Use Libcore's stat instead of FileUtils#getFileStatus

kruton · kruton · commit 98e15e78934a · 2012-08-16T15:27:55.000-07:00
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
diff --git 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.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 @@ private void loadFromDiskLocked() {
         }
 
         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 @@ private boolean hasFileChangedUnexpectedly() {
                 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 @@ private void writeToFile(MemoryCommitResult mcr) {
             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
@@ -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%+,./=_-]+");
diff --git a/core/jni/android_os_FileUtils.cpp b/core/jni/android_os_FileUtils.cpp
@@ -33,19 +33,6 @@
 
 namespace android {
 
-static jfieldID gFileStatusDevFieldID;
-static jfieldID gFileStatusInoFieldID;
-static jfieldID gFileStatusModeFieldID;
-static jfieldID gFileStatusNlinkFieldID;
-static jfieldID gFileStatusUidFieldID;
-static jfieldID gFileStatusGidFieldID;
-static jfieldID gFileStatusSizeFieldID;
-static jfieldID gFileStatusBlksizeFieldID;
-static jfieldID gFileStatusBlocksFieldID;
-static jfieldID gFileStatusAtimeFieldID;
-static jfieldID gFileStatusMtimeFieldID;
-static jfieldID gFileStatusCtimeFieldID;
-
 jint android_os_FileUtils_setPermissions(JNIEnv* env, jobject clazz,
                                          jstring file, jint mode,
                                          jint uid, jint gid)
@@ -94,62 +81,16 @@ jint android_os_FileUtils_getFatVolumeId(JNIEnv* env, jobject clazz, jstring pat
     return result;
 }
 
-jboolean android_os_FileUtils_getFileStatus(JNIEnv* env, jobject clazz, jstring path, jobject fileStatus) {
-    const char* pathStr = env->GetStringUTFChars(path, NULL);
-    jboolean ret = false;
-
-    struct stat s;
-    int res = stat(pathStr, &s);
-    if (res == 0) {
-        ret = true;
-        if (fileStatus != NULL) {
-            env->SetIntField(fileStatus, gFileStatusDevFieldID, s.st_dev);
-            env->SetIntField(fileStatus, gFileStatusInoFieldID, s.st_ino);
-            env->SetIntField(fileStatus, gFileStatusModeFieldID, s.st_mode);
-            env->SetIntField(fileStatus, gFileStatusNlinkFieldID, s.st_nlink);
-            env->SetIntField(fileStatus, gFileStatusUidFieldID, s.st_uid);
-            env->SetIntField(fileStatus, gFileStatusGidFieldID, s.st_gid);
-            env->SetLongField(fileStatus, gFileStatusSizeFieldID, s.st_size);
-            env->SetIntField(fileStatus, gFileStatusBlksizeFieldID, s.st_blksize);
-            env->SetLongField(fileStatus, gFileStatusBlocksFieldID, s.st_blocks);
-            env->SetLongField(fileStatus, gFileStatusAtimeFieldID, s.st_atime);
-            env->SetLongField(fileStatus, gFileStatusMtimeFieldID, s.st_mtime);
-            env->SetLongField(fileStatus, gFileStatusCtimeFieldID, s.st_ctime);
-        }
-    }
-
-    env->ReleaseStringUTFChars(path, pathStr);
-
-    return ret;
-}
-
 static const JNINativeMethod methods[] = {
     {"setPermissions",  "(Ljava/lang/String;III)I", (void*)android_os_FileUtils_setPermissions},
     {"setUMask",        "(I)I",                    (void*)android_os_FileUtils_setUMask},
     {"getFatVolumeId",  "(Ljava/lang/String;)I", (void*)android_os_FileUtils_getFatVolumeId},
-    {"getFileStatusNative", "(Ljava/lang/String;Landroid/os/FileUtils$FileStatus;)Z", (void*)android_os_FileUtils_getFileStatus},
 };
 
 static const char* const kFileUtilsPathName = "android/os/FileUtils";
 
 int register_android_os_FileUtils(JNIEnv* env)
 {
-    jclass fileStatusClass = env->FindClass("android/os/FileUtils$FileStatus");
-    LOG_FATAL_IF(fileStatusClass == NULL, "Unable to find class android.os.FileUtils$FileStatus");
-
-    gFileStatusDevFieldID = env->GetFieldID(fileStatusClass, "dev", "I");
-    gFileStatusInoFieldID = env->GetFieldID(fileStatusClass, "ino", "I");
-    gFileStatusModeFieldID = env->GetFieldID(fileStatusClass, "mode", "I");
-    gFileStatusNlinkFieldID = env->GetFieldID(fileStatusClass, "nlink", "I");
-    gFileStatusUidFieldID = env->GetFieldID(fileStatusClass, "uid", "I");
-    gFileStatusGidFieldID = env->GetFieldID(fileStatusClass, "gid", "I");
-    gFileStatusSizeFieldID = env->GetFieldID(fileStatusClass, "size", "J");
-    gFileStatusBlksizeFieldID = env->GetFieldID(fileStatusClass, "blksize", "I");
-    gFileStatusBlocksFieldID = env->GetFieldID(fileStatusClass, "blocks", "J");
-    gFileStatusAtimeFieldID = env->GetFieldID(fileStatusClass, "atime", "J");
-    gFileStatusMtimeFieldID = env->GetFieldID(fileStatusClass, "mtime", "J");
-    gFileStatusCtimeFieldID = env->GetFieldID(fileStatusClass, "ctime", "J");
-
     return AndroidRuntime::registerNativeMethods(
         env, kFileUtilsPathName,
         methods, NELEM(methods));
diff --git a/core/tests/coretests/src/android/os/FileUtilsTest.java b/core/tests/coretests/src/android/os/FileUtilsTest.java
@@ -17,21 +17,13 @@
 package android.os;
 
 import android.content.Context;
-import android.os.FileUtils;
-import android.os.FileUtils.FileStatus;
 import android.test.AndroidTestCase;
-import android.test.suitebuilder.annotation.LargeTest;
 import android.test.suitebuilder.annotation.MediumTest;
-import android.test.suitebuilder.annotation.SmallTest;
 
 import java.io.ByteArrayInputStream;
 import java.io.File;
-import java.io.FileWriter;
-import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
-import java.io.IOException;
-
-import junit.framework.Assert;
+import java.io.FileWriter;
 
 public class FileUtilsTest extends AndroidTestCase {
     private static final String TEST_DATA =
@@ -60,60 +52,6 @@ protected void tearDown() throws Exception {
         if (mCopyFile.exists()) mCopyFile.delete();
     }
 
-    @LargeTest
-    public void testGetFileStatus() {
-        final byte[] MAGIC = { 0xB, 0xE, 0x0, 0x5 };
-
-        try {
-            // truncate test file and write MAGIC (4 bytes) to it.
-            FileOutputStream os = new FileOutputStream(mTestFile, false);
-            os.write(MAGIC, 0, 4);
-            os.flush();
-            os.close();
-        } catch (FileNotFoundException e) {
-            Assert.fail("File was removed durning test" + e);
-        } catch (IOException e) {
-            Assert.fail("Unexpected IOException: " + e);
-        }
-        
-        Assert.assertTrue(mTestFile.exists());
-        Assert.assertTrue(FileUtils.getFileStatus(mTestFile.getPath(), null));
-        
-        FileStatus status1 = new FileStatus();
-        FileUtils.getFileStatus(mTestFile.getPath(), status1);
-        
-        Assert.assertEquals(4, status1.size);
-        
-        // Sleep for at least one second so that the modification time will be different.
-        try {
-            Thread.sleep(1000);
-        } catch (InterruptedException e) {
-        }
-
-        try {
-            // append so we don't change the creation time.
-            FileOutputStream os = new FileOutputStream(mTestFile, true);
-            os.write(MAGIC, 0, 4);
-            os.flush();
-            os.close();
-        } catch (FileNotFoundException e) {
-            Assert.fail("File was removed durning test" + e);
-        } catch (IOException e) {
-            Assert.fail("Unexpected IOException: " + e);
-        }
-        
-        FileStatus status2 = new FileStatus();
-        FileUtils.getFileStatus(mTestFile.getPath(), status2);
-        
-        Assert.assertEquals(8, status2.size);
-        Assert.assertTrue(status2.mtime > status1.mtime);
-        
-        mTestFile.delete();
-        
-        Assert.assertFalse(mTestFile.exists());
-        Assert.assertFalse(FileUtils.getFileStatus(mTestFile.getPath(), null));
-    }
-
     // TODO: test setPermissions(), getPermissions()
 
     @MediumTest
