Reducing memory fragmentation by coalescing and redistributing previously distributed page strips

• US 6,130,759 A
• Filed: 08/26/1997
• Issued: 10/10/2000
• Est. Priority Date: 08/26/1997
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Blair, Timothy P.
• Primary Examiner(s): Coles, Edward L.
• Assistant Examiner(s): HASKINS, TWYLER LAMB
• Application Number:
  US08/918,835
• Time in Patent Office: 1,141 Days
• Field of Search: 395/114, 395/115, 395/116, 395/110, 395/101, 395/100, 395/112, 711/171, 358/1.15, 358/1.17, 358/1.1, 358/1, 358/1.13, 358/1.16
• US Class Current: 358/1.17
• CPC Class Codes: G06F 12/023 Free address space management
• CPC Class Codes: G06K 15/00 Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printersprinting or plotting combined with another operation, e.g. with conveying, G06K17/00
• CPC Class Codes: G06K 2215/0071 Post-treatment of the composed image, e.g. compression, rotation

Abstract

Fragmentation is reduced in a memory of an image transfer device by coalescing segments of rasterized, compressed and distributed page strips into preallocated buffers, and then redistributing the strips back into the memory such that smaller holes in the memory are filled before larger holes. Alternatively, the rasterized and compressed page strips are stored directly into preallocated buffers before ever being distributed into memory. Then, when the buffers are filled, the strips are distributed into the memory such that smaller holes in the memory are filled before larger holes.

Claims

1. A method of reducing fragmentation in a first memory, comprising:

(a) removing a subset of data from the first memory; and

,

(b) redistributing the subset of data back into the first memory such that fragments of the subset of data fill smaller holes in the first memory before filling larger holes.

2. The method of claim 1 wherein the first memory is in an imaging device.

3. The method of claim 2 wherein the subset of data includes fragments of rasterized page strips.

4. The method of claim 3 further including coalescing the fragments of rasterized page strips in at least a second memory prior to redistributing back into the first memory.

5. The method of claim 4 wherein the first memory is a main memory and the at least a second memory includes at least one video buffer of the imaging device.

6. The method of claim 1 further including temporarily storing the subset of data in at least a second memory prior to redistributing back into the first memory.

7. The method of claim 1 further including coalescing the subset of data in at least a second memory prior to redistributing back into the first memory.

8. A method of reducing fragmentation in a first memory of an image transfer device, the first memory having fragments of rasterized page strips distributed therein, the method comprising:

(a) coalescing the fragments of a subset of the rasterized page strips into respective whole strips; and

,

(b) redistributing the respective whole strips back into the first memory in fragments such that the fragments fill smaller holes in the first memory before filling larger holes.

9. The method of claim 8 further including coalescing the fragments of the subset of the rasterized page strips in at least a second memory prior to redistributing back into the first memory.

10. The method of claim 9 wherein the first memory is a main memory and the at least a second memory includes at least one video buffer of the imaging device.

11. A computer-readable medium having computer-executable instructions for performing steps including:

(a) removing a subset of data from a first memory; and

,

(b) redistributing the subset of data back into the first memory such that fragments of the subset of data fill smaller holes in the first memory before filling larger holes.

12. An image forming device comprising:

(a) a first memory in communication with a print engine;

(b) means for removing a subset of data from the first memory; and

,

(c) means for redistributing the subset of data back into the first memory such that fragments of the subset of data fill smaller holes in the first memory before filling larger holes.

13. The image forming device of claim 12 further including a second memory for storing the subset of data upon removing the subset of data from the first memory.

14. The image forming device of claim 13 wherein the subset of data includes fragments of rasterized page strips.

15. The image forming device of claim 14 further including means for coalescing the fragments of rasterized page strips in the second memory prior to redistributing back into the main memory.

16. A method of reducing fragmentation in a memory of an image forming device, the method comprising:

(a) storing a plurality of rasterized page strips into at least one preallocated buffer; and

, then,

(b) distributing segments of the page strips that are stored in the at least one preallocated buffer into the memory such that the segments fill smaller holes in the memory before filling larger holes.

17. The method of claim 16 wherein the plurality of rasterized strips are compressed.

18. A computer-readable medium having computer-executable instructions for performing steps including:

(a) storing a plurality of rasterized page strips into at least one preallocated buffer in an imaging device; and

, then,

(b) distributing segments of the page strips that are stored in the at least one preallocated buffer into a memory of the imaging device such that the segments fill smaller holes in the memory before filling larger holes.