common.rs

use crate::io as std_io;
use core::sync::atomic::{AtomicUsize, Ordering::Relaxed};
use std_io::ErrorKind;
pub mod memchr {
    pub use core::slice::memchr::{memchr, memrchr};
}

// SAFETY: must be called only once during runtime initialization.
// NOTE: this is not guaranteed to run, for example when Rust code is called externally.
pub unsafe fn init(_argc: isize, _argv: *const *const u8, _sigpipe: u8) {
    // `sys::unix::init` normally does several things, none of which are
    // appropriate for postgrestd:
    //
    // 1. If fd 0/1/2 are closed, open them to `/dev/null` so that
    //    `std::sys::stdio` doesn't clobber something unexpected. This is not
    //    needed (and arguably wrong) for `postgrestd` because it does not
    //    expose stdio at all.
    //
    // 2. Reset sigpipe, which is bad because postgres has very strong opinions
    //    on its signal handlers.
    //
    // 3. Store program args into globals, but we do not expose args
    //
    // 4. Install guard pages, which should only be done once.
    //
    // 5. Register signal handlers for stack overflow, which should not be done
    //    from something which may be unloaded, and especially not from .
}

// SAFETY: must be called only once during runtime cleanup.
// NOTE: this is not guaranteed to run, for example when the program aborts.
pub unsafe fn cleanup() {}

pub fn unsupported<T>() -> std_io::Result<T> {
    Err(unsupported_err())
}

pub fn unsupported_err() -> std_io::Error {
    std_io::const_io_error!(
        std_io::ErrorKind::Unsupported,
        "operation not supported on this platform",
    )
}

pub fn decode_error_kind(errno: i32) -> ErrorKind {
    use ErrorKind::*;
    match errno as libc::c_int {
        libc::E2BIG => ArgumentListTooLong,
        libc::EADDRINUSE => AddrInUse,
        libc::EADDRNOTAVAIL => AddrNotAvailable,
        libc::EBUSY => ResourceBusy,
        libc::ECONNABORTED => ConnectionAborted,
        libc::ECONNREFUSED => ConnectionRefused,
        libc::ECONNRESET => ConnectionReset,
        libc::EDEADLK => Deadlock,
        libc::EDQUOT => FilesystemQuotaExceeded,
        libc::EEXIST => AlreadyExists,
        libc::EFBIG => FileTooLarge,
        libc::EHOSTUNREACH => HostUnreachable,
        libc::EINTR => Interrupted,
        libc::EINVAL => InvalidInput,
        libc::EISDIR => IsADirectory,
        libc::ELOOP => FilesystemLoop,
        libc::ENOENT => NotFound,
        libc::ENOMEM => OutOfMemory,
        libc::ENOSPC => StorageFull,
        libc::ENOSYS => Unsupported,
        libc::EMLINK => TooManyLinks,
        libc::ENAMETOOLONG => InvalidFilename,
        libc::ENETDOWN => NetworkDown,
        libc::ENETUNREACH => NetworkUnreachable,
        libc::ENOTCONN => NotConnected,
        libc::ENOTDIR => NotADirectory,
        libc::ENOTEMPTY => DirectoryNotEmpty,
        libc::EPIPE => BrokenPipe,
        libc::EROFS => ReadOnlyFilesystem,
        libc::ESPIPE => NotSeekable,
        libc::ESTALE => StaleNetworkFileHandle,
        libc::ETIMEDOUT => TimedOut,
        libc::ETXTBSY => ExecutableFileBusy,
        libc::EXDEV => CrossesDevices,

        libc::EACCES | libc::EPERM => PermissionDenied,

        // These two constants can have the same value on some systems,
        // but different values on others, so we can't use a match
        // clause
        x if x == libc::EAGAIN || x == libc::EWOULDBLOCK => WouldBlock,

        _ => Uncategorized,
    }
}

pub fn abort_internal() -> ! {
    // Aborting is bad for pg, but we end up crashing if we panic in several of
    // these anyway, and aborting is at least a clean exit.
    core::intrinsics::abort();
}