tracy/server/TracyFileRead.hpp
2018-04-20 14:27:20 +02:00

133 lines
3.1 KiB
C++

#ifndef __TRACYFILEREAD_HPP__
#define __TRACYFILEREAD_HPP__
#include <algorithm>
#include <stdio.h>
#include <string.h>
#include "../common/tracy_lz4.hpp"
#include "../common/TracyForceInline.hpp"
namespace tracy
{
class FileRead
{
public:
static FileRead* Open( const char* fn )
{
auto f = fopen( fn, "rb" );
return f ? new FileRead( f ) : nullptr;
}
~FileRead()
{
fclose( m_file );
LZ4_freeStreamDecode( m_stream );
}
tracy_force_inline void Read( void* ptr, size_t size )
{
if( size <= BufSize - m_offset )
{
ReadSmall( ptr, size );
}
else
{
ReadBig( ptr, size );
}
}
void Skip( size_t size )
{
if( size <= BufSize - m_offset )
{
m_offset += size;
}
else
{
char m_lz4buf[LZ4Size];
while( size > 0 )
{
if( m_offset == BufSize )
{
m_active = 1 - m_active;
m_offset = 0;
uint32_t sz;
fread( &sz, 1, sizeof( sz ), m_file );
fread( m_lz4buf, 1, sz, m_file );
m_lastBlock = LZ4_decompress_safe_continue( m_stream, m_lz4buf, m_buf[m_active], sz, BufSize );
}
const auto sz = std::min( size, BufSize - m_offset );
m_offset += sz;
size -= sz;
}
}
}
bool IsEOF()
{
if( m_lastBlock != BufSize && m_offset == m_lastBlock ) return true;
if( m_offset == BufSize )
{
if( fseek( m_file, 1, SEEK_CUR ) != 0 ) return true;
fseek( m_file, -1, SEEK_CUR );
}
return false;
}
private:
FileRead( FILE* f )
: m_stream( LZ4_createStreamDecode() )
, m_file( f )
, m_offset( BufSize )
, m_active( 1 )
, m_lastBlock( 0 )
{}
tracy_force_inline void ReadSmall( void* ptr, size_t size )
{
memcpy( ptr, m_buf[m_active] + m_offset, size );
m_offset += size;
}
void ReadBig( void* ptr, size_t size )
{
char m_lz4buf[LZ4Size];
auto dst = (char*)ptr;
while( size > 0 )
{
if( m_offset == BufSize )
{
m_active = 1 - m_active;
m_offset = 0;
uint32_t sz;
fread( &sz, 1, sizeof( sz ), m_file );
fread( m_lz4buf, 1, sz, m_file );
m_lastBlock = LZ4_decompress_safe_continue( m_stream, m_lz4buf, m_buf[m_active], sz, BufSize );
}
const auto sz = std::min( size, BufSize - m_offset );
memcpy( dst, m_buf[m_active] + m_offset, sz );
m_offset += sz;
dst += sz;
size -= sz;
}
}
enum { BufSize = 64 * 1024 };
enum { LZ4Size = LZ4_COMPRESSBOUND( BufSize ) };
LZ4_streamDecode_t* m_stream;
FILE* m_file;
char m_buf[2][BufSize];
size_t m_offset;
uint8_t m_active;
int m_lastBlock;
};
}
#endif