DBSchemaEdit

java.lang.Object
- arlut.csd.ganymede.server.DBSchemaEdit

All Implemented Interfaces:

SchemaEdit, java.rmi.Remote, java.rmi.server.Unreferenced
```
public final class DBSchemaEdit
extends java.lang.Object
implements java.rmi.server.Unreferenced, SchemaEdit
```
Server-side schema editing class. This class implements the SchemaEdit remote interface to support schema editing by the admin console.

Only one DBSchemaEdit object may be active in the server at a time; only one admin console can edit the server's schema at a time. While the server's schema is being edited, no users may be logged on to the system. An admin console puts the server into schema-editing mode by calling the editSchema() method on a server-side GanymedeAdmin object.

When the DBSchemaEdit object is created, it makes copies of all of the DBObjectBase type definition objects in the server. The admin console can then talk to those DBObjectBase objects remotely by way of the Base remote interface, accessing data fields, reordering the type tree visible in the client, and so forth.

When the user has made the desired changes, the commit() method is called, which replaces the set of DBObjectBase objects held in the server's DBStore with the modified set that was created and modified by DBSchemaEdit.

The schema editing code in the server currently has only a limited ability to verify that changes made in the schema editor will not break the database's consistency constraints in some fashion. Generally speaking, you should be using the schema editor to define new fields, or to change field definitions for fields that are not yet in use in the database, not to try to redefine parts of the database that are in actual use and which hold actual data.

The schema editing system is really the most fragile thing in the Ganymede server. It generally works, but it is not as robust as it ought to be. It's always a good idea to make a backup copy of your ganymede.db file before going in and editing your database schema.

Field Summary

Fields
Modifier and Type	Field and Description
`private java.lang.String`	`adminName` The name of the admin who is editing the schema.
`(package private) static boolean`	`debug`
`private java.lang.String`	`disableToken` The token that was used to lock the server for schema edit.
`private boolean`	`locked` if true, this DBSchemaEdit object has already been committed or aborted
`(package private) java.util.Hashtable<java.lang.Short,DBObjectBase>`	`newBases` A copy of the DBObjectBase objects comprising the DBStore's database.
`(package private) java.util.Vector<DBNameSpace>`	`oldNameSpaces` The original vector of namespace objects extant at the time the DBSchemaEdit editing session is established.
`(package private) DBBaseCategory`	`rootCategory` Root node of the working DBBaseCategory tree.. if the DBSchemaEdit session is committed, this DBBaseCategory tree will replace store.rootCategory.
`private DBStore`	`store` the DBStore object whose DBObjectBases are being edited
`(package private) static TranslationService`	`ts` TranslationService object for handling string localization in the Ganymede server.

Constructor Summary

Constructors
Constructor and Description

DBSchemaEdit(java.lang.String adminName)
Constructor.

Constructors
Constructor and Description
`DBSchemaEdit(java.lang.String adminName)` Constructor.

Method Summary

Methods
Modifier and Type	Method and Description
`private ReturnVal`	`checkCommitState()` This private helper method verifies that the proposed schema is acceptable to be committed.
`ReturnVal`	`commit()` Commits this schema edit, replaces the server's schema with the modified schema produced by this DBSchemaEdit session.
`Base`	`createNewBase(Category category, boolean embedded, boolean lowRange)` This method creates a new `DBObjectBase` object and returns a remote handle to it so that the admin client can set fields on the base, set attributes, and generally make a nuisance of itself.
`Base`	`createNewBase(Category category, boolean embedded, short id)` This method creates a new `DBObjectBase` object and returns a remote handle to it so that the admin client can set fields on the base, set attributes, and generally make a nuisance of itself.
`NameSpace`	`createNewNameSpace(java.lang.String name, boolean caseInsensitive)` This method creates a new `DBNameSpace` object and returns a remote handle to it so that the admin client can set attributes on the DBNameSpace, and generally make a nuisance of itself.
`ReturnVal`	`deleteBase(java.lang.String baseName)` This method deletes a `DBObjectBase`, removing it from the Schema Editor's working set of bases.
`ReturnVal`	`deleteNameSpace(java.lang.String name)` This method deletes a `DBNameSpace` object, returning true if the deletion could be carried out, false otherwise.
`ReturnVal`	`deleteUnusedNameSpaces()` This method deletes all `DBNameSpace` objects in the server's schema that are not currently attached to any namespace-constrained field.
`Base`	`getBase(short id)` Returns a `Base` reference to match the id, or null if no match.
`Base`	`getBase(java.lang.String baseName)` Returns a `Base` reference to match the baseName, or null if no match.
`Base[]`	`getBases()` Returns an array of Base references from the current (non-committed) state of the system.
`Base[]`	`getBases(boolean embedded)` Returns an array of Base references from the current (non-committed) state of the system.
`CategoryNode`	`getCategoryNode(java.lang.String pathName)` Gets a category from the category list, by it's fully qualified path name.
`DBObjectBase[]`	`getDBBases()` Returns an array of DBObjectBases from the current (non-committed) state of the system.
`DBObjectBase[]`	`getDBBases(boolean embedded)` Returns an array of DBObjectBase from the current (non-committed) state of the system.
`NameSpace`	`getNameSpace(java.lang.String name)` This method returns a `NameSpace` by matching name, or null if no match is found.
`NameSpace[]`	`getNameSpaces()` This method returns an array of defined `NameSpace` objects.
`Category`	`getRootCategory()` Returns the root category node from the server
`void`	`release()` Abort this schema edit, return the schema to its prior state.
`private void`	`unexportNameSpaces()`
`void`	`unreferenced()` This method is called when the client loses connection.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - debug
```
static final boolean debug
```
    See Also:
    Constant Field Values
  - ts
```
static final TranslationService ts
```
    TranslationService object for handling string localization in the Ganymede server.
  - locked
```
private boolean locked
```
    if true, this DBSchemaEdit object has already been committed or aborted
  - store
```
private final DBStore store
```
    the DBStore object whose DBObjectBases are being edited
  - adminName
```
private final java.lang.String adminName
```
    The name of the admin who is editing the schema.
  - disableToken
```
private final java.lang.String disableToken
```
    The token that was used to lock the server for schema edit.
  - newBases
```
java.util.Hashtable<java.lang.Short,DBObjectBase> newBases
```
    A copy of the DBObjectBase objects comprising the DBStore's database. All changes made during Base editing are performed on the copies held in this hashtable.. if the DBSchemaEdit session is aborted, newBases is thrown away. If the DBSchemaEdit session is confirmed, newBases replaces store.db.objectBases.
  - oldNameSpaces
```
java.util.Vector<DBNameSpace> oldNameSpaces
```
    The original vector of namespace objects extant at the time the DBSchemaEdit editing session is established.
  - rootCategory
```
DBBaseCategory rootCategory
```
    Root node of the working DBBaseCategory tree.. if the DBSchemaEdit session is committed, this DBBaseCategory tree will replace store.rootCategory.
- Constructor Detail
  - DBSchemaEdit
```
public DBSchemaEdit(java.lang.String adminName)
             throws java.rmi.RemoteException
```
    Constructor. This constructor should only be called in a critical section synchronized on the Ganymede.db.lockSync object.
    
    Throws:
    
    java.rmi.RemoteException
- Method Detail
  - getRootCategory
```
public Category getRootCategory()
```
    Returns the root category node from the server
    
    Specified by:
    
    getRootCategory in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - getCategoryNode
```
public CategoryNode getCategoryNode(java.lang.String pathName)
```
    Gets a category from the category list, by it's fully qualified path name.
  - getBases
```
public Base[] getBases(boolean embedded)
```
    Returns an array of Base references from the current (non-committed) state of the system.
    
    Specified by:
    
    getBases in interface SchemaEdit
    
    Parameters:
    embedded - If true, getBases() will only show bases that are intended for embedding in other objects. If false, getBases() will only show bases that are not to be embedded.
    See Also:
    SchemaEdit
  - getDBBases
```
public DBObjectBase[] getDBBases(boolean embedded)
```
    Returns an array of DBObjectBase from the current (non-committed) state of the system.
    
    Parameters:
    embedded - If true, getBases() will only show bases that are intended for embedding in other objects. If false, getBases() will only show bases that are not to be embedded.
  - getBases
```
public Base[] getBases()
```
    Returns an array of Base references from the current (non-committed) state of the system.
    
    Specified by:
    
    getBases in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - getDBBases
```
public DBObjectBase[] getDBBases()
```
    Returns an array of DBObjectBases from the current (non-committed) state of the system.
  - getBase
```
public Base getBase(short id)
```
    Returns a Base reference to match the id, or null if no match.
    
    Specified by:
    
    getBase in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - getBase
```
public Base getBase(java.lang.String baseName)
```
    Returns a Base reference to match the baseName, or null if no match.
    
    Specified by:
    
    getBase in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - createNewBase
```
public Base createNewBase(Category category,
                 boolean embedded,
                 boolean lowRange)
```
    This method creates a new DBObjectBase object and returns a remote handle to it so that the admin client can set fields on the base, set attributes, and generally make a nuisance of itself.
    
    Specified by:
    
    createNewBase in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - createNewBase
```
public Base createNewBase(Category category,
                 boolean embedded,
                 short id)
```
    This method creates a new DBObjectBase object and returns a remote handle to it so that the admin client can set fields on the base, set attributes, and generally make a nuisance of itself.
  - deleteBase
```
public ReturnVal deleteBase(java.lang.String baseName)
                     throws java.rmi.RemoteException
```
    This method deletes a DBObjectBase, removing it from the Schema Editor's working set of bases. The removal won't take place for real unless the SchemaEdit is committed.
    
    Specified by:
    
    deleteBase in interface SchemaEdit
    
    Throws:
    
    java.rmi.RemoteException
    See Also:
    SchemaEdit
  - getNameSpaces
```
public NameSpace[] getNameSpaces()
```
    This method returns an array of defined NameSpace objects.
    
    Specified by:
    
    getNameSpaces in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - getNameSpace
```
public NameSpace getNameSpace(java.lang.String name)
```
    This method returns a NameSpace by matching name, or null if no match is found.
    
    Specified by:
    
    getNameSpace in interface SchemaEdit
    
    See Also:
    NameSpace, SchemaEdit
  - createNewNameSpace
```
public NameSpace createNewNameSpace(java.lang.String name,
                           boolean caseInsensitive)
```
    This method creates a new DBNameSpace object and returns a remote handle to it so that the admin client can set attributes on the DBNameSpace, and generally make a nuisance of itself.
    
    Specified by:
    
    createNewNameSpace in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - deleteNameSpace
```
public ReturnVal deleteNameSpace(java.lang.String name)
```
    This method deletes a DBNameSpace object, returning true if the deletion could be carried out, false otherwise.
    
    Specified by:
    
    deleteNameSpace in interface SchemaEdit
    
    See Also:
    SchemaEdit
  - deleteUnusedNameSpaces
```
public ReturnVal deleteUnusedNameSpaces()
                                 throws java.rmi.RemoteException
```
    This method deletes all DBNameSpace objects in the server's schema that are not currently attached to any namespace-constrained field.
    
    Specified by:
    
    deleteUnusedNameSpaces in interface SchemaEdit
    
    Throws:
    
    java.rmi.RemoteException
  - commit
```
public ReturnVal commit()
```
    Commits this schema edit, replaces the server's schema with the modified schema produced by this DBSchemaEdit session.
    
    It is an error to attempt any schema editing operations after this method has been called.
    
    Specified by:
    
    commit in interface SchemaEdit
  - checkCommitState
```
private ReturnVal checkCommitState()
```
    This private helper method verifies that the proposed schema is acceptable to be committed.
  - release
```
public void release()
```
    Abort this schema edit, return the schema to its prior state.
    
    It is an error to attempt any schema editing operations after this method has been called.
    
    Specified by:
    
    release in interface SchemaEdit
  - unexportNameSpaces
```
private void unexportNameSpaces()
```
  - unreferenced
```
public void unreferenced()
```
    This method is called when the client loses connection. unreferenced() should do cleanup.
    
    Specified by:
    
    unreferenced in interface java.rmi.server.Unreferenced

Class DBSchemaEdit

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

debug

ts

locked

store

adminName

disableToken

newBases

oldNameSpaces

rootCategory

Constructor Detail

DBSchemaEdit

Method Detail

getRootCategory

getCategoryNode

getBases

getDBBases

getBases

getDBBases

getBase

getBase

createNewBase

createNewBase

deleteBase

getNameSpaces

getNameSpace

createNewNameSpace

deleteNameSpace

deleteUnusedNameSpaces

commit

checkCommitState

release

unexportNameSpaces

unreferenced