mirrors/Odin
1
0
Fork 0
mirror of https://github.com/odin-lang/Odin.git synced 2026-04-18 20:40:28 +00:00
Code Issues Packages Projects Releases Wiki Activity

Make read_at and write_at more consistent between platforms

Browse Source
This commit is contained in:
Colin Davidson
2023-05-06 17:14:11 -07:00
parent 9f39209712
commit 47693da4aa
1 changed files with 26 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
core/os/file_windows.odin
View File

@@ -220,6 +220,7 @@ file_size :: proc(fd: Handle) -> (i64, Errno) {
@(private)
MAX_RW :: 1<<30
ERROR_EOF :: 38
@(private)
pread :: proc(fd: Handle, data: []byte, offset: i64) -> (int, Errno) {
@@ -228,11 +229,6 @@ pread :: proc(fd: Handle, data: []byte, offset: i64) -> (int, Errno) {
buf = buf[:MAX_RW]
}
curr_offset, e := seek(fd, offset, 1)
if e != 0 {
return 0, e
}
defer seek(fd, curr_offset, 0)
o := win32.OVERLAPPED{
OffsetHigh = u32(offset>>32),
@@ -246,6 +242,11 @@ pread :: proc(fd: Handle, data: []byte, offset: i64) -> (int, Errno) {
if !win32.ReadFile(h, raw_data(buf), u32(len(buf)), &done, &o) {
e = Errno(win32.GetLastError())
done = 0
// this makes behavior between *nix and windows consistent when EOF is hit
if e == ERROR_EOF {
e = 0
}
}
return int(done), e
}
@@ -256,11 +257,6 @@ pwrite :: proc(fd: Handle, data: []byte, offset: i64) -> (int, Errno) {
buf = buf[:MAX_RW]
}
curr_offset, e := seek(fd, offset, 1)
if e != 0 {
return 0, e
}
defer seek(fd, curr_offset, 0)
o := win32.OVERLAPPED{
OffsetHigh = u32(offset>>32),
@@ -276,6 +272,16 @@ pwrite :: proc(fd: Handle, data: []byte, offset: i64) -> (int, Errno) {
return int(done), e
}
/*
read_at returns n: 0, err: 0 on EOF
on Windows, read_at changes the position of the file cursor, on *nix, it does not.
bytes: [8]u8{}
read_at(fd, bytes, 0)
read(fd, bytes)
will read from the location twice on *nix, and from two different locations on Windows
*/
read_at :: proc(fd: Handle, data: []byte, offset: i64) -> (n: int, err: Errno) {
if offset < 0 {
return 0, ERROR_NEGATIVE_OFFSET
@@ -294,6 +300,16 @@ read_at :: proc(fd: Handle, data: []byte, offset: i64) -> (n: int, err: Errno) {
}
return
}
/*
on Windows, write_at changes the position of the file cursor, on *nix, it does not.
bytes: [8]u8{}
write_at(fd, bytes, 0)
write(fd, bytes)
will write to the location twice on *nix, and to two different locations on Windows
*/
write_at :: proc(fd: Handle, data: []byte, offset: i64) -> (n: int, err: Errno) {
if offset < 0 {
return 0, ERROR_NEGATIVE_OFFSET