303 lines
6.7 KiB
C++
303 lines
6.7 KiB
C++
#pragma once
|
||
|
||
#include <memory>
|
||
|
||
#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; }
|
||
|
||
void operator () (const std::string & s)
|
||
{
|
||
(*this)((const unsigned char *) s.data(), s.size());
|
||
}
|
||
};
|
||
|
||
|
||
/* A buffered abstract sink. */
|
||
struct BufferedSink : Sink
|
||
{
|
||
size_t bufSize, bufPos;
|
||
std::unique_ptr<unsigned char[]> buffer;
|
||
|
||
BufferedSink(size_t bufSize = 32 * 1024)
|
||
: bufSize(bufSize), bufPos(0), buffer(nullptr) { }
|
||
|
||
void operator () (const unsigned char * data, size_t len) override;
|
||
|
||
void operator () (const std::string & s)
|
||
{
|
||
Sink::operator()(s);
|
||
}
|
||
|
||
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. It blocks until at least
|
||
one byte is available. */
|
||
virtual size_t read(unsigned char * data, size_t len) = 0;
|
||
|
||
virtual bool good() { return true; }
|
||
|
||
std::string drain();
|
||
};
|
||
|
||
|
||
/* A buffered abstract source. */
|
||
struct BufferedSource : Source
|
||
{
|
||
size_t bufSize, bufPosIn, bufPosOut;
|
||
std::unique_ptr<unsigned char[]> buffer;
|
||
|
||
BufferedSource(size_t bufSize = 32 * 1024)
|
||
: bufSize(bufSize), bufPosIn(0), bufPosOut(0), buffer(nullptr) { }
|
||
|
||
size_t read(unsigned char * data, size_t len) override;
|
||
|
||
|
||
bool hasData();
|
||
|
||
protected:
|
||
/* Underlying read call, to be overridden. */
|
||
virtual size_t readUnbuffered(unsigned char * data, size_t len) = 0;
|
||
};
|
||
|
||
|
||
/* 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(FdSink&&) = default;
|
||
|
||
FdSink& operator=(FdSink && s)
|
||
{
|
||
flush();
|
||
fd = s.fd;
|
||
s.fd = -1;
|
||
warn = s.warn;
|
||
written = s.written;
|
||
return *this;
|
||
}
|
||
|
||
~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) { }
|
||
FdSource(FdSource&&) = default;
|
||
|
||
FdSource& operator=(FdSource && s)
|
||
{
|
||
fd = s.fd;
|
||
s.fd = -1;
|
||
read = s.read;
|
||
return *this;
|
||
}
|
||
|
||
bool good() override;
|
||
protected:
|
||
size_t readUnbuffered(unsigned char * data, size_t len) override;
|
||
private:
|
||
bool _good = true;
|
||
};
|
||
|
||
|
||
/* A sink that writes data to a string. */
|
||
struct StringSink : Sink
|
||
{
|
||
ref<std::string> s;
|
||
StringSink() : s(make_ref<std::string>()) { };
|
||
StringSink(ref<std::string> s) : s(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;
|
||
};
|
||
|
||
|
||
/* Adapter class of a Source that saves all data read to `s'. */
|
||
struct TeeSource : Source
|
||
{
|
||
Source & orig;
|
||
ref<std::string> data;
|
||
TeeSource(Source & orig)
|
||
: orig(orig), data(make_ref<std::string>()) { }
|
||
size_t read(unsigned char * data, size_t len)
|
||
{
|
||
size_t n = orig.read(data, len);
|
||
this->data->append((const char *) data, n);
|
||
return n;
|
||
}
|
||
};
|
||
|
||
|
||
/* Convert a function into a sink. */
|
||
struct LambdaSink : Sink
|
||
{
|
||
typedef std::function<void(const unsigned char *, size_t)> lambda_t;
|
||
|
||
lambda_t lambda;
|
||
|
||
LambdaSink(const lambda_t & lambda) : lambda(lambda) { }
|
||
|
||
virtual void operator () (const unsigned char * data, size_t len)
|
||
{
|
||
lambda(data, len);
|
||
}
|
||
};
|
||
|
||
|
||
/* Convert a function into a source. */
|
||
struct LambdaSource : Source
|
||
{
|
||
typedef std::function<size_t(unsigned char *, size_t)> lambda_t;
|
||
|
||
lambda_t lambda;
|
||
|
||
LambdaSource(const lambda_t & lambda) : lambda(lambda) { }
|
||
|
||
size_t read(unsigned char * data, size_t len) override
|
||
{
|
||
return lambda(data, len);
|
||
}
|
||
};
|
||
|
||
|
||
/* Convert a function that feeds data into a Sink into a Source. The
|
||
Source executes the function as a coroutine. */
|
||
std::unique_ptr<Source> sinkToSource(std::function<void(Sink &)> fun);
|
||
|
||
|
||
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] = (unsigned char) (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);
|
||
|
||
|
||
MakeError(SerialisationError, Error)
|
||
|
||
|
||
template<typename T>
|
||
T readNum(Source & source)
|
||
{
|
||
unsigned char buf[8];
|
||
source(buf, sizeof(buf));
|
||
|
||
uint64_t n =
|
||
((unsigned long long) buf[0]) |
|
||
((unsigned long long) buf[1] << 8) |
|
||
((unsigned long long) buf[2] << 16) |
|
||
((unsigned long long) buf[3] << 24) |
|
||
((unsigned long long) buf[4] << 32) |
|
||
((unsigned long long) buf[5] << 40) |
|
||
((unsigned long long) buf[6] << 48) |
|
||
((unsigned long long) buf[7] << 56);
|
||
|
||
if (n > std::numeric_limits<T>::max())
|
||
throw SerialisationError("serialised integer %d is too large for type '%s'", n, typeid(T).name());
|
||
|
||
return (T) n;
|
||
}
|
||
|
||
|
||
inline unsigned int readInt(Source & source)
|
||
{
|
||
return readNum<unsigned int>(source);
|
||
}
|
||
|
||
|
||
inline uint64_t readLongLong(Source & source)
|
||
{
|
||
return readNum<uint64_t>(source);
|
||
}
|
||
|
||
|
||
void readPadding(size_t len, 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);
|
||
|
||
template<typename T>
|
||
Source & operator >> (Source & in, T & n)
|
||
{
|
||
n = readNum<T>(in);
|
||
return in;
|
||
}
|
||
|
||
template<typename T>
|
||
Source & operator >> (Source & in, bool & b)
|
||
{
|
||
b = readNum<uint64_t>(in);
|
||
return in;
|
||
}
|
||
|
||
|
||
}
|