From 816f8746fb3936dae84672406913c2eb2c3eae52 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 20 Mar 2020 14:14:45 +0100
Subject: [PATCH] Implement a ScancodeStream type

---
 Cargo.lock           | 30 ++++++++++++++++++++++++++++++
 Cargo.toml           |  5 +++++
 src/main.rs          |  3 ++-
 src/task/keyboard.rs | 43 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index ad1356c5..67a5ba21 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -25,6 +25,7 @@ dependencies = [
  "bootloader",
  "conquer-once",
  "crossbeam-queue",
+ "futures-util",
  "lazy_static",
  "linked_list_allocator",
  "pc-keyboard",
@@ -86,6 +87,29 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "futures-core"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f25592f769825e89b92358db00d26f965761e094951ac44d3663ef25b7ac464a"
+
+[[package]]
+name = "futures-task"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b0a34e53cf6cdcd0178aa573aed466b646eb3db769570841fda0c7ede375a27"
+
+[[package]]
+name = "futures-util"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22766cf25d64306bedf0384da004d05c9974ab104fcc4528f1236181c18004c5"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "pin-utils",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -128,6 +152,12 @@ dependencies = [
  "cpuio",
 ]
 
+[[package]]
+name = "pin-utils"
+version = "0.1.0-alpha.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5894c618ce612a3fa23881b152b608bafb8c56cfc22f434a3ba3120b40f7b587"
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index 39198cd9..b0d0db9e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,6 +35,11 @@ features = ["alloc"]
 version = "0.2.0"
 default-features = false
 
+[dependencies.futures-util]
+version = "0.3.4"
+default-features = false
+features = ["alloc", "async-await"]
+
 [package.metadata.bootimage]
 test-args = [
     "-device", "isa-debug-exit,iobase=0xf4,iosize=0x04", "-serial", "stdio",
diff --git a/src/main.rs b/src/main.rs
index 40da8c06..2c0448f3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -15,7 +15,7 @@ entry_point!(kernel_main);
 fn kernel_main(boot_info: &'static BootInfo) -> ! {
     use blog_os::allocator;
     use blog_os::memory::{self, BootInfoFrameAllocator};
-    use blog_os::task::{simple_executor::SimpleExecutor, Task};
+    use blog_os::task::{simple_executor::SimpleExecutor, Task, keyboard::ScancodeStream};
     use x86_64::VirtAddr;
 
     println!("Hello World{}", "!");
@@ -29,6 +29,7 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
 
     let mut executor = SimpleExecutor::new();
     executor.spawn(Task::new(example_task()));
+    executor.spawn(Task::new(ScancodeStream::new().print_keypresses()));
     executor.run();
 
     #[cfg(test)]
diff --git a/src/task/keyboard.rs b/src/task/keyboard.rs
index 68f0029a..5f394a64 100644
--- a/src/task/keyboard.rs
+++ b/src/task/keyboard.rs
@@ -1,4 +1,47 @@
 use conquer_once::spin::OnceCell;
 use crossbeam_queue::ArrayQueue;
+use futures_util::stream::{Stream, StreamExt};
+use core::{pin::Pin, task::{Context, Poll}};
+use pc_keyboard::{layouts, DecodedKey, HandleControl, Keyboard, ScancodeSet1};
+use crate::print;
 
 static SCANCODE_QUEUE: OnceCell<ArrayQueue<u8>> = OnceCell::uninit();
+
+pub struct ScancodeStream;
+
+impl ScancodeStream {
+    pub fn new() -> Self {
+        SCANCODE_QUEUE.try_init_once(|| ArrayQueue::new(100))
+            .expect("ScancodeStream::new should only be called once");
+        ScancodeStream
+    }
+
+    pub async fn print_keypresses(mut self) {
+        let mut keyboard = Keyboard::new(layouts::Us104Key, ScancodeSet1, HandleControl::Ignore);
+
+        while let Some(scancode) = self.next().await {
+            if let Ok(Some(key_event)) = keyboard.add_byte(scancode) {
+                if let Some(key) = keyboard.process_keyevent(key_event) {
+                    match key {
+                        DecodedKey::Unicode(character) => print!("{}", character),
+                        DecodedKey::RawKey(key) => print!("{:?}", key),
+                    }
+                }
+            }
+        }
+    }
+}
+
+impl Stream for ScancodeStream {
+    type Item = u8;
+
+    fn poll_next(self: Pin<&mut Self>, context: &mut Context) -> Poll<Option<u8>> {
+        let queue = SCANCODE_QUEUE
+            .try_get()
+            .expect("scancode queue not initialized");
+        match queue.pop() {
+            Ok(scancode) => Poll::Ready(Some(scancode)),
+            Err(crossbeam_queue::PopError) => Poll::Pending,
+        }
+    }
+}