1 files changed, 74 insertions, 0 deletions
diff --git a/src/common/safe_io.h b/src/common/safe_io.h
new file mode 100644
index 00000000..7ccbf37b
--- /dev/null
+++ b/src/common/safe_io.h
@@ -0,0 +1,74 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2011 New Dream Network
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef CEPH_SAFE_IO
+#define CEPH_SAFE_IO
+
+#include "common/compiler_extensions.h"
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  /*
+   * Safe functions wrapping the raw read() and write() libc functions.
+   * These retry on EINTR, and on error return -errno instead of returning
+   * -1 and setting errno).
+   */
+  ssize_t safe_read(int fd, void *buf, size_t count)
+      WARN_UNUSED_RESULT;
+  ssize_t safe_write(int fd, const void *buf, size_t count)
+      WARN_UNUSED_RESULT;
+  ssize_t safe_pread(int fd, void *buf, size_t count, off_t offset)
+      WARN_UNUSED_RESULT;
+  ssize_t safe_pwrite(int fd, const void *buf, size_t count, off_t offset)
+      WARN_UNUSED_RESULT;
+#ifdef CEPH_HAVE_SPLICE
+  /*
+   * Similar to the above (non-exact version) and below (exact version).
+   * See splice(2) for parameter descriptions.
+   */
+  ssize_t safe_splice(int fd_in, off_t *off_in, int fd_out, off_t *off_out,
+		      size_t len, unsigned int flags)
+    WARN_UNUSED_RESULT;
+  ssize_t safe_splice_exact(int fd_in, off_t *off_in, int fd_out,
+			    off_t *off_out, size_t len, unsigned int flags)
+    WARN_UNUSED_RESULT;
+#endif
+
+  /*
+   * Same as the above functions, but return -EDOM unless exactly the requested
+   * number of bytes can be read.
+   */
+  ssize_t safe_read_exact(int fd, void *buf, size_t count)
+      WARN_UNUSED_RESULT;
+  ssize_t safe_pread_exact(int fd, void *buf, size_t count, off_t offset)
+      WARN_UNUSED_RESULT;
+
+
+  /*
+   * Safe functions to read and write an entire file.
+   */
+  int safe_write_file(const char *base, const char *file,
+		      const char *val, size_t vallen,
+		      unsigned mode);
+  int safe_read_file(const char *base, const char *file,
+		     char *val, size_t vallen);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif