134 lines
3.2 KiB
C++
134 lines
3.2 KiB
C++
#pragma once
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#include "types.hh"
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namespace nix {
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/* Abstract destination of binary data. */
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struct Sink
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{
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virtual ~Sink() { }
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virtual void operator () (const unsigned char * data, size_t len) = 0;
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};
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/* A buffered abstract sink. */
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struct BufferedSink : Sink
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{
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size_t bufSize, bufPos;
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unsigned char * buffer;
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BufferedSink(size_t bufSize = 32 * 1024)
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: bufSize(bufSize), bufPos(0), buffer(0) { }
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~BufferedSink();
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void operator () (const unsigned char * data, size_t len);
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void flush();
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virtual void write(const unsigned char * data, size_t len) = 0;
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};
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/* Abstract source of binary data. */
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struct Source
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{
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virtual ~Source() { }
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/* Store exactly ‘len’ bytes in the buffer pointed to by ‘data’.
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It blocks until all the requested data is available, or throws
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an error if it is not going to be available. */
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void operator () (unsigned char * data, size_t len);
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/* Store up to ‘len’ in the buffer pointed to by ‘data’, and
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return the number of bytes stored. If blocks until at least
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one byte is available. */
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virtual size_t read(unsigned char * data, size_t len) = 0;
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};
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/* A buffered abstract source. */
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struct BufferedSource : Source
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{
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size_t bufSize, bufPosIn, bufPosOut;
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unsigned char * buffer;
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BufferedSource(size_t bufSize = 32 * 1024)
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: bufSize(bufSize), bufPosIn(0), bufPosOut(0), buffer(0) { }
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~BufferedSource();
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size_t read(unsigned char * data, size_t len);
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/* Underlying read call, to be overridden. */
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virtual size_t readUnbuffered(unsigned char * data, size_t len) = 0;
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bool hasData();
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};
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/* A sink that writes data to a file descriptor. */
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struct FdSink : BufferedSink
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{
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int fd;
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FdSink() : fd(-1) { }
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FdSink(int fd) : fd(fd) { }
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~FdSink();
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void write(const unsigned char * data, size_t len);
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};
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/* A source that reads data from a file descriptor. */
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struct FdSource : BufferedSource
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{
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int fd;
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FdSource() : fd(-1) { }
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FdSource(int fd) : fd(fd) { }
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size_t readUnbuffered(unsigned char * data, size_t len);
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};
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/* A sink that writes data to a string. */
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struct StringSink : Sink
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{
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string s;
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void operator () (const unsigned char * data, size_t len)
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{
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s.append((const char *) data, len);
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}
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};
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/* A source that reads data from a string. */
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struct StringSource : Source
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{
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const string & s;
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size_t pos;
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StringSource(const string & _s) : s(_s), pos(0) { }
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size_t read(unsigned char * data, size_t len);
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};
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void writePadding(size_t len, Sink & sink);
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void writeInt(unsigned int n, Sink & sink);
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void writeLongLong(unsigned long long n, Sink & sink);
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void writeString(const unsigned char * buf, size_t len, Sink & sink);
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void writeString(const string & s, Sink & sink);
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template<class T> void writeStrings(const T & ss, Sink & sink);
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void readPadding(size_t len, Source & source);
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unsigned int readInt(Source & source);
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unsigned long long readLongLong(Source & source);
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size_t readString(unsigned char * buf, size_t max, Source & source);
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string readString(Source & source);
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template<class T> T readStrings(Source & source);
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MakeError(SerialisationError, Error)
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}
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