todo comment

src/main.rs

@@ -8,8 +8,16 @@ mod work;
 
 mod consts;
 
-pub const BUFSIZE: usize = 4096; // 4kb
-
 fn main() {
     println!("Hello, world!");
+    // todo:
+    //  - create and open output file
+    //  - open and stat all input files (`job::create_from_file`).
+    //  - `fallocate` the output file fd to the sum of all input file sizes
+    //  - `mmap` the output file as writable
+    //
+    //  - spawn the task thread pool
+    //  - dispatch jobs with their fds, stats, and calculated output offsets along with a reference to the output mapped file (`job::Prelude::start`)
+    //  - wait on all worker threads to complete.
+    //  - ensure all data was written.
 }

src/pool.rs

@@ -44,14 +44,14 @@ fn spawn_for_lazy(recv: state::PendingReceiver<Job>) -> impl Iterator<Item = Joi
 }
 
 /// Spawn the thread pool and return handles to the spawned threads as a `Pool`.
-#[inline] pub fn spawn_for_pool(recv: state::PendingReceiver<Job>) -> Pool
+#[inline] fn spawn_for_pool(recv: state::PendingReceiver<Job>) -> Pool
 {
     spawn_for_lazy(recv).collect()
 }
 
 /// Spawn and then immediately wait on a thread pool to complete.
 ///
-/// Has the same behaviour as `drop(spawn_for_pool(recv))` but skips a heap allocation.
+/// Has the same behaviour as `drop(spawn_for_pool(recv))` but skips a potential heap allocation.
 #[inline] pub fn spawn_for_and_join(recv: state::PendingReceiver<Job>)
 {
     join_all(spawn_for_lazy(recv));
@@ -125,3 +125,12 @@ impl Drop for Pool
 	}
     }
 }
+
+/// Spawn a thread pool.
+///
+/// The pool can be spawned in different ways, this uses the default one.
+/// The others are not made public except [`spawn_for_and_join`], as their behaviour differences are very subtle.
+#[inline(always)] pub fn pool(recv: state::PendingReceiver<Job>) -> Pool
+{
+    spawn_for_pool(recv)
+}

src/work.rs

@@ -1,14 +1,15 @@
 use super::*;
 use job::Job;
-use std::io::Read;
+use std::io::{self, Read};
 
-pub fn work_on(job: &mut Job) -> Result<usize, Box<dyn std::error::Error>>
+pub fn work_on(job: &mut Job) -> io::Result<usize>
 {
     let output = job.output_slice();
     let output = unsafe {
-	// Required because the compiler thinks we're mutably borrowing the same data later on, even though they are unrelated fields of the struct
+	// SAFETY: Required because the compiler thinks we're mutably borrowing the same data later on, even though they are unrelated fields of the struct
 	std::slice::from_raw_parts_mut(output.as_mut_ptr(), output.len())
     };
+    
     let mut read=0;
     while read < job.len() {
 	match job.read(&mut output[read..])? {