Magisk/native/jni/utils/include/stream.h
2019-11-23 04:57:52 -05:00

85 lines
2.0 KiB
C++

#pragma once
#include <stdio.h>
#include <memory>
#include "../files.h"
class stream;
using stream_ptr = std::unique_ptr<stream>;
sFILE make_stream(stream_ptr &&strm);
template <class T, class... Args>
sFILE make_stream(Args &&... args) {
return make_stream(stream_ptr(new T(std::forward<Args>(args)...)));
}
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;
};
// Delegates all operations to the base FILE pointer
class filter_stream : public stream {
public:
filter_stream() = default;
filter_stream(sFILE &&fp) : fp(std::move(fp)) {}
int read(void *buf, size_t len) override;
int write(const void *buf, size_t len) override;
void set_base(sFILE &&f);
template <class T, class... Args >
void set_base(Args&&... args) {
set_base(make_stream<T>(std::forward<Args>(args)...));
}
protected:
sFILE fp;
};
// Handy interface for classes that need custom seek logic
class seekable_stream : public stream {
protected:
size_t _pos = 0;
off_t seek_pos(off_t off, int whence);
virtual size_t end_pos() = 0;
};
// Byte stream that dynamically allocates memory
class byte_stream : public seekable_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 _cap = 0;
void resize(size_t new_pos, bool zero = false);
size_t end_pos() final { return _len; }
};
// 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;
};