www.pudn.com > bp_cpp.zip > func_cache.cpp

/* 
 * public/ann/annfunc/func_cache.cpp 
 * 2004-05-10 by ShanLanshan 
 */ 
#include "public/ann/annbase.h" 
#include "public/ann/annfunc/func_cache.h" 
 
namespace ann { 
 
		FuncCache::FuncCache(cache_func_t func) 
		{ 
			assert(func != NULL); 
			m_func = func; 
			m_cache = NULL; 
			m_low = m_high = 0.0; 
			m_step = 0.01; 
		} 
 
		FuncCache::~FuncCache() 
		{ 
			if (m_cache != NULL) { 
				delete m_cache; 
				m_cache = NULL; 
			} 
		} 
 
		bool FuncCache::build_cache(ann_float low, ann_float high, ann_float step) 
		{ 
			assert(high > low); 
			assert(step != 0.0); 
 
			int size; 
			size = static_cast ((high - low) / step); 
 
			assert(size * sizeof(float) < MAX_ALLOC_SIZE); 
 
			if (size > m_cache_size) { 
				if (m_cache != NULL) { 
					delete[] m_cache; 
					m_cache = NULL; 
				} 
 
				m_cache = new ann_float[size * sizeof(ann_float)]; 
				assert(m_cache != NULL); 
			} 
 
			assert(m_func != NULL); 
			for (int i=0; i ((v - m_low) / m_step); 
 
			if (idx >= m_cache_size || idx < 0) { 
				assert(m_func != NULL); 
				return m_func(v); 
			} 
 
			//printf("find table [%d]\n", idx); 
			return m_cache[idx]; 
		} 
 
 
} // namespace ann