#include "IndexOutput.h"

IndexOutput::IndexOutput()
{
	
}

IndexOutput::~IndexOutput(){
	if(!isClose){
		close();
	}
}

IndexOutput::IndexOutput(char * m_file,bool create){
	isClose=false;
	m_buffersize=1024;
	m_bufferPos=0;
	 std::string str=string("wb");
	if(!create)
		str=string("r+b");
	m_buffer=new char[m_buffersize];
	if   ((fp=fopen(m_file,str.c_str()))==NULL)  
	 {  
           
	 }   
	if(!create)
		fseek(fp,0,SEEK_END);
	 m_bufferStart=ftell(fp);
}
void IndexOutput::close(){
	this->flush();
	delete  m_buffer;
	fclose(fp);
	isClose=true;
}

//写Vint 变长32位整数
void IndexOutput::writeVint(int32_t value){
	  uint32_t ui=value;
	  while((ui&~0x7f)!=0){
		  this->writeByte((byte)((ui&0x7f)|0x80));
		  ui>>=7;
	  }
	  this->writeByte((byte)ui);
}
//
void IndexOutput::writeVlong(int64_t value){
	uint64_t u=value;
	  while((u&~0x7f)!=0){
		  this->writeByte((byte)((u&0x7f)|0x80));
		  u>>=7;
	  }
	  this->writeByte((byte)u);
}
//写64位整数
void IndexOutput::writeLong(int64_t value){
	this->writeInt((int32_t)(value>>32));
	this->writeInt((int32_t)value);
}

//写32 位整数
void IndexOutput:: writeInt( int32_t value){
	//for( int i=0;i<4;i++){
		writeByte((byte)(value>>24));
		writeByte((byte)(value>>16));
		writeByte((byte)(value>>8));
		writeByte((byte)(value));
//	}
}
//写8位二进制
void  IndexOutput::writeByte(byte  b){
	if(this->m_bufferPos>=this->m_buffersize)
		     this->flush();
	this->m_buffer[this->m_bufferPos++]=b;
}
int64_t  IndexOutput::getFilePointer(){
	return (m_bufferStart+(int64_t)m_bufferPos);
}
void  IndexOutput::writeChars(const char * s ,int64_t start, int64_t len){
	int64_t end = start + len;
	for (int64_t i = start; i < end; i++)
	{
		int32_t code = (int32_t) s[i];
		if (code >= 0x01 && code <= 0x7F)
			writeByte((byte) code);
		else if (((code >= 0x80) && (code <= 0x7FF)) || code == 0)
		{
			writeByte((byte) (0xC0 | (code >> 6)));
			writeByte((byte) (0x80 | (code & 0x3F)));
		}
		else
		{
			writeByte((byte) (0xE0 | (((int32_t) code) >> 12)));
			writeByte((byte) (0x80 | ((code >> 6) & 0x3F)));
			writeByte((byte) (0x80 | (code & 0x3F)));
		}
	}
}
void IndexOutput:: writeString(std::string  &str){
	int32_t len=str.length();
	this->writeVint(len);
	this->writeChars(str.c_str(),0,len);
}
void	IndexOutput::flush(){
	this->m_bufferStart+=this->m_bufferPos;
	this->flushBuffer();
	this->m_bufferPos=0;
}
void  IndexOutput::seek(int64_t pos){
	flush();
	m_bufferStart=pos;
	fseek(fp,pos,SEEK_SET);
}
void IndexOutput:: flushBuffer() {
	fwrite(m_buffer,m_bufferPos,1,fp);
}