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#pragma once
#include <cstdio>
#include <iostream>
#include <streambuf>
#include <vector>
namespace dictzip {
// Warning: The inherent statefulness of stream buffers interferes with
// multithreaded access. Users of this class should perform appropriate
// locking, since they are in a better position to do so.
class IstreamBuf : public std::streambuf {
private:
struct Chunk {
Chunk(size_t offset, size_t size):
offset(offset),
size(size) {};
const size_t offset;
const size_t size;
};
FILE* dictzip_file_;
std::vector<unsigned char> buffer_;
std::vector<unsigned char> header_;
std::vector<Chunk> chunks_;
size_t chunk_length_;
long data_offset_;
long curr_chunk_;
void readChunk(long n);
void readHeader();
void readExtra();
void skipOptional();
protected:
int underflow();
std::streamsize xsgetn(char *dest, std::streamsize n);
public:
using pos_type = std::streambuf::pos_type;
using off_type = std::streambuf::off_type;
typedef std::ios::seekdir seekdir;
typedef std::ios::openmode openmode;
IstreamBuf(char const* filename);
~IstreamBuf();
pos_type seekoff(off_type off, seekdir dir, openmode);
pos_type seekpos(pos_type off, openmode mode);
};
}
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