Whole installer

installer/src/installer-lib/database.h

Index: installer/src/installer-lib/database.h
===================================================================
--- a/installer/src/installer-lib/database.h
+++ b/installer/src/installer-lib/database.h
@@ -1,74 +1,204 @@
 /**
- * \file database.h MSI database
- */
+* \file database.h MSI database
+*/
 
 #ifndef DATABASE_H
 #define DATABASE_H
 
 #include <string>
-#include "windows.h"
-#include "msi.h"
+#include <memory>
 
+#include <Windows.h>
+#include <Msi.h>
+#include <MsiQuery.h>
+
+#include "installer-lib.h"
+#include "handle.h"
 #include "session.h"
 
+// Forward declarations
+class View ;
+
+//-------------------------------------------------------
+// Database
+//-------------------------------------------------------
 /**
- * A Windows Installer database as contained in an MSI file.
- *
- * The API for MSI databases is shared between installation and non-installation contexts.
- * Roughly speaking, outside an installation the database supports both read and write,
- *   but inside an installation the database is read-only.
- * The life cycle functions are not shared, in addition.
- * Outside of these restrictions, however, the API is mostly common.
- * This class is the base class for the common API.
- * Subclasses provide public constructors and provide access to API calls not in common.
- */
+* A Windows Installer database as contained in an MSI file.
+*
+* The API for MSI databases is shared between installation and non-installation contexts.
+* Roughly speaking, outside an installation the database supports both read and write,
+*   but inside an installation the database is read-only.
+* The life cycle functions are not shared, in addition.
+* Outside of these restrictions, however, the API is mostly common.
+* This class is the base class for the common API.
+* Subclasses provide public constructors and provide access to API calls not in common.
+*/
 class Database
 {
 protected:
-  /**
-   * Protected constructor. Life cycle depends strongly on context.
-   */
-  Database( MSIHANDLE handle );
+  typedef handle< MSIHANDLE, Disallow_Null, MSI_Generic_Destruction > handle_type ;
 
   /**
-   * Destructor.
-   */
-  ~Database();
+  * Protected constructor. 
+  *
+  * An MSI database handle is an overloaded type, used both for installation databases and one opened outside an installation.
+  * These database handles, while both databases, have different capabilities and are thus defined in subclasses.
+  * Each subclass has the responsibility for obtaining a database handle appropriate to its circumstance.
+  * 
+  * \sa MSDN "Obtaining a Database Handle"
+  *    http://msdn.microsoft.com/en-us/library/windows/desktop/aa370541(v=vs.85).aspx
+  */
+  Database( MSIHANDLE handle )
+    : handle( handle )
+  {}
 
-protected:
   /**
-   */
-  MSIHANDLE handle;
+  */
+  handle_type handle ;
 
 private:
   /**
-   * Private copy constructor is declared but not defined.
-   */
-  Database( const Database & );
+  * Private copy constructor is declared but not defined.
+  */
+  Database( const Database & ) ;
 
   /**
-   * Private assignment operator is declared but not defined.
-   */
+  * Private assignment operator is declared but not defined.
+  */
   Database & operator=( const Database & ) ;
-};
+
+  /**
+  * Open a new view for this database.
+  *
+  * \param query
+  *    An SQL query using the restricted MSI syntax
+  *
+  * \sa
+  *   - MSDN [MsiDatabaseOpenView function](http://msdn.microsoft.com/en-us/library/aa370082%28v=vs.85%29.aspx)
+  */
+  msi_handle open_view( const wchar_t * query ) ;
+
+  friend class View ;
+} ;
 
 /**
- * A Windows Installer database in an installation context.
- */
+* A Windows Installer database in an installation context.
+*/
 class Installation_Database : public Database
 {
 public:
   /**
-   * The constructor of a database in an installation context has no arguments because the database is a part of that context.
-   */
-  Installation_Database( Immediate_Session & session );
-};
+  * The constructor of a database in an installation context has no arguments because the database is a part of that context.
+  */
+  Installation_Database( Immediate_Session & session ) ;
+} ;
 
+//-------------------------------------------------------
+//
+//-------------------------------------------------------
 /**
- * A Windows Installer database in a non-installation context.
- */
-class Non_Installation_Database : public Database
+* A Windows Installer database outside of an installation context, opened as a file from the file system.
+*
+* This is a read-only version of a file-system database.
+* Refactor the class to obtain other open-modes.
+*
+*/
+class File_System_Database : public Database
 {
-};
+  /**
+  * Open function is separate to enable initializing base class before constructor body.
+  *
+  * \sa
+  *   - MSDN [MsiOpenDatabase function](http://msdn.microsoft.com/en-us/library/aa370338%28v=vs.85%29.aspx)
+  */
+  msi_handle handle_from_pathname( const wchar_t * pathname )
+  {
+    MSIHANDLE handle ;
+    UINT x = MsiOpenDatabaseW( pathname, MSIDBOPEN_READONLY, & handle ) ;
+    if ( x != ERROR_SUCCESS )
+    {
+      throw windows_api_error( "MsiOpenDatabaseW", x, "MSI database on file system" ) ;
+    }
+    return msi_handle( handle ) ;
+  }
+
+public:
+  File_System_Database( const wchar_t * pathname )
+    : Database( handle_from_pathname( pathname ) )
+  {}
+} ;
+
+//-------------------------------------------------------
+// View
+//-------------------------------------------------------
+/*
+* The MSI database is accessible through a cut-down version of SQL.
+* There's no distinction between view and query in this dialect.
+*
+* \sa
+*   - MSDN [Working with Queries](http://msdn.microsoft.com/en-us/library/aa372879%28v=vs.85%29.aspx)
+*/
+class View
+{
+  /**
+  * Policy class to close a view handle.
+  * View handles don't get closed with the generic close function for other MSI handles.
+  */
+  template< class T >
+  struct View_Destruction
+  {
+    /**
+    * \sa MSDN [MsiViewClose function](http://msdn.microsoft.com/en-us/library/aa370510%28v=vs.85%29.aspx)
+    */
+    inline static void close( T handle )
+    {
+      ::MsiViewClose( handle ) ;
+    }
+  } ;
+
+  typedef handle< MSIHANDLE, Disallow_Null, View_Destruction > handle_type ;
+
+  /**
+  * Handle for the MSI view object
+  */
+  handle_type _handle;
+
+public:
+  /**
+  * Ordinary constructor
+  */
+  View( Database & db, wchar_t * query )
+    : _handle( db.open_view( query ) )
+  {}
+
+  /**
+  * Execute the query and return the first record in its results.
+  * 
+  * \param arguments
+  *    List of parameters to supply as the query arguments (question marks).
+  */
+  Record first( Record & arguments ) ;
+
+  /**
+  * Execute the query and return the first record in its results.
+  * 
+  * With no arguments, this version of the function may only be used with a query that takes no arguments.
+  */
+  Record first() ;
+
+  /**
+  * Retrieve the next record.
+  */
+  Record next() ;
+
+  /**
+  * End marker
+  */
+  inline Record end()
+  {
+    return Record( Record::null_t() ) ;
+  }
+} ;
+
 
 #endif