PEAK Release 0.5 alpha 1 |
PEAK Release 0.5 alpha 4 |
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Copyright (C) 1996-2003 by Phillip J. Eby and Tyler C. Sarna. |
Copyright (C) 1996-2004 by Phillip J. Eby and Tyler C. Sarna. |
All rights reserved. This software may be used under the same terms |
All rights reserved. This software may be used under the same terms |
as Zope or Python. THERE ARE ABSOLUTELY NO WARRANTIES OF ANY KIND. |
as Zope or Python. THERE ARE ABSOLUTELY NO WARRANTIES OF ANY KIND. |
Code quality varies between modules, from "beta" to "experimental |
Code quality varies between modules, from "beta" to "experimental |
larger scale, and with fewer defects than ever before. The key is |
larger scale, and with fewer defects than ever before. The key is |
component-based development, on a reliable infrastructure. |
component-based development, on a reliable infrastructure. |
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PEAK is an application kit, and applications are made from components. |
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PEAK provides you with a component architecture, component infrastructure, |
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and various general-purpose components and component frameworks for |
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building applications. As with J2EE, the idea is to let you stop |
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reinventing architectural and infrastructure wheels, so you can put more |
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time into your actual application. |
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But PEAK is different from J2EE: it's a single, free implementation of |
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simpler API's based on an easier-to-use language that can nonetheless |
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scale with better performance than J2EE. |
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PEAK is the successor to TransWarp, an experimental toolkit for software |
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automation in Python. PEAK takes the best of the techniques and ideas |
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from TransWarp, and repackages them as an enterprise software toolkit. |
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Where TransWarp emphasized techniques like generative programming and |
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aspect-oriented programming, PEAK emphasizes enterprise applications, |
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and hides the computer science stuff "under the hood", so you can focus |
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on building your application. |
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PEAK tools can be used with other "Python Enterprise" frameworks such as |
PEAK tools can be used with other "Python Enterprise" frameworks such as |
Zope, Twisted, and the Python DBAPI to construct web-based, GUI, or |
Zope, Twisted, and the Python DBAPI to construct web-based, GUI, or |
command-line applications, interacting with any kind of storage, or with |
command-line applications, interacting with any kind of storage, or with |
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Package Features |
Package Features |
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As of version 0.5a1, PEAK features include: |
Far too many to list even briefly here: see FEATURES.txt for a very high |
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level overview. |
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* A component binding framework that makes it easy to parameterize |
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components and thus more easily combine and "wire" them together. |
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* A comprehensive configuration framework that allows accessing |
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"utilities" and "configuration properties" in context. Properties |
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and utilities can be loaded or computed on demand, supplied by rules, |
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defined in configuration files or code, in a supplied or custom |
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format. Properties and utilities are contextual and can be safely |
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acquired from parent/context components automatically. |
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* Naming system/framework that's midway between J2EE's JNDI and CORBA's |
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cosNaming in features, but much easier to use and extend than either |
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of those systems. |
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* A storage management and persistence system, including: |
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- Atomic, multi-database transactions with two-phase commit. |
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- "Data Manager" class framework for persistence management, that |
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allows you to separate business logic from storage implementation. |
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If you can write a few simple methods like "load" and "save" for |
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a given object type and storage approach, you can create your own |
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"DM" components. You can think of a DM as an advanced form of |
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Python "shelve", that supports references to other objects, |
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transactions, arbitrary back-end storages, and caching. |
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- "Stackable" data managers: one DM might serialize a set of objects |
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to XML, which could then be stored in a database record by another |
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DM, and then the database record might be implemented via a DM |
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that writes to disk files! Each DM only needs to know how to |
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manipulate objects offered by the next-level DM, not the details |
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of the next DM's implementation, so all the DM's are potentially |
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replaceable with alternate storage mechanisms. |
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- RDBMS and LDAP connection framework based on the Python DBAPI, |
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that handles data type conversions (via the configuration |
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framework) and seamlessly integrates with the transaction system |
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and naming services framework. DB Connections can be accessed |
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by name or URL, and bound as default collaborators or utilities |
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for access by other application components. |
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* CASE/modelling tools: PEAK includes APIs to read object |
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models created in the XML-based XMI format. Many open-source and |
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commercial modelling tools support XMI, inlcuding Argo/Poseidon and |
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MagicDraw UML. PEAK includes pre-built support for UML version 1.3 |
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and MOF 1.3.1, using XMI versions 1.0 and 1.1. (UML 1.4, UML 1.5, |
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CWM 1.0, CWM 1.1, and XMI 1.2 are anticipated for 0.5a2, and possibly |
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XMI 2.0 by 0.5 final.) Also included is a MOF->Python code generator, |
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which was used to generate the UML and CWM support, and which you can |
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use to generate support for other modelling languages based on the MOF. |
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For the specifications of XMI, MOF, CWM, and UML, visit: |
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http://www.omg.org/technology/documents/modeling_spec_catalog.htm |
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* A domain modelling framework for creating "business object models" |
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with unidirectional and bidirectional associations, generated |
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getters/setters and validators for fields, etc., and all necessary |
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persistence support for use with the PEAK storage framework. |
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The business object framework supplies structural metadata about |
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classes built with it, so you can query a class for its fields and |
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links, and their names, types, etc. This can be useful for |
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implementing model-driven storage or user interfaces. And the |
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metadata is aligned with the MOF, so generating MOF, UML, or CWM |
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from PEAK models (and vice versa) is possible (although |
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not yet implemented for anything but MOF->PEAK). |
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* Application Runtime tools, including: |
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- a "command objects" framework for creating command-line applications |
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- a "periodic tasks" framework for executing tasks that perform "as |
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needed", scheduling themselves in response to their available workloads |
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- a CGI/FastCGI publishing framework that uses 'zope.publisher' to |
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publish a PEAK component tree and its associated transaction service |
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- an event-driven "reactor" framework that seamlessly integrates with |
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Twisted, but can also be used without Twisted for applications that are |
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mostly scheduling-oriented, or which use only third-party protocol |
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implementations such as FAM, FastCGI, ReadyExec, etc. |
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* AOP and SOP: PEAK allows you to separate concerns as modules, then |
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combine the modules via a "module inheritance" technique. This |
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lets you define a generated business object model as a |
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"structural" concern, and then combine it with a "behavioral" |
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concern. This is as simple as writing classes that contain only |
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what you want to add, and then telling PEAK that your new module |
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"inherits" from the generated module. This is similar to (but |
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designed independently from) the "MixJuice" tool for AOP in Java. |
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Known Issues and Risks of this Version |
Known Issues and Risks of this Version |
in areas not covered by the test suites. Also, many system interfaces |
in areas not covered by the test suites. Also, many system interfaces |
are still subject to change. |
are still subject to change. |
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PEAK includes early copies of Zope X3's 'zope.interface' and 'persistence' |
PEAK includes early copies of Zope X3's 'ZConfig' and 'persistence' |
packages, which have had - and will continue to have - significant |
packages, which have had - and may continue to have - significant |
implementation changes. We will be tracking Zope X3 periodically, but |
implementation changes. We will be tracking Zope X3 periodically, but |
can't guarantee compatibility with arbitrary (e.g. CVS) versions of |
can't guarantee compatibility with arbitrary (e.g. CVS) versions of |
Zope X3. |
Zope X3. |
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Third-Party Software Included with PEAK |
Third-Party Software Included with PEAK |
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All third-party software included with PEAK are understood by PEAK's |
All third-party software included with PEAK are understood by PEAK's |
please see the 'src/kjbuckets/COPYRIGHT.txt' file for details of its |
please see the 'src/kjbuckets/COPYRIGHT.txt' file for details of its |
license. |
license. |
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The 'persistence' and 'ZConfig' packages are Copyright Zope Corporation |
The 'csv' module is part of Python 2.3 and above, and is included for |
and contributors; please see the 'LICENSE.txt' files in their directories |
backward compatibility in Python 2.2. See the Python license for license |
for details of their licenses. |
details. |
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The included 'pyexpat' module comes from Python 2.4, and is included for |
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backward compatibility in Python 2.2 and 2.3. See the Python license for |
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license details. |
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The 'expat' XML parser is Copyright (c) 1998, 1999, 2000 Thai Open Source |
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Software Center Ltd and Clark Cooper, and Copyright (c) 2001, 2002, 2003 |
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Expat maintainers. See the 'COPYING' file in 'src/expat' for details of |
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its license. |
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The 'datetime', 'persistence' and 'ZConfig' packages are Copyright Zope |
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Corporation and contributors; please see the 'LICENSE.txt' files in their |
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directories for details of their licenses. |
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The 'fcgiapp' module is Copyright Digital Creations, LC (now Zope Corp.); |
The 'fcgiapp' module is Copyright Digital Creations, LC (now Zope Corp.); |
see the 'fcgiappmodule.c' for details of its license. In the same |
see the 'fcgiappmodule.c' for details of its license. In the same |
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