.Dd January 24, 2024
.Dt SQLITE_IOCAP_ATOMIC 3
.Os
.Sh NAME
.Nm SQLITE_IOCAP_ATOMIC ,
.Nm SQLITE_IOCAP_ATOMIC512 ,
.Nm SQLITE_IOCAP_ATOMIC1K ,
.Nm SQLITE_IOCAP_ATOMIC2K ,
.Nm SQLITE_IOCAP_ATOMIC4K ,
.Nm SQLITE_IOCAP_ATOMIC8K ,
.Nm SQLITE_IOCAP_ATOMIC16K ,
.Nm SQLITE_IOCAP_ATOMIC32K ,
.Nm SQLITE_IOCAP_ATOMIC64K ,
.Nm SQLITE_IOCAP_SAFE_APPEND ,
.Nm SQLITE_IOCAP_SEQUENTIAL ,
.Nm SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN ,
.Nm SQLITE_IOCAP_POWERSAFE_OVERWRITE ,
.Nm SQLITE_IOCAP_IMMUTABLE ,
.Nm SQLITE_IOCAP_BATCH_ATOMIC
.Nd device characteristics
.Sh SYNOPSIS
.In sqlite3.h
.Fd #define SQLITE_IOCAP_ATOMIC
.Fd #define SQLITE_IOCAP_ATOMIC512
.Fd #define SQLITE_IOCAP_ATOMIC1K
.Fd #define SQLITE_IOCAP_ATOMIC2K
.Fd #define SQLITE_IOCAP_ATOMIC4K
.Fd #define SQLITE_IOCAP_ATOMIC8K
.Fd #define SQLITE_IOCAP_ATOMIC16K
.Fd #define SQLITE_IOCAP_ATOMIC32K
.Fd #define SQLITE_IOCAP_ATOMIC64K
.Fd #define SQLITE_IOCAP_SAFE_APPEND
.Fd #define SQLITE_IOCAP_SEQUENTIAL
.Fd #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
.Fd #define SQLITE_IOCAP_POWERSAFE_OVERWRITE
.Fd #define SQLITE_IOCAP_IMMUTABLE
.Fd #define SQLITE_IOCAP_BATCH_ATOMIC
.Sh DESCRIPTION
The xDeviceCharacteristics method of the sqlite3_io_methods
object returns an integer which is a vector of these bit values expressing
I/O characteristics of the mass storage device that holds the file
that the sqlite3_io_methods refers to.
.Pp
The SQLITE_IOCAP_ATOMIC property means that all writes of any size
are atomic.
The SQLITE_IOCAP_ATOMICnnn values mean that writes of blocks that are
nnn bytes in size and are aligned to an address which is an integer
multiple of nnn are atomic.
The SQLITE_IOCAP_SAFE_APPEND value means that when data is appended
to a file, the data is appended first then the size of the file is
extended, never the other way around.
The SQLITE_IOCAP_SEQUENTIAL property means that information is written
to disk in the same order as calls to xWrite().
The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that after reboot
following a crash or power loss, the only bytes in a file that were
written at the application level might have changed and that adjacent
bytes, even bytes within the same sector are guaranteed to be unchanged.
The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN flag indicates that a file cannot
be deleted when open.
The SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on read-only
media and cannot be changed even by processes with elevated privileges.
.Pp
The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying filesystem
supports doing multiple write operations atomically when those write
operations are bracketed by SQLITE_FCNTL_BEGIN_ATOMIC_WRITE
and SQLITE_FCNTL_COMMIT_ATOMIC_WRITE.
.Sh IMPLEMENTATION NOTES
These declarations were extracted from the
interface documentation at line 622.
.Bd -literal
#define SQLITE_IOCAP_ATOMIC                 0x00000001
#define SQLITE_IOCAP_ATOMIC512              0x00000002
#define SQLITE_IOCAP_ATOMIC1K               0x00000004
#define SQLITE_IOCAP_ATOMIC2K               0x00000008
#define SQLITE_IOCAP_ATOMIC4K               0x00000010
#define SQLITE_IOCAP_ATOMIC8K               0x00000020
#define SQLITE_IOCAP_ATOMIC16K              0x00000040
#define SQLITE_IOCAP_ATOMIC32K              0x00000080
#define SQLITE_IOCAP_ATOMIC64K              0x00000100
#define SQLITE_IOCAP_SAFE_APPEND            0x00000200
#define SQLITE_IOCAP_SEQUENTIAL             0x00000400
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
#define SQLITE_IOCAP_IMMUTABLE              0x00002000
#define SQLITE_IOCAP_BATCH_ATOMIC           0x00004000
.Ed
.Sh SEE ALSO
.Xr sqlite3_io_methods 3 ,
.Xr SQLITE_FCNTL_LOCKSTATE 3