diff options
13 files changed, 263 insertions, 12 deletions
diff --git a/api/current.txt b/api/current.txt index f987d5e..491bc07 100644 --- a/api/current.txt +++ b/api/current.txt @@ -22524,6 +22524,17 @@ package android.util { ctor public AndroidRuntimeException(java.lang.Exception); } + public class AtomicFile { + ctor public AtomicFile(java.io.File); + method public void delete(); + method public void failWrite(java.io.FileOutputStream); + method public void finishWrite(java.io.FileOutputStream); + method public java.io.File getBaseFile(); + method public java.io.FileInputStream openRead() throws java.io.FileNotFoundException; + method public byte[] readFully() throws java.io.IOException; + method public java.io.FileOutputStream startWrite() throws java.io.IOException; + } + public abstract interface AttributeSet { method public abstract boolean getAttributeBooleanValue(java.lang.String, java.lang.String, boolean); method public abstract boolean getAttributeBooleanValue(int, boolean); diff --git a/core/java/android/content/SyncStorageEngine.java b/core/java/android/content/SyncStorageEngine.java index 226e107..773e0fe 100644 --- a/core/java/android/content/SyncStorageEngine.java +++ b/core/java/android/content/SyncStorageEngine.java @@ -16,7 +16,6 @@ package android.content; -import com.android.internal.os.AtomicFile; import com.android.internal.util.ArrayUtils; import com.android.internal.util.FastXmlSerializer; @@ -37,7 +36,7 @@ import android.os.Message; import android.os.Parcel; import android.os.RemoteCallbackList; import android.os.RemoteException; -import android.os.SystemClock; +import android.util.AtomicFile; import android.util.Log; import android.util.SparseArray; import android.util.Xml; diff --git a/core/java/android/content/pm/RegisteredServicesCache.java b/core/java/android/content/pm/RegisteredServicesCache.java index d8f9204..0bc0f91 100644 --- a/core/java/android/content/pm/RegisteredServicesCache.java +++ b/core/java/android/content/pm/RegisteredServicesCache.java @@ -26,6 +26,7 @@ import android.content.res.Resources; import android.content.res.XmlResourceParser; import android.os.Environment; import android.os.Handler; +import android.util.AtomicFile; import android.util.Log; import android.util.AttributeSet; import android.util.Xml; @@ -44,7 +45,6 @@ import java.io.PrintWriter; import java.io.IOException; import java.io.FileInputStream; -import com.android.internal.os.AtomicFile; import com.android.internal.util.FastXmlSerializer; import com.google.android.collect.Maps; diff --git a/core/java/android/util/AtomicFile.java b/core/java/android/util/AtomicFile.java new file mode 100644 index 0000000..4fca570 --- /dev/null +++ b/core/java/android/util/AtomicFile.java @@ -0,0 +1,233 @@ +/* + * Copyright (C) 2009 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package android.util; + +import android.os.FileUtils; +import android.util.Log; + +import java.io.File; +import java.io.FileInputStream; +import java.io.FileNotFoundException; +import java.io.FileOutputStream; +import java.io.IOException; + +/** + * Helper class for performing atomic operations on a file by creating a + * backup file until a write has successfully completed. If you need this + * on older versions of the platform you can use + * {@link android.support.v4.util.AtomicFile} in the v4 support library. + * <p> + * Atomic file guarantees file integrity by ensuring that a file has + * been completely written and sync'd to disk before removing its backup. + * As long as the backup file exists, the original file is considered + * to be invalid (left over from a previous attempt to write the file). + * </p><p> + * Atomic file does not confer any file locking semantics. + * Do not use this class when the file may be accessed or modified concurrently + * by multiple threads or processes. The caller is responsible for ensuring + * appropriate mutual exclusion invariants whenever it accesses the file. + * </p> + */ +public class AtomicFile { + private final File mBaseName; + private final File mBackupName; + + /** + * Create a new AtomicFile for a file located at the given File path. + * The secondary backup file will be the same file path with ".bak" appended. + */ + public AtomicFile(File baseName) { + mBaseName = baseName; + mBackupName = new File(baseName.getPath() + ".bak"); + } + + /** + * Return the path to the base file. You should not generally use this, + * as the data at that path may not be valid. + */ + public File getBaseFile() { + return mBaseName; + } + + /** + * Delete the atomic file. This deletes both the base and backup files. + */ + public void delete() { + mBaseName.delete(); + mBackupName.delete(); + } + + /** + * Start a new write operation on the file. This returns a FileOutputStream + * to which you can write the new file data. The existing file is replaced + * with the new data. You <em>must not</em> directly close the given + * FileOutputStream; instead call either {@link #finishWrite(FileOutputStream)} + * or {@link #failWrite(FileOutputStream)}. + * + * <p>Note that if another thread is currently performing + * a write, this will simply replace whatever that thread is writing + * with the new file being written by this thread, and when the other + * thread finishes the write the new write operation will no longer be + * safe (or will be lost). You must do your own threading protection for + * access to AtomicFile. + */ + public FileOutputStream startWrite() throws IOException { + // Rename the current file so it may be used as a backup during the next read + if (mBaseName.exists()) { + if (!mBackupName.exists()) { + if (!mBaseName.renameTo(mBackupName)) { + Log.w("AtomicFile", "Couldn't rename file " + mBaseName + + " to backup file " + mBackupName); + } + } else { + mBaseName.delete(); + } + } + FileOutputStream str = null; + try { + str = new FileOutputStream(mBaseName); + } catch (FileNotFoundException e) { + File parent = mBaseName.getParentFile(); + if (!parent.mkdir()) { + throw new IOException("Couldn't create directory " + mBaseName); + } + FileUtils.setPermissions( + parent.getPath(), + FileUtils.S_IRWXU|FileUtils.S_IRWXG|FileUtils.S_IXOTH, + -1, -1); + try { + str = new FileOutputStream(mBaseName); + } catch (FileNotFoundException e2) { + throw new IOException("Couldn't create " + mBaseName); + } + } + return str; + } + + /** + * Call when you have successfully finished writing to the stream + * returned by {@link #startWrite()}. This will close, sync, and + * commit the new data. The next attempt to read the atomic file + * will return the new file stream. + */ + public void finishWrite(FileOutputStream str) { + if (str != null) { + FileUtils.sync(str); + try { + str.close(); + mBackupName.delete(); + } catch (IOException e) { + Log.w("AtomicFile", "finishWrite: Got exception:", e); + } + } + } + + /** + * Call when you have failed for some reason at writing to the stream + * returned by {@link #startWrite()}. This will close the current + * write stream, and roll back to the previous state of the file. + */ + public void failWrite(FileOutputStream str) { + if (str != null) { + FileUtils.sync(str); + try { + str.close(); + mBaseName.delete(); + mBackupName.renameTo(mBaseName); + } catch (IOException e) { + Log.w("AtomicFile", "failWrite: Got exception:", e); + } + } + } + + /** @hide + * @deprecated This is not safe. + */ + @Deprecated public void truncate() throws IOException { + try { + FileOutputStream fos = new FileOutputStream(mBaseName); + FileUtils.sync(fos); + fos.close(); + } catch (FileNotFoundException e) { + throw new IOException("Couldn't append " + mBaseName); + } catch (IOException e) { + } + } + + /** @hide + * @deprecated This is not safe. + */ + @Deprecated public FileOutputStream openAppend() throws IOException { + try { + return new FileOutputStream(mBaseName, true); + } catch (FileNotFoundException e) { + throw new IOException("Couldn't append " + mBaseName); + } + } + + /** + * Open the atomic file for reading. If there previously was an + * incomplete write, this will roll back to the last good data before + * opening for read. You should call close() on the FileInputStream when + * you are done reading from it. + * + * <p>Note that if another thread is currently performing + * a write, this will incorrectly consider it to be in the state of a bad + * write and roll back, causing the new data currently being written to + * be dropped. You must do your own threading protection for access to + * AtomicFile. + */ + public FileInputStream openRead() throws FileNotFoundException { + if (mBackupName.exists()) { + mBaseName.delete(); + mBackupName.renameTo(mBaseName); + } + return new FileInputStream(mBaseName); + } + + /** + * A convenience for {@link #openRead()} that also reads all of the + * file contents into a byte array which is returned. + */ + public byte[] readFully() throws IOException { + FileInputStream stream = openRead(); + try { + int pos = 0; + int avail = stream.available(); + byte[] data = new byte[avail]; + while (true) { + int amt = stream.read(data, pos, data.length-pos); + //Log.i("foo", "Read " + amt + " bytes at " + pos + // + " of avail " + data.length); + if (amt <= 0) { + //Log.i("foo", "**** FINISHED READING: pos=" + pos + // + " len=" + data.length); + return data; + } + pos += amt; + avail = stream.available(); + if (avail > data.length-pos) { + byte[] newData = new byte[pos+avail]; + System.arraycopy(data, 0, newData, 0, pos); + data = newData; + } + } + } finally { + stream.close(); + } + } +} diff --git a/core/java/com/android/internal/util/JournaledFile.java b/core/java/com/android/internal/util/JournaledFile.java index af0c6c6..eeffc16 100644 --- a/core/java/com/android/internal/util/JournaledFile.java +++ b/core/java/com/android/internal/util/JournaledFile.java @@ -19,6 +19,15 @@ package com.android.internal.util; import java.io.File; import java.io.IOException; +/** + * @Deprecated Use {@link com.android.internal.os.AtomicFile} instead. It would + * be nice to update all existing uses of this to switch to AtomicFile, but since + * their on-file semantics are slightly different that would run the risk of losing + * data if at the point of the platform upgrade to the new code it would need to + * roll back to the backup file. This can be solved... but is it worth it and + * all of the testing needed to make sure it is correct? + */ +@Deprecated public class JournaledFile { File mReal; File mTemp; diff --git a/services/java/com/android/server/AppWidgetServiceImpl.java b/services/java/com/android/server/AppWidgetServiceImpl.java index 8836bac..46b968a 100644 --- a/services/java/com/android/server/AppWidgetServiceImpl.java +++ b/services/java/com/android/server/AppWidgetServiceImpl.java @@ -44,6 +44,7 @@ import android.os.IBinder; import android.os.RemoteException; import android.os.SystemClock; import android.os.UserId; +import android.util.AtomicFile; import android.util.AttributeSet; import android.util.Log; import android.util.Pair; @@ -55,7 +56,6 @@ import android.view.WindowManager; import android.widget.RemoteViews; import com.android.internal.appwidget.IAppWidgetHost; -import com.android.internal.os.AtomicFile; import com.android.internal.util.FastXmlSerializer; import com.android.internal.widget.IRemoteViewsAdapterConnection; import com.android.internal.widget.IRemoteViewsFactory; diff --git a/services/java/com/android/server/InputMethodManagerService.java b/services/java/com/android/server/InputMethodManagerService.java index fdb278d..1e39492 100644 --- a/services/java/com/android/server/InputMethodManagerService.java +++ b/services/java/com/android/server/InputMethodManagerService.java @@ -16,7 +16,6 @@ package com.android.server; import com.android.internal.content.PackageMonitor; -import com.android.internal.os.AtomicFile; import com.android.internal.os.HandlerCaller; import com.android.internal.util.FastXmlSerializer; import com.android.internal.view.IInputContext; @@ -74,6 +73,7 @@ import android.provider.Settings.Secure; import android.provider.Settings.SettingNotFoundException; import android.text.TextUtils; import android.text.style.SuggestionSpan; +import android.util.AtomicFile; import android.util.EventLog; import android.util.LruCache; import android.util.Pair; diff --git a/services/java/com/android/server/NotificationManagerService.java b/services/java/com/android/server/NotificationManagerService.java index f6d3b608..9ab1a9d 100755 --- a/services/java/com/android/server/NotificationManagerService.java +++ b/services/java/com/android/server/NotificationManagerService.java @@ -53,6 +53,7 @@ import android.os.Vibrator; import android.provider.Settings; import android.telephony.TelephonyManager; import android.text.TextUtils; +import android.util.AtomicFile; import android.util.EventLog; import android.util.Log; import android.util.Slog; @@ -61,7 +62,6 @@ import android.view.accessibility.AccessibilityEvent; import android.view.accessibility.AccessibilityManager; import android.widget.Toast; -import com.android.internal.os.AtomicFile; import com.android.internal.statusbar.StatusBarNotification; import com.android.internal.util.FastXmlSerializer; diff --git a/services/java/com/android/server/am/CompatModePackages.java b/services/java/com/android/server/am/CompatModePackages.java index 3ba3fbb..3a6492e 100644 --- a/services/java/com/android/server/am/CompatModePackages.java +++ b/services/java/com/android/server/am/CompatModePackages.java @@ -4,7 +4,6 @@ import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.util.HashMap; -import java.util.HashSet; import java.util.Iterator; import java.util.Map; @@ -12,7 +11,6 @@ import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import org.xmlpull.v1.XmlSerializer; -import com.android.internal.os.AtomicFile; import com.android.internal.util.FastXmlSerializer; import android.app.ActivityManager; @@ -24,6 +22,7 @@ import android.content.res.CompatibilityInfo; import android.os.Handler; import android.os.Message; import android.os.RemoteException; +import android.util.AtomicFile; import android.util.Slog; import android.util.Xml; diff --git a/services/java/com/android/server/am/UsageStatsService.java b/services/java/com/android/server/am/UsageStatsService.java index ba65f39..7059674 100644 --- a/services/java/com/android/server/am/UsageStatsService.java +++ b/services/java/com/android/server/am/UsageStatsService.java @@ -27,12 +27,12 @@ import android.os.Parcel; import android.os.Process; import android.os.ServiceManager; import android.os.SystemClock; +import android.util.AtomicFile; import android.util.Slog; import android.util.Xml; import com.android.internal.app.IUsageStats; import com.android.internal.content.PackageMonitor; -import com.android.internal.os.AtomicFile; import com.android.internal.os.PkgUsageStats; import com.android.internal.util.FastXmlSerializer; diff --git a/services/java/com/android/server/input/PersistentDataStore.java b/services/java/com/android/server/input/PersistentDataStore.java index fbe3e8b..71de776 100644 --- a/services/java/com/android/server/input/PersistentDataStore.java +++ b/services/java/com/android/server/input/PersistentDataStore.java @@ -16,7 +16,6 @@ package com.android.server.input; -import com.android.internal.os.AtomicFile; import com.android.internal.util.ArrayUtils; import com.android.internal.util.FastXmlSerializer; import com.android.internal.util.XmlUtils; @@ -25,6 +24,7 @@ import org.xmlpull.v1.XmlPullParser; import org.xmlpull.v1.XmlPullParserException; import org.xmlpull.v1.XmlSerializer; +import android.util.AtomicFile; import android.util.Slog; import android.util.Xml; diff --git a/services/java/com/android/server/net/NetworkPolicyManagerService.java b/services/java/com/android/server/net/NetworkPolicyManagerService.java index fe43d11..3eb29db 100644 --- a/services/java/com/android/server/net/NetworkPolicyManagerService.java +++ b/services/java/com/android/server/net/NetworkPolicyManagerService.java @@ -117,6 +117,7 @@ import android.provider.Settings; import android.telephony.TelephonyManager; import android.text.format.Formatter; import android.text.format.Time; +import android.util.AtomicFile; import android.util.Log; import android.util.NtpTrustedTime; import android.util.Slog; @@ -127,7 +128,6 @@ import android.util.TrustedTime; import android.util.Xml; import com.android.internal.R; -import com.android.internal.os.AtomicFile; import com.android.internal.util.FastXmlSerializer; import com.android.internal.util.IndentingPrintWriter; import com.android.internal.util.Objects; diff --git a/services/java/com/android/server/net/NetworkStatsCollection.java b/services/java/com/android/server/net/NetworkStatsCollection.java index 9ddf011..60666b4 100644 --- a/services/java/com/android/server/net/NetworkStatsCollection.java +++ b/services/java/com/android/server/net/NetworkStatsCollection.java @@ -29,8 +29,8 @@ import android.net.NetworkStatsHistory; import android.net.NetworkTemplate; import android.net.TrafficStats; import android.text.format.DateUtils; +import android.util.AtomicFile; -import com.android.internal.os.AtomicFile; import com.android.internal.util.FileRotator; import com.android.internal.util.IndentingPrintWriter; import com.android.internal.util.Objects; |