From c821a68da70c8de58adad65a4599a9447fa360ee Mon Sep 17 00:00:00 2001
From: Lofty <dan.ravensloft@gmail.com>
Date: Mon, 21 Nov 2022 02:48:00 +0000
Subject: [PATCH] awooter: add net import code

---
 common/route/awooter.cc               | 23 +++++++++++++--
 common/route/awooter/rust/src/lib.rs  | 22 +++++++++++++--
 common/route/awooter/rust/src/npnr.rs | 40 +++++++++++++++++++++++----
 common/route/awooter/rust/src/part.rs |  6 ----
 4 files changed, 76 insertions(+), 15 deletions(-)
 delete mode 100644 common/route/awooter/rust/src/part.rs

diff --git a/common/route/awooter.cc b/common/route/awooter.cc
index 39592d0b..8426473d 100644
--- a/common/route/awooter.cc
+++ b/common/route/awooter.cc
@@ -127,11 +127,30 @@ extern "C" {
 
     void npnr_context_check(const Context *const ctx) { ctx->check(); }
     bool npnr_context_debug(const Context *const ctx) { return ctx->debug; }
-    IdString npnr_context_id(const Context *const ctx, const char *const str) { return ctx->id(str); }
+    int npnr_context_id(const Context *const ctx, const char *const str) { return ctx->id(str).hash(); }
     const char *npnr_context_name_of(const Context *const ctx, IdString str) { return ctx->nameOf(str); }
     bool npnr_context_verbose(const Context *const ctx) { return ctx->verbose; }
 
-    //NetInfo** npnr_context_nets(Context *ctx) { /* oh no */ }
+    // Yes, this is quadratic. It gets imported once and then never worried about again.
+    // There are bigger fish to fry.
+    int npnr_context_nets_key(Context *ctx, uint32_t n) {
+        for (auto& item : ctx->nets) {
+            if (n == 0) {
+                return item.first.hash();
+            }
+            n--;
+        }
+        return 0;
+    }
+    NetInfo* npnr_context_nets_value(Context *ctx, uint32_t n) {
+        for (auto& item : ctx->nets) {
+            if (n == 0) {
+                return item.second.get();
+            }
+            n--;
+        }
+        return nullptr;
+    }
 
     extern bool npnr_router_awooter(Context *ctx);
 }
diff --git a/common/route/awooter/rust/src/lib.rs b/common/route/awooter/rust/src/lib.rs
index 1278efd4..a479f464 100644
--- a/common/route/awooter/rust/src/lib.rs
+++ b/common/route/awooter/rust/src/lib.rs
@@ -2,7 +2,21 @@ use std::ptr::NonNull;
 
 #[macro_use]
 mod npnr;
-mod part;
+
+enum Subpartition {
+    Part(Box<Partition>),
+    Nets(Vec<Net>),
+}
+
+struct Partition {
+    parts: [Option<Subpartition>; 4],
+    borders: [[Vec<npnr::WireId>; 4]; 4]
+}
+
+struct Net {
+    source: npnr::WireId,
+    sinks: Vec<npnr::WireId>
+}
 
 #[no_mangle]
 pub extern "C" fn npnr_router_awooter(ctx: Option<NonNull<npnr::Context>>) -> bool {
@@ -25,7 +39,11 @@ fn route(ctx: &mut npnr::Context) -> bool {
         ctx.grid_dim_x(),
         ctx.grid_dim_y()
     );
-    // let _belid = npnr::BelId::null();
+    let _belid = npnr::BelId::null();
     log_info!("Managed to survive BelId()\n");
+
+    let nets = npnr::NetIter::new(ctx).into_iter().collect::<Vec<_>>();
+    log_info!("Found {} nets\n", nets.len());
+
     true
 }
\ No newline at end of file
diff --git a/common/route/awooter/rust/src/npnr.rs b/common/route/awooter/rust/src/npnr.rs
index 408555b5..173514e4 100644
--- a/common/route/awooter/rust/src/npnr.rs
+++ b/common/route/awooter/rust/src/npnr.rs
@@ -1,4 +1,4 @@
-use std::ffi::CStr;
+use std::{ffi::CStr, collections::binary_heap::Iter};
 
 use libc::c_char;
 
@@ -24,10 +24,8 @@ pub struct NetInfo {
     private: [u8; 0],
 }
 
-#[repr(C)]
-pub struct IdString {
-    index: libc::c_int,
-}
+#[repr(transparent)]
+pub struct IdString(libc::c_int);
 
 /// A type representing a bel name.
 #[derive(Clone, Copy)]
@@ -200,9 +198,41 @@ extern "C" {
     fn npnr_context_name_of(ctx: *const Context, s: IdString) -> *const libc::c_char;
     fn npnr_context_verbose(ctx: *const Context) -> bool;
 
+    fn npnr_context_nets_key(ctx: *const Context, n: u32) -> IdString;
+    fn npnr_context_nets_value(ctx: *const Context, n: u32) -> *mut NetInfo;
     // fn npnr_context_nets(ctx: *const Context) -> *mut *mut NetInfo;
 }
 
+/// In case you missed the C++ comment; this is O(n^2) because FFI is misert.
+/// It's probably best to run it exactly once.
+pub struct NetIter<'a> {
+    ctx: &'a Context,
+    n: u32
+}
+
+impl<'a> NetIter<'a> {
+    pub fn new(ctx: &'a Context) -> Self {
+        Self {
+            ctx,
+            n: 0
+        }
+    }
+}
+
+impl<'a> Iterator for NetIter<'a> {
+    type Item = (IdString, *mut NetInfo);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let str = unsafe { npnr_context_nets_key(self.ctx, self.n) };
+        let val = unsafe { npnr_context_nets_value(self.ctx, self.n) };
+        if val.is_null() {
+            return None;
+        }
+        self.n += 1;
+        Some((str, val))
+    }
+}
+
 macro_rules! log_info {
     ($($t:tt)*) => {
         let s = std::ffi::CString::new(format!($($t)*)).unwrap();
diff --git a/common/route/awooter/rust/src/part.rs b/common/route/awooter/rust/src/part.rs
deleted file mode 100644
index daeec3f3..00000000
--- a/common/route/awooter/rust/src/part.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-use crate::npnr;
-
-pub struct Partition {
-    parts: [Option<Box<Partition>>; 4],
-    borders: [[Vec<npnr::WireId>; 4]; 4]
-}