2020-03-09 01:50:30 -07:00

85 lines
2.0 KiB
C++

#pragma once
#include <stdio.h>
#include <memory>
#include "../files.hpp"
class stream {
public:
virtual int read(void *buf, size_t len);
virtual int write(const void *buf, size_t len);
virtual off_t seek(off_t off, int whence);
virtual ~stream() = default;
};
using stream_ptr = std::unique_ptr<stream>;
// Delegates all operations to base stream
class filter_stream : public stream {
public:
filter_stream(stream_ptr &&base) : base(std::move(base)) {}
int read(void *buf, size_t len) override;
int write(const void *buf, size_t len) override;
protected:
stream_ptr base;
};
// Byte stream that dynamically allocates memory
class byte_stream : public stream {
public:
byte_stream(uint8_t *&buf, size_t &len);
template <class byte>
byte_stream(byte *&buf, size_t &len) : byte_stream(reinterpret_cast<uint8_t *&>(buf), len) {}
int read(void *buf, size_t len) override;
int write(const void *buf, size_t len) override;
off_t seek(off_t off, int whence) override;
private:
uint8_t *&_buf;
size_t &_len;
size_t _pos = 0;
size_t _cap = 0;
void resize(size_t new_pos, bool zero = false);
};
// File stream but does not close the file descriptor at any time
class fd_stream : public stream {
public:
fd_stream(int fd) : fd(fd) {}
int read(void *buf, size_t len) override;
int write(const void *buf, size_t len) override;
off_t seek(off_t off, int whence) override;
private:
int fd;
};
/* ****************************************
* Bridge between stream class and C stdio
* ****************************************/
// sFILE -> stream_ptr
class fp_stream final : public stream {
public:
fp_stream(FILE *fp = nullptr) : fp(fp, fclose) {}
fp_stream(sFILE &&fp) : fp(std::move(fp)) {}
int read(void *buf, size_t len) override;
int write(const void *buf, size_t len) override;
off_t seek(off_t off, int whence) override;
private:
sFILE fp;
};
// stream_ptr -> sFILE
sFILE make_stream_fp(stream_ptr &&strm);
template <class T, class... Args>
sFILE make_stream_fp(Args &&... args) {
return make_stream_fp(stream_ptr(new T(std::forward<Args>(args)...)));
}