[dart:io] Adds functions to set file access and modification time

runtime/bin/file_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "bin/file.h"
 
 #include <errno.h>         // NOLINT
 #include <fcntl.h>         // NOLINT
 #include <libgen.h>        // NOLINT
 #include <sys/mman.h>      // NOLINT
 #include <sys/sendfile.h>  // NOLINT
 #include <sys/stat.h>      // NOLINT
 #include <sys/types.h>     // NOLINT
 #include <unistd.h>        // NOLINT
+#include <utime.h>         // NOLINT
 
 #include "bin/builtin.h"
 #include "bin/fdutils.h"
 #include "bin/log.h"
 #include "platform/signal_blocker.h"
 #include "platform/utils.h"
 
 namespace dart {
 namespace bin {
 
@@ skipping 352 matching lines @@
   VOID_TEMP_FAILURE_RETRY(close(new_fd));
   if (result < 0) {
     VOID_NO_RETRY_EXPECTED(unlink(new_path));
     errno = e;
     return false;
   }
   return true;
 }
 
 
+static bool StatHelper(const char* name, struct stat64* st) {
+  if (TEMP_FAILURE_RETRY(stat64(name, st)) != 0) {
+    return false;
+  }
+  // Signal an error if it's a directory.
+  if (S_ISDIR(st->st_mode)) {
+    errno = EISDIR;
+    return false;
+  }
+  // Otherwise assume the caller knows what it's doing.
+  return true;
+}
+
+
 int64_t File::LengthFromPath(const char* name) {
   struct stat64 st;
-  if (TEMP_FAILURE_RETRY(stat64(name, &st)) == 0) {
-    // Signal an error if it's a directory.
-    if (S_ISDIR(st.st_mode)) {
-      errno = EISDIR;
-      return -1;
-    }
-    // Otherwise assume the caller knows what it's doing.
-    return st.st_size;
+  if (!StatHelper(name, &st)) {
+    return -1;
   }
-  return -1;
+  return st.st_size;
 }
 
 
 static int64_t TimespecToMilliseconds(const struct timespec& t) {
   return static_cast<int64_t>(t.tv_sec) * 1000L +
          static_cast<int64_t>(t.tv_nsec) / 1000000L;
 }
 
 
 void File::Stat(const char* name, int64_t* data) {
@@ skipping 14 matching lines @@
     data[kMode] = st.st_mode;
     data[kSize] = st.st_size;
   } else {
     data[kType] = kDoesNotExist;
   }
 }
 
 
 time_t File::LastModified(const char* name) {
   struct stat64 st;
-  if (TEMP_FAILURE_RETRY(stat64(name, &st)) == 0) {
-    // Signal an error if it's a directory.
-    if (S_ISDIR(st.st_mode)) {
-      errno = EISDIR;
-      return -1;
-    }
-    // Otherwise assume the caller knows what it's doing.
-    return st.st_mtime;
+  if (!StatHelper(name, &st)) {
+    return -1;
   }
-  return -1;
+  return st.st_mtime;
 }
 
 
+time_t File::LastAccessed(const char* name) {
+  struct stat64 st;
+  if (!StatHelper(name, &st)) {
+    return -1;
+  }
+  return st.st_atime;
+}
+
+
+bool File::SetLastAccessed(const char* name, int64_t millis) {
+  // First get the current times.
+  struct stat64 st;
+  if (!StatHelper(name, &st)) {
+    return false;
+  }
+
+  // Set the new time:
+  struct utimbuf times;
+  times.actime = millis / kMillisecondsPerSecond;
+  times.modtime = st.st_mtime;
+  return utime(name, &times) == 0;
+}
+
+
+bool File::SetLastModified(const char* name, int64_t millis) {
+  // First get the current times.
+  struct stat64 st;
+  if (!StatHelper(name, &st)) {
+    return false;
+  }
+
+  // Set the new time:
+  struct utimbuf times;
+  times.actime = st.st_atime;
+  times.modtime = millis / kMillisecondsPerSecond;
+  return utime(name, &times) == 0;
+}
+
+
 const char* File::LinkTarget(const char* pathname) {
   struct stat64 link_stats;
   if (TEMP_FAILURE_RETRY(lstat64(pathname, &link_stats)) != 0) {
     return NULL;
   }
   if (!S_ISLNK(link_stats.st_mode)) {
     errno = ENOENT;
     return NULL;
   }
   // Don't rely on the link_stats.st_size for the size of the link
@@ skipping 80 matching lines @@
   return ((file_1_info.st_ino == file_2_info.st_ino) &&
           (file_1_info.st_dev == file_2_info.st_dev))
              ? File::kIdentical
              : File::kDifferent;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)