System and method for upgrading client software

A method for constructing an upgrade file to upgrade from an old version of software to a new version of software, comprising the following steps:

• comparing an old character string from the old version with a new character string from the new version;
• finding longest common substrings beginning at first positions in the old character string and second positions in the new character string;
• for a particular second position in the new character string, ascertaining the longest common substring beginning at the particular second position;
• inserting, in the upgrade file, a pointer header representing the longest common substring in lieu of inserting the longest common substring, the pointer header indicating a corresponding position in the old character string at which the longest common substring begins;
• inserting, in the upgrade file, characters from the new character string that are not included in the longest common substring;
• and
• placing a data header indicating that the characters being inserted are not matched in the old character string.

A method for constructing an upgrade file to upgrade from an old version of software to a new version of software, comprising the following steps:

• hashing every possible group of k contiguous bytes in the old version to form first hash values;
• hashing every possible group of k contiguous bytes in the new version to form second hash values;
• in an event that one of the first hash values equals one of the second hash values, comparing an old character string from the old version that includes the k contiguous bytes forming said one first hash value with a new character string from the new version that includes the k contiguous bytes forming said one second hash value;
• finding longest common substrings beginning at first positions in the old character string and second positions in the new character string;
• and
• for a particular second position in the new character string, ascertaining the longest common substring beginning at the particular second position.

A method for upgrading software in a client remotely from an upgrade server, comprising the following steps:

• at the upgrade server, performing the following steps:
• comparing an old character string from an old version of software with a new character string from a new version of software;
• finding longest common substrings beginning at a first position in the old character string and a second position in the new character string;
• for a particular second position in the new character string, ascertaining the longest common substring beginning at the particular second position;
• inserting, in an upgrade file, a pointer header representing the longest common substring in lieu of inserting the longest common substring, the pointer header indicating a corresponding position in the old character string at which the longest common substring begins;
• inserting, in the upgrade file, characters from the new character string that are not included in the longest common substring;
• placing a data header indicating that the characters being inserted are not matched in the old character string;
• and
• transferring the upgrade file to the client;
• at the client, performing the following steps:
• receiving the upgrade file from the upgrade server;
• processing the upgrade server to reconstruct the new version of software;
• for any section in the upgrade file demarcated by the data header, adding the new characters to the reconstructed new version;
• and
• for any section in the upgrade file demarcated by the pointer header, copying the longest common substring from the old version into the reconstructed new version.

A software upgrading system, comprising:

• a client having a processor and a memory, the memory storing an old version of software;
• an upgrade server having a processor and a memory, the upgrade server memory storing both the old version of software and a new version of software, the upgrade server identifying a longest common substring that is common to both the old version and the new version and creating an upgrade file with a pointer header representing the longest common substring in lieu of the longest common substring, the pointer header indicating a corresponding position in the old version at which the longest common substring begins, and the upgrade file further containing at least one section from the new version that is not included in the longest common substring and a data header indicating that the section is new;
• and
• the client processing the upgrade file to reconstruct the new version of software by adding the new section corresponding to the data header and using the longest common substring in the old version that is identified by the pointer header.

A computer-readable medium that stores computer-executable instructions for directing a computer to perform the following steps:

• comparing an old character string from an old version of software with a new character string from a new version of software;
• finding longest common substrings beginning at first positions in the old character string and second positions in the new character string;
• for a particular second position in the new character string, ascertaining the longest common substring beginning at the particular second position;
• inserting, in the upgrade file, a pointer header representing the longest common substring in lieu of inserting the longest common substring, the pointer header indicating a corresponding position in the old character string at which the longest common substring begins;
• inserting, in the upgrade file, characters from the new character string that are not included in the longest common substring;
• and
• placing a data header indicating that the characters being inserted are not matched in the old character string.

A computer-readable medium that stores computer-executable instructions for directing a computer to perform the following steps:

• hashing every possible group of k contiguous bytes in the old version to form first hash values;
• hashing every possible group of k contiguous bytes in the new version to form second hash values;
• in an event that one of the first hash values equals one of the second hash values, comparing an old character string from the old version that includes the k contiguous bytes forming said one first hash value with a new character string from the new version that includes the k contiguous bytes forming said one second hash value;
• finding longest common substrings beginning at first positions in the old character string and second positions in the new character string;
• and
• for a particular second position in the new character string, ascertaining the longest common substring beginning at the particular second position.