Storing compressed data

A processing device comprising a processing unit and a storage medium coupled to the processing unit, the storage medium being adapted to store data in sectors of a predetermined sector size, the processing unit being adapted to access data stored in the storage medium as one or more pages of data, each page having a predetermined page size and a corresponding virtual memory address, the processing device being adapted to have stored compressed data items in the storage medium, each compressed data item including compressed data corresponding to a corresponding memory page of uncompressed data;

• wherein the processing device is configured to have stored each compressed data item that is larger than a predetermined size as a corresponding initial part and a supplementary part;
• wherein the processing device is further configured to store each initial part in the storage medium together with a corresponding index data item at a respective first memory location associated with the corresponding memory page, wherein the processing device is further configured to determine a respective second memory location for each supplementary part so as to at least approximately minimize the number of sectors each supplementary part at least partially occupies and to store each supplementary part in the storage medium at the determined respective second memory location;
• wherein each index data item is indicative of the second memory location of the supplementary part corresponding to the initial part stored together with the index data item;
• wherein the processing device being configured to determine the respective second memory location for each supplementary part so as to at least approximately minimize the number of sectors each supplementary part at least partially occupies comprises the processing device being configured to:
• pair at least a subset of the supplementary parts;
• and
• for each pair of supplementary parts:
• determine a start address of a first member of said each pair of supplementary parts by aligning the start address of the first member of said each pair of supplementary parts with a start address of a corresponding initial sector of a range of consecutive sectors of the storage medium;
• and
• determine a final address of a second member of said each pair of supplementary parts by aligning the final address of the second member of said each pair of supplementary parts with a final address of a corresponding last sector of the range of consecutive sectors of the storage medium.

A data processing system for generating a memory image including data for storage in a storage medium coupled to a processing unit, the data processing system being configured to perform the steps of a method of processing data for storage in the storage medium coupled to the processing unit adapted to access data stored in the storage medium as one or more memory pages of data, each memory page having a predetermined page size and a corresponding memory page address, the storage medium being adapted to store data in sectors of a predetermined sector size, the method comprising:

• obtaining one or more compressed data items, each including compressed data corresponding to a respective memory page of uncompressed data;
• dividing each of the one or more compressed data items having a compressed data item size larger than a predetermined size into an initial part and a supplementary part;
• allocating each initial part together with a respective index data item at respective first memory location associated with the corresponding memory page;
• determining respective second memory locations for each of the one or more supplementary parts so as to at least approximately minimize the number of sectors each supplementary part at least partially occupies;
• and
• allocating each supplementary part at the determined respective second memory location, wherein each index data item is indicative of the determined second memory location of the supplementary part corresponding to the initial part allocated together with the index data item;
• wherein determining respective second memory locations for each of the one or more supplementary parts so as to at least approximately minimize the number of sectors each supplementary part at least partially occupies comprises:
• pairing at least a subset of the supplementary parts;
• and
• for each pair of supplementary parts:
• determining a start address of a first member of said each pair of supplementary parts by aligning the start address of the first member of said each pair of supplementary parts with a start address of a corresponding initial sector of a range of consecutive sectors of the storage medium;
• and
• determining a final address of a second member of said each pair of supplementary parts by aligning the final address of the second member of said each pair of supplementary parts with a final address of a corresponding last sector of the range of consecutive sectors of the storage medium.

A non-transitory computer readable storage medium having stored therein program code adapted to cause, when executed by a data processing system including a storage medium coupled to a processing unit, the data processing system to perform the steps of a method of processing data for storage in the storage medium coupled to the processing unit adapted to access data stored in the storage medium as one or more memory pages of data, each memory page having a predetermined page size and a corresponding memory page address, the storage medium being adapted to store data in sectors of a predetermined sector size, the method comprising:

• obtaining one or more compressed data items, each including compressed data corresponding to a respective memory page of uncompressed data;
• dividing each of the one or more compressed data items having a compressed data item size larger than a predetermined size into an initial part and a supplementary part;
• allocating each initial part together with a respective index data item at respective first memory location associated with the corresponding memory page;
• determining respective second memory locations for each of the one or more supplementary parts so as to at least approximately minimize the number of sectors each supplementary part at least partially occupies;
• and
• allocating each supplementary part at the determined respective second memory location, wherein each index data item is indicative of the determined second memory location of the supplementary part corresponding to the initial part allocated together with the index data item;
• wherein determining respective second memory locations for each of the one or more supplementary parts so as to at least approximately minimize the number of sectors each supplementary part at least partially occupies comprises:
• pairing at least a subset of the supplementary parts;
• and
• for each pair of supplementary parts:
• determining a start address of a first member of said each pair of supplementary parts by aligning the start address of the first member of said each pair of supplementary parts with a start address of a corresponding initial sector of a range of consecutive sectors of the storage medium;
• and
• determining a final address of a second member of said each pair of supplementary parts by aligning the final address of the second member of said each pair of supplementary parts with a final address of a corresponding last sector of the range of consecutive sectors of the storage medium.