94 lines
2.0 KiB
C++
94 lines
2.0 KiB
C++
#include <string.h>
|
|
#include "MemoryFile.h"
|
|
#include "Utility.h"
|
|
|
|
namespace corona {
|
|
|
|
COR_EXPORT(File*) CorCreateMemoryFile(const void* buffer, int size) {
|
|
if (size && !buffer) {
|
|
return 0;
|
|
}
|
|
if (size < 0) {
|
|
return 0;
|
|
}
|
|
|
|
return new MemoryFile(buffer, size);
|
|
}
|
|
|
|
|
|
int getNextPowerOfTwo(int value) {
|
|
int i = 1;
|
|
while (i < value) {
|
|
i *= 2;
|
|
}
|
|
return i;
|
|
}
|
|
|
|
MemoryFile::MemoryFile(const void* buffer, int size) {
|
|
m_capacity = getNextPowerOfTwo(size);
|
|
m_size = size;
|
|
m_buffer = new byte[m_capacity];
|
|
memcpy(m_buffer, buffer, size);
|
|
|
|
m_position = 0;
|
|
}
|
|
|
|
MemoryFile::~MemoryFile() {
|
|
delete[] m_buffer;
|
|
}
|
|
|
|
int COR_CALL MemoryFile::read(void* buffer, int size) {
|
|
int real_read = std::min((m_size - m_position), size);
|
|
memcpy(buffer, m_buffer + m_position, real_read);
|
|
m_position += real_read;
|
|
return real_read;
|
|
}
|
|
|
|
int COR_CALL MemoryFile::write(const void* buffer, int size) {
|
|
ensureSize(m_position + size);
|
|
memcpy(m_buffer + m_position, buffer, size);
|
|
m_position += size;
|
|
return size;
|
|
}
|
|
|
|
bool COR_CALL MemoryFile::seek(int position, SeekMode mode) {
|
|
int real_pos;
|
|
switch (mode) {
|
|
case BEGIN: real_pos = position; break;
|
|
case CURRENT: real_pos = m_position + position; break;
|
|
case END: real_pos = m_size + position; break;
|
|
default: return false;
|
|
}
|
|
|
|
if (real_pos < 0 || real_pos > m_size) {
|
|
m_position = 0;
|
|
return false;
|
|
} else {
|
|
m_position = real_pos;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
int COR_CALL MemoryFile::tell() {
|
|
return m_position;
|
|
}
|
|
|
|
void MemoryFile::ensureSize(int min_size) {
|
|
bool realloc_needed = false;
|
|
while (m_capacity < min_size) {
|
|
m_capacity *= 2;
|
|
realloc_needed = true;
|
|
}
|
|
|
|
if (realloc_needed) {
|
|
byte* new_buffer = new byte[m_capacity];
|
|
memcpy(new_buffer, m_buffer, m_size);
|
|
delete[] m_buffer;
|
|
m_buffer = new_buffer;
|
|
}
|
|
|
|
m_size = min_size;
|
|
}
|
|
|
|
};
|