Add LoggingOpenFileFor{Read|Write}

util/file/file_io_posix.cc

Index: util/file/file_io_posix.cc
diff --git a/util/file/file_io_posix.cc b/util/file/file_io_posix.cc
index ff32009021679f3690e9a7eb65c402dfc2e5f6d1..e8dbe9aab4a9e1f89ed491639182fad29f4fcbde 100644
--- a/util/file/file_io_posix.cc
+++ b/util/file/file_io_posix.cc
@@ -14,8 +14,10 @@
 
 #include "util/file/file_io.h"
 
+#include <fcntl.h>
 #include <unistd.h>
 
+#include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/posix/eintr_wrapper.h"
@@ -74,6 +76,33 @@ ssize_t WriteFile(FileHandle file, const void* buffer, size_t size) {
   return ReadOrWrite<WriteTraits>(file, buffer, size);
 }
 
+FileHandle LoggingOpenFileForWrite(const base::FilePath& path,
+                                   FileWriteMode mode,
+                                   bool world_readable) {
+  int flags = O_WRONLY;

[Mark Mentovai, 2014/12/18 21:52:32]

This should be O_WRONLY | O_CREAT, because we always want to create the file
even if it doesn’t exist. The cases below should adapt accordingly.

[scottmg, 2014/12/18 22:12:44]

Done.

+  switch (mode) {
+    case FileWriteMode::kAppend:
+      // Nothing to add.
+      break;
+    case FileWriteMode::kCreate:
+      flags |= O_CREAT | O_TRUNC;
+      break;
+    case FileWriteMode::kCreateNew:
+      flags |= O_CREAT | O_EXCL;
+      break;
+  }
+  int fd = HANDLE_EINTR(
+      open(path.value().c_str(), flags, world_readable ? 0644 : 0600));
+  PLOG_IF(ERROR, fd < 0) << "open " << path.value();
+  return fd;
+}
+
+FileHandle LoggingOpenFileForRead(const base::FilePath& path) {
+  int fd = HANDLE_EINTR(open(path.value().c_str(), O_RDONLY));
+  PLOG_IF(ERROR, fd < 0) << "open " << path.value();
+  return fd;
+}
+
 bool LoggingCloseFile(FileHandle file) {
   int rv = IGNORE_EINTR(close(file));
   PLOG_IF(ERROR, rv != 0) << "close";