misc.hh

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/*
 * Dillo Widget
 *
 * Copyright 2005-2007 Sebastian Geerken <sgeerken@dillo.org>
 * Copyright 2024 Rodrigo Arias Mallo <rodarima@gmail.com>
 *
 * This program 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/>.
 */
 
#ifndef __LOUT_MISC_HH__
#define __LOUT_MISC_HH__
 
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "dlib/dlib.h"
 
namespace lout {
 
namespace misc {
 
template <class T> inline T min (T a, T b) { return a < b ? a : b; }
template <class T> inline T max (T a, T b) { return a > b ? a : b; }
 
template <class T> inline T min (T a, T b, T c)
{
   return (min (a, min (b, c)));
}
template <class T> inline T max (T a, T b, T c)
{
   return (max (a, max (b, c)));
}
 
extern const char *prgName;
 
void init (int argc, char *argv[]);
 
inline void assertNotReached ()
{
   fprintf (stderr, "*** [%s] This should not happen! ***\n", prgName);
   abort ();
}
 
inline void assertNotReached (const char *fmt, ...)
{
   va_list argp;
   va_start(argp, fmt);
 
   fprintf (stderr, "*** [%s] This should not happen: ", prgName);
   vfprintf(stderr, fmt, argp);
   fprintf (stderr, "! ***\n");
 
   va_end(argp);
 
   abort ();
}
 
inline void notImplemented (const char *name)
{
   fprintf (stderr, "*** [%s] Not implemented: %s ***\n", prgName, name);
   abort ();
}
 
inline int roundInt(double d)
{
   return (int) ((d > 0) ? (d + 0.5) : (d - 0.5));
}
 
inline int AsciiTolower(char c)
{
   return ((c >= 'A' && c <= 'Z') ? c + 0x20 : c);
}
 
inline int AsciiToupper(char c)
{
   return ((c >= 'a' && c <= 'z') ? c - 0x20 : c);
}
 
inline int AsciiStrcasecmp(const char *s1, const char *s2)
{
   int ret = 0;
 
   while ((*s1 || *s2) && !(ret = AsciiTolower(*s1) - AsciiTolower(*s2))) {
      s1++;
      s2++;
   }
   return ret;
}
 
inline const char *boolToStr (bool b) { return b ? "true" : "false"; }
 
template <class T> class SimpleVector
{
private:
   T *array;
   int num, numAlloc;
 
   inline void resize ()
   {
      /* This algorithm was tuned for memory&speed with this huge page:
       *   http://downloads.mysql.com/docs/refman-6.0-en.html.tar.gz
       */
      if (array == NULL) {
         this->numAlloc = 1;
         this->array = (T*) malloc (sizeof (T));
      }
      if (this->numAlloc < this->num) {
         this->numAlloc = (this->num < 100) ?
                          this->num : this->num + this->num/10;
         this->array =
            (T*) realloc(this->array, (this->numAlloc * sizeof (T)));
      }
   }
 
public:
   inline SimpleVector (int initAlloc = 1)
   {
      this->num = 0;
      this->numAlloc = initAlloc;
      this->array = NULL;
   }
 
   inline SimpleVector (const SimpleVector &o) {
      this->array = NULL;
      this->num = o.num;
      this->numAlloc = o.numAlloc;
      resize ();
      memcpy (this->array, o.array, sizeof (T) * num);
   }
 
   inline ~SimpleVector ()
   {
      if (this->array)
         free (this->array);
   }
 
   inline int size() const { return this->num; }
 
   inline bool empty() const { return size() == 0; }
 
   inline T* getArray() const { return array; }
 
   inline T* detachArray() {
      T* arr = array;
      array = NULL;
      numAlloc = 0;
      num = 0;
      return arr;
   }
 
   inline void increase() { setSize(this->num + 1); }
 
   inline void setSize(int newSize) {
      assert (newSize >= 0);
      this->num = newSize;
      this->resize ();
   }
 
   inline void setSize (int newSize, T t) {
      int oldSize = this->num;
      setSize (newSize);
      for (int i = oldSize; i < newSize; i++)
         set (i, t);
   }
 
   inline T* getRef (int i) const {
      assert (i >= 0 && this->num - i > 0);
      return array + i;
   }
 
   inline T get (int i) const {
      assert (i >= 0 && this->num - i > 0);
      return this->array[i];
   }
 
   inline T* getFirstRef () const {
      assert (this->num > 0);
      return this->array;
   }
 
   inline T getFirst () const {
      assert (this->num > 0);
      return this->array[0];
   }
 
   inline T* getLastRef () const {
      assert (this->num > 0);
      return this->array + this->num - 1;
   }
 
   inline T getLast () const {
      assert (this->num > 0);
      return this->array[this->num - 1];
   }
 
   inline void set (int i, T t) {
      assert (i >= 0 && this->num - i > 0);
      this->array[i] = t;
   }
 
   inline void setLast (T t) {
      assert (this->num > 0);
      this->array[this->num - 1] = t;
   }
 
   inline void copyTo(SimpleVector<T> *dest, int thisStart = 0,
                      int thisLast = -1, int destStart = 0) {
      assert (dest != this);
      if (thisLast == -1)
         thisLast = this->size () - 1;
      for (int i = thisStart; i <= thisLast; i++)
         dest->set (i - thisStart + destStart, get (i));
   }
};
 
template <class T> class NotSoSimpleVector
{
private:
   T *arrayMain, *arrayExtra1, *arrayExtra2;
   int numMain, numExtra, numAllocMain, numAllocExtra, startExtra;
 
   inline void resizeMain ()
   {
      /* This algorithm was tuned for memory&speed with this huge page:
       *   http://downloads.mysql.com/docs/refman-6.0-en.html.tar.gz
       */
      if (arrayMain == NULL) {
         this->numAllocMain = 1;
         this->arrayMain = (T*) malloc (sizeof (T));
      }
      if (this->numAllocMain < this->numMain) {
         this->numAllocMain = (this->numMain < 100) ?
                          this->numMain : this->numMain + this->numMain/10;
         this->arrayMain =
            (T*) realloc(this->arrayMain, (this->numAllocMain * sizeof (T)));
      }
   }
 
   inline void resizeExtra ()
   {
      /* This algorithm was tuned for memory&speed with this huge page:
       *   http://downloads.mysql.com/docs/refman-6.0-en.html.tar.gz
       */
      if (arrayExtra1 == NULL) {
         this->numAllocExtra = 1;
         this->arrayExtra1 = (T*) malloc (sizeof (T));
         this->arrayExtra2 = (T*) malloc (sizeof (T));
      }
      if (this->numAllocExtra < this->numExtra) {
         this->numAllocExtra = (this->numExtra < 100) ?
                          this->numExtra : this->numExtra + this->numExtra/10;
         this->arrayExtra1 =
            (T*) realloc(this->arrayExtra1, (this->numAllocExtra * sizeof (T)));
         this->arrayExtra2 =
            (T*) realloc(this->arrayExtra2, (this->numAllocExtra * sizeof (T)));
      }
   }
 
   void consolidate ()
   {
      if (startExtra != -1) {
         numMain += numExtra;
         resizeMain ();
         memmove (arrayMain + startExtra + numExtra, arrayMain + startExtra,
                  (numMain - (startExtra + numExtra)) * sizeof (T));
         memmove (arrayMain + startExtra, arrayExtra1, numExtra * sizeof (T));
         startExtra = -1;
         numExtra = 0;
      }
   }
 
public:
   inline NotSoSimpleVector (int initAlloc)
   {
      this->numMain = this->numExtra = 0;
      this->numAllocMain = initAlloc;
      this->numAllocExtra = initAlloc;
      this->arrayMain = this->arrayExtra1 = this->arrayExtra2 = NULL;
      this->startExtra = -1;
   }
 
   inline ~NotSoSimpleVector ()
   {
      if (this->arrayMain)
         free (this->arrayMain);
      if (this->arrayExtra1)
         free (this->arrayExtra1);
      if (this->arrayExtra2)
         free (this->arrayExtra2);
   }
 
   inline int size() const { return this->numMain + this->numExtra; }
 
   inline bool empty() const { return size() == 0; }
 
   inline void increase() { setSize(size() + 1); }
 
   inline void setSize(int newSize)
   {
      assert (newSize >= 0);
      this->numMain = newSize - numExtra;
      this->resizeMain ();
   }
 
   void insert (int index, int numInsert)
   {
      assert (numInsert >= 0);
 
      // The following lines are a simple (but inefficient) replacement.
      //setSize (numMain + numInsert);
      //memmove (arrayMain + index + numInsert, arrayMain + index,
      //         (numMain - index - numInsert) * sizeof (T));
      //return;
 
      if (this->startExtra == -1) {
         // simple case
         this->numExtra = numInsert;
         this->startExtra = index;
         resizeExtra ();
      } else {
         if (index < startExtra) {
            consolidate ();
            insert (index, numInsert);
         } else if (index < startExtra + numExtra) {
            int oldNumExtra = numExtra;
            numExtra += numInsert;
            resizeExtra ();
 
            int toMove = startExtra + oldNumExtra - index;
            memmove (arrayExtra1 + numExtra - toMove,
                     arrayExtra1 + index - startExtra,
                     toMove * sizeof (T));
         } else {
            int oldNumExtra = numExtra;
            numExtra += numInsert;
            resizeExtra ();
 
            // Note: index refers to the *logical* adress, not to the
            // *physical* one.
            int diff = index - this->startExtra - oldNumExtra;
            T *arrayMainI = arrayMain + this->startExtra;
            for (int i = diff + oldNumExtra - 1; i >= 0; i--) {
               T *src = i < oldNumExtra ?
                  this->arrayExtra1 + i : arrayMainI + (i - oldNumExtra);
               T *dest = i < diff ?
                  arrayMainI + i : arrayExtra2 + (i - diff);
               *dest = *src;
            }
 
            memcpy (arrayExtra1, arrayExtra2, sizeof (T) * oldNumExtra);
            startExtra = index - oldNumExtra;
         }
      }
   }
 
   inline T* getRef (int i) const
   {
      if (this->startExtra == -1) {
         assert (i >= 0 && i < this->numMain);
         return this->arrayMain + i;
      } else {
         if (i < this->startExtra) {
            assert (i >= 0);
            return this->arrayMain + i;
         } else if (i >= this->startExtra + this->numExtra) {
            // The original assertion
            //    "assert (i < this->numMain + this->numExtra)"
            //
            // causes this warnung in dw::Textblock::breakAdded:
            //
            //    "assuming signed overflow does not occur when assuming that
            //     (X - c) > X is always false [-Wstrict-overflow]"
            //
            // Subtracting numExtra from both sides solves this,
            // interrestingly.
 
            assert (i - this->numExtra < this->numMain);
            return this->arrayMain + i - this->numExtra;
         } else
            return this->arrayExtra1 + i - this->startExtra;
      }
   }
 
   inline T get (int i) const
   {
      return *(this->getRef(i));
   }
 
   inline T* getFirstRef () const {
      assert (size () > 0);
      return this->getRef(0);
   }
 
   inline T getFirst () const {
      return *(this->getFirstRef());
   }
 
   inline T* getLastRef () const {
      assert (size () > 0);
      return this->getRef(size () - 1);
   }
 
   inline T getLast () const {
      return *(this->getLastRef());
   }
 
   inline void set (int i, T t) {
      *(this->getRef(i)) = t;
   }
 
   inline void setLast (T t) {
      *(this->getLastRef()) = t;
   }
};
 
class StringBuffer
{
private:
   struct Node
   {
      char *data;
      Node *next;
   };
 
   Node *firstNode, *lastNode;
   int numChars;
   char *str;
   bool strValid;
 
public:
   StringBuffer();
   ~StringBuffer();
 
   inline void append(const char *str) { appendNoCopy(dStrdup(str)); }
   inline void appendInt(int n)
   { char buf[32]; sprintf (buf, "%d", n); append (buf); }
   inline void appendPointer(void *p)
   { char buf[32]; sprintf (buf, "%p", p); append (buf); }
   inline void appendBool(bool b) { append (b ? "true" : "false"); }
   void appendNoCopy(char *str);
   const char *getChars();
   void clear ();
};
 
 
class BitSet
{
private:
   unsigned char *bits;
   int numBits, numBytes;
 
   inline int bytesForBits(int bits) { return bits == 0 ? 1 : (bits + 7) / 8; }
 
public:
   BitSet(int initBits);
   ~BitSet();
   void intoStringBuffer(misc::StringBuffer *sb);
   bool get(int i) const;
   void set(int i, bool val);
   void clear();
};
 
class ZoneAllocator
{
private:
   size_t poolSize, poolLimit, freeIdx;
   SimpleVector <char*> *pools;
   SimpleVector <char*> *bulk;
 
public:
   ZoneAllocator (size_t poolSize) {
      this->poolSize = poolSize;
      this->poolLimit = poolSize / 4;
      this->freeIdx = poolSize;
      this->pools = new SimpleVector <char*> (1);
      this->bulk = new SimpleVector <char*> (1);
   };
 
   ~ZoneAllocator () {
      zoneFree ();
      delete pools;
      delete bulk;
   }
 
   inline void * zoneAlloc (size_t t) {
      void *ret;
 
      if (t > poolLimit) {
         bulk->increase ();
         bulk->set (bulk->size () - 1, (char*) malloc (t));
         return bulk->get (bulk->size () - 1);
      }
 
      if (t > poolSize - freeIdx) {
         pools->increase ();
         pools->set (pools->size () - 1, (char*) malloc (poolSize));
         freeIdx = 0;
      }
 
      ret = pools->get (pools->size () - 1) + freeIdx;
      freeIdx += t;
      return ret;
   }
 
   inline void zoneFree () {
      for (int i = 0; i < pools->size (); i++)
         free (pools->get (i));
      pools->setSize (0);
      for (int i = 0; i < bulk->size (); i++)
         free (bulk->get (i));
      bulk->setSize (0);
      freeIdx = poolSize;
   }
 
   inline const char *strndup (const char *str, size_t t) {
      char *new_str = (char *) zoneAlloc (t + 1);
      memcpy (new_str, str, t);
      new_str[t] = '\0';
      return new_str;
   }
 
   inline const char *strdup (const char *str) {
      return strndup (str, strlen (str));
   }
};
 
} // namespace misc
 
} // namespace lout
 
#endif // __LOUT_MISC_HH__