NTRS - NASA Technical Reports Server

Back to Results
Zero-Copy Objects SystemZero-Copy Objects System software enables application data to be encapsulated in layers of communication protocol without being copied. Indirect referencing enables application source data, either in memory or in a file, to be encapsulated in place within an unlimited number of protocol headers and/or trailers. Zero-copy objects (ZCOs) are abstract data access representations designed to minimize I/O (input/output) in the encapsulation of application source data within one or more layers of communication protocol structure. They are constructed within the heap space of a Simple Data Recorder (SDR) data store to which all participating layers of the stack must have access. Each ZCO contains general information enabling access to the core source data object (an item of application data), together with (a) a linked list of zero or more specific extents that reference portions of this source data object, and (b) linked lists of protocol header and trailer capsules. The concatenation of the headers (in ascending stack sequence), the source data object extents, and the trailers (in descending stack sequence) constitute the transmitted data object constructed from the ZCO. This scheme enables a source data object to be encapsulated in a succession of protocol layers without ever having to be copied from a buffer at one layer of the protocol stack to an encapsulating buffer at a lower layer of the stack. For large source data objects, the savings in copy time and reduction in memory consumption may be considerable.
Document ID
Document Type
Other - NASA Tech Brief
Burleigh, Scott C. (ACRO Service Corp. Los Angeles, CA, United States)
Date Acquired
August 25, 2013
Publication Date
October 1, 2011
Publication Information
Publication: NASA Tech Briefs, October 2011
Subject Category
Computer Programming and Software
Report/Patent Number
Distribution Limits
Public Use Permitted.

Available Downloads

NameType 20120006510.pdf STI

Related Records

IDRelationTitle20120006504Analytic PrimaryNASA Tech Briefs, October 2011