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diff --git a/rse/doc/org.eclipse.dstore.doc.isv/guide/DataElements.html b/rse/doc/org.eclipse.dstore.doc.isv/guide/DataElements.html deleted file mode 100755 index 50eb1468e..000000000 --- a/rse/doc/org.eclipse.dstore.doc.isv/guide/DataElements.html +++ /dev/null @@ -1,206 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> -<html> -<head> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8"> -<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> -<meta name="copyright" content="Copyright (c) IBM Corporation and others 2000, 2006. This page is made available under license. For full details see the LEGAL in the documentation book that contains this page." > -<title>RSE Model</title> -<link rel="stylesheet" type="text/css" HREF="../book.css"> -</head> - -<body> -<h1><a name="dataelements">DataElements</a></h1> -<p> -All information in the DataStore repository is stored in the form of <b>DataElements</b>. DataElements are objects -that have attributes and may contain other DataElements. The attributes of a DataElement are stored as an array of -strings. A particular attribute is retrieved by calling <code>getAttribute(</code><i>attribute index</i><code>)</code>. -A particular attribute is set by calling <code>setAttribute(</code><i>attribute index</i><code>, </code><i>attribute value</i><code>)</code>. -The attribute indices that can be used are as follows: -<table> -<tr><td><b>Attribute</b></td><td><b>Description</b></td></tr> -<tr><td><code>A_TYPE</code></td><td>Attribute indicating the type of object. The type can be used to indicate the type of an instance of data, a descriptor, a relationship or a commnad.</td></tr> -<tr><td><code>A_NAME</code></td><td>Attribute indicating the name of object.</td></tr> -<tr><td><code>A_VALUE</code></td><td>Attribute indicating the more information about that object</td></tr> -<tr><td><code>A_SOURCE</code></td><td>Attribute indicating source information about an object, if applicable</td></tr> -<tr><td><code>A_REF_TYPE</code></td><td>Attribute indicating whether the object is a normal object ("value"), a spirit ("spirit"), or a reference to another DataElement ("reference"). In the DataStore, a reference to another DataElement is represented with a DataElement. For more information on spirit elements, see <a href="MemoryManagement.html">Memory Management in DataStore</a> </td></tr> -<tr><td><code>A_ID</code></td><td>The unique ID of a DataElement.</td></tr>. -</table> -</p> -<p> -Rather than representing different types of objects as different classes, the type attribute of a DataElement -indicates its type. There are two general categories of DataElements. There are schema elements, <A href="#descriptors">descriptors</a>, and instances of -those schema elements, <a href="#instances">instances</a>. -</p> - -<h2><a name="descriptors">Descriptors</a></h2> -<p> -A descriptor is a DataElement that describes some type of object. The <code>A_TYPE</code> attribute of a descriptor indicates what type of -descriptor it is. The <code>A_NAME</code> attribute of a descriptor identifies the type that the descriptor describes. -</p> -<p> -A descriptor may be of one of the following types: -</p> -<table> -<tr><td><code>T_OBJECT_DESCRIPTOR</code></td><td>Describes a type of object</td></tr> -<tr><td><code>T_RELATION_DESCRIPTOR</code></td><td>Describes a type of relationship that may exist between two DataElements.</td></tr> -<tr><td><code>T_COMMAND_DESCRIPTOR</code></td><td>Describes a type of command</td></tr> -</table> - -<h3><a name="objectdescriptors">Object Descriptors</a></h3> -<p> -<b>Object descriptors</b> describe the different types of data that can be represented in the DataStore repository. Object descriptors -can describe types of object instances as well as other types of object descriptors. Each object descriptor is related to other object, -relationship and command descriptors. -</p> - -<h3><a name="relationdescriptors">Relation Descriptors</a></h3> -<p> -<b>Relation descriptors</b> describe the different types of relationships that can be represented in the DataStore repository. Relation -descriptors describe types of relationships between object instances, object descriptors, command instances and command descriptors. -</p> - -<h3><a name="commanddescriptors">Command Descriptors</a></h3> -<p> -<b>Command descriptors</b> describe the different types of commands that can be executed on an object in the DataStore repository. -In the DataStore schema, object descriptors are related to command descriptors to indicate that an object instance of a certain type can -have the described command run on it. Command descriptors are always contained by the object descriptors they are associated with. The -<code>A_SOURCE</code> attribute of a command descriptor indicates which miner(s) may execute an instance of such a command. -</p> - -<p> -These three types of objects are used to define the DataStore schema. Instances of relation descriptors are used to define -relationships between descriptors in the schema. -</p> - - -<h2><a name="instances">Instances</a></h2> -<p> -An instance object is a DataElement that is an instance of a descriptor. An instance may either by an object, a -relation or a command. An instance uses its descriptor's <code>A_NAME</code> attribute as its <code>A_TYPE</code> attribute. -</p> - -<h3><a name="objects">Objects</a></h3> -<p> -<b>Objects</b> are instances of <b>object descriptors</b>. Objects are used to the represent the external or internal -entities that are being interacted with. An instance object can be related in a certain way to another type of -instance object if its object descriptor has the same kind of relationship to the other object's object descriptor. -An instance object may be associated with a particular command if its object descriptor is associated with the command descriptor -for that command. -</p> - -<h3><a name="relations">Relations</a></h3> -<p> -<b>Relations</b> are instances of <b>relation descriptors</b>. A relation is really a typed reference to another object. Relations -may exist from one object to another if the schema indicates that the object descriptor for the first object may have a relationship -of that type to the other object's descriptor. Relations are used to describe the relationship between two instances, the -relationship between two descriptors and the relationship between an instance and a descriptor. A relation is able to reference -another element by storing the other element's <code>A_ID</code> attribute in its <code>A_SOURCE</code> attribute. If a relation object -needs to be dereferenced, it uses this attribute to query the DataStore for the object being referenced. -</p> -<p> -A relation is typically represented by having an instance object DataElement contain a relation DataElement. -There are two types of relationships between elements that are implicit. These are the <i>contains</i> and -the <i>parent of</i> relationships. If an element is directly contained within another element, the -relationship between those two elements is implied to be <i>contains/parent of</i> relationships. -</p> - -<h3><a name="commands">Commands</a></h3> -<p> -<b>Commands</b> are instances of <b>command descriptors</b>. A command is always associated with an instance object such that -the command is to be performed on that object. The object associated with a command is referred to as the <i>subject</i> of -the command. Only a command that has a command descriptor that is related to the object descriptor of the subject may be -constructed. A command object is constructed when the DataStore method <code>command()</code> is called. The command is -created with a reference to the subject, an optional set of arguments, also instance objects, and a status object instance, used -to indicate the state of the command. The tree of elements for a command is communicated, via the DataStore comm layer, to -the appropriate miner(s), where it is interpreted and executed. -</p> -<p> -The structure of a command looks like the following: -</p> -<ul> -<li>Command - <ul> - <li>subject - a reference to the instance that this command applies to</li> - <li>arg 1 - an optional argument represented as a DataElement</li> - <li>...</li> - <li>arg n - an optional argument represented as a DataElement</li> - <li>status - element that represents the current status of a command</li> - </ul> -</li> -</ul> - -<p> -As an example, suppose the DataStore is being used for browsing a filesystem. The filesystem entities and how to interact -with the filesystem needs to be defined in the schema. The following descriptors could be used to describe this. -</p> - -<ul> -<li>Object Descriptors - <ul> - <li>"generic file object" - describes a generic file system object</li> - <li>"file" - describes a file object</li> - <li>"folder" - describes a folder object</li> - </ul> -</li> -<li>Relation Descriptors - <ul> - <li>"contains" - represents the containment relationship between two objects</li> - <li>"abstracts" - represents a derives relationship between two object descriptors</li> - <li>"abstracted by" - represents an inherits relationship between two object descriptors</li> - </ul> -</li> -<li>Command Descriptors - <ul> - <li>"query" - a command to list the contents of a folder</li> - <li>"rename" - a command to rename a file or folder</li> - <li>"delete" - a command to delete a file or folder</li> - <li>"create" - a command to create a new file or folder from an existing folder</li> - </ul> -</li> -</ul> - -<p> -Now that all the required descriptors are defined, relations between descriptors are needed. Note that the -symbol "->" implies a "contains" relationship and "IO()" implies an instance of a specified descriptor. -</p> - -<ul> -<li>"generic file object" - <ul> - <li>->"rename"</li> - <li>->"delete"</li> - <li>->IO("abstracts")->"folder"</li> - <li>->IO("abstracts")->"file"</li> - </ul> -</li> -<li>"folder" - <ul> - <li>->"create"</li> - <li>->"query"</li> - <li>->IO("abstracted by")->"generic file object"</li> - <li>->IO("contains")->"generic file object"</li> - </ul> -</li> -<li>"file" - <ul> - <li>->IO("abstracted by")->"generic file object"</li> - </ul> -</li> -</ul> - -<p> -DataStore schemas are created by the DataStore <b>miners</b>. Each tool contributes it's -own schema to the DataStore schema, referencing descriptors of other schemas, such -that one tool can contribute to another tool. All the command descriptors that are -contributed by a miner are expected to be handled by the contributing miner. Whenever -a miner creates a new command descriptor, the <code>A_SOURCE</code> attribute indicates -to the DataStore that an instance of that command should be routed to that miner when -it's issued. -<p> - -<p> -See the section, <a href="Miners.html">Miners</a> to find out how miners contribute schemas -and execute commands. -</p> -</body> -</html>
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