sharpetronics/PostgreSQL
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-12-31 00:03:29 -05:00
Code Issues Projects Releases Wiki Activity

Upgrade BufFile to use int64 for byte positions

Browse Source 
This change has the advantage of removing some weird type casts, caused
by offset calculations based on pgoff_t but saved as int (on older
branches we use off_t, which could be 4 or 8 bytes depending on the
environment).  These are safe currently because capped by
MAX_PHYSICAL_FILESIZE, but we would run into problems when to make
MAX_PHYSICAL_FILESIZE larger or allow callers of these routines to use a
larger physical max size on demand.

While on it, this improves BufFileDumpBuffer() so as we do not use an
offset for "availbytes".  It is not a file offset per-set, but a number
of available bytes.

This change should lead to no functional changes.

Author: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aUStrqoOCDRFAq1M@paquier.xyz
This commit is contained in:
Michael Paquier 2025-12-26 08:41:56 +09:00
parent eee19a30d6
commit bde3a46160
1 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/backend/storage/file/buffile.c
View File

@ -93,8 +93,8 @@ struct BufFile
*/
int curFile; /* file index (0..n) part of current pos */
pgoff_t curOffset; /* offset part of current pos */
int pos; /* next read/write position in buffer */
int nbytes; /* total # of valid bytes in buffer */
int64 pos; /* next read/write position in buffer */
int64 nbytes; /* total # of valid bytes in buffer */
/*
* XXX Should ideally use PGIOAlignedBlock, but might need a way to avoid
@ -493,8 +493,8 @@ BufFileLoadBuffer(BufFile *file)
static void
BufFileDumpBuffer(BufFile *file)
{
int wpos = 0;
int bytestowrite;
int64 wpos = 0;
int64 bytestowrite;
File thisfile;
/*
@ -503,7 +503,7 @@ BufFileDumpBuffer(BufFile *file)
*/
while (wpos < file->nbytes)
{
pgoff_t availbytes;
int64 availbytes;
instr_time io_start;
instr_time io_time;
@ -524,8 +524,8 @@ BufFileDumpBuffer(BufFile *file)
bytestowrite = file->nbytes - wpos;
availbytes = MAX_PHYSICAL_FILESIZE - file->curOffset;
if ((pgoff_t) bytestowrite > availbytes)
bytestowrite = (int) availbytes;
if (bytestowrite > availbytes)
bytestowrite = availbytes;
thisfile = file->files[file->curFile];
@ -794,7 +794,7 @@ BufFileSeek(BufFile *file, int fileno, pgoff_t offset, int whence)
* whether reading or writing, but buffer remains dirty if we were
* writing.
*/
file->pos = (int) (newOffset - file->curOffset);
file->pos = (int64) (newOffset - file->curOffset);
return 0;
}
/* Otherwise, must reposition buffer, so flush any dirty data */
@ -983,10 +983,10 @@ BufFileTruncateFileSet(BufFile *file, int fileno, pgoff_t offset)
{
/* No need to reset the current pos if the new pos is greater. */
if (newOffset <= file->curOffset + file->pos)
file->pos = (int) (newOffset - file->curOffset);
file->pos = (int64) newOffset - file->curOffset;
/* Adjust the nbytes for the current buffer. */
file->nbytes = (int) (newOffset - file->curOffset);
file->nbytes = (int64) newOffset - file->curOffset;
}
else if (newFile == file->curFile &&
newOffset < file->curOffset)