Merge remote-tracking branch 'origin/master' into fsync-store-paths

src/libutil/file-descriptor.cc

@@ -0,0 +1,149 @@
+#include "file-system.hh"
+#include "signals.hh"
+#include "finally.hh"
+#include "serialise.hh"
+
+#include <fcntl.h>
+#include <unistd.h>
+#ifdef _WIN32
+# include <winnt.h>
+# include <fileapi.h>
+# include "windows-error.hh"
+#endif
+
+namespace nix {
+
+void writeLine(Descriptor fd, std::string s)
+{
+    s += '\n';
+    writeFull(fd, s);
+}
+
+
+std::string drainFD(Descriptor fd, bool block, const size_t reserveSize)
+{
+    // the parser needs two extra bytes to append terminating characters, other users will
+    // not care very much about the extra memory.
+    StringSink sink(reserveSize + 2);
+#ifdef _WIN32
+    // non-blocking is not supported this way on Windows
+    assert(block);
+    drainFD(fd, sink);
+#else
+    drainFD(fd, sink, block);
+#endif
+    return std::move(sink.s);
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+AutoCloseFD::AutoCloseFD() : fd{INVALID_DESCRIPTOR} {}
+
+
+AutoCloseFD::AutoCloseFD(Descriptor fd) : fd{fd} {}
+
+
+AutoCloseFD::AutoCloseFD(AutoCloseFD && that) : fd{that.fd}
+{
+    that.fd = INVALID_DESCRIPTOR;
+}
+
+
+AutoCloseFD & AutoCloseFD::operator =(AutoCloseFD && that)
+{
+    close();
+    fd = that.fd;
+    that.fd = INVALID_DESCRIPTOR;
+    return *this;
+}
+
+
+AutoCloseFD::~AutoCloseFD()
+{
+    try {
+        close();
+    } catch (...) {
+        ignoreException();
+    }
+}
+
+
+Descriptor AutoCloseFD::get() const
+{
+    return fd;
+}
+
+
+void AutoCloseFD::close()
+{
+    if (fd != INVALID_DESCRIPTOR) {
+        if(
+#ifdef _WIN32
+           ::CloseHandle(fd)
+#else
+           ::close(fd)
+#endif
+           == -1)
+            /* This should never happen. */
+            throw NativeSysError("closing file descriptor %1%", fd);
+        fd = INVALID_DESCRIPTOR;
+    }
+}
+
+void AutoCloseFD::fsync() const
+{
+    if (fd != INVALID_DESCRIPTOR) {
+        int result;
+        result =
+#ifdef _WIN32
+            ::FlushFileBuffers(fd)
+#elif __APPLE__
+            ::fcntl(fd, F_FULLFSYNC)
+#else
+            ::fsync(fd)
+#endif
+            ;
+        if (result == -1)
+            throw NativeSysError("fsync file descriptor %1%", fd);
+    }
+}
+
+
+
+void AutoCloseFD::startFsync() const
+{
+#if __linux__
+        if (fd != -1) {
+            /* Ignore failure, since fsync must be run later anyway. This is just a performance optimization. */
+            ::sync_file_range(fd, 0, 0, SYNC_FILE_RANGE_WRITE);
+        }
+#endif
+}
+
+
+AutoCloseFD::operator bool() const
+{
+    return fd != INVALID_DESCRIPTOR;
+}
+
+
+Descriptor AutoCloseFD::release()
+{
+    Descriptor oldFD = fd;
+    fd = INVALID_DESCRIPTOR;
+    return oldFD;
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
+void Pipe::close()
+{
+    readSide.close();
+    writeSide.close();
+}
+
+}