/*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* limitations under the License.
*/
-#include "folly/FileUtil.h"
+#include <folly/FileUtil.h>
#include <cerrno>
-#ifdef __APPLE__
-#include <fcntl.h>
-#endif
-#include "folly/detail/FileUtilDetail.h"
+#include <folly/Exception.h>
+#include <folly/detail/FileUtilDetail.h>
+#include <folly/portability/Fcntl.h>
+#include <folly/portability/Sockets.h>
+#include <folly/portability/Stdlib.h>
+#include <folly/portability/SysFile.h>
+#include <folly/portability/SysStat.h>
namespace folly {
using namespace fileutil_detail;
int openNoInt(const char* name, int flags, mode_t mode) {
- return wrapNoInt(open, name, flags, mode);
+ return int(wrapNoInt(open, name, flags, mode));
}
int closeNoInt(int fd) {
// Interestingly enough, the Single Unix Specification says that the state
// of the file descriptor is unspecified if close returns EINTR. In that
// case, the safe thing to do is also not to retry close() -- leaking a file
- // descriptor is probably better than closing the wrong file.
+ // descriptor is definitely better than closing the wrong file.
if (r == -1 && errno == EINTR) {
r = 0;
}
}
int fsyncNoInt(int fd) {
- return wrapNoInt(fsync, fd);
+ return int(wrapNoInt(fsync, fd));
+}
+
+int dupNoInt(int fd) {
+ return int(wrapNoInt(dup, fd));
+}
+
+int dup2NoInt(int oldfd, int newfd) {
+ return int(wrapNoInt(dup2, oldfd, newfd));
}
int fdatasyncNoInt(int fd) {
-#ifndef __APPLE__
- return wrapNoInt(fdatasync, fd);
+#if defined(__APPLE__)
+ return int(wrapNoInt(fcntl, fd, F_FULLFSYNC));
+#elif defined(__FreeBSD__) || defined(_MSC_VER)
+ return int(wrapNoInt(fsync, fd));
#else
- return wrapNoInt(fcntl, fd, F_FULLFSYNC);
+ return int(wrapNoInt(fdatasync, fd));
#endif
}
int ftruncateNoInt(int fd, off_t len) {
- return wrapNoInt(ftruncate, fd, len);
+ return int(wrapNoInt(ftruncate, fd, len));
}
int truncateNoInt(const char* path, off_t len) {
- return wrapNoInt(truncate, path, len);
+ return int(wrapNoInt(truncate, path, len));
+}
+
+int flockNoInt(int fd, int operation) {
+ return int(wrapNoInt(flock, fd, operation));
+}
+
+int shutdownNoInt(int fd, int how) {
+ return int(wrapNoInt(portability::sockets::shutdown, fd, how));
}
ssize_t readNoInt(int fd, void* buf, size_t count) {
}
ssize_t readvNoInt(int fd, const iovec* iov, int count) {
- return wrapNoInt(writev, fd, iov, count);
+ return wrapNoInt(readv, fd, iov, count);
}
ssize_t writeNoInt(int fd, const void* buf, size_t count) {
return wrapvFull(readv, fd, iov, count);
}
-#ifdef FOLLY_HAVE_PREADV
ssize_t preadvFull(int fd, iovec* iov, int count, off_t offset) {
return wrapvFull(preadv, fd, iov, count, offset);
}
-#endif
ssize_t writevFull(int fd, iovec* iov, int count) {
return wrapvFull(writev, fd, iov, count);
}
-#ifdef FOLLY_HAVE_PWRITEV
ssize_t pwritevFull(int fd, iovec* iov, int count, off_t offset) {
return wrapvFull(pwritev, fd, iov, count, offset);
}
-#endif
-} // namespaces
+int writeFileAtomicNoThrow(
+ StringPiece filename,
+ iovec* iov,
+ int count,
+ mode_t permissions) {
+ // We write the data to a temporary file name first, then atomically rename
+ // it into place. This ensures that the file contents will always be valid,
+ // even if we crash or are killed partway through writing out data.
+ //
+ // Create a buffer that will contain two things:
+ // - A nul-terminated version of the filename
+ // - The temporary file name
+ std::vector<char> pathBuffer;
+ // Note that we have to explicitly pass in the size here to make
+ // sure the nul byte gets included in the data.
+ constexpr folly::StringPiece suffix(".XXXXXX\0", 8);
+ pathBuffer.resize((2 * filename.size()) + 1 + suffix.size());
+ // Copy in the filename and then a nul terminator
+ memcpy(pathBuffer.data(), filename.data(), filename.size());
+ pathBuffer[filename.size()] = '\0';
+ const char* const filenameCStr = pathBuffer.data();
+ // Now prepare the temporary path template
+ char* const tempPath = pathBuffer.data() + filename.size() + 1;
+ memcpy(tempPath, filename.data(), filename.size());
+ memcpy(tempPath + filename.size(), suffix.data(), suffix.size());
+
+ auto tmpFD = mkstemp(tempPath);
+ if (tmpFD == -1) {
+ return errno;
+ }
+ bool success = false;
+ SCOPE_EXIT {
+ if (tmpFD != -1) {
+ close(tmpFD);
+ }
+ if (!success) {
+ unlink(tempPath);
+ }
+ };
+
+ auto rc = writevFull(tmpFD, iov, count);
+ if (rc == -1) {
+ return errno;
+ }
+
+ rc = fchmod(tmpFD, permissions);
+ if (rc == -1) {
+ return errno;
+ }
+
+ // Close the file before renaming to make sure all data has
+ // been successfully written.
+ rc = close(tmpFD);
+ tmpFD = -1;
+ if (rc == -1) {
+ return errno;
+ }
+
+ rc = rename(tempPath, filenameCStr);
+ if (rc == -1) {
+ return errno;
+ }
+ success = true;
+ return 0;
+}
+
+void writeFileAtomic(
+ StringPiece filename,
+ iovec* iov,
+ int count,
+ mode_t permissions) {
+ auto rc = writeFileAtomicNoThrow(filename, iov, count, permissions);
+ checkPosixError(rc, "writeFileAtomic() failed to update ", filename);
+}
+
+void writeFileAtomic(StringPiece filename, ByteRange data, mode_t permissions) {
+ iovec iov;
+ iov.iov_base = const_cast<unsigned char*>(data.data());
+ iov.iov_len = data.size();
+ auto rc = writeFileAtomicNoThrow(filename, &iov, 1, permissions);
+ checkPosixError(rc, "writeFileAtomic() failed to update ", filename);
+}
+
+void writeFileAtomic(
+ StringPiece filename,
+ StringPiece data,
+ mode_t permissions) {
+ writeFileAtomic(filename, ByteRange(data), permissions);
+}
+} // namespace folly
projects / folly.git / blobdiff