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/* see copyright notice in squirrel.h */
#ifndef _SQSTD_BLOBIMPL_H_
#define _SQSTD_BLOBIMPL_H_
struct SQBlob : public SQStream
{
SQBlob(SQInteger size) {
_size = size;
_allocated = size;
_buf = (unsigned char *)sq_malloc(size);
memset(_buf, 0, _size);
_ptr = 0;
_owns = true;
}
virtual ~SQBlob() {
sq_free(_buf, _allocated);
}
SQInteger Write(void *buffer, SQInteger size) {
if(!CanAdvance(size)) {
GrowBufOf(_ptr + size - _size);
}
memcpy(&_buf[_ptr], buffer, size);
_ptr += size;
return size;
}
SQInteger Read(void *buffer,SQInteger size) {
SQInteger n = size;
if(!CanAdvance(size)) {
if((_size - _ptr) > 0)
n = _size - _ptr;
else return 0;
}
memcpy(buffer, &_buf[_ptr], n);
_ptr += n;
return n;
}
bool Resize(SQInteger n) {
if(!_owns) return false;
if(n != _allocated) {
unsigned char *newbuf = (unsigned char *)sq_malloc(n);
memset(newbuf,0,n);
if(_size > n)
memcpy(newbuf,_buf,n);
else
memcpy(newbuf,_buf,_size);
sq_free(_buf,_allocated);
_buf=newbuf;
_allocated = n;
if(_size > _allocated)
_size = _allocated;
if(_ptr > _allocated)
_ptr = _allocated;
}
return true;
}
bool GrowBufOf(SQInteger n)
{
bool ret = true;
if(_size + n > _allocated) {
if(_size + n > _size * 2)
ret = Resize(_size + n);
else
ret = Resize(_size * 2);
}
_size = _size + n;
return ret;
}
bool CanAdvance(SQInteger n) {
if(_ptr+n>_size)return false;
return true;
}
SQInteger Seek(SQInteger offset, SQInteger origin) {
switch(origin) {
case SQ_SEEK_SET:
if(offset > _size || offset < 0) return -1;
_ptr = offset;
break;
case SQ_SEEK_CUR:
if(_ptr + offset > _size || _ptr + offset < 0) return -1;
_ptr += offset;
break;
case SQ_SEEK_END:
if(_size + offset > _size || _size + offset < 0) return -1;
_ptr = _size + offset;
break;
default: return -1;
}
return 0;
}
bool IsValid() {
return _buf?true:false;
}
bool EOS() {
return _ptr == _size;
}
SQInteger Flush() { return 0; }
SQInteger Tell() { return _ptr; }
SQInteger Len() { return _size; }
SQUserPointer GetBuf(){ return _buf; }
private:
SQInteger _size;
SQInteger _allocated;
SQInteger _ptr;
unsigned char *_buf;
bool _owns;
};
#endif //_SQSTD_BLOBIMPL_H_
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