inline bool FileLoader::readByte(int32_t &value)
{
if(m_use_cache)
{
if(m_cache_index == NO_VALID_CACHE)
{
m_lastError = ERROR_CACHE_ERROR;
return false;
}
if(m_cache_offset >= m_cached_data[m_cache_index].size)
{
int32_t pos = m_cache_offset + m_cached_data[m_cache_index].base;
int32_t tmp = getCacheBlock(pos);
if(tmp < 0)
return false;
m_cache_index = tmp;
m_cache_offset = pos - m_cached_data[m_cache_index].base;
if(m_cache_offset >= m_cached_data[m_cache_index].size)
return false;
}
value = m_cached_data[m_cache_index].data[m_cache_offset];
m_cache_offset++;
return true;
}
value = fgetc(m_file);
if(value != EOF)
return true;
m_lastError = ERROR_EOF;
return false;
}
inline bool FileLoader::readBytes(uint8_t* buffer, uint32_t size, int32_t pos)
{
//seek at pos
uint32_t remain = size, bufferPos = 0;
do {
//prepare cache
uint32_t i = getCacheBlock(pos);
if (i == NO_VALID_CACHE) {
return false;
}
m_cache_index = i;
m_cache_offset = pos - m_cached_data[i].base;
//get maximum read block size and calculate remaining bytes
uint32_t reading = std::min<int32_t>(remain, m_cached_data[i].size - m_cache_offset);
remain -= reading;
//read it
memcpy(buffer + bufferPos, m_cached_data[m_cache_index].data + m_cache_offset, reading);
//update variables
m_cache_offset += reading;
bufferPos += reading;
pos += reading;
} while (remain > 0);
return true;
}
inline bool FileLoader::safeSeek(uint32_t pos)
{
uint32_t i = getCacheBlock(pos);
if (i == NO_VALID_CACHE) {
return false;
}
m_cache_index = i;
m_cache_offset = pos - m_cached_data[i].base;
return true;
}
inline bool FileLoader::readBytes(unsigned char* buffer, int32_t size, int32_t pos)
{
if(m_use_cache)
{
//seek at pos
uint32_t reading, remain = size, bufferPos = 0;
do
{
//prepare cache
uint32_t i = getCacheBlock(pos);
if(i == NO_VALID_CACHE)
return false;
m_cache_index = i;
m_cache_offset = pos - m_cached_data[i].base;
//get maximum read block size and calculate remaining bytes
reading = std::min<uint32_t>(remain, m_cached_data[i].size - m_cache_offset);
remain = remain - reading;
//read it
memcpy(buffer + bufferPos, m_cached_data[m_cache_index].data + m_cache_offset, reading);
//update variables
m_cache_offset = m_cache_offset + reading;
bufferPos = bufferPos + reading;
pos = pos + reading;
}
while(remain > 0);
return true;
}
else
{
if(fseek(m_file, pos, SEEK_SET))
{
m_lastError = ERROR_SEEK_ERROR;
return false;
}
int32_t value = fread(buffer, 1, size, m_file);
if(value != size)
{
m_lastError = ERROR_EOF;
return false;
}
else
return true;
}
}
inline bool FileLoader::safeSeek(unsigned long pos)
{
if(m_use_cache){
unsigned long i = getCacheBlock(pos);
if(i == NO_VALID_CACHE)
return false;
m_cache_index = i;
m_cache_offset = pos - m_cached_data[i].base;
}
else{
if(fseek(m_file, pos, SEEK_SET)){
m_lastError = ERROR_SEEK_ERROR;
return false;
}
}
return true;
}