Parse - Updates for better memory efficiency (hopefully)

4 files changed, 116 insertions, 10 deletions

diff --git a/src/include/rc_string.hpp b/src/include/rc_string.hpp
new file mode 100644
index 00000000..6091d748
--- /dev/null
+++ b/src/include/rc_string.hpp
@@ -0,0 +1,104 @@
+/*
+ */
+#pragma once
+
+#include <cstring>
+#include <ostream>
+
+class RcString
+{
+    unsigned int*   m_ptr;
+    unsigned int    m_len;
+public:
+    RcString():
+        m_ptr(nullptr),
+        m_len(0)
+    {}
+    RcString(const char* s, unsigned int len):
+        m_ptr( new unsigned int[1 + (len+1 + sizeof(unsigned int)-1) / sizeof(unsigned int)] ),
+        m_len(len)
+    {
+        *m_ptr = 1;
+        char* data_mut = reinterpret_cast<char*>(m_ptr + 1);
+        for(unsigned int j = 0; j < len; j ++ )
+            data_mut[j] = s[j];
+        data_mut[len] = '\0';
+    }
+    RcString(const char* s):
+        RcString(s, ::std::strlen(s))
+    {
+    }
+    RcString(const ::std::string& s):
+        RcString(s.data(), s.size())
+    {
+    }
+    
+    RcString(const RcString& x):
+        m_ptr(x.m_ptr),
+        m_len(x.m_len)
+    {
+        *m_ptr += 1;
+    }
+    RcString(RcString&& x):
+        m_ptr(x.m_ptr),
+        m_len(x.m_len)
+    {
+        x.m_ptr = nullptr;
+        x.m_len = 0;
+    }
+    
+    ~RcString()
+    {
+        if(m_ptr)
+        {
+            *m_ptr -= 1;
+            if( *m_ptr == 0 )
+            {
+                delete[] m_ptr;
+                m_ptr = nullptr;
+            }
+        }
+    }
+    
+    RcString& operator=(const RcString& x)
+    {
+        if( &x != this )
+        {
+            this->~RcString();
+            m_ptr = x.m_ptr;
+            m_len = x.m_len;
+            *m_ptr += 1;
+        }
+        return *this;
+    }
+    RcString& operator=(RcString&& x)
+    {
+        if( &x != this )
+        {
+            this->~RcString();
+            m_ptr = x.m_ptr;
+            m_len = x.m_len;
+            x.m_ptr = nullptr;
+            x.m_len = 0;
+        }
+        return *this;
+    }
+    
+    
+    const char* c_str() const {
+        return reinterpret_cast<const char*>(m_ptr + 1);
+    }
+    bool operator==(const char* s) const {
+        if( m_len == 0 )
+            return *s == '\0';
+        auto m = this->c_str();
+        do {
+            if( *m != *s )
+                return false;
+        } while( *m++ != '\0' && *s++ != '\0' );
+        return true;
+    }
+    friend ::std::ostream& operator<<(::std::ostream& os, const RcString& x) {
+        return os << x.c_str();
+    }
+};
diff --git a/src/include/serialise.hpp b/src/include/serialise.hpp
index 5556a510..9af379e7 100644
--- a/src/include/serialise.hpp
+++ b/src/include/serialise.hpp
@@ -26,13 +26,13 @@ class Deserialiser;
 class DeserialiseFailure:
     public ::std::runtime_error
 {
-    const char *m_fcn;
-    const char *m_message;
+    //const char *m_fcn;
+    //const char *m_message;
 public:
     DeserialiseFailure(const char *fcn, const char *message):
-        ::std::runtime_error("Deserialise failure"),
-        m_fcn(fcn),
-        m_message(message)
+        ::std::runtime_error("Deserialise failure")//,
+        //m_fcn(fcn),
+        //m_message(message)
     {}
 };
 
diff --git a/src/include/span.hpp b/src/include/span.hpp
index e5dd8ccc..f57fa8a9 100644
--- a/src/include/span.hpp
+++ b/src/include/span.hpp
@@ -5,9 +5,10 @@
  * include/span.hpp
  * - Spans and error handling
  */
-
 #pragma once
 
+#include <rc_string.hpp>
+
 enum ErrorType
 {
     E0000,
@@ -21,22 +22,22 @@ class Position;
 
 struct ProtoSpan
 {
-    ::std::string   filename;
+    RcString   filename;
     
     unsigned int start_line;
     unsigned int start_ofs;
 };
 struct Span
 {
-    ::std::string   filename;
+    RcString    filename;
     
     unsigned int start_line;
     unsigned int start_ofs;
     unsigned int end_line;
     unsigned int end_ofs;
     
-    Span(::std::string filename, unsigned int start_line, unsigned int start_ofs,  unsigned int end_line, unsigned int end_ofs):
-        filename(filename),
+    Span(RcString filename, unsigned int start_line, unsigned int start_ofs,  unsigned int end_line, unsigned int end_ofs):
+        filename( ::std::move(filename) ),
         start_line(start_line),
         start_ofs(start_ofs),
         end_line(end_line),
diff --git a/src/include/tagged_union.hpp b/src/include/tagged_union.hpp
index 9f1becc5..2c8d4f31 100644
--- a/src/include/tagged_union.hpp
+++ b/src/include/tagged_union.hpp
@@ -9,6 +9,7 @@
 #define INCLUDED_TAGGED_UNION_H_
 
 //#include "cpp_unpack.h"
+#include <cassert>
 
 #define TU_CASE_ITEM(src, mod, var, name)	mod auto& name = src.as_##var(); (void)&name;
 #define TU_CASE_BODY(class,var, ...)	case class::var: { __VA_ARGS__ } break;