--- deliantra/server/include/shstr.h	2006/09/03 07:57:56	1.6
+++ deliantra/server/include/shstr.h	2008/12/31 17:35:37	1.24
@@ -1,87 +1,234 @@
+/*
+ * This file is part of Deliantra, the Roguelike Realtime MMORPG.
+ * 
+ * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
+ * 
+ * Deliantra is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ * 
+ * The authors can be reached via e-mail to <support@deliantra.net>
+ */
+
 #ifndef SHSTR_H__
 #define SHSTR_H__
 
-extern int buf_overflow(const char *buf1, const char *buf2, int bufsize);
+#include <cstring>
+#include <sstream>
+
+#include "util.h"
+
+extern size_t shstr_alloc;
 
-struct shstr
+extern int buf_overflow (const char *buf1, const char *buf2, int bufsize);
+
+// this class is a non-refcounted shared string
+// it cannot be used to create or store shared strings, but
+// it can be used to apss shared strings around, i.e. as function arguments
+// or return values. their lifetime must not span a gc () call, i.e.
+// they are only valid as temporary values within the same server tick.
+struct shstr_tmp
 {
+  static const char *null;
+
   const char *s;
 
-  int &refcnt ()
+  static unsigned int &length (const char *s)
   {
-    return *((int *)s - 1);
+    return *((unsigned int *)s - 2);
   }
 
-  static const char *find (const char *s);
-  static const char *intern (const char *s);
+  int length () const
+  {
+    return length (s);
+  }
 
-  static void gc (); // garbage collect a few strings
+  // returns whether this shared string begins with the given prefix,
+  // used mainly for searches when users give only the start of a name.
+  bool starts_with (const char *prefix) const
+  {
+    int plen = strlen (prefix);
+
+    return length () >= plen && !strncasecmp (s, prefix, plen);
+  }
+
+  bool contains (const char *substring) const
+  {
+    return strstr (s, substring);
+  }
+
+  shstr_tmp ()
+  : s (null)
+  {
+  }
+
+  shstr_tmp (const shstr_tmp &sh)
+  : s (sh.s)
+  {
+  }
+
+  shstr_tmp operator =(const shstr_tmp &sh)
+  {
+    s = sh.s;
+
+    return *this;
+  }
 
   // this is used for informational messages and the like
-  const char *operator &() const { return s ? s : "<nil>"; }
+  const char *operator &() const { return s; }
 
-  const char &operator [](int i) const { return s[i]; }
-  operator const char *() const { return s; }
+  operator const char *() const { return s == null ? 0 : s; }
+};
 
-  int length () const
+inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
+{
+  return a.s == b.s;
+}
+
+inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
+{
+  return a.s != b.s;
+}
+
+inline int strlen (const shstr_tmp &sh)
+{
+  return sh.length ();
+}
+
+// undefined external reference to catch people using strcmp when they shouldn't
+int strcmp (const shstr_tmp &a, const shstr_tmp &b);
+
+static std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
+{
+  o.write (sh.s, sh.length ());
+
+  return o;
+}
+
+struct shstr : shstr_tmp
+{
+  static unsigned int &refcnt (const char *s)
   {
-    return s ? *((int *)s - 2) : 0;
+    return *((unsigned int *)s - 1);
+  }
+
+  unsigned int &refcnt () const
+  {
+    return refcnt (s);
   }
 
   shstr ()
-  : s (0)
   {
   }
 
+  static const char *find (const char *s);
+  static const char *intern (const char *s);
+
+  static void gc (); // garbage collect a few strings
+
   shstr (const shstr &sh)
-  : s (sh.s)
+  : shstr_tmp (sh)
   {
-    if (s) ++refcnt ();
+    ++refcnt ();
   }
 
-  explicit shstr (const char *s)
-  : s (intern (s))
+  shstr (const shstr_tmp &sh)
+  : shstr_tmp (sh)
   {
-    if (s) ++refcnt ();
+    ++refcnt ();
+  }
+
+  explicit shstr (const char *str)
+  {
+    s = is_constant (str) && !str ? null : intern (str);
   }
 
   ~shstr ()
   {
-    if (s) --refcnt ();
+    --refcnt ();
   }
 
-  const shstr &operator =(const shstr &sh)
+  using shstr_tmp::operator &;
+  using shstr_tmp::operator const char *;
+
+  // (note: not the copy constructor)
+  shstr &operator =(const shstr_tmp &sh)
   {
-    if (s) --refcnt ();
+    --refcnt ();
     s = sh.s;
-    if (s) ++refcnt ();
+    ++refcnt ();
 
     return *this;
   }
 
-  const shstr &operator =(const char *str)
+  // here it comes
+  shstr &operator =(const shstr &sh)
+  {
+    return (*this) = (shstr_tmp)sh;
+  }
+
+  // shstr_tmp doesn't have this one
+  shstr &operator =(const char *str)
   {
-    if (s) --refcnt ();
-    s = intern (str);
+    --refcnt ();
+    s = is_constant (str) && !str ? null : intern (str);
 
     return *this;
   }
 };
 
-inline int strlen (const shstr &sh)
+// only good for mass comparisons to shstr objects, or very
+// temporary passing, basically a non-refcounted shstr
+struct shstr_cmp
 {
-  return sh.length ();
-}
+  const char *s;
+
+  explicit shstr_cmp (const char *str)
+  : s (shstr::find (str))
+  {
+  }
+
+  shstr_cmp (const shstr_cmp &sh)
+  : s (sh.s)
+  {
+  }
+
+  shstr_cmp (const shstr &sh)
+  : s (sh.s)
+  {
+  }
 
-inline bool operator ==(const shstr &a, const shstr &b)
+  // this is used for informational messages and the like
+  const char *operator &() const { return s; }
+
+  shstr_cmp operator =(const shstr_cmp sh) { s = sh.s; return *this; }
+  operator const char *() const { return s; }
+};
+
+inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
 {
   return a.s == b.s;
 }
 
-inline bool operator !=(const shstr &a, const shstr &b)
+inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
 {
-  return !(a == b);
+  return a.s == b.s;
 }
 
+extern const shstr shstr_null;
+
+#define def(str) extern const shstr shstr_ ## str;
+# include "shstrinc.h"
+#undef def
+
 #endif