166 lines
3.8 KiB
C++
166 lines
3.8 KiB
C++
#pragma once
|
||
|
||
#include "types.hh"
|
||
#include "util.hh"
|
||
|
||
|
||
namespace nix {
|
||
|
||
|
||
/* Abstract destination of binary data. */
|
||
struct Sink
|
||
{
|
||
virtual ~Sink() { }
|
||
virtual void operator () (const unsigned char * data, size_t len) = 0;
|
||
virtual bool good() { return true; }
|
||
};
|
||
|
||
|
||
/* A buffered abstract sink. */
|
||
struct BufferedSink : Sink
|
||
{
|
||
size_t bufSize, bufPos;
|
||
unsigned char * buffer;
|
||
|
||
BufferedSink(size_t bufSize = 32 * 1024)
|
||
: bufSize(bufSize), bufPos(0), buffer(0) { }
|
||
~BufferedSink();
|
||
|
||
void operator () (const unsigned char * data, size_t len) override;
|
||
|
||
void flush();
|
||
|
||
virtual void write(const unsigned char * data, size_t len) = 0;
|
||
};
|
||
|
||
|
||
/* Abstract source of binary data. */
|
||
struct Source
|
||
{
|
||
virtual ~Source() { }
|
||
|
||
/* Store exactly ‘len’ bytes in the buffer pointed to by ‘data’.
|
||
It blocks until all the requested data is available, or throws
|
||
an error if it is not going to be available. */
|
||
void operator () (unsigned char * data, size_t len);
|
||
|
||
/* Store up to ‘len’ in the buffer pointed to by ‘data’, and
|
||
return the number of bytes stored. If blocks until at least
|
||
one byte is available. */
|
||
virtual size_t read(unsigned char * data, size_t len) = 0;
|
||
|
||
virtual bool good() { return true; }
|
||
};
|
||
|
||
|
||
/* A buffered abstract source. */
|
||
struct BufferedSource : Source
|
||
{
|
||
size_t bufSize, bufPosIn, bufPosOut;
|
||
unsigned char * buffer;
|
||
|
||
BufferedSource(size_t bufSize = 32 * 1024)
|
||
: bufSize(bufSize), bufPosIn(0), bufPosOut(0), buffer(0) { }
|
||
~BufferedSource();
|
||
|
||
size_t read(unsigned char * data, size_t len) override;
|
||
|
||
/* Underlying read call, to be overridden. */
|
||
virtual size_t readUnbuffered(unsigned char * data, size_t len) = 0;
|
||
|
||
bool hasData();
|
||
};
|
||
|
||
|
||
/* A sink that writes data to a file descriptor. */
|
||
struct FdSink : BufferedSink
|
||
{
|
||
int fd;
|
||
bool warn = false;
|
||
size_t written = 0;
|
||
|
||
FdSink() : fd(-1) { }
|
||
FdSink(int fd) : fd(fd) { }
|
||
~FdSink();
|
||
|
||
void write(const unsigned char * data, size_t len) override;
|
||
|
||
bool good() override;
|
||
|
||
private:
|
||
bool _good = true;
|
||
};
|
||
|
||
|
||
/* A source that reads data from a file descriptor. */
|
||
struct FdSource : BufferedSource
|
||
{
|
||
int fd;
|
||
size_t read = 0;
|
||
|
||
FdSource() : fd(-1) { }
|
||
FdSource(int fd) : fd(fd) { }
|
||
size_t readUnbuffered(unsigned char * data, size_t len) override;
|
||
bool good() override;
|
||
private:
|
||
bool _good = true;
|
||
};
|
||
|
||
|
||
/* A sink that writes data to a string. */
|
||
struct StringSink : Sink
|
||
{
|
||
string s;
|
||
void operator () (const unsigned char * data, size_t len) override;
|
||
};
|
||
|
||
|
||
/* A source that reads data from a string. */
|
||
struct StringSource : Source
|
||
{
|
||
const string & s;
|
||
size_t pos;
|
||
StringSource(const string & _s) : s(_s), pos(0) { }
|
||
size_t read(unsigned char * data, size_t len) override;
|
||
};
|
||
|
||
|
||
void writePadding(size_t len, Sink & sink);
|
||
void writeString(const unsigned char * buf, size_t len, Sink & sink);
|
||
|
||
inline Sink & operator << (Sink & sink, uint64_t n)
|
||
{
|
||
unsigned char buf[8];
|
||
buf[0] = n & 0xff;
|
||
buf[1] = (n >> 8) & 0xff;
|
||
buf[2] = (n >> 16) & 0xff;
|
||
buf[3] = (n >> 24) & 0xff;
|
||
buf[4] = (n >> 32) & 0xff;
|
||
buf[5] = (n >> 40) & 0xff;
|
||
buf[6] = (n >> 48) & 0xff;
|
||
buf[7] = (n >> 56) & 0xff;
|
||
sink(buf, sizeof(buf));
|
||
return sink;
|
||
}
|
||
|
||
Sink & operator << (Sink & sink, const string & s);
|
||
Sink & operator << (Sink & sink, const Strings & s);
|
||
Sink & operator << (Sink & sink, const StringSet & s);
|
||
|
||
|
||
void readPadding(size_t len, Source & source);
|
||
unsigned int readInt(Source & source);
|
||
unsigned long long readLongLong(Source & source);
|
||
size_t readString(unsigned char * buf, size_t max, Source & source);
|
||
string readString(Source & source);
|
||
template<class T> T readStrings(Source & source);
|
||
|
||
Source & operator >> (Source & in, string & s);
|
||
Source & operator >> (Source & in, unsigned int & n);
|
||
|
||
|
||
MakeError(SerialisationError, Error)
|
||
|
||
|
||
}
|