remove vestigial prolog/ directory (#444)

src/machine/heap.rs

@@ -0,0 +1,544 @@
+use core::marker::PhantomData;
+
+use crate::prolog_parser::ast::Constant;
+
+use crate::machine::machine_indices::*;
+use crate::machine::partial_string::*;
+use crate::machine::raw_block::*;
+
+use std::convert::TryFrom;
+use std::mem;
+use std::ops::{Index, IndexMut};
+use std::ptr;
+
+#[derive(Debug)]
+pub(crate) struct StandardHeapTraits {}
+
+impl RawBlockTraits for StandardHeapTraits {
+    #[inline]
+    fn init_size() -> usize {
+        256 * mem::size_of::<HeapCellValue>()
+    }
+
+    #[inline]
+    fn align() -> usize {
+        mem::align_of::<HeapCellValue>()
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct HeapTemplate<T: RawBlockTraits> {
+    buf: RawBlock<T>,
+    _marker: PhantomData<HeapCellValue>,
+}
+
+pub(crate) type Heap = HeapTemplate<StandardHeapTraits>;
+
+impl<T: RawBlockTraits> Drop for HeapTemplate<T> {
+    fn drop(&mut self) {
+        self.clear();
+        self.buf.deallocate();
+    }
+}
+
+#[derive(Debug)]
+pub(crate)
+struct HeapIntoIter<T: RawBlockTraits> {
+    offset: usize,
+    buf: RawBlock<T>,
+}
+
+impl<T: RawBlockTraits> Drop for HeapIntoIter<T> {
+    fn drop(&mut self) {
+        let mut heap =
+            HeapTemplate { buf: self.buf.take(), _marker: PhantomData };
+
+        heap.truncate(self.offset / mem::size_of::<HeapCellValue>());
+        heap.buf.deallocate();
+    }
+}
+
+impl<T: RawBlockTraits> Iterator for HeapIntoIter<T> {
+    type Item = HeapCellValue;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let ptr = self.buf.base as usize + self.offset;
+        self.offset += mem::size_of::<HeapCellValue>();
+
+        if ptr < self.buf.top as usize {
+            unsafe {
+                Some(ptr::read(ptr as *const HeapCellValue))
+            }
+        } else {
+            None
+        }
+    }
+}
+
+#[derive(Debug)]
+pub(crate)
+struct HeapIter<'a, T: RawBlockTraits> {
+    offset: usize,
+    buf: &'a RawBlock<T>,
+}
+
+impl<'a, T: RawBlockTraits> HeapIter<'a, T> {
+    pub(crate)
+    fn new(buf: &'a RawBlock<T>, offset: usize) -> Self {
+        HeapIter { buf, offset }
+    }
+}
+
+impl<'a, T: RawBlockTraits> Iterator for HeapIter<'a, T> {
+    type Item = &'a HeapCellValue;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let ptr = self.buf.base as usize + self.offset;
+        self.offset += mem::size_of::<HeapCellValue>();
+
+        if ptr < self.buf.top as usize {
+            unsafe {
+                Some(&*(ptr as *const _))
+            }
+        } else {
+            None
+        }
+    }
+}
+
+#[allow(dead_code)]
+pub(crate)
+fn print_heap_terms<'a, I: Iterator<Item = &'a HeapCellValue>>(heap: I, h: usize) {
+    for (index, term) in heap.enumerate() {
+        println!("{} : {}", h + index, term);
+    }
+}
+
+#[derive(Debug)]
+pub(crate)
+struct HeapIterMut<'a, T: RawBlockTraits> {
+    offset: usize,
+    buf: &'a mut RawBlock<T>,
+}
+
+impl<'a, T: RawBlockTraits> HeapIterMut<'a, T> {
+    pub(crate)
+    fn new(buf: &'a mut RawBlock<T>, offset: usize) -> Self {
+        HeapIterMut { buf, offset }
+    }
+}
+
+impl<'a, T: RawBlockTraits> Iterator for HeapIterMut<'a, T> {
+    type Item = &'a mut HeapCellValue;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let ptr = self.buf.base as usize + self.offset;
+        self.offset += mem::size_of::<HeapCellValue>();
+
+        if ptr < self.buf.top as usize {
+            unsafe {
+                Some(&mut *(ptr as *mut _))
+            }
+        } else {
+            None
+        }
+    }
+}
+
+impl<T: RawBlockTraits> HeapTemplate<T> {
+    #[inline]
+    pub(crate)
+    fn new() -> Self {
+        HeapTemplate { buf: RawBlock::new(), _marker: PhantomData }
+    }
+
+    #[inline]
+    pub(crate)
+    fn clone(&self, h: usize) -> HeapCellValue {
+        match &self[h] {
+            &HeapCellValue::Addr(addr) => {
+                HeapCellValue::Addr(addr)
+            }
+            &HeapCellValue::Atom(ref name, ref op) => {
+                HeapCellValue::Atom(name.clone(), op.clone())
+            }
+            &HeapCellValue::DBRef(ref db_ref) => {
+                HeapCellValue::DBRef(db_ref.clone())
+            }
+            &HeapCellValue::Integer(ref n) => {
+                HeapCellValue::Integer(n.clone())
+            }
+            &HeapCellValue::NamedStr(arity, ref name, ref op) => {
+                HeapCellValue::NamedStr(arity, name.clone(), op.clone())
+            }
+            &HeapCellValue::PartialString(..) => {
+                HeapCellValue::Addr(Addr::PStrLocation(h, 0))
+            }
+            &HeapCellValue::Rational(ref r) => {
+                HeapCellValue::Rational(r.clone())
+            }
+            &HeapCellValue::Stream(_) => {
+                HeapCellValue::Addr(Addr::Stream(h))
+            }
+            &HeapCellValue::TcpListener(_) => {
+                HeapCellValue::Addr(Addr::TcpListener(h))
+            }
+        }
+    }
+
+    #[inline]
+    pub(crate)
+    fn put_complete_string(&mut self, s: &str) -> Addr {
+        if s.is_empty() {
+            return Addr::EmptyList;
+        }
+
+        let addr = self.allocate_pstr(s);
+        self.pop();
+
+        let h = self.h();
+
+        match &mut self[h - 1] {
+            &mut HeapCellValue::PartialString(_, ref mut has_tail) => {
+                *has_tail = false;
+            }
+            _ => {
+                unreachable!()
+            }
+        }
+
+        addr
+    }
+
+    #[inline]
+    pub(crate)
+    fn put_constant(&mut self, c: Constant) -> Addr {
+        match c {
+            Constant::Atom(name, op) => {
+                Addr::Con(self.push(HeapCellValue::Atom(name, op)))
+            }
+            Constant::Char(c) => {
+                Addr::Char(c)
+            }
+            Constant::EmptyList => {
+                Addr::EmptyList
+            }
+            Constant::Fixnum(n) => {
+                Addr::Fixnum(n)
+            }
+            Constant::Integer(n) => {
+                Addr::Con(self.push(HeapCellValue::Integer(n)))
+            }
+            Constant::Rational(r) => {
+                Addr::Con(self.push(HeapCellValue::Rational(r)))
+            }
+            Constant::Float(f) => {
+                Addr::Float(f)
+            }
+            Constant::String(s) => {
+                if s.is_empty() {
+                    Addr::EmptyList
+                } else {
+                    self.put_complete_string(&s)
+                }
+            }
+            Constant::Usize(n) => {
+                Addr::Usize(n)
+            }
+        }
+    }
+
+    #[inline]
+    pub(crate)
+    fn pop(&mut self) {
+        let h = self.h();
+
+        if h > 0 {
+            self.truncate(h - 1);
+        }
+    }
+
+    #[inline]
+    pub(crate)
+    fn push(&mut self, val: HeapCellValue) -> usize {
+        let h = self.h();
+
+        unsafe {
+            let new_top = self.buf.new_block(mem::size_of::<HeapCellValue>());
+            ptr::write(self.buf.top as *mut _, val);
+            self.buf.top = new_top;
+        }
+
+        h
+    }
+
+    #[inline]
+    pub(crate)
+    fn atom_at(&self, h: usize) -> bool {
+        if let HeapCellValue::Atom(..) = &self[h] {
+            true
+        } else {
+            false
+        }
+    }
+
+    #[inline]
+    pub(crate)
+    fn to_unifiable(&mut self, non_heap_value: HeapCellValue) -> Addr {
+        match non_heap_value {
+            HeapCellValue::Addr(addr) => {
+                addr
+            }
+            val @ HeapCellValue::Atom(..) |
+            val @ HeapCellValue::Integer(_) |
+            val @ HeapCellValue::DBRef(_) |
+            val @ HeapCellValue::Rational(_) => {
+                Addr::Con(self.push(val))
+            }
+            val @ HeapCellValue::NamedStr(..) => {
+                Addr::Str(self.push(val))
+            }
+            HeapCellValue::PartialString(pstr, has_tail) => {
+                let h = self.push(HeapCellValue::PartialString(pstr, has_tail));
+
+                if has_tail {
+                    self.push(HeapCellValue::Addr(Addr::EmptyList));
+                }
+
+                Addr::Con(h)
+            }
+            val @ HeapCellValue::Stream(..) => {
+                Addr::Stream(self.push(val))
+            }
+            val @ HeapCellValue::TcpListener(..) => {
+                Addr::TcpListener(self.push(val))
+            }
+        }
+    }
+
+    #[inline]
+    pub(crate)
+    fn allocate_pstr(&mut self, src: &str) -> Addr {
+        self.write_pstr(src)
+            .unwrap_or_else(|| Addr::EmptyList)
+    }
+
+    #[inline]
+    fn write_pstr(&mut self, mut src: &str) -> Option<Addr> {
+        let orig_h = self.h();
+
+        loop {
+            if src == "" {
+                return if orig_h == self.h() {
+                    None
+                } else {
+                    let tail_h = self.h() - 1;
+                    self[tail_h] = HeapCellValue::Addr(Addr::HeapCell(tail_h));
+
+                    Some(Addr::PStrLocation(orig_h, 0))
+                };
+            }
+
+            let h = self.h();
+
+            let (pstr, rest_src) =
+                match PartialString::new(src) {
+                    Some(tuple) => {
+                        tuple
+                    }
+                    None => {
+                        if src.len() > '\u{0}'.len_utf8() {
+                            src = &src['\u{0}'.len_utf8() ..];
+                            continue;
+                        } else if orig_h == h {
+                            return None;
+                        } else {
+                            self[h - 1] = HeapCellValue::Addr(Addr::HeapCell(h - 1));
+                            return Some(Addr::PStrLocation(orig_h, 0));
+                        }
+                    }
+                };
+
+            self.push(HeapCellValue::PartialString(pstr, true));
+
+            if rest_src != "" {
+                self.push(HeapCellValue::Addr(Addr::PStrLocation(h + 2, 0)));
+                src = rest_src;
+            } else {
+                self.push(HeapCellValue::Addr(Addr::HeapCell(h + 1)));
+                return Some(Addr::PStrLocation(orig_h, 0));
+            }
+        }
+    }
+
+    #[inline]
+    pub(crate)
+    fn take(&mut self) -> Self {
+        HeapTemplate {
+            buf: self.buf.take(),
+            _marker: PhantomData,
+        }
+    }
+
+    #[inline]
+    pub(crate)
+    fn truncate(&mut self, h: usize) {
+        let new_top = h * mem::size_of::<HeapCellValue>() + self.buf.base as usize;
+        let mut h = new_top;
+
+        unsafe {
+            while h as *const _ < self.buf.top {
+                let val = h as *mut HeapCellValue;
+                ptr::drop_in_place(val);
+                h += mem::size_of::<HeapCellValue>();
+            }
+        }
+
+        self.buf.top = new_top as *const _;
+    }
+
+    #[inline]
+    pub(crate)
+    fn h(&self) -> usize {
+        (self.buf.top as usize - self.buf.base as usize) / mem::size_of::<HeapCellValue>()
+    }
+
+    pub(crate)
+    fn append(&mut self, vals: Vec<HeapCellValue>) {
+        for val in vals {
+            self.push(val);
+        }
+    }
+
+    pub(crate)
+    fn clear(&mut self) {
+        if !self.buf.base.is_null() {
+            self.truncate(0);
+            self.buf.top = self.buf.base;
+        }
+    }
+
+    pub(crate)
+    fn to_list<Iter, SrcT>(&mut self, values: Iter) -> usize
+        where Iter: Iterator<Item = SrcT>,
+              SrcT: Into<HeapCellValue>
+    {
+        let head_addr = self.h();
+        let mut h = head_addr;
+
+        for value in values.map(|v| v.into()) {
+            self.push(HeapCellValue::Addr(Addr::Lis(h + 1)));
+            self.push(value);
+
+            h += 2;
+        }
+
+        self.push(HeapCellValue::Addr(Addr::EmptyList));
+
+        head_addr
+    }
+
+    /* Create an iterator starting from the passed offset. */
+    pub(crate)
+    fn iter_from<'a>(&'a self, offset: usize) -> HeapIter<'a, T> {
+        HeapIter::new(&self.buf, offset * mem::size_of::<HeapCellValue>())
+    }
+
+    pub(crate)
+    fn iter_mut_from<'a>(&'a mut self, offset: usize) -> HeapIterMut<'a, T> {
+        HeapIterMut::new(&mut self.buf, offset * mem::size_of::<HeapCellValue>())
+    }
+
+    pub(crate)
+    fn into_iter(mut self) -> HeapIntoIter<T> {
+        HeapIntoIter { buf: self.buf.take(), offset: 0 }
+    }
+
+    pub(crate)
+    fn extend<Iter: Iterator<Item = HeapCellValue>>(&mut self, iter: Iter) {
+        for hcv in iter {
+            self.push(hcv);
+        }
+    }
+
+    pub(crate)
+    fn to_local_code_ptr(&self, addr: &Addr) -> Option<LocalCodePtr> {
+        let extract_integer = |s: usize| -> Option<usize> {
+            match &self[s] {
+                &HeapCellValue::Addr(Addr::Fixnum(n)) => usize::try_from(n).ok(),
+                &HeapCellValue::Integer(ref n) => n.to_usize(),
+                _ => None
+            }
+        };
+
+        match addr {
+            Addr::Str(s) => {
+                match &self[*s] {
+                    HeapCellValue::NamedStr(arity, ref name, _) => {
+                        match (name.as_str(), *arity) {
+                            ("dir_entry", 1) => {
+                                extract_integer(s+1).map(LocalCodePtr::DirEntry)
+                            }
+                            ("in_situ_dir_entry", 1) => {
+                                extract_integer(s+1).map(LocalCodePtr::InSituDirEntry)
+                            }
+                            ("top_level", 2) => {
+                                if let Some(chunk_num) = extract_integer(s+1) {
+                                    if let Some(p) = extract_integer(s+2) {
+                                        return Some(LocalCodePtr::TopLevel(chunk_num, p));
+                                    }
+                                }
+
+                                None
+                            }
+                            ("user_goal_expansion", 1) => {
+                                extract_integer(s+1).map(LocalCodePtr::UserGoalExpansion)
+                            }
+                            ("user_term_expansion", 1) => {
+                                extract_integer(s+1).map(LocalCodePtr::UserTermExpansion)
+                            }
+                            _ => None
+                        }
+                    }
+                    _ => unreachable!()
+                }
+            }
+            _ => None
+        }
+    }
+
+    #[inline]
+    pub
+    fn index_addr<'a>(&'a self, addr: &Addr) -> RefOrOwned<'a, HeapCellValue> {
+        match addr {
+            &Addr::Con(h) | &Addr::Str(h) | &Addr::Stream(h) | &Addr::TcpListener(h) => {
+                RefOrOwned::Borrowed(&self[h])
+            }
+            addr => {
+                RefOrOwned::Owned(HeapCellValue::Addr(*addr))
+            }
+        }
+    }
+}
+
+impl<T: RawBlockTraits> Index<usize> for HeapTemplate<T> {
+    type Output = HeapCellValue;
+
+    #[inline]
+    fn index(&self, index: usize) -> &Self::Output {
+        unsafe {
+            let ptr = self.buf.base as usize + index * mem::size_of::<HeapCellValue>();
+            &*(ptr as *const HeapCellValue)
+        }
+    }
+}
+
+impl<T: RawBlockTraits> IndexMut<usize> for HeapTemplate<T> {
+    #[inline]
+    fn index_mut(&mut self, index: usize) -> &mut Self::Output {
+        unsafe {
+            let ptr = self.buf.base as usize + index * mem::size_of::<HeapCellValue>();
+            &mut *(ptr as *mut HeapCellValue)
+        }
+    }
+}