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use crate::{
mem_writer::{Buffer, MemoryArrayWriter, MemoryWriterError},
minidump_format::MDRawDirectory,
};
use std::io::{Error, Seek, Write};
pub type DumpBuf = Buffer;
#[derive(Debug, thiserror::Error)]
pub enum FileWriterError {
#[error("IO error")]
IOError(#[from] Error),
#[error("Failed to write to memory")]
MemoryWriterError(#[from] MemoryWriterError),
}
/// Utility that wraps writing minidump directory entries to an I/O stream, generally
/// a [`std::fs::File`].
#[derive(Debug)]
pub struct DirSection<'a, W>
where
W: Write + Seek,
{
curr_idx: usize,
section: MemoryArrayWriter<MDRawDirectory>,
/// If we have to append to some file, we have to know where we currently are
destination_start_offset: u64,
destination: &'a mut W,
last_position_written_to_file: u64,
}
impl<'a, W> DirSection<'a, W>
where
W: Write + Seek,
{
pub fn new(
buffer: &mut DumpBuf,
index_length: u32,
destination: &'a mut W,
) -> std::result::Result<Self, FileWriterError> {
let dir_section =
MemoryArrayWriter::<MDRawDirectory>::alloc_array(buffer, index_length as usize)?;
Ok(Self {
curr_idx: 0,
section: dir_section,
destination_start_offset: destination.stream_position()?,
destination,
last_position_written_to_file: 0,
})
}
#[inline]
pub fn position(&self) -> u32 {
self.section.position
}
pub fn dump_dir_entry(
&mut self,
buffer: &mut DumpBuf,
dirent: MDRawDirectory,
) -> std::result::Result<(), FileWriterError> {
self.section.set_value_at(buffer, dirent, self.curr_idx)?;
// Now write it to file
// First get all the positions
let curr_file_pos = self.destination.stream_position()?;
let idx_pos = self.section.location_of_index(self.curr_idx);
self.curr_idx += 1;
self.destination.seek(std::io::SeekFrom::Start(
self.destination_start_offset + idx_pos.rva as u64,
))?;
let start = idx_pos.rva as usize;
let end = (idx_pos.rva + idx_pos.data_size) as usize;
self.destination.write_all(&buffer[start..end])?;
// Reset file-position
self.destination
.seek(std::io::SeekFrom::Start(curr_file_pos))?;
Ok(())
}
/// Writes 2 things to file:
/// 1. The given dirent into the dir section in the header (if any is given)
/// 2. Everything in the in-memory buffer that was added since the last call to this function
pub fn write_to_file(
&mut self,
buffer: &mut DumpBuf,
dirent: Option<MDRawDirectory>,
) -> std::result::Result<(), FileWriterError> {
if let Some(dirent) = dirent {
self.dump_dir_entry(buffer, dirent)?;
}
let start_pos = self.last_position_written_to_file as usize;
self.destination.write_all(&buffer[start_pos..])?;
self.last_position_written_to_file = buffer.position();
Ok(())
}
}