Use Libcore's stat instead of FileUtils#getFileStatus

Remove the last user of FileUtils#getFileStatus and move it to
Libcore.os.stat instead. Then we can remove the JNI code that does the
equivalent of a stat.

Change-Id: Ieb566a2a8a17c2dd0150724b4eb3ac1cc41c823d

2 files changed, 44 insertions, 63 deletions

diff --git a/core/java/android/app/SharedPreferencesImpl.java b/core/java/android/app/SharedPreferencesImpl.java
index 615e8ce..201d7b2 100644
--- a/core/java/android/app/SharedPreferencesImpl.java
+++ b/core/java/android/app/SharedPreferencesImpl.java
@@ -17,7 +17,6 @@
 package android.app;
 
 import android.content.SharedPreferences;
-import android.os.FileUtils.FileStatus;
 import android.os.FileUtils;
 import android.os.Looper;
 import android.util.Log;
@@ -45,6 +44,11 @@ import java.util.WeakHashMap;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 
+import libcore.io.ErrnoException;
+import libcore.io.IoUtils;
+import libcore.io.Libcore;
+import libcore.io.StructStat;
+
 final class SharedPreferencesImpl implements SharedPreferences {
     private static final String TAG = "SharedPreferencesImpl";
     private static final boolean DEBUG = false;
@@ -105,26 +109,32 @@ final class SharedPreferencesImpl implements SharedPreferences {
         }
 
         Map map = null;
-        FileStatus stat = new FileStatus();
-        if (FileUtils.getFileStatus(mFile.getPath(), stat) && mFile.canRead()) {
-            try {
-                BufferedInputStream str = new BufferedInputStream(
-                        new FileInputStream(mFile), 16*1024);
-                map = XmlUtils.readMapXml(str);
-                str.close();
-            } catch (XmlPullParserException e) {
-                Log.w(TAG, "getSharedPreferences", e);
-            } catch (FileNotFoundException e) {
-                Log.w(TAG, "getSharedPreferences", e);
-            } catch (IOException e) {
-                Log.w(TAG, "getSharedPreferences", e);
+        StructStat stat = null;
+        try {
+            stat = Libcore.os.stat(mFile.getPath());
+            if (mFile.canRead()) {
+                BufferedInputStream str = null;
+                try {
+                    str = new BufferedInputStream(
+                            new FileInputStream(mFile), 16*1024);
+                    map = XmlUtils.readMapXml(str);
+                } catch (XmlPullParserException e) {
+                    Log.w(TAG, "getSharedPreferences", e);
+                } catch (FileNotFoundException e) {
+                    Log.w(TAG, "getSharedPreferences", e);
+                } catch (IOException e) {
+                    Log.w(TAG, "getSharedPreferences", e);
+                } finally {
+                    IoUtils.closeQuietly(str);
+                }
             }
+        } catch (ErrnoException e) {
         }
         mLoaded = true;
         if (map != null) {
             mMap = map;
-            mStatTimestamp = stat.mtime;
-            mStatSize = stat.size;
+            mStatTimestamp = stat.st_mtime;
+            mStatSize = stat.st_size;
         } else {
             mMap = new HashMap<String, Object>();
         }
@@ -155,12 +165,21 @@ final class SharedPreferencesImpl implements SharedPreferences {
                 return false;
             }
         }
-        FileStatus stat = new FileStatus();
-        if (!FileUtils.getFileStatus(mFile.getPath(), stat)) {
+
+        final StructStat stat;
+        try {
+            /*
+             * Metadata operations don't usually count as a block guard
+             * violation, but we explicitly want this one.
+             */
+            BlockGuard.getThreadPolicy().onReadFromDisk();
+            stat = Libcore.os.stat(mFile.getPath());
+        } catch (ErrnoException e) {
             return true;
         }
+
         synchronized (this) {
-            return mStatTimestamp != stat.mtime || mStatSize != stat.size;
+            return mStatTimestamp != stat.st_mtime || mStatSize != stat.st_size;
         }
     }
 
@@ -577,12 +596,14 @@ final class SharedPreferencesImpl implements SharedPreferences {
             FileUtils.sync(str);
             str.close();
             ContextImpl.setFilePermissionsFromMode(mFile.getPath(), mMode, 0);
-            FileStatus stat = new FileStatus();
-            if (FileUtils.getFileStatus(mFile.getPath(), stat)) {
+            try {
+                final StructStat stat = Libcore.os.stat(mFile.getPath());
                 synchronized (this) {
-                    mStatTimestamp = stat.mtime;
-                    mStatSize = stat.size;
+                    mStatTimestamp = stat.st_mtime;
+                    mStatSize = stat.st_size;
                 }
+            } catch (ErrnoException e) {
+                // Do nothing
             }
             // Writing was successful, delete the backup file if there is one.
             mBackupFile.delete();
diff --git a/core/java/android/os/FileUtils.java b/core/java/android/os/FileUtils.java
index 213e3ae..7c103aa 100644
--- a/core/java/android/os/FileUtils.java
+++ b/core/java/android/os/FileUtils.java
@@ -47,46 +47,6 @@ public class FileUtils {
     public static final int S_IROTH = 00004;
     public static final int S_IWOTH = 00002;
     public static final int S_IXOTH = 00001;
-    
-    
-    /**
-     * File status information. This class maps directly to the POSIX stat structure.
-     * @deprecated use {@link StructStat} instead.
-     * @hide
-     */
-    @Deprecated
-    public static final class FileStatus {
-        public int dev;
-        public int ino;
-        public int mode;
-        public int nlink;
-        public int uid;
-        public int gid;
-        public int rdev;
-        public long size;
-        public int blksize;
-        public long blocks;
-        public long atime;
-        public long mtime;
-        public long ctime;
-    }
-    
-    /**
-     * Get the status for the given path. This is equivalent to the POSIX stat(2) system call. 
-     * @param path The path of the file to be stat'd.
-     * @param status Optional argument to fill in. It will only fill in the status if the file
-     * exists. 
-     * @return true if the file exists and false if it does not exist. If you do not have 
-     * permission to stat the file, then this method will return false.
-     * @deprecated use {@link Os#stat(String)} instead.
-     */
-    @Deprecated
-    public static boolean getFileStatus(String path, FileStatus status) {
-        StrictMode.noteDiskRead();
-        return getFileStatusNative(path, status);
-    }
-
-    private static native boolean getFileStatusNative(String path, FileStatus status);
 
     /** Regular expression for safe filenames: no spaces or metacharacters */
     private static final Pattern SAFE_FILENAME_PATTERN = Pattern.compile("[\\w%+,./=_-]+");