions that, when executed by a processor of a near end network optimizer, cause said processor to perform operations comprising:

• receiving, from a first one of a plurality of client devices coupled with the near end network optimizer, a first request for a network resource, wherein the first client device is physically separate from the near end network optimizer;
• responsive to determining that a version of the network resource is not stored in the near end network optimizer, transmitting a second request for the network resource to a far end network optimizer;
• receiving, from the far end network optimizer, a first response that includes the requested network resource;
• transmitting, to the first client device, a second response that includes the requested network resource;
• storing, in the near end network optimizer, the requested network resource as a first version of the network resource;
• receiving, from a second one of the plurality of client devices, a third request for the network resource, wherein the second client device is physically separate from the near end network optimizer;
• responsive to determining that the first version of the network resource is stored in the near end network optimizer, transmitting a fourth request for the network resource to the far end network optimizer, the fourth request including a first version identifier that identifies the first version of the network resource stored in the near end network optimizer;
• receiving, from the far end network optimizer, a third response that includes a differences file that specifies a set of one or more differences between the first version of the network resource stored in the near end network optimizer with a most current version of the network resource, wherein the third response does not include the entire network resource;
• applying the set of differences specified in the differences file to the version of the network resource stored in the near end network optimizer to generate an updated version of the network resource;
• and
• transmitting, to the second client device, a fourth response that includes the updated version of the network resource.

A non-transitory machine-readable storage medium that provides instructions that, when executed by a processor of a far end network optimizer, cause said processor to perform operations comprising:

• receiving, from a first one of a plurality of near end network optimizers that are each coupled with the far end network optimizer, a first request for a network resource on behalf of one of a plurality of client devices;
• in response to receiving the first request,
• retrieving the requested network resource from an origin server that hosts the requested network resource,
• transmitting the retrieved network resource to the first near end network optimizer, and
• storing the retrieved network resource as a first version of the requested network resource in a dynamic dictionary of the far end network optimizer;
• receiving, from a second one of the plurality of near end network optimizers, a second request for a network resource on behalf of one of the plurality of client devices, the second request including a version identifier that identifies a second version of the network resource stored in the second near end network optimizer;
• responsive to determining that the second version of the network resource is not stored in the dynamic dictionary of the far end network optimizer, performing the following:
• retrieving a third version that is a most current version of the network resource from the origin server that hosts the network resource,
• transmitting a response to the first near end network optimizer that includes the third version of the network resource, and
• storing the third version of the requested network resource in the dynamic dictionary of the far end network optimizer;
• receiving, from a third one of the plurality of near end network optimizers, a third request for the network resource on behalf of one of the plurality of client devices, the third request including a version identifier that identifies the first version of the network resource and indicates that the first version of the network resource is stored in the third near end network optimizer;
• and
• in response to the third request and responsive to determining that the first version of the network resource is stored in the dynamic dictionary of the far end network optimizer, performing the following:
• retrieving a fourth version of the network resource that is a most current version of the network resource from the origin server that hosts the network resource,
• determining a set of one or more differences between the first version and the fourth version of the network resource,
• transmitting the set of differences to the third near end network optimizer, and
• storing the fourth version of the network resource in the dynamic dictionary of the far end network optimizer.