Overview

# NetBeans Architecture Answers for Filesystems module

- Author: rmatous@netbeans.org
- Answers as of: Dec 7, 2006
- Answers for questions version: 1.12
- Latest available version of questions: 1.26

WARNING: answering questions version 1.12 rather than the current 1.26.

## Interfaces table

##### Group of java interfaces

Interface Name | In/Out | Stability | Specified in What Document?
FilesystemsAPI | Exported | Official | .../openide/filesystems/doc-files/api.html
UtilitiesAPI | Imported | Official | .../org/openide/util/doc-files/api.html ../org-openide-util/overview-summary.html The module is needed for compilation. The module is used during runtime. Specification version 6.2 is required.
LookupAPI | Imported | Official | .../org/openide/util/doc-files/api.html

##### Group of property interfaces

Interface Name | In/Out | Stability | Specified in What Document?
org.openide.filesystems.DefaultAttributes.ATTR_NAME_EXT_XML | Exported | Private | Name of attribute file can be changed , if .nbattrs can't be used.
netbeans.debug.heap | Imported | Private | Periodic refresh can be blocked.
org.openide.filesystems.LocalFileSystem.REFRESH_TIME | Exported | Private | Periodic refresh can be set.
org.openide.filesystems.annotateUnclosedStreams | Exported | Private | If `true`, better diagnostic information will be available as to when file input or output streams were opened that prevent a file from being deleted because they were not closed. This information comes at a performance cost, however.

##### Group of dtd interfaces

Interface Name | In/Out | Stability | Specified in What Document?
attributes-1_0.dtd | Exported | Stable | .../www.netbeans.org/dtds/attributes-1_0.dtd `-//NetBeans//DTD DefaultAttributes 1.0//EN`
filesystem-1_0.dtd | Exported | Stable | .../www.netbeans.org/dtds/filesystem-1_0.dtd `-//NetBeans//DTD Filesystem 1.0//EN`

## General Information

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

Answer: The Filesystems API provides a common API to access files in a uniform manner. It is available as standalone library and also is bundled together with other parts of the openide. Specification

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

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

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?

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

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

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

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

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

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:

- UtilitiesAPI
- LookupAPI

Default answer to this question is:

These modules are required in project.xml file:

- 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: SAX parser is used to parse layers and attributes in .nbattrs files.

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

Answer: Platform independent. But filesystem impl. on OS must satisfy usual naming conventions.

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

Answer: JRE 1.3.

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

Answer: JRE is enough.

## Deployment

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

Answer: Filesystems API and SPI is part of `openide.jar`.

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

Answer: Yes (`openide.nbm`).

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: As part of openide.jar needs to be in the system directory.

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

Answer: No.

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

WARNING: Question with id="deploy-dependencies" has not been answered!

## Compatibility with environment

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

Answer: Yes.

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

Answer: It defines and implements the FilesystemsAPI

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: Yes.

## Access to resources

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

Answer: Yes, naturally.

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: Implementations of MIMEResolver and URLMapper are looked up .

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

Answer: No

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

Answer: No.

## Execution Environment

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

Answer:

- org.openide.filesystems.DefaultAttributes.ATTR_NAME_EXT_XML - Name of attribute file can be changed , if .nbattrs can't be used.
- netbeans.debug.heap - Periodic refresh can be blocked.
- org.openide.filesystems.LocalFileSystem.REFRESH_TIME - Periodic refresh can be set.
- org.openide.filesystems.annotateUnclosedStreams -

  If `true`, better diagnostic information will be available as to when file input or output streams were opened that prevent a file from being deleted because they were not closed. This information comes at a performance cost, however.

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: Yes, attributes can contain also dynamic values associated with keys (`methodvalue` and `newvalue`).

- `"-//NetBeans//DTD DefaultAttributes 1.0//EN"`
- `"-//NetBeans//DTD Filesystem 1.0//EN"`

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

Answer: Yes, AutomountSupport stores content of Repository as settings files. Then setting infrastructure registers its own PropertyChangeListener. So method addPropertyChangeListener is invoked by reflection.

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 external process.

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

Answer: No answer

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

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

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

WARNING: Question with id="security-policy" has not been answered!

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

WARNING: Question with id="security-grant" has not been answered!

## 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:

- attributes-1_0.dtd - `-//NetBeans//DTD DefaultAttributes 1.0//EN`
- filesystem-1_0.dtd - `-//NetBeans//DTD Filesystem 1.0//EN`

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: As far as I know the code scales linearily.

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

Answer: No.

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

Answer: Hardly to estimate, depends on many factors. Instances of FileObject can be kept weak or hard, implementatins of FileObject may differ each other. Approximately for FileObject that comes from AbstractFileSystem impl. probably 100 B if size of name is average .

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. Periodic refresh is disabled at the moment as default.

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

Answer: There are no such long running tasks except refresh operation, that may be time consuming. Naturally also operations on FileSystem, that access remote files over network.

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?

WARNING: Question with id="perf-spi" has not been answered!

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