00001 /* 00002 * The Apache Software License, Version 1.1 00003 * 00004 * 00005 * Copyright (c) 2000 The Apache Software Foundation. All rights 00006 * reserved. 00007 * 00008 * Redistribution and use in source and binary forms, with or without 00009 * modification, are permitted provided that the following conditions 00010 * are met: 00011 * 00012 * 1. Redistributions of source code must retain the above copyright 00013 * notice, this list of conditions and the following disclaimer. 00014 * 00015 * 2. Redistributions in binary form must reproduce the above copyright 00016 * notice, this list of conditions and the following disclaimer in 00017 * the documentation and/or other materials provided with the 00018 * distribution. 00019 * 00020 * 3. The end-user documentation included with the redistribution, 00021 * if any, must include the following acknowledgment: 00022 * "This product includes software developed by the 00023 * Apache Software Foundation (http://www.apache.org/)." 00024 * Alternately, this acknowledgment may appear in the software itself, 00025 * if and wherever such third-party acknowledgments normally appear. 00026 * 00027 * 4. The names "Xalan" and "Apache Software Foundation" must 00028 * not be used to endorse or promote products derived from this 00029 * software without prior written permission. For written 00030 * permission, please contact apache@apache.org. 00031 * 00032 * 5. Products derived from this software may not be called "Apache", 00033 * nor may "Apache" appear in their name, without prior written 00034 * permission of the Apache Software Foundation. 00035 * 00036 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 00037 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00038 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 00039 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 00040 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00041 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 00042 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 00043 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 00044 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 00045 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 00046 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00047 * SUCH DAMAGE. 00048 * ==================================================================== 00049 * 00050 * This software consists of voluntary contributions made by many 00051 * individuals on behalf of the Apache Software Foundation and was 00052 * originally based on software copyright (c) 1999, International 00053 * Business Machines, Inc., http://www.ibm.com. For more 00054 * information on the Apache Software Foundation, please see 00055 * <http://www.apache.org/>. 00056 */ 00057 00058 #if !defined(ARENABLOCK_INCLUDE_GUARD_1357924680) 00059 #define ARENABLOCK_INCLUDE_GUARD_1357924680 00060 00061 00062 00063 #include <algorithm> 00064 #include <cassert> 00065 #include <set> 00066 #include <memory> 00067 00068 00069 00070 #if defined(XALAN_NO_STD_ALLOCATORS) && !defined(XALAN_NO_SELECTIVE_TEMPLATE_INSTANTIATION) 00071 #include <PlatformSupport/XalanAllocator.hpp> 00072 #endif 00073 00074 00075 #define XALAN_NO_SELECTIVE_TEMPLATE_INSTANTIATION 00076 #if defined(XALAN_NO_SELECTIVE_TEMPLATE_INSTANTIATION) 00077 00078 template <class Type> 00079 class ArenaBlockAllocator 00080 { 00081 public: 00082 00083 typedef size_t size_type; 00084 typedef ptrdiff_t difference_type; 00085 typedef Type* pointer; 00086 typedef const Type* const_pointer; 00087 typedef Type& reference; 00088 typedef const Type& const_reference; 00089 typedef Type value_type; 00090 00091 ArenaBlockAllocator() 00092 { 00093 } 00094 00095 ArenaBlockAllocator(const ArenaBlockAllocator<Type>&) 00096 { 00097 }; 00098 00099 ~ArenaBlockAllocator() 00100 { 00101 } 00102 00103 pointer 00104 allocate( 00105 size_type size, 00106 const void* /* hint */ = 0) 00107 { 00108 return (pointer)operator new(size * sizeof(Type)); 00109 } 00110 00111 void 00112 deallocate( 00113 pointer p, 00114 size_type /* n */) 00115 { 00116 operator delete(p); 00117 } 00118 }; 00119 #endif 00120 00121 00122 00123 template<class ObjectType> 00124 class ArenaBlockDestroy 00125 { 00126 public: 00127 00128 void 00129 operator()(ObjectType& theObject) const 00130 { 00131 theObject.ObjectType::~ObjectType(); 00132 } 00133 }; 00134 00135 00136 00137 template<class ObjectType> 00138 class ArenaBlock 00139 { 00140 public: 00141 00142 #if defined(XALAN_NO_SELECTIVE_TEMPLATE_INSTANTIATION) 00143 typedef ArenaBlockAllocator<ObjectType> AllocatorType; 00144 #elif defined(XALAN_NO_STD_ALLOCATORS) 00145 typedef XalanAllocator<ObjectType> AllocatorType; 00146 #else 00147 typedef std::allocator<ObjectType> AllocatorType; 00148 #endif 00149 00150 typedef ArenaBlockDestroy<ObjectType> DestroyFunctionType; 00151 00152 typedef AllocatorType::size_type size_type; 00153 00154 /* 00155 * Construct an ArenaBlock of the specified size 00156 * of objects. 00157 * 00158 * @param theBlockSize The size of the block (the number of objects it can contain). 00159 */ 00160 ArenaBlock(size_type theBlockSize) : 00161 m_destroyFunction(DestroyFunctionType()), 00162 m_objectCount(0), 00163 m_blockSize(theBlockSize), 00164 m_objectBlock(0), 00165 m_allocator() 00166 { 00167 assert(theBlockSize > 0); 00168 } 00169 00170 ~ArenaBlock() 00171 { 00172 destroyAll(); 00173 00174 // Release the memory... 00175 m_allocator.deallocate(m_objectBlock, 0); 00176 } 00177 00178 /* 00179 * Allocate a block. Once the object is constructed, you must call 00180 * commitAllocation(). 00181 * 00182 * @return a pointer to the new block. 00183 */ 00184 virtual ObjectType* 00185 allocateBlock() 00186 { 00187 // If no memory has yet been allocated, then allocate it... 00188 if (m_objectBlock == 0) 00189 { 00190 m_objectBlock = m_allocator.allocate(m_blockSize, 0); 00191 } 00192 assert(m_objectBlock != 0); 00193 00194 // Any space left? 00195 if (m_objectCount == m_blockSize) 00196 { 00197 return 0; 00198 } 00199 else 00200 { 00201 return m_objectBlock + m_objectCount; 00202 } 00203 } 00204 00205 /* 00206 * Commit the previous allocation. 00207 * 00208 * @param theBlock the address that was returned by allocateBlock() 00209 */ 00210 virtual void 00211 #if defined (NDEBUG) 00212 commitAllocation(ObjectType* /* theBlock */) 00213 #else 00214 commitAllocation(ObjectType* theBlock) 00215 #endif 00216 { 00217 assert(theBlock == m_objectBlock + m_objectCount); 00218 assert(m_objectCount < m_blockSize); 00219 00220 m_objectCount++; 00221 } 00222 00223 /* 00224 * Find out if there is a block available. 00225 * 00226 * @return true if one is available, false if not. 00227 */ 00228 virtual bool 00229 blockAvailable() const 00230 { 00231 return m_objectCount < m_blockSize ? true : false; 00232 } 00233 00234 /* 00235 * Get the number of objects currently allocated in the 00236 * block. 00237 * 00238 * @return The number of objects allocated. 00239 */ 00240 virtual size_type 00241 getCountAllocated() const 00242 { 00243 return m_objectCount; 00244 } 00245 00246 /* 00247 * Get the block size, that is, the number 00248 * of objects in each block. 00249 * 00250 * @return The size of the block 00251 */ 00252 size_type 00253 getBlockSize() const 00254 { 00255 return m_blockSize; 00256 } 00257 00258 /* 00259 * Determine if this block owns the specified object. Note 00260 * that even if the object address is within our block, this 00261 * call will return false if no object currently occupies the 00262 * block. See also ownsBlock(). 00263 * 00264 * @param theObject the address of the object. 00265 * @return true if we own the object, false if not. 00266 */ 00267 virtual bool 00268 ownsObject(const ObjectType* theObject) const 00269 { 00270 #if !defined(XALAN_NO_NAMESPACES) 00271 using std::less; 00272 #endif 00273 00274 // Use less<>, since it's guaranteed to do pointer 00275 // comparisons correctly... 00276 less<const ObjectType*> functor; 00277 00278 if (functor(theObject, m_objectBlock) == false && 00279 functor(theObject, m_objectBlock + m_objectCount) == true) 00280 { 00281 return true; 00282 } 00283 else 00284 { 00285 return false; 00286 } 00287 } 00288 00289 /* 00290 * Determine if this block owns the specified object block. 00291 * Note that, unlike ownsObject(), there does not need to 00292 * be an object at the address. 00293 * 00294 * @param theObject the address of the object 00295 * @return true if we own the object block, false if not. 00296 */ 00297 bool 00298 ownsBlock(const ObjectType* theObject) const 00299 { 00300 #if !defined(XALAN_NO_NAMESPACES) 00301 using std::less; 00302 #endif 00303 00304 // Use less<>, since it's guaranteed to do pointer 00305 // comparisons correctly... 00306 less<const ObjectType*> functor; 00307 00308 if (functor(theObject, m_objectBlock) == false && 00309 functor(theObject, m_objectBlock + m_blockSize) == true) 00310 { 00311 return true; 00312 } 00313 else 00314 { 00315 return false; 00316 } 00317 } 00318 00319 /* 00320 * Destroy all objects in the block. You can then reuse the 00321 * block. 00322 */ 00323 void 00324 destroyAll() 00325 { 00326 #if !defined(XALAN_NO_NAMESPACES) 00327 using std::for_each; 00328 #endif 00329 00330 // Destroy all existing objects... 00331 for_each(m_objectBlock, 00332 m_objectBlock + m_objectCount, 00333 DeleteFunctor(*this, m_destroyFunction)); 00334 00335 m_objectCount = 0; 00336 } 00337 00338 protected: 00339 00340 /* 00341 * Determine if the block should be destroyed. Called by 00342 * an instance of DeleteFunctor, this function is for 00343 * deriving classes that might want to control the destruction 00344 * of things. 00345 * 00346 * @param theObject the address of the object 00347 * @return true if block should be destroyed, false if not. 00348 */ 00349 virtual bool 00350 shouldDestroyBlock(const ObjectType* /* theObject */) const 00351 { 00352 return true; 00353 } 00354 00355 /* 00356 * Determine the offset into the block for the given address. 00357 * Behavior is undefined if the address is not within our 00358 * block 00359 * 00360 * @param theObject the address of the object 00361 * @return the offset 00362 */ 00363 size_type 00364 getBlockOffset(const ObjectType* theObject) const 00365 { 00366 assert(theObject - m_objectBlock < m_blockSize); 00367 00368 return theObject - m_objectBlock; 00369 } 00370 00371 /* 00372 * Determine the address within our block of the object 00373 * at the specified offset. 00374 * Behavior is undefined if the offset is greater than the 00375 * block size. 00376 * 00377 * @param theObject the address of the object 00378 * @return the offset 00379 */ 00380 ObjectType* 00381 getBlockAddress(size_type theOffset) const 00382 { 00383 assert(theOffset < m_blockSize); 00384 00385 return m_objectBlock + theOffset; 00386 } 00387 00388 struct DeleteFunctor 00389 { 00390 DeleteFunctor( 00391 const ArenaBlock<ObjectType>& theArenaBlock, 00392 const DestroyFunctionType& theDestroyFunction) : 00393 m_arenaBlock(theArenaBlock), 00394 m_destroyFunction(theDestroyFunction) 00395 { 00396 } 00397 00398 void 00399 operator()(ObjectType& theObject) const 00400 { 00401 if (m_arenaBlock.shouldDestroyBlock(&theObject) == true) 00402 { 00403 m_destroyFunction(theObject); 00404 } 00405 } 00406 00407 private: 00408 00409 const ArenaBlock<ObjectType>& m_arenaBlock; 00410 const DestroyFunctionType& m_destroyFunction; 00411 }; 00412 00413 friend struct DeleteFunctor; 00414 00415 const DestroyFunctionType m_destroyFunction; 00416 00417 private: 00418 00419 // Not implemented... 00420 ArenaBlock(const ArenaBlock<ObjectType>&); 00421 00422 ArenaBlock<ObjectType>& 00423 operator=(const ArenaBlock<ObjectType>&); 00424 00425 bool 00426 operator==(const ArenaBlock<ObjectType>&) const; 00427 00428 00429 // data members... 00430 size_type m_objectCount; 00431 00432 const size_type m_blockSize; 00433 00434 ObjectType* m_objectBlock; 00435 00436 AllocatorType m_allocator; 00437 }; 00438 00439 00440 00441 #endif // !defined(ARENABLOCK_INCLUDE_GUARD_1357924680)
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