eldritch horrors
c65f5dd18e
the `*Source` name is a slight misnomer since we do also have a Source type, but we can probably live with this for time being. Change-Id: I54eb2e59a4009014e324797f16b80b962759c7d3
82 lines
1.6 KiB
C++
82 lines
1.6 KiB
C++
#pragma once
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///@file
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#include "error.hh"
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#include "generator.hh"
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namespace nix {
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struct Sink;
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struct Source;
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/**
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* Read a line from a file descriptor.
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*/
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std::string readLine(int fd);
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/**
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* Write a line to a file descriptor.
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*/
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void writeLine(int fd, std::string s);
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/**
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* Read the contents of a file into a string.
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*/
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std::string readFile(int fd);
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/**
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* Wrappers arount read()/write() that read/write exactly the
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* requested number of bytes.
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*/
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void readFull(int fd, char * buf, size_t count);
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void writeFull(int fd, std::string_view s, bool allowInterrupts = true);
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/**
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* Read a file descriptor until EOF occurs.
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*/
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std::string drainFD(int fd, bool block = true, const size_t reserveSize=0);
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Generator<Bytes> drainFDSource(int fd, bool block = true);
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class AutoCloseFD
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{
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int fd;
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public:
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AutoCloseFD();
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explicit AutoCloseFD(int fd);
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AutoCloseFD(const AutoCloseFD & fd) = delete;
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AutoCloseFD(AutoCloseFD&& fd);
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~AutoCloseFD();
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AutoCloseFD& operator =(const AutoCloseFD & fd) = delete;
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AutoCloseFD& operator =(AutoCloseFD&& fd) noexcept(false);
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int get() const;
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explicit operator bool() const;
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int release();
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void close();
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void fsync();
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void reset() { *this = {}; }
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};
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class Pipe
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{
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public:
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AutoCloseFD readSide, writeSide;
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void create();
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void close();
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};
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/**
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* Close all file descriptors except those listed in the given set.
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* Good practice in child processes.
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*/
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void closeMostFDs(const std::set<int> & exceptions);
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/**
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* Set the close-on-exec flag for the given file descriptor.
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*/
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void closeOnExec(int fd);
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MakeError(EndOfFile, Error);
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}
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