Overview

# NetBeans Architecture Answers for projects/queries module

- Author: jglick@netbeans.org
- Answers as of: Dec 7, 2006
- Answers for questions version: 1.24
- Latest available version of questions: 1.26

WARNING: answering questions version 1.24 rather than the current 1.26.

## Interfaces table

##### Group of java interfaces

Interface Name | In/Out | Stability | Specified in What Document?
GeneralQueriesAPI | Exported | Official | The General Queries API provides generic queries, or sources of concrete information, useful throughout the build system and perhaps elsewhere. Each query is split into an API component intended for clients to find the answer to a particular question without knowledge of the underlying structure or origin of the answer; and an SPI interface (using lookup) permitting answers to be provided from any source. These queries currently pertain to VCS and compilation status and user visibility of files.
FilesystemsAPI | Imported | Official | .../overview-summary.html The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.
UtilitiesAPI | Imported | Official | ../org-openide-util/overview-summary.html The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.

## General Information

Question (arch-what): What is this project good for?

Answer:

General kinds of queries between modules. Queries are one way of solving the intermodule communication problem when it is necessary for some modules to obtain basic information about the system (e.g. whether a particular file is intended for version control) without needing direct dependencies on the module providing the answer (e.g. the project type which controls the file). Details are covered in the Javadoc.

Question (arch-overall): Describe the overall architecture.

Answer: GeneralQueriesAPI - The General Queries API provides generic queries, or sources of concrete information, useful throughout the build system and perhaps elsewhere. Each query is split into an API component intended for clients to find the answer to a particular question without knowledge of the underlying structure or origin of the answer; and an SPI interface (using lookup) permitting answers to be provided from any source. These queries currently pertain to VCS and compilation status and user visibility of files.

Question (arch-usecases): Describe the main use cases of the new API. Who will use it under what circumstances? What kind of code would typically need to be written to use the module?

Answer:

Particular use cases are enumerated in the Javadoc for each query API. Usage consists of simple static method calls. Potentially a wide variety of modules could use these queries; implementations are typically registered by project type providers, though also by Java library and platform implementations.

Question (arch-time): What are the time estimates of the work?

Answer:

Essentially done.

Question (arch-quality): How will the quality of your code be tested and how are future regressions going to be prevented?

Answer:

All functionality specified in Javadoc should be covered by unit tests. Since query implementations are found in lookup, it is straightforward to register test implementations and confirm that the API produces the correct answer.

Question (arch-where): Where one can find sources for your module?

WARNING: Question with id="arch-where" has not been answered!

## Project and platform dependencies

Question (dep-nb): What other NetBeans projects and modules does this one depend on?

Answer:

Uses the NetBeans Filesystems and Lookup APIs.

Default answer to this question is:

These modules are required in project.xml file:

- FilesystemsAPI - The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.
- UtilitiesAPI - The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.

Question (dep-non-nb): What other projects outside NetBeans does this one depend on?

Answer:

None.

Question (dep-platform): On which platforms does your module run? Does it run in the same way on each?

Answer:

Should be platform-independent.

Question (dep-jre): Which version of JRE do you need (1.2, 1.3, 1.4, etc.)?

Answer:

JRE 1.4+.

Question (dep-jrejdk): Do you require the JDK or is the JRE enough?

Answer:

Just the JRE.

## Deployment

Question (deploy-jar): Do you deploy just module JAR file(s) or other files as well?

Answer:

Just a JAR file.

Question (deploy-nbm): Can you deploy an NBM via the Update Center?

Answer:

Yes.

Question (deploy-shared): Do you need to be installed in the shared location only, or in the user directory only, or can your module be installed anywhere?

Answer:

Should work anywhere.

Question (deploy-packages): Are packages of your module made inaccessible by not declaring them public?

Answer:

Only official API and SPI packages are made public.

Question (deploy-dependencies): What do other modules need to do to declare a dependency on this one?

Answer:

       OpenIDE-Module-Module-Dependencies: org.netbeans.modules.queries/1 > 1.7.22

## Compatibility with environment

Question (compat-i18n): Is your module correctly internationalized?

Answer:

There are no I18N issues in this module.

Question (compat-standards): Does the module implement or define any standards? Is the implementation exact or does it deviate somehow?

Answer:

There are no known relevant standards.

Question (compat-version): Can your module coexist with earlier and future versions of itself? Can you correctly read all old settings? Will future versions be able to read your current settings? Can you read or politely ignore settings stored by a future version?

Answer:

The module uses no persistent settings.

## Access to resources

Question (resources-file): Does your module use `java.io.File` directly?

Answer:

`CollocationQuery` and `SharabilityQuery` use `File` directly as they only make sense for disk files and need to work with paths of nonexistent files.

Question (resources-layer): Does your module provide own layer? Does it create any files or folders in it? What it is trying to communicate by that and with which components?

Answer:

No.

Question (resources-read): Does your module read any resources from layers? For what purpose?

Answer:

No.

Question (resources-mask): Does your module mask/hide/override any resources provided by other modules in their layers?

Answer:

No.

## Lookup of components

Question (lookup-lookup): Does your module use `org.openide.util.Lookup` or any similar technology to find any components to communicate with? Which ones?

Answer:

Yes, query implementations are found via global lookup. Order is significant in case two queries supply different answers; generally the first one wins.

Question (lookup-register): Do you register anything into lookup for other code to find?

Answer:

None.

Question (lookup-remove): Do you remove entries of other modules from lookup?

Answer:

None.

## Execution Environment

Question (exec-property): Is execution of your code influenced by any environment or Java system (`System.getProperty`) property?

Answer:

No.

Question (exec-component): Is execution of your code influenced by any (string) property of any of your components?

Answer:

No.

Question (exec-ant-tasks): Do you define or register any ant tasks that other can use?

WARNING: Question with id="exec-ant-tasks" has not been answered!

Question (exec-classloader): Does your code create its own class loader(s)?

Answer:

No.

Question (exec-reflection): Does your code use Java Reflection to execute other code?

Answer:

No.

Question (exec-privateaccess): Are you aware of any other parts of the system calling some of your methods by reflection?

Answer:

No.

Question (exec-process): Do you execute an external process from your module? How do you ensure that the result is the same on different platforms? Do you parse output? Do you depend on result code?

Answer:

No.

Question (exec-introspection): Does your module use any kind of runtime type information (`instanceof`, work with `java.lang.Class`, etc.)?

Answer:

No.

Question (exec-threading): What threading models, if any, does your module adhere to?

Answer:

Most general queries should be treated similarly to API and SPI calls in the Filesystems API. `FileBuiltQuery` is intended to be thread-safe for callers.

Question (security-policy): Does your functionality require modifications to the standard policy file?

Answer:

No.

Question (security-grant): Does your code grant additional rights to some other code?

Answer:

No.

## Format of files and protocols

Question (format-types): Which protocols and file formats (if any) does your module read or write on disk, or transmit or receive over the network? Do you generate an ant build script? Can it be edited and modified?

Answer:

None.

Question (format-dnd): Which protocols (if any) does your code understand during Drag & Drop?

Answer:

None.

Question (format-clipboard): Which data flavors (if any) does your code read from or insert to the clipboard (by access to clipboard on means calling methods on `java.awt.datatransfer.Transferable`?

Answer:

None.

## Performance and Scalability

Question (perf-startup): Does your module run any code on startup?

Answer:

No.

Question (perf-exit): Does your module run any code on exit?

Answer:

No.

Question (perf-scale): Which external criteria influence the performance of your program (size of file in editor, number of files in menu, in source directory, etc.) and how well your code scales?

Answer:

Number of query implementations (typically only a few) and their own performance.

Question (perf-limit): Are there any hard-coded or practical limits in the number or size of elements your code can handle?

Answer:

Performance of queries scales linearly in number of query implementations, but typical implementations are singletons which delegate to other implementations in constant time.

Question (perf-mem): How much memory does your component consume? Estimate with a relation to the number of windows, etc.

Answer:

Trivial, except in case of `FileBuiltQuery.Status` which is proportional to number of files.

Question (perf-wakeup): Does any piece of your code wake up periodically and do something even when the system is otherwise idle (no user interaction)?

Answer:

No.

Question (perf-progress): Does your module execute any long-running tasks?

Answer:

No.

Question (perf-huge_dialogs): Does your module contain any dialogs or wizards with a large number of GUI controls such as combo boxes, lists, trees, or text areas?

Answer:

No.

Question (perf-menus): Does your module use dynamically updated context menus, or context-sensitive actions with complicated and slow enablement logic?

Answer:

No.

Question (perf-spi): How the performance of the plugged in code will be enforced?

Answer:

Query implementations are intended to be fast.

Built on December 7 2006. | Portions Copyright 1997-2005 Sun Microsystems, Inc. All rights reserved.