|
Perst Lite Embedded Micro-Database for J2ME
Perst Lite™ is McObject’s version of the Perst™ open source, object-oriented embedded database for embedded systems and intelligent devices developed on the Java 2 Platform, Micro Edition (J2ME). Perst Lite brings much-needed object-oriented database services to the fast-growing embedded Java development community.
The Perst Lite J2ME database upholds Perst’s well-deserved reputation for simplicity of design and high performance, and also achieves a code size that is about 30% smaller than standard Perst, well within the resource constraints of most intelligent mobile and embedded devices.
Embedded systems developers increasingly use Java, especially as micro-processors improve in their speed executing Java code. Sun Microsystems’ J2ME, with its flexible user interfaces, robust security, and built-in networking, is proving especially popular for consumer electronics and mobile devices. In April 2006, Evans Data Corp. announced survey results in which 52 percent of a sample of 500 wireless application developers reported using J2ME, up from 46 percent six months earlier.
But J2ME differs in major respects from standard Java (Java 2 Platform, Standard Edition, or J2SE). One of Perst Lite’s major achievements is to substitute its own lightweight code for standard Java’s reflection mechanism (reflection is not supported in some J2ME variants). Another Perst Lite achievement is its efficient memory management that bypasses the use of ‘weak references’ (also not fully supported).
McObject developers’ programming techniques in developing Perst Lite are described in detail in an Embedded Systems Design article. For example, Perst Lite contains the SerGen utility that generates object serialization and de-serialization code for the application that incorporates the database. This code replaces reflection, but without the complexity and large run-time code footprint that caused reflection to be dropped from J2ME.
Perst Lite retains most of the features that have become popular with the thousands of developer who have downloaded the open source Perst since 2003. These include B-tree, Patricia Trie, Bit index, T-Tree and R-Tree indexes as well as List, Relation, and Set collections, all protected by transactions supporting the ACID properties (Atomicity, Consistency, Isolation and Durability). Perst Lite also offers multithreaded access, data encryption and asynchronous replication.
Under Perst’s dual license, users can modify Perst and Perst Lite database source code and use it freely in other open source applications (software for which source code is made available) under the GNU General Public License (GPL). McObject’s commercial license is required if source code of the Perst- or Perst Lite-based applications is to be withheld.
Perst Lite J2ME database software is included in the standard edition Perst embedded database download package. To access this software, click here.
For more information about the standard edition Perst embedded database, see www.mcobject.com/perst.
|
