Added libs/minisat (copy of minisat git master)

libs/minisat/Alloc.h

@@ -0,0 +1,131 @@
+/*****************************************************************************************[Alloc.h]
+Copyright (c) 2008-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+
+#ifndef Minisat_Alloc_h
+#define Minisat_Alloc_h
+
+#include "libs/minisat/XAlloc.h"
+#include "libs/minisat/Vec.h"
+
+namespace Minisat {
+
+//=================================================================================================
+// Simple Region-based memory allocator:
+
+template<class T>
+class RegionAllocator
+{
+    T*        memory;
+    uint32_t  sz;
+    uint32_t  cap;
+    uint32_t  wasted_;
+
+    void capacity(uint32_t min_cap);
+
+ public:
+    // TODO: make this a class for better type-checking?
+    typedef uint32_t Ref;
+    enum { Ref_Undef = UINT32_MAX };
+    enum { Unit_Size = sizeof(T) };
+
+    explicit RegionAllocator(uint32_t start_cap = 1024*1024) : memory(NULL), sz(0), cap(0), wasted_(0){ capacity(start_cap); }
+    ~RegionAllocator()
+    {
+        if (memory != NULL)
+            ::free(memory);
+    }
+
+
+    uint32_t size      () const      { return sz; }
+    uint32_t wasted    () const      { return wasted_; }
+
+    Ref      alloc     (int size); 
+    void     free      (int size)    { wasted_ += size; }
+
+    // Deref, Load Effective Address (LEA), Inverse of LEA (AEL):
+    T&       operator[](Ref r)       { assert(r < sz); return memory[r]; }
+    const T& operator[](Ref r) const { assert(r < sz); return memory[r]; }
+
+    T*       lea       (Ref r)       { assert(r < sz); return &memory[r]; }
+    const T* lea       (Ref r) const { assert(r < sz); return &memory[r]; }
+    Ref      ael       (const T* t)  { assert((void*)t >= (void*)&memory[0] && (void*)t < (void*)&memory[sz-1]);
+        return  (Ref)(t - &memory[0]); }
+
+    void     moveTo(RegionAllocator& to) {
+        if (to.memory != NULL) ::free(to.memory);
+        to.memory = memory;
+        to.sz = sz;
+        to.cap = cap;
+        to.wasted_ = wasted_;
+
+        memory = NULL;
+        sz = cap = wasted_ = 0;
+    }
+
+
+};
+
+template<class T>
+void RegionAllocator<T>::capacity(uint32_t min_cap)
+{
+    if (cap >= min_cap) return;
+
+    uint32_t prev_cap = cap;
+    while (cap < min_cap){
+        // NOTE: Multiply by a factor (13/8) without causing overflow, then add 2 and make the
+        // result even by clearing the least significant bit. The resulting sequence of capacities
+        // is carefully chosen to hit a maximum capacity that is close to the '2^32-1' limit when
+        // using 'uint32_t' as indices so that as much as possible of this space can be used.
+        uint32_t delta = ((cap >> 1) + (cap >> 3) + 2) & ~1;
+        cap += delta;
+
+        if (cap <= prev_cap)
+            throw OutOfMemoryException();
+    }
+    // printf(" .. (%p) cap = %u\n", this, cap);
+
+    assert(cap > 0);
+    memory = (T*)xrealloc(memory, sizeof(T)*cap);
+}
+
+
+template<class T>
+typename RegionAllocator<T>::Ref
+RegionAllocator<T>::alloc(int size)
+{ 
+    // printf("ALLOC called (this = %p, size = %d)\n", this, size); fflush(stdout);
+    assert(size > 0);
+    capacity(sz + size);
+
+    uint32_t prev_sz = sz;
+    sz += size;
+    
+    // Handle overflow:
+    if (sz < prev_sz)
+        throw OutOfMemoryException();
+
+    return prev_sz;
+}
+
+
+//=================================================================================================
+}
+
+#endif