diff options
Diffstat (limited to 'third_party/nix/src/libutil/serialise.cc')
| -rw-r--r-- | third_party/nix/src/libutil/serialise.cc | 466 |
1 files changed, 210 insertions, 256 deletions
diff --git a/third_party/nix/src/libutil/serialise.cc b/third_party/nix/src/libutil/serialise.cc index 8201549fd7..6d7cb1d8d1 100644 --- a/third_party/nix/src/libutil/serialise.cc +++ b/third_party/nix/src/libutil/serialise.cc @@ -1,323 +1,277 @@ #include "serialise.hh" -#include "util.hh" - -#include <cstring> +#include <boost/coroutine2/coroutine.hpp> #include <cerrno> +#include <cstring> #include <memory> - -#include <boost/coroutine2/coroutine.hpp> - +#include "util.hh" namespace nix { +void BufferedSink::operator()(const unsigned char* data, size_t len) { + if (!buffer) buffer = decltype(buffer)(new unsigned char[bufSize]); -void BufferedSink::operator () (const unsigned char * data, size_t len) -{ - if (!buffer) buffer = decltype(buffer)(new unsigned char[bufSize]); - - while (len) { - /* Optimisation: bypass the buffer if the data exceeds the - buffer size. */ - if (bufPos + len >= bufSize) { - flush(); - write(data, len); - break; - } - /* Otherwise, copy the bytes to the buffer. Flush the buffer - when it's full. */ - size_t n = bufPos + len > bufSize ? bufSize - bufPos : len; - memcpy(buffer.get() + bufPos, data, n); - data += n; bufPos += n; len -= n; - if (bufPos == bufSize) flush(); + while (len) { + /* Optimisation: bypass the buffer if the data exceeds the + buffer size. */ + if (bufPos + len >= bufSize) { + flush(); + write(data, len); + break; } + /* Otherwise, copy the bytes to the buffer. Flush the buffer + when it's full. */ + size_t n = bufPos + len > bufSize ? bufSize - bufPos : len; + memcpy(buffer.get() + bufPos, data, n); + data += n; + bufPos += n; + len -= n; + if (bufPos == bufSize) flush(); + } } - -void BufferedSink::flush() -{ - if (bufPos == 0) return; - size_t n = bufPos; - bufPos = 0; // don't trigger the assert() in ~BufferedSink() - write(buffer.get(), n); +void BufferedSink::flush() { + if (bufPos == 0) return; + size_t n = bufPos; + bufPos = 0; // don't trigger the assert() in ~BufferedSink() + write(buffer.get(), n); } - -FdSink::~FdSink() -{ - try { flush(); } catch (...) { ignoreException(); } +FdSink::~FdSink() { + try { + flush(); + } catch (...) { + ignoreException(); + } } - size_t threshold = 256 * 1024 * 1024; -static void warnLargeDump() -{ - printError("warning: dumping very large path (> 256 MiB); this may run out of memory"); +static void warnLargeDump() { + printError( + "warning: dumping very large path (> 256 MiB); this may run out of " + "memory"); } - -void FdSink::write(const unsigned char * data, size_t len) -{ - written += len; - static bool warned = false; - if (warn && !warned) { - if (written > threshold) { - warnLargeDump(); - warned = true; - } - } - try { - writeFull(fd, data, len); - } catch (SysError & e) { - _good = false; - throw; +void FdSink::write(const unsigned char* data, size_t len) { + written += len; + static bool warned = false; + if (warn && !warned) { + if (written > threshold) { + warnLargeDump(); + warned = true; } + } + try { + writeFull(fd, data, len); + } catch (SysError& e) { + _good = false; + throw; + } } +bool FdSink::good() { return _good; } -bool FdSink::good() -{ - return _good; +void Source::operator()(unsigned char* data, size_t len) { + while (len) { + size_t n = read(data, len); + data += n; + len -= n; + } } - -void Source::operator () (unsigned char * data, size_t len) -{ - while (len) { - size_t n = read(data, len); - data += n; len -= n; - } -} - - -std::string Source::drain() -{ - std::string s; - std::vector<unsigned char> buf(8192); - while (true) { - size_t n; - try { - n = read(buf.data(), buf.size()); - s.append((char *) buf.data(), n); - } catch (EndOfFile &) { - break; - } +std::string Source::drain() { + std::string s; + std::vector<unsigned char> buf(8192); + while (true) { + size_t n; + try { + n = read(buf.data(), buf.size()); + s.append((char*)buf.data(), n); + } catch (EndOfFile&) { + break; } - return s; -} - - -size_t BufferedSource::read(unsigned char * data, size_t len) -{ - if (!buffer) buffer = decltype(buffer)(new unsigned char[bufSize]); - - if (!bufPosIn) bufPosIn = readUnbuffered(buffer.get(), bufSize); - - /* Copy out the data in the buffer. */ - size_t n = len > bufPosIn - bufPosOut ? bufPosIn - bufPosOut : len; - memcpy(data, buffer.get() + bufPosOut, n); - bufPosOut += n; - if (bufPosIn == bufPosOut) bufPosIn = bufPosOut = 0; - return n; + } + return s; } +size_t BufferedSource::read(unsigned char* data, size_t len) { + if (!buffer) buffer = decltype(buffer)(new unsigned char[bufSize]); -bool BufferedSource::hasData() -{ - return bufPosOut < bufPosIn; -} - + if (!bufPosIn) bufPosIn = readUnbuffered(buffer.get(), bufSize); -size_t FdSource::readUnbuffered(unsigned char * data, size_t len) -{ - ssize_t n; - do { - checkInterrupt(); - n = ::read(fd, (char *) data, len); - } while (n == -1 && errno == EINTR); - if (n == -1) { _good = false; throw SysError("reading from file"); } - if (n == 0) { _good = false; throw EndOfFile("unexpected end-of-file"); } - read += n; - return n; + /* Copy out the data in the buffer. */ + size_t n = len > bufPosIn - bufPosOut ? bufPosIn - bufPosOut : len; + memcpy(data, buffer.get() + bufPosOut, n); + bufPosOut += n; + if (bufPosIn == bufPosOut) bufPosIn = bufPosOut = 0; + return n; } - -bool FdSource::good() -{ - return _good; +bool BufferedSource::hasData() { return bufPosOut < bufPosIn; } + +size_t FdSource::readUnbuffered(unsigned char* data, size_t len) { + ssize_t n; + do { + checkInterrupt(); + n = ::read(fd, (char*)data, len); + } while (n == -1 && errno == EINTR); + if (n == -1) { + _good = false; + throw SysError("reading from file"); + } + if (n == 0) { + _good = false; + throw EndOfFile("unexpected end-of-file"); + } + read += n; + return n; } +bool FdSource::good() { return _good; } -size_t StringSource::read(unsigned char * data, size_t len) -{ - if (pos == s.size()) throw EndOfFile("end of string reached"); - size_t n = s.copy((char *) data, len, pos); - pos += n; - return n; +size_t StringSource::read(unsigned char* data, size_t len) { + if (pos == s.size()) throw EndOfFile("end of string reached"); + size_t n = s.copy((char*)data, len, pos); + pos += n; + return n; } - #if BOOST_VERSION >= 106300 && BOOST_VERSION < 106600 #error Coroutines are broken in this version of Boost! #endif -std::unique_ptr<Source> sinkToSource( - std::function<void(Sink &)> fun, - std::function<void()> eof) -{ - struct SinkToSource : Source - { - typedef boost::coroutines2::coroutine<std::string> coro_t; - - std::function<void(Sink &)> fun; - std::function<void()> eof; - std::optional<coro_t::pull_type> coro; - bool started = false; - - SinkToSource(std::function<void(Sink &)> fun, std::function<void()> eof) - : fun(fun), eof(eof) - { - } - - std::string cur; - size_t pos = 0; - - size_t read(unsigned char * data, size_t len) override - { - if (!coro) - coro = coro_t::pull_type([&](coro_t::push_type & yield) { - LambdaSink sink([&](const unsigned char * data, size_t len) { - if (len) yield(std::string((const char *) data, len)); - }); - fun(sink); - }); - - if (!*coro) { eof(); abort(); } - - if (pos == cur.size()) { - if (!cur.empty()) (*coro)(); - cur = coro->get(); - pos = 0; - } - - auto n = std::min(cur.size() - pos, len); - memcpy(data, (unsigned char *) cur.data() + pos, n); - pos += n; - - return n; - } - }; - - return std::make_unique<SinkToSource>(fun, eof); -} - - -void writePadding(size_t len, Sink & sink) -{ - if (len % 8) { - unsigned char zero[8]; - memset(zero, 0, sizeof(zero)); - sink(zero, 8 - (len % 8)); +std::unique_ptr<Source> sinkToSource(std::function<void(Sink&)> fun, + std::function<void()> eof) { + struct SinkToSource : Source { + typedef boost::coroutines2::coroutine<std::string> coro_t; + + std::function<void(Sink&)> fun; + std::function<void()> eof; + std::optional<coro_t::pull_type> coro; + bool started = false; + + SinkToSource(std::function<void(Sink&)> fun, std::function<void()> eof) + : fun(fun), eof(eof) {} + + std::string cur; + size_t pos = 0; + + size_t read(unsigned char* data, size_t len) override { + if (!coro) + coro = coro_t::pull_type([&](coro_t::push_type& yield) { + LambdaSink sink([&](const unsigned char* data, size_t len) { + if (len) yield(std::string((const char*)data, len)); + }); + fun(sink); + }); + + if (!*coro) { + eof(); + abort(); + } + + if (pos == cur.size()) { + if (!cur.empty()) (*coro)(); + cur = coro->get(); + pos = 0; + } + + auto n = std::min(cur.size() - pos, len); + memcpy(data, (unsigned char*)cur.data() + pos, n); + pos += n; + + return n; } -} - + }; -void writeString(const unsigned char * buf, size_t len, Sink & sink) -{ - sink << len; - sink(buf, len); - writePadding(len, sink); + return std::make_unique<SinkToSource>(fun, eof); } - -Sink & operator << (Sink & sink, const string & s) -{ - writeString((const unsigned char *) s.data(), s.size(), sink); - return sink; +void writePadding(size_t len, Sink& sink) { + if (len % 8) { + unsigned char zero[8]; + memset(zero, 0, sizeof(zero)); + sink(zero, 8 - (len % 8)); + } } - -template<class T> void writeStrings(const T & ss, Sink & sink) -{ - sink << ss.size(); - for (auto & i : ss) - sink << i; +void writeString(const unsigned char* buf, size_t len, Sink& sink) { + sink << len; + sink(buf, len); + writePadding(len, sink); } -Sink & operator << (Sink & sink, const Strings & s) -{ - writeStrings(s, sink); - return sink; +Sink& operator<<(Sink& sink, const string& s) { + writeString((const unsigned char*)s.data(), s.size(), sink); + return sink; } -Sink & operator << (Sink & sink, const StringSet & s) -{ - writeStrings(s, sink); - return sink; +template <class T> +void writeStrings(const T& ss, Sink& sink) { + sink << ss.size(); + for (auto& i : ss) sink << i; } - -void readPadding(size_t len, Source & source) -{ - if (len % 8) { - unsigned char zero[8]; - size_t n = 8 - (len % 8); - source(zero, n); - for (unsigned int i = 0; i < n; i++) - if (zero[i]) throw SerialisationError("non-zero padding"); - } +Sink& operator<<(Sink& sink, const Strings& s) { + writeStrings(s, sink); + return sink; } - -size_t readString(unsigned char * buf, size_t max, Source & source) -{ - auto len = readNum<size_t>(source); - if (len > max) throw SerialisationError("string is too long"); - source(buf, len); - readPadding(len, source); - return len; +Sink& operator<<(Sink& sink, const StringSet& s) { + writeStrings(s, sink); + return sink; } - -string readString(Source & source, size_t max) -{ - auto len = readNum<size_t>(source); - if (len > max) throw SerialisationError("string is too long"); - std::string res(len, 0); - source((unsigned char*) res.data(), len); - readPadding(len, source); - return res; +void readPadding(size_t len, Source& source) { + if (len % 8) { + unsigned char zero[8]; + size_t n = 8 - (len % 8); + source(zero, n); + for (unsigned int i = 0; i < n; i++) + if (zero[i]) throw SerialisationError("non-zero padding"); + } } -Source & operator >> (Source & in, string & s) -{ - s = readString(in); - return in; +size_t readString(unsigned char* buf, size_t max, Source& source) { + auto len = readNum<size_t>(source); + if (len > max) throw SerialisationError("string is too long"); + source(buf, len); + readPadding(len, source); + return len; } - -template<class T> T readStrings(Source & source) -{ - auto count = readNum<size_t>(source); - T ss; - while (count--) - ss.insert(ss.end(), readString(source)); - return ss; +string readString(Source& source, size_t max) { + auto len = readNum<size_t>(source); + if (len > max) throw SerialisationError("string is too long"); + std::string res(len, 0); + source((unsigned char*)res.data(), len); + readPadding(len, source); + return res; } -template Paths readStrings(Source & source); -template PathSet readStrings(Source & source); - +Source& operator>>(Source& in, string& s) { + s = readString(in); + return in; +} -void StringSink::operator () (const unsigned char * data, size_t len) -{ - static bool warned = false; - if (!warned && s->size() > threshold) { - warnLargeDump(); - warned = true; - } - s->append((const char *) data, len); +template <class T> +T readStrings(Source& source) { + auto count = readNum<size_t>(source); + T ss; + while (count--) ss.insert(ss.end(), readString(source)); + return ss; } +template Paths readStrings(Source& source); +template PathSet readStrings(Source& source); +void StringSink::operator()(const unsigned char* data, size_t len) { + static bool warned = false; + if (!warned && s->size() > threshold) { + warnLargeDump(); + warned = true; + } + s->append((const char*)data, len); } + +} // namespace nix |