The Inbox: System-cbr.354.mcz

A new version of System was added to project The Inbox:
http://source.squeak.org/inbox/System-cbr.354.mcz

==================== Summary ====================

Name: System-cbr.354
Author: cbr
Time: 27 July 2010, 9:40:25.256 pm
UUID: f49d8aa0-ca22-47c9-880c-7713a9667439
Ancestors: System-eem.353

Removed cruft from Project class comment to do with project isolation, which is deprecated.

If any of the good people of Squeak who are familiar with this stuff would look this over to make certain that I haven't nixed anything that's still relevant, I'd be much obliged.

=============== Diff against System-eem.353 ===============

Item was changed:
  Model subclass: #Project
  instanceVariableNames: 'world uiManager changeSet transcript parentProject previousProject displayDepth viewSize thumbnail nextProject guards projectParameters version urlList environment lastDirectory lastSavedAtSeconds projectPreferenceFlagDictionary resourceManager'
  classVariableNames: 'AllProjects CurrentProject GoalFreePercent GoalNotMoreThan LastScreenModeSelected UIProcess'
  poolDictionaries: ''
  category: 'System-Support'!
 
+ !Project commentStamp: 'cbr 7/27/2010 21:36' prior: 0!
- !Project commentStamp: 'tk 12/2/2004 12:38' prior: 0!
  A Project stores the state of a complete Squeak desktop, including
  the windows, and the currently active changeSet.  A project knows who
  its parent project is.  When you change projects, whether by entering
  or exiting, the screen state of the project being exited is saved in
  that project.
 
  A project is retained by its view in the parent world.  It is
  effectively named by the name of its changeSet, which can be changed
  either by renaming in a changeSorter, or by editing the label of its
  view from the parent project.
 
  As the site of major context switch, Projects are the locus of
  swapping between the old MVC and the new Morphic worlds.  The
  distinction is based on whether the variable 'world' contains a
  WorldMorph or a ControlManager.
 
  Saving and Loading
  Projects may be stored on the disk in external format.  (Project
  named: 'xxx') exportSegment, or choose 'store project on file...'.
  Projects may be loaded from a server and stored back.  Storing on a
  server never overwrites;  it always makes a new version.  A project
  remembers the url of where it lives in urlList.  The list is length
  one, for now.  The url may point to a local disk instead of a server.
+ All projects that the user looks at are cached in the Squeaklet
- All projects that the user looks at, are cached in the Squeaklet
  folder.  Sorted by server.  The cache holds the most recent version
  only.
 
  When a project is loaded into Squeak, its objects are converted to
  the current version.  There are three levels of conversion.  First,
  each object is converted from raw bits to an object in its old
  format.  Then it is sent some or all of these messages:
  comeFullyUpOnReload: smartRefStream   Used to
  re-discover an object that already exists in this image, such as a
  resource, global variable, Character, or Symbol.  (sent to objects in
  outPointers)
  convertToCurrentVersion: varDict refStream: smartRefStrm
  fill in fields that have been added to a class since
  the object was stored.  Used to set the extra inst var to a default
  value.  Or, return a new object of a different class.  (sent to
  objects that changed instance variables)
  fixUponLoad: aProject refStream: smartRefStrm
  change the object due to conventions that have changed on the
  project level.  (sent to all objects in the incoming project)
 
  Here is the calling sequence for storing out a Project:
  Project saveAs
  Project storeOnServer
  Project storeOnServerWithProgressInfo
  Project storeOnServerInnards
  Project exportSegmentFileName:directory:
  Project exportSegmentWithChangeSet:fileName:directory:
  ImageSegment writeForExportWithSources:inDirectory:changeSet:
- ---------
- Isolation (not used any more)
- When you accept a method, the entire system feels the change, except
- projects that are "isolated".  In an isolated project, all new global
- variables (including new classes) arestored in the project-local
- environment, and all changes to preexisting classes are revoked when
- you leave the project.  When you enter another project, that
- project's changes are invoked.  Invocation and revocation are handled
- efficiently by swapping pointers.  To make a project be isolated,
- choose 'isolate changes of this project' from the 'changes...'
- section of the screen menu.  You can use an isolated project for
- making dangerous change to a system, and you can get out if it
- crashes.  A foreign application can have the separate environment it
- wants.  Also, you can freeze part of the system for a demo that you
- don't want to disturb.  An isolated project shares methods with all
- subprojects inside it, unless they are isolated themselves.   Each
- isolated project is the head of a tree of projects with which it
- shares all methods.
 
- You may 'assert' all changes ever made in the current project to take
- effect above this project.  This amounts to exporting all the globals
- in the current environment, and zapping the revocation lists to that
- the current state of the world will remain in force upon exit from
- this project.
-
- [Later: A project may be 'frozen'.  Asserts do not apply to it after
- that.  (Great for demos.)  You should be informed when an assert was
- blocked in a frozen project.]
-
- Class definitions are layered by the isolation mechanism.  You are
- only allowed to change the shape of a class in projects that lie
- within its isolation scope.  All versions of the methods are
- recompiled, in all projects.  If you remove an inst var that is in
- use in an isolated project, it will become an Undeclared global.  It
- is best not to remove an inst var when it is being used in another
- isolated project. [If we recompile them all, why can't we diagnose
- the problem before allowing the change??]
-
- Senders and Implementors do not see versions of a method in isolated
- projects.  [again, we might want to make this possible at a cost].
- When you ask for versions of a method, you will not get the history
- in other isolated projects.
-
- Moving methods and classes between changeSets, and merging changeSets
- has no effect on which methods are in force.  But, when you look at a
- changeSet from a different isolated project, the methods will contain
- code that is not in force.  A changeSet is just a list of method
- names, and does not keep separate copies of any code.
-
- When finer grained assertion is needed, use the method (aProject
- assertClass: aClass from: thisProject warn: warnConflicts).
-
- How isolated changes work: The first time a class changes, store its
- MethodDictionary object.  Keep parallel arrays of associations to
- Classes and MethodDictionaries.  Traverse these and install them when
- you enter an "ioslated project".  When you leave, store this
- project's own MethodDictionaries there.
- To do an assert, we must discover which methods changed here,
- and which changed only in the project we are asserting into.  There
- is one copy of the 'virgin' method dictionaries in the system.  It is
- always being temporarily stored by the currently inForce isolated
- project.
-
- isolatedHead - true for the top project, and for each isolated
- project.  false or nil for any subproject that shares all methods
- with its parent project.
-
- inForce -  true if my methods are installed now.  false if I am
- dormant. [is this equivalent to self == Project Current?]
-
- classArray - list of associations to classes
-
- methodDictArray - the method dictionaries of those classes before we
- started changing methods.  They hang onto the original
- compiledMethods.  (If this project is dormant, it contains the method
- dictionaries of those classes as they will be here, in this project).
-
- orgArray - the class organizations of the classes in classArray.
-
- UsingIsolation (class variable) - No longer used.
-
- When you want to save a project in export format from within that
- very project, it gets tricky.  We set two flags in parentProject,
- exit to it, and let parentProject write the project.
- ProjectViewMorph in parentProject checks in its step method, does the
- store, clears the flags, and reenters the subProject.
-
  !