diff options
Diffstat (limited to 'src/libutil/serialise.hh')
| -rw-r--r-- | src/libutil/serialise.hh | 164 |
1 files changed, 102 insertions, 62 deletions
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh index 13da26c6a..2cf527023 100644 --- a/src/libutil/serialise.hh +++ b/src/libutil/serialise.hh @@ -1,4 +1,5 @@ #pragma once +///@file #include <memory> @@ -10,7 +11,9 @@ namespace boost::context { struct stack_context; } namespace nix { -/* Abstract destination of binary data. */ +/** + * Abstract destination of binary data. + */ struct Sink { virtual ~Sink() { } @@ -18,7 +21,9 @@ struct Sink virtual bool good() { return true; } }; -/* Just throws away data. */ +/** + * Just throws away data. + */ struct NullSink : Sink { void operator () (std::string_view data) override @@ -32,8 +37,10 @@ struct FinishSink : virtual Sink }; -/* A buffered abstract sink. Warning: a BufferedSink should not be - used from multiple threads concurrently. */ +/** + * A buffered abstract sink. Warning: a BufferedSink should not be + * used from multiple threads concurrently. + */ struct BufferedSink : virtual Sink { size_t bufSize, bufPos; @@ -50,19 +57,25 @@ struct BufferedSink : virtual Sink }; -/* Abstract source of binary data. */ +/** + * 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. */ + /** + * 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 () (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. */ + /** + * 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(char * data, size_t len) = 0; virtual bool good() { return true; } @@ -73,8 +86,10 @@ struct Source }; -/* A buffered abstract source. Warning: a BufferedSource should not be - used from multiple threads concurrently. */ +/** + * A buffered abstract source. Warning: a BufferedSource should not be + * used from multiple threads concurrently. + */ struct BufferedSource : Source { size_t bufSize, bufPosIn, bufPosOut; @@ -88,28 +103,30 @@ struct BufferedSource : Source bool hasData(); protected: - /* Underlying read call, to be overridden. */ + /** + * Underlying read call, to be overridden. + */ virtual size_t readUnbuffered(char * data, size_t len) = 0; }; -/* A sink that writes data to a file descriptor. */ +/** + * 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) + FdSink & operator=(FdSink && s) { flush(); fd = s.fd; s.fd = -1; - warn = s.warn; written = s.written; return *this; } @@ -125,7 +142,9 @@ private: }; -/* A source that reads data from a file descriptor. */ +/** + * A source that reads data from a file descriptor. + */ struct FdSource : BufferedSource { int fd; @@ -151,7 +170,9 @@ private: }; -/* A sink that writes data to a string. */ +/** + * A sink that writes data to a string. + */ struct StringSink : Sink { std::string s; @@ -165,7 +186,9 @@ struct StringSink : Sink }; -/* A source that reads data from a string. */ +/** + * A source that reads data from a string. + */ struct StringSource : Source { std::string_view s; @@ -175,7 +198,9 @@ struct StringSource : Source }; -/* A sink that writes all incoming data to two other sinks. */ +/** + * A sink that writes all incoming data to two other sinks. + */ struct TeeSink : Sink { Sink & sink1, & sink2; @@ -188,7 +213,9 @@ struct TeeSink : Sink }; -/* Adapter class of a Source that saves all data read to a sink. */ +/** + * Adapter class of a Source that saves all data read to a sink. + */ struct TeeSource : Source { Source & orig; @@ -203,7 +230,9 @@ struct TeeSource : Source } }; -/* A reader that consumes the original Source until 'size'. */ +/** + * A reader that consumes the original Source until 'size'. + */ struct SizedSource : Source { Source & orig; @@ -221,7 +250,9 @@ struct SizedSource : Source return n; } - /* Consume the original source until no remain data is left to consume. */ + /** + * Consume the original source until no remain data is left to consume. + */ size_t drainAll() { std::vector<char> buf(8192); @@ -234,7 +265,9 @@ struct SizedSource : Source } }; -/* A sink that that just counts the number of bytes given to it */ +/** + * A sink that that just counts the number of bytes given to it + */ struct LengthSink : Sink { uint64_t length = 0; @@ -245,7 +278,9 @@ struct LengthSink : Sink } }; -/* Convert a function into a sink. */ +/** + * Convert a function into a sink. + */ struct LambdaSink : Sink { typedef std::function<void(std::string_view data)> lambda_t; @@ -261,7 +296,9 @@ struct LambdaSink : Sink }; -/* Convert a function into a source. */ +/** + * Convert a function into a source. + */ struct LambdaSource : Source { typedef std::function<size_t(char *, size_t)> lambda_t; @@ -276,8 +313,10 @@ struct LambdaSource : Source } }; -/* Chain two sources together so after the first is exhausted, the second is - used */ +/** + * Chain two sources together so after the first is exhausted, the second is + * used + */ struct ChainSource : Source { Source & source1, & source2; @@ -291,8 +330,10 @@ struct ChainSource : Source std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun); -/* Convert a function that feeds data into a Sink into a Source. The - Source executes the function as a coroutine. */ +/** + * 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, std::function<void()> eof = []() { @@ -333,17 +374,9 @@ T readNum(Source & source) unsigned char buf[8]; source((char *) buf, sizeof(buf)); - uint64_t n = - ((uint64_t) buf[0]) | - ((uint64_t) buf[1] << 8) | - ((uint64_t) buf[2] << 16) | - ((uint64_t) buf[3] << 24) | - ((uint64_t) buf[4] << 32) | - ((uint64_t) buf[5] << 40) | - ((uint64_t) buf[6] << 48) | - ((uint64_t) buf[7] << 56); - - if (n > (uint64_t)std::numeric_limits<T>::max()) + auto n = readLittleEndian<uint64_t>(buf); + + if (n > (uint64_t) std::numeric_limits<T>::max()) throw SerialisationError("serialised integer %d is too large for type '%s'", n, typeid(T).name()); return (T) n; @@ -386,7 +419,9 @@ Source & operator >> (Source & in, bool & b) Error readError(Source & source); -/* An adapter that converts a std::basic_istream into a source. */ +/** + * An adapter that converts a std::basic_istream into a source. + */ struct StreamToSourceAdapter : Source { std::shared_ptr<std::basic_istream<char>> istream; @@ -409,13 +444,14 @@ struct StreamToSourceAdapter : Source }; -/* A source that reads a distinct format of concatenated chunks back into its - logical form, in order to guarantee a known state to the original stream, - even in the event of errors. - - Use with FramedSink, which also allows the logical stream to be terminated - in the event of an exception. -*/ +/** + * A source that reads a distinct format of concatenated chunks back into its + * logical form, in order to guarantee a known state to the original stream, + * even in the event of errors. + * + * Use with FramedSink, which also allows the logical stream to be terminated + * in the event of an exception. + */ struct FramedSource : Source { Source & from; @@ -460,11 +496,12 @@ struct FramedSource : Source } }; -/* Write as chunks in the format expected by FramedSource. - - The exception_ptr reference can be used to terminate the stream when you - detect that an error has occurred on the remote end. -*/ +/** + * Write as chunks in the format expected by FramedSource. + * + * The exception_ptr reference can be used to terminate the stream when you + * detect that an error has occurred on the remote end. + */ struct FramedSink : nix::BufferedSink { BufferedSink & to; @@ -497,17 +534,20 @@ struct FramedSink : nix::BufferedSink }; }; -/* Stack allocation strategy for sinkToSource. - Mutable to avoid a boehm gc dependency in libutil. - - boost::context doesn't provide a virtual class, so we define our own. +/** + * Stack allocation strategy for sinkToSource. + * Mutable to avoid a boehm gc dependency in libutil. + * + * boost::context doesn't provide a virtual class, so we define our own. */ struct StackAllocator { virtual boost::context::stack_context allocate() = 0; virtual void deallocate(boost::context::stack_context sctx) = 0; - /* The stack allocator to use in sinkToSource and potentially elsewhere. - It is reassigned by the initGC() method in libexpr. */ + /** + * The stack allocator to use in sinkToSource and potentially elsewhere. + * It is reassigned by the initGC() method in libexpr. + */ static StackAllocator *defaultAllocator; }; |