paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-08-30 18:00:43 +02:00
Code Issues Packages Projects Releases Wiki Activity

amicommon: a better, faster implementation of do_filesize(). since it no longer seeks, speed should be constant and not depend on the filesize and underlying FS fragmentation, among others

Browse Source 
git-svn-id: trunk@29379 -
This commit is contained in:
Károly Balogh 2015-01-04 01:32:37 +00:00
parent b0c7415f3a
commit 3d2fca152b
1 changed files with 26 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
rtl/amicommon/sysfile.inc
View File

@ -278,17 +278,41 @@ begin
end;
end;
{$DEFINE ASYS_FILESIZE_NO_DOUBLE_SEEK}
{ I changed the double-Seek filesize method which we
were using for 10+ years to the new ExamineFH() method.
It should be available AmigaOS 2.0+, and much faster.
(I actually measured several magnitudes of improvement,
especially on large files.)
It should be safe since there are several libc implementations
using the same method on all Amiga flavors, but if anyone has
a problem with it, disable this define to revert to the old
method and report the issue. (KB) }
function do_filesize(handle : longint) : longint;
var currfilepos: longint;
var
{$IFDEF ASYS_FILESIZE_NO_DOUBLE_SEEK}
fib: PFileInfoBlock;
{$ENDIF}
currfilepos: longint;
begin
checkCTRLC;
do_filesize:=-1;
if CheckInList(ASYS_fileList,handle)<>nil then begin
{$IFDEF ASYS_FILESIZE_NO_DOUBLE_SEEK}
fib:=AllocDosObject(DOS_FIB,nil);
if fib <> nil then begin
if ExamineFH(handle, fib) then
do_filesize:=fib^.fib_Size;
FreeDosObject(DOS_FIB,fib);
end;
{$ELSE}
currfilepos:=do_filepos(handle);
do_filesize:=do_seekend(handle);
do_seek(handle,currfilepos);
{$ENDIF}
end;
end;