tg2sip/BufferInputStream.cpp

114 lines
2.7 KiB
C++
Raw Normal View History

//
// libtgvoip is free and unencumbered public domain software.
// For more information, see http://unlicense.org or the UNLICENSE file
// you should have received with this source code distribution.
//
#include "BufferInputStream.h"
#include <assert.h>
#include <string.h>
#include <exception>
#include <stdexcept>
using namespace tgvoip;
BufferInputStream::BufferInputStream(unsigned char* data, size_t length){
this->buffer=data;
this->length=length;
offset=0;
}
BufferInputStream::~BufferInputStream(){
}
void BufferInputStream::Seek(size_t offset){
if(offset>length){
throw std::out_of_range("Not enough bytes in buffer");
}
this->offset=offset;
}
size_t BufferInputStream::GetLength(){
return length;
}
size_t BufferInputStream::GetOffset(){
return offset;
}
size_t BufferInputStream::Remaining(){
return length-offset;
}
unsigned char BufferInputStream::ReadByte(){
EnsureEnoughRemaining(1);
return (unsigned char)buffer[offset++];
}
int32_t BufferInputStream::ReadInt32(){
EnsureEnoughRemaining(4);
int32_t res=((int32_t)buffer[offset] & 0xFF) |
(((int32_t)buffer[offset+1] & 0xFF) << 8) |
(((int32_t)buffer[offset+2] & 0xFF) << 16) |
(((int32_t)buffer[offset+3] & 0xFF) << 24);
offset+=4;
return res;
}
int64_t BufferInputStream::ReadInt64(){
EnsureEnoughRemaining(8);
int64_t res=((int64_t)buffer[offset] & 0xFF) |
(((int64_t)buffer[offset+1] & 0xFF) << 8) |
(((int64_t)buffer[offset+2] & 0xFF) << 16) |
(((int64_t)buffer[offset+3] & 0xFF) << 24) |
(((int64_t)buffer[offset+4] & 0xFF) << 32) |
(((int64_t)buffer[offset+5] & 0xFF) << 40) |
(((int64_t)buffer[offset+6] & 0xFF) << 48) |
(((int64_t)buffer[offset+7] & 0xFF) << 56);
offset+=8;
return res;
}
int16_t BufferInputStream::ReadInt16(){
EnsureEnoughRemaining(2);
int16_t res=(uint16_t)buffer[offset] | ((uint16_t)buffer[offset+1] << 8);
offset+=2;
return res;
}
int32_t BufferInputStream::ReadTlLength(){
unsigned char l=ReadByte();
if(l<254)
return l;
assert(length-offset>=3);
EnsureEnoughRemaining(3);
int32_t res=((int32_t)buffer[offset] & 0xFF) |
(((int32_t)buffer[offset+1] & 0xFF) << 8) |
(((int32_t)buffer[offset+2] & 0xFF) << 16);
offset+=3;
return res;
}
void BufferInputStream::ReadBytes(unsigned char *to, size_t count){
EnsureEnoughRemaining(count);
memcpy(to, buffer+offset, count);
offset+=count;
}
BufferInputStream BufferInputStream::GetPartBuffer(size_t length, bool advance){
EnsureEnoughRemaining(length);
BufferInputStream s=BufferInputStream(buffer+offset, length);
if(advance)
offset+=length;
return s;
}
void BufferInputStream::EnsureEnoughRemaining(size_t need){
if(length-offset<need){
throw std::out_of_range("Not enough bytes in buffer");
}
}