use memmap2::{Mmap, MmapOptions};
use std::ops::Deref;
use std::fs::File;
use std::fmt::Display;
use std::io::{Seek, SeekFrom::Start};
use crate::headers::{NitfHeader, NitfSegmentHeader};
#[derive(Default, Debug, Clone, Eq, PartialEq)]
pub struct FileHeader {
pub meta: NitfHeader,
pub header_size: u64,
}
impl FileHeader {
pub fn read(&mut self, reader: &mut File) {
self.meta.read(reader);
self.header_size = reader.stream_position().unwrap();
}
}
impl Display for FileHeader {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.meta)
}
}
#[derive(Debug)]
pub struct NitfSegment<T: NitfSegmentHeader> {
pub meta: T,
pub data: Mmap,
pub header_offset: u64,
pub header_size: u32,
pub data_offset: u64,
pub data_size: u64,
}
impl<T: NitfSegmentHeader> NitfSegment<T> {
pub fn initialize(reader: &mut File, header_size: u32, data_size: u64) -> Self {
let header_offset = reader.stream_position().unwrap();
let header_size = header_size;
let data_size = data_size;
let data_offset = header_offset + header_size as u64;
let meta = T::from_reader(reader);
let mut memmap_opts = MmapOptions::new();
let data = unsafe {
memmap_opts
.offset(data_offset)
.len(data_size as usize)
.map(reader.deref())
.unwrap()
};
reader.seek(Start(data_offset + data_size)).unwrap();
Self {
meta,
data,
header_offset,
header_size,
data_size,
data_offset,
}
}
}
impl<T: NitfSegmentHeader + Display> Display for NitfSegment<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.meta)
}
}
impl<T: NitfSegmentHeader + PartialEq> PartialEq for NitfSegment<T> {
fn eq(&self, other: &Self) -> bool {
let b0 = self.meta == other.meta;
let b1 = self.header_offset == other.header_offset;
let b2 = self.header_size == other.header_size;
let b3 = self.data_offset == other.data_offset;
let b4 = self.data_size == other.data_size;
b0 & b1 & b2 & b3 & b4
}
}
impl<T: NitfSegmentHeader + Eq> Eq for NitfSegment<T> {}