152 lines
3.2 KiB
Rust
152 lines
3.2 KiB
Rust
//! Binary data conversion utilities.
|
|
|
|
use crate::durandal::err::*;
|
|
use serde::Serialize;
|
|
use std::{fmt, num::NonZeroU16, slice::SliceIndex};
|
|
|
|
/// Returns a byte array from `b` at `i`.
|
|
pub fn c_data<I>(b: &[u8], i: I) -> ResultS<&<I as SliceIndex<[u8]>>::Output>
|
|
where I: SliceIndex<[u8]>
|
|
{
|
|
ok!(b.get(i), "not enough data")
|
|
}
|
|
|
|
/// Returns a byte from `b` at `i`.
|
|
pub fn c_byte(b: &[u8], i: usize) -> ResultS<u8>
|
|
{
|
|
match b.get(i) {
|
|
Some(&v) => Ok(v),
|
|
None => Err(err_msg("not enough data")),
|
|
}
|
|
}
|
|
|
|
/// Returns a four-character-code identifier from `b` at `i`.
|
|
pub fn c_iden(b: &[u8], i: usize) -> ResultS<Ident>
|
|
{
|
|
ok!(o_iden(b, i), "not enough data")
|
|
}
|
|
|
|
/// Returns a big-endian `u32` from `b` at `i`.
|
|
pub fn c_u32b(b: &[u8], i: usize) -> ResultS<u32>
|
|
{
|
|
ok!(o_u32b(b, i), "not enough data")
|
|
}
|
|
|
|
/// Returns a big-endian `u16` from `b` at `i`.
|
|
pub fn c_u16b(b: &[u8], i: usize) -> ResultS<u16>
|
|
{
|
|
ok!(o_u16b(b, i), "not enough data")
|
|
}
|
|
|
|
/// Returns a big-endian `i32` from `b` at `i`.
|
|
pub fn c_i32b(b: &[u8], i: usize) -> ResultS<i32>
|
|
{
|
|
ok!(o_i32b(b, i), "not enough data")
|
|
}
|
|
|
|
/// Returns a big-endian `i16` from `b` at `i`.
|
|
pub fn c_i16b(b: &[u8], i: usize) -> ResultS<i16>
|
|
{
|
|
ok!(o_i16b(b, i), "not enough data")
|
|
}
|
|
|
|
/// Returns a four-character-code identifier from `b` at `i`.
|
|
pub fn o_iden(b: &[u8], i: usize) -> Option<Ident>
|
|
{
|
|
if i + 3 < b.len() {
|
|
Some([b[i], b[i + 1], b[i + 2], b[i + 3]])
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Returns a big-endian `u32` from `b` at `i`.
|
|
pub fn o_u32b(b: &[u8], i: usize) -> Option<u32>
|
|
{
|
|
if i + 3 < b.len() {
|
|
Some(u32::from_be_bytes([b[i], b[i + 1], b[i + 2], b[i + 3]]))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Returns a big-endian `u16` from `b` at `i`.
|
|
pub fn o_u16b(b: &[u8], i: usize) -> Option<u16>
|
|
{
|
|
if i + 1 < b.len() {
|
|
Some(u16::from_be_bytes([b[i], b[i + 1]]))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
/// Returns a big-endian `i32` from `b` at `i`.
|
|
pub fn o_i32b(b: &[u8], i: usize) -> Option<i32>
|
|
{
|
|
match o_u32b(b, i) {
|
|
Some(n) => Some(n as i32),
|
|
None => None,
|
|
}
|
|
}
|
|
|
|
/// Returns a big-endian `i16` from `b` at `i`.
|
|
pub fn o_i16b(b: &[u8], i: usize) -> Option<i16>
|
|
{
|
|
match o_u16b(b, i) {
|
|
Some(n) => Some(n as i16),
|
|
None => None,
|
|
}
|
|
}
|
|
|
|
impl ObjID
|
|
{
|
|
/// Creates an `ObjID` from a `u16`.
|
|
pub fn from_repr(n: u16) -> ObjID
|
|
{
|
|
if n == u16::max_value() {
|
|
ObjID(None)
|
|
} else {
|
|
ObjID(NonZeroU16::new(n + 1))
|
|
}
|
|
}
|
|
|
|
/// Returns the `u16` representation of an `ObjID`.
|
|
pub fn get_repr(&self) -> u16
|
|
{
|
|
match self.0 {
|
|
None => u16::max_value(),
|
|
Some(n) => n.get() - 1,
|
|
}
|
|
}
|
|
|
|
/// Returns the `Option` representation of an `ObjID`.
|
|
pub fn get(&self) -> Option<u16>
|
|
{
|
|
match self.0 {
|
|
None => None,
|
|
Some(n) => Some(n.get()),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for ObjID
|
|
{
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result
|
|
{
|
|
match self.0 {
|
|
None => write!(f, "ObjID(None)"),
|
|
Some(n) => write!(f, "ObjID({})", n.get()),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A four-character-code identifier.
|
|
pub type Ident = [u8; 4];
|
|
|
|
/// An object identified by a `u16` which may be `u16::max_value()` to
|
|
/// represent None.
|
|
#[derive(Serialize)]
|
|
pub struct ObjID(Option<NonZeroU16>);
|
|
|
|
// EOF
|