Re: [Jdbm-general] RecordManager Browser

[Mark P. <mpr...@co...>]

I've made this into some reusable code with unit tests. Provides two 
static help methods, one returns the id's as a List, the other returns 
the id's with values as a Map.

The later could probably become a concrete Map implementation to lazy 
retrieve the data direct from the recman, rather than loading all the 
data - but it's a quick hack for now.

Mark
Mark Proctor wrote:
> I've implemented something, based on the dumputility, that will iterate 
> over recid's putthem them into a list. My feedback on issues for this are:
> BaseRecordManager is final, so can't be extended
> Had to use reflection, and setting accessible, to access _pageman and _file
> PageCursor is package protected so all of my code has to live in the 
> jdbm.recman namespace.
>
> Anyway here is the code, hope others find it useful. It generates a 
> number of strings and inserts them into a db, and then iterates it 
> retrieving all entries, it then asserts that all the information is correct:
>
>     public static void test1() {
>         RecordManager recman;
>
>         File fileDb = new File( DATABASE + ".db" );
>         if ( fileDb.exists() ) {
>             fileDb.delete();
>         }
>         File fileLg = new File( DATABASE + ".lg" );
>         if ( fileLg.exists() ) {
>             fileLg.delete();
>         }
>
>         fileDb = new File( DATABASE + ".db" );
>         fileLg = new File( DATABASE + ".lg" );
>         assertTrue( !fileDb.exists() );
>         assertTrue( !fileLg.exists() );
>
>         Properties props;
>         props = new Properties();
>
>         List<Long> ids = new ArrayList<Long>();
>
>         try {
>             // open database and setup an object cache
>
>             recman = new BaseRecordManager( DATABASE );
>             for ( int i = 0; i < 1000; i++ ) {
>                 String str = StringGenerator.getUniqueID();
>                 //System.out.println( "Insert: " + str );
>                 ids.add( recman.insert( str ) );
>             }                                   
>
>             Field pageManagerField = recman.getClass().getDeclaredField( 
> "_pageman" );
>             Field fileField = recman.getClass().getDeclaredField( "_file" );
>
>             PageManager pageManager = null;
>             RecordFile file = null;
>             try {
>                 pageManagerField.setAccessible( true );
>                 pageManager = (PageManager) pageManagerField.get( recman );
>
>                 fileField.setAccessible( true );
>                 file = (RecordFile) fileField.get( recman );
>             } catch ( Exception e ) {
>                 e.printStackTrace();
>             }
>
>             //System.out.println( ids );
>
>             // #of translation pages scanned.
>             long npages = 0L;
>
>            
>             List<Long> list = new ArrayList<Long>();
>             PageCursor cursor = new PageCursor( pageManager,
>                                                 Magic.TRANSLATION_PAGE );
>             for ( long blockId = cursor.next(); blockId != 0; blockId = 
> cursor.next() ) {
>                 BlockIo block = file.get( blockId );
>                 //System.out.println( "usedblock : " + block );
>
>                 TranslationPage xlatPage = 
> TranslationPage.getTranslationPageView( block );
>
>                 for ( int i = 0; i < TranslationPage.ELEMS_PER_PAGE; i++ ) {
>                     short offset = (short) ( TranslationPage.O_TRANS + ( 
> i * PhysicalRowId.SIZE ) );
>                     Location physid = new Location( xlatPage.get( offset 
> ) );
>                     if( physid.getBlock() == 0 ) {                   
>                         //  Skip empty slot.                   
>                         continue;                   
>                     }                   
>                     long recid = new Location( blockId, offset ).toLong();
>                     list.add ( recid 
> );                                       
>                 }
>                 file.release( block );
>             }
>            
>             // check the assigned list size is the same as the search 
> list sized
>             //System.out.println( "now print data" ); 
>             assertEquals( ids.size(), list.size() );
>             for ( long id : list ) {
>                 // check all searched ids match
>                 //System.out.println( "id : " + id + " : " + 
> recman.fetch( id ) );
>                 assertTrue( ids.contains( id ) );
>             }
>            
>         } catch ( Exception except ) {
>             except.printStackTrace();
>         }
>     }
>    
>     public static class StringGenerator {
>         private static final int NUM_CHARS = 500;
>        
>         private static String chars = 
> "abcdefghijklmonpqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
>        
>         private static Random r = new Random();
>      
>         public static String getUniqueID() {   
>             char[] buf = new char[NUM_CHARS];                        
>             for (int i = 0; i < buf.length; i++) {       
>                 buf[i] = chars.charAt(r.nextInt(chars.length()));       
>             }                        
>             return new String(buf);   
>         }
>     }
>
>
>
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