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Enhanced optimal block size copy algorithm to reduce time required to move or copy partitions 

svn path=/trunk/; revision=880
This commit is contained in:
Curtis Gedak 2008-08-07 02:06:00 +00:00
parent 0e75f133d7
commit a2b96b0094
2 changed files with 20 additions and 14 deletions
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7
ChangeLog
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@ -1,5 +1,12 @@
2008-08-06 Curtis Gedak <gedakc@gmail.com>
* src/GParted_Core.cc: Enhanced optimal block size copy algorithm.
- Changed algorithm to try all block size possibilities instead of
stopping as soon as next larger block size took longer to copy than
the prior block size. Due to anomalies in benchmark times, the
previous algorithm would favour smaller block sizes.
- Closes GParted bugs #546423, and #438574
* README: Updated with new directories for GParted Manual
2008-08-05 Curtis Gedak <gedakc@gmail.com>

25
src/GParted_Core.cc
View File

@ -1723,7 +1723,8 @@ bool GParted_Core::copy_filesystem( const Glib::ustring & src_device,
operationdetail .add_child( OperationDetail( _("finding optimal blocksize"), STATUS_NONE ) ) ;
Sector optimal_blocksize = readonly ? 128 : 64, N = 32768 ;
Sector benchmark_blocksize = readonly ? 128 : 64, N = 65536 ;
Sector optimal_blocksize = benchmark_blocksize ;
Sector offset_read = src_start,
offset_write = dst_start ;
@ -1739,24 +1740,18 @@ bool GParted_Core::copy_filesystem( const Glib::ustring & src_device,
double smallest_time = 1000000 ;
bool succes = true ;
//Benchmark copy times using different block sizes to determine optimal size
while ( succes &&
timer .elapsed() <= smallest_time &&
std::llabs( done ) + N <= length &&
optimal_blocksize * 2 < N )
benchmark_blocksize <= N )
{
if ( done != 0 )
{
smallest_time = timer .elapsed() ;
optimal_blocksize *= 2 ;
}
timer .reset() ;
succes = copy_blocks( src_device,
dst_device,
offset_read + done,
offset_write + done,
N,
optimal_blocksize,
benchmark_blocksize,
operationdetail .get_last_child(),
readonly,
total_done ) ;
@ -1765,15 +1760,19 @@ bool GParted_Core::copy_filesystem( const Glib::ustring & src_device,
operationdetail .get_last_child() .get_last_child() .add_child( OperationDetail(
String::ucompose( _("%1 seconds"), timer .elapsed() ), STATUS_NONE, FONT_ITALIC ) ) ;
if ( timer .elapsed() <= smallest_time )
{
smallest_time = timer .elapsed() ;
optimal_blocksize = benchmark_blocksize ;
}
benchmark_blocksize *= 2 ;
if ( ( dst_start > src_start ) )
done -= N ;
else
done += N ;
}
if ( timer .elapsed() > smallest_time )
optimal_blocksize /= 2 ;
if ( succes )
operationdetail .get_last_child() .add_child( OperationDetail( String::ucompose( _("optimal blocksize is %1 sectors (%2)"),
optimal_blocksize,