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Merge pchardin@bk-internal.mysql.com:/home/bk/mysql-5.1

Browse source 
into  mysql.com:/home/cps/mysql/trees/5.1-team
This commit is contained in:
petr@owlet. 2006-06-30 11:17:53 +04:00
commit b655968123
1 changed files with 58 additions and 12 deletions
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70
mysys/my_pread.c
View file

@ -27,7 +27,7 @@ uint my_pread(File Filedes, byte *Buffer, uint Count, my_off_t offset,
myf MyFlags)
{
uint readbytes;
int error;
int error= 0;
DBUG_ENTER("my_pread");
DBUG_PRINT("my",("Fd: %d Seek: %lu Buffer: 0x%lx Count: %u MyFlags: %d",
Filedes, (ulong) offset, Buffer, Count, MyFlags));
@ -38,17 +38,40 @@ uint my_pread(File Filedes, byte *Buffer, uint Count, my_off_t offset,
errno=0; /* Linux doesn't reset this */
#endif
#ifndef HAVE_PREAD
off_t old_offset;
pthread_mutex_lock(&my_file_info[Filedes].mutex);
readbytes= (uint) -1;
error= (lseek(Filedes, offset, MY_SEEK_SET) == -1L ||
(readbytes = (uint) read(Filedes, Buffer, Count)) != Count);
/*
As we cannot change the file pointer, we save the old position,
before seeking to the given offset
*/
error= (old_offset= lseek(Filedes, 0L, MY_SEEK_CUR)) == -1L ||
lseek(Filedes, offset, MY_SEEK_SET) == -1L;
if (!error) /* Seek was successful */
{
if ((readbytes = (uint) read(Filedes, Buffer, Count)) == -1L)
my_errno= errno;
/*
We should seek back, even if read failed. If this fails,
we will return an error. If read failed as well, we will
save the errno from read, not from lseek().
*/
if ((error= (lseek(Filedes, old_offset, MY_SEEK_SET) == -1L)) &&
readbytes != -1L)
my_errno= errno;
}
pthread_mutex_unlock(&my_file_info[Filedes].mutex);
#else
error=((readbytes = (uint) pread(Filedes, Buffer, Count, offset)) != Count);
if ((error= ((readbytes =
(uint) pread(Filedes, Buffer, Count, offset)) != Count)))
my_errno= errno;
#endif
if (error)
if (error || readbytes != Count)
{
my_errno=errno;
DBUG_PRINT("warning",("Read only %ld bytes off %ld from %d, errno: %d",
readbytes,Count,Filedes,my_errno));
#ifdef THREAD
@ -89,17 +112,41 @@ uint my_pwrite(int Filedes, const byte *Buffer, uint Count, my_off_t offset,
for (;;)
{
#ifndef HAVE_PREAD
int error;
int error= 0;
off_t old_offset;
writenbytes= (uint) -1;
pthread_mutex_lock(&my_file_info[Filedes].mutex);
error=(lseek(Filedes, offset, MY_SEEK_SET) != -1L &&
(writenbytes = (uint) write(Filedes, Buffer, Count)) == Count);
/*
As we cannot change the file pointer, we save the old position,
before seeking to the given offset
*/
error= ((old_offset= lseek(Filedes, 0L, MY_SEEK_CUR)) == -1L ||
lseek(Filedes, offset, MY_SEEK_SET) == -1L);
if (!error) /* Seek was successful */
{
if ((writenbytes = (uint) write(Filedes, Buffer, Count)) == -1L)
my_errno= errno;
/*
We should seek back, even if write failed. If this fails,
we will return an error. If write failed as well, we will
save the errno from write, not from lseek().
*/
if ((error= (lseek(Filedes, old_offset, MY_SEEK_SET) == -1L)) &&
writenbytes != -1L)
my_errno= errno;
}
pthread_mutex_unlock(&my_file_info[Filedes].mutex);
if (error)
if (!error && writenbytes == Count)
break;
#else
if ((writenbytes = (uint) pwrite(Filedes, Buffer, Count,offset)) == Count)
break;
else
my_errno= errno;
#endif
if ((int) writenbytes != -1)
{ /* Safegueard */
@ -108,7 +155,6 @@ uint my_pwrite(int Filedes, const byte *Buffer, uint Count, my_off_t offset,
Count-=writenbytes;
offset+=writenbytes;
}
my_errno=errno;
DBUG_PRINT("error",("Write only %d bytes",writenbytes));
#ifndef NO_BACKGROUND
#ifdef THREAD