From: rkinyon <rkinyon@50811bd7-b8ce-0310-adc1-d9db26280581>
Date: Wed, 27 Dec 2006 04:51:11 +0000 (+0000)
Subject: Parameterized the freespace management to allow for new sector types more easily... 
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=c0507636bb3275a41067bc1b6feb4ce822bc168a;p=dbsrgits%2FDBM-Deep.git

Parameterized the freespace management to allow for new sector types more easily - clunky, but it works for now
---

diff --git a/lib/DBM/Deep/Engine3.pm b/lib/DBM/Deep/Engine3.pm
index 0da89a8..7270a67 100644
--- a/lib/DBM/Deep/Engine3.pm
+++ b/lib/DBM/Deep/Engine3.pm
@@ -642,24 +642,20 @@ sub _apply_digest {
     return $self->{digest}->(@_);
 }
 
-#XXX Parameterize the staleness counter stuff here
+sub _add_free_blist_sector { shift->_add_free_sector( 0, @_ ) }
+sub _add_free_data_sector { shift->_add_free_sector( 1, @_ ) }
+sub _add_free_index_sector { shift->_add_free_sector( 2, @_ ) }
+
 sub _add_free_sector {
     my $self = shift;
-    my ($offset, $size) = @_;
+    my ($multiple, $offset, $size) = @_;
 
-    my $chains_offset;
-    # Data sector
-    if ( $size == 256 ) {
-        $chains_offset = $self->byte_size;
-    }
-    # Blist sector
-    else {
-        $chains_offset = 0;
-    }
+    my $chains_offset = $multiple * $self->byte_size;
 
     my $storage = $self->storage;
 
     # Increment staleness.
+    # XXX Can this increment+modulo be done by "&= 0x1" ?
     my $staleness = unpack( $StP{STALE_SIZE()}, $storage->read_at( $offset + SIG_SIZE, STALE_SIZE ) );
     $staleness = ($staleness + 1 ) % ( 2 ** ( 8 * STALE_SIZE ) );
     $storage->print_at( $offset + SIG_SIZE, pack( $StP{STALE_SIZE()}, $staleness ) );
@@ -674,19 +670,15 @@ sub _add_free_sector {
     $storage->print_at( $offset + SIG_SIZE + STALE_SIZE, $old_head );
 }
 
+sub _request_blist_sector { shift->_request_sector( 0, @_ ) }
+sub _request_data_sector { shift->_request_sector( 1, @_ ) }
+sub _request_index_sector { shift->_request_sector( 2, @_ ) }
+
 sub _request_sector {
     my $self = shift;
-    my ($size) = @_;
+    my ($multiple, $size) = @_;
 
-    my $chains_offset;
-    # Data sector
-    if ( $size == 256 ) {
-        $chains_offset = $self->byte_size;
-    }
-    # Blist sector
-    else {
-        $chains_offset = 0;
-    }
+    my $chains_offset = $multiple * $self->byte_size;
 
     my $old_head = $self->storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size );
     my $loc = unpack( $StP{$self->byte_size}, $old_head );
@@ -842,9 +834,8 @@ sub free {
         chr(0) x ($self->size - $self->base_size),
     );
 
-    $e->_add_free_sector(
-        $self->offset, $self->size,
-    );
+    my $free_meth = $self->free_meth;
+    $e->$free_meth( $self->offset, $self->size );
 
     return;
 }
@@ -855,6 +846,7 @@ our @ISA = qw( DBM::Deep::Engine::Sector );
 
 # This is in bytes
 sub size { return 256 }
+sub free_meth { return '_add_free_data_sector' }
 
 sub clone {
     my $self = shift;
@@ -892,7 +884,7 @@ sub _init {
     unless ( $self->offset ) {
         my $data_section = $self->size - $self->base_size - 1 * $engine->byte_size - 1;
 
-        $self->{offset} = $engine->_request_sector( $self->size );
+        $self->{offset} = $engine->_request_data_sector( $self->size );
 
         my $data = delete $self->{data};
         my $dlen = length $data;
@@ -909,7 +901,7 @@ sub _init {
                 $chunk = substr( $data, 0, $this_len );
 
                 $dlen -= $data_section;
-                $next_offset = $engine->_request_sector( $self->size );
+                $next_offset = $engine->_request_data_sector( $self->size );
                 $data = substr( $data, $this_len );
             }
             else {
@@ -989,7 +981,7 @@ sub _init {
     unless ( $self->offset ) {
         my $leftover = $self->size - $self->base_size - 1 * $engine->byte_size - 1;
 
-        $self->{offset} = $engine->_request_sector( $self->size );
+        $self->{offset} = $engine->_request_data_sector( $self->size );
         $engine->storage->print_at( $self->offset, $self->type ); # Sector type
         # Skip staleness counter
         $engine->storage->print_at( $self->offset + $self->base_size,
@@ -1024,13 +1016,13 @@ sub _init {
             $class_offset = $class_sector->offset;
         }
 
-        $self->{offset} = $e->_request_sector( $self->size );
+        $self->{offset} = $e->_request_data_sector( $self->size );
         $e->storage->print_at( $self->offset, $self->type ); # Sector type
         # Skip staleness counter
         $e->storage->print_at( $self->offset + $self->base_size,
             pack( $StP{$e->byte_size}, 0 ),             # Index/BList loc
             pack( $StP{$e->byte_size}, $class_offset ), # Classname loc
-            chr(0) x $leftover,                              # Zero-fill the rest
+            chr(0) x $leftover,                         # Zero-fill the rest
         );
     }
     else {
@@ -1263,7 +1255,7 @@ sub _init {
     unless ( $self->offset ) {
         my $leftover = $self->size - $self->base_size;
 
-        $self->{offset} = $engine->_request_sector( $self->size );
+        $self->{offset} = $engine->_request_blist_sector( $self->size );
         $engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type
         # Skip staleness counter
         $engine->storage->print_at( $self->offset + $self->base_size,
@@ -1287,6 +1279,8 @@ sub size {
     return $self->{size};
 }
 
+sub free_meth { return '_add_free_blist_sector' }
+
 sub bucket_size {
     my $self = shift;
     unless ( $self->{bucket_size} ) {
@@ -1514,7 +1508,7 @@ sub _init {
     unless ( $self->offset ) {
         my $leftover = $self->size - $self->base_size;
 
-        $self->{offset} = $engine->_request_sector( $self->size );
+        $self->{offset} = $engine->_request_index_sector( $self->size );
         $engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type
         # Skip staleness counter
         $engine->storage->print_at( $self->offset + $self->base_size,
@@ -1534,5 +1528,7 @@ sub size {
     return $self->{size};
 }
 
+sub free_meth { return '_add_free_index_sector' }
+
 1;
 __END__