/*
* 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.os;
import com.android.internal.os.IDropBoxManagerService;
import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.GZIPInputStream;
/**
* Enqueues chunks of data (from various sources -- application crashes, kernel
* log records, etc.). The queue is size bounded and will drop old data if the
* enqueued data exceeds the maximum size. You can think of this as a
* persistent, system-wide, blob-oriented "logcat".
*
* <p>You can obtain an instance of this class by calling
* {@link android.content.Context#getSystemService}
* with {@link android.content.Context#DROPBOX_SERVICE}.
*
* <p>DropBoxManager entries are not sent anywhere directly, but other system
* services and debugging tools may scan and upload entries for processing.
*/
public class DropBoxManager {
private static final String TAG = "DropBoxManager";
private final IDropBoxManagerService mService;
/** Flag value: Entry's content was deleted to save space. */
public static final int IS_EMPTY = 1;
/** Flag value: Content is human-readable UTF-8 text (can be combined with IS_GZIPPED). */
public static final int IS_TEXT = 2;
/** Flag value: Content can be decompressed with {@link java.util.zip.GZIPOutputStream}. */
public static final int IS_GZIPPED = 4;
/** Flag value for serialization only: Value is a byte array, not a file descriptor */
private static final int HAS_BYTE_ARRAY = 8;
/**
* Broadcast Action: This is broadcast when a new entry is added in the dropbox.
* You must hold the {@link android.Manifest.permission#READ_LOGS} permission
* in order to receive this broadcast.
*
* <p class="note">This is a protected intent that can only be sent
* by the system.
*/
public static final String ACTION_DROPBOX_ENTRY_ADDED =
"android.intent.action.DROPBOX_ENTRY_ADDED";
/**
* Extra for {@link android.os.DropBoxManager#ACTION_DROPBOX_ENTRY_ADDED}:
* string containing the dropbox tag.
*/
public static final String EXTRA_TAG = "tag";
/**
* Extra for {@link android.os.DropBoxManager#ACTION_DROPBOX_ENTRY_ADDED}:
* long integer value containing time (in milliseconds since January 1, 1970 00:00:00 UTC)
* when the entry was created.
*/
public static final String EXTRA_TIME = "time";
/**
* A single entry retrieved from the drop box.
* This may include a reference to a stream, so you must call
* {@link #close()} when you are done using it.
*/
public static class Entry implements Parcelable, Closeable {
private final String mTag;
private final long mTimeMillis;
private final byte[] mData;
private final ParcelFileDescriptor mFileDescriptor;
private final int mFlags;
/** Create a new empty Entry with no contents. */
public Entry(String tag, long millis) {
if (tag == null) throw new NullPointerException("tag == null");
mTag = tag;
mTimeMillis = millis;
mData = null;
mFileDescriptor = null;
mFlags = IS_EMPTY;
}
/** Create a new Entry with plain text contents. */
public Entry(String tag, long millis, String text) {
if (tag == null) throw new NullPointerException("tag == null");
if (text == null) throw new NullPointerException("text == null");
mTag = tag;
mTimeMillis = millis;
mData = text.getBytes();
mFileDescriptor = null;
mFlags = IS_TEXT;
}
/**
* Create a new Entry with byte array contents.
* The data array must not be modified after creating this entry.
*/
public Entry(String tag, long millis, byte[] data, int flags) {
if (tag == null) throw new NullPointerException("tag == null");
if (((flags & IS_EMPTY) != 0) != (data == null)) {
throw new IllegalArgumentException("Bad flags: " + flags);
}
mTag = tag;
mTimeMillis = millis;
mData = data;
mFileDescriptor = null;
mFlags = flags;
}
/**
* Create a new Entry with streaming data contents.
* Takes ownership of the ParcelFileDescriptor.
*/
public Entry(String tag, long millis, ParcelFileDescriptor data, int flags) {
if (tag == null) throw new NullPointerException("tag == null");
if (((flags & IS_EMPTY) != 0) != (data == null)) {
throw new IllegalArgumentException("Bad flags: " + flags);
}
mTag = tag;
mTimeMillis = millis;
mData = null;
mFileDescriptor = data;
mFlags = flags;
}
/**
* Create a new Entry with the contents read from a file.
* The file will be read when the entry's contents are requested.
*/
public Entry(String tag, long millis, File data, int flags) throws IOException {
if (tag == null) throw new NullPointerException("tag == null");
if ((flags & IS_EMPTY) != 0) throw new IllegalArgumentException("Bad flags: " + flags);
mTag = tag;
mTimeMillis = millis;
mData = null;
mFileDescriptor = ParcelFileDescriptor.open(data, ParcelFileDescriptor.MODE_READ_ONLY);
mFlags = flags;
}
/** Close the input stream associated with this entry. */
public void close() {
try { if (mFileDescriptor != null) mFileDescriptor.close(); } catch (IOException e) { }
}
/** @return the tag originally attached to the entry. */
public String getTag() { return mTag; }
/** @return time when the entry was originally created. */
public long getTimeMillis() { return mTimeMillis; }
/** @return flags describing the content returned by {@link #getInputStream()}. */
public int getFlags() { return mFlags & ~IS_GZIPPED; } // getInputStream() decompresses.
/**
* @param maxBytes of string to return (will truncate at this length).
* @return the uncompressed text contents of the entry, null if the entry is not text.
*/
public String getText(int maxBytes) {
if ((mFlags & IS_TEXT) == 0) return null;
if (mData != null) return new String(mData, 0, Math.min(maxBytes, mData.length));
InputStream is = null;
try {
is = getInputStream();
if (is == null) return null;
byte[] buf = new byte[maxBytes];
int readBytes = 0;
int n = 0;
while (n >= 0 && (readBytes += n) < maxBytes) {
n = is.read(buf, readBytes, maxBytes - readBytes);
}
return new String(buf, 0, readBytes);
} catch (IOException e) {
return null;
} finally {
try { if (is != null) is.close(); } catch (IOException e) {}
}
}
/** @return the uncompressed contents of the entry, or null if the contents were lost */
public InputStream getInputStream() throws IOException {
InputStream is;
if (mData != null) {
is = new ByteArrayInputStream(mData);
} else if (mFileDescriptor != null) {
is = new ParcelFileDescriptor.AutoCloseInputStream(mFileDescriptor);
} else {
return null;
}
return (mFlags & IS_GZIPPED) != 0 ? new GZIPInputStream(is) : is;
}
public static final Parcelable.Creator<Entry> CREATOR = new Parcelable.Creator() {
public Entry[] newArray(int size) { return new Entry[size]; }
public Entry createFromParcel(Parcel in) {
String tag = in.readString();
long millis = in.readLong();
int flags = in.readInt();
if ((flags & HAS_BYTE_ARRAY) != 0) {
return new Entry(tag, millis, in.createByteArray(), flags & ~HAS_BYTE_ARRAY);
} else {
return new Entry(tag, millis, in.readFileDescriptor(), flags);
}
}
};
public int describeContents() {
return mFileDescriptor != null ? Parcelable.CONTENTS_FILE_DESCRIPTOR : 0;
}
public void writeToParcel(Parcel out, int flags) {
out.writeString(mTag);
out.writeLong(mTimeMillis);
if (mFileDescriptor != null) {
out.writeInt(mFlags & ~HAS_BYTE_ARRAY); // Clear bit just to be safe
mFileDescriptor.writeToParcel(out, flags);
} else {
out.writeInt(mFlags | HAS_BYTE_ARRAY);
out.writeByteArray(mData);
}
}
}
/** {@hide} */
public DropBoxManager(IDropBoxManagerService service) { mService = service; }
/**
* Create a dummy instance for testing. All methods will fail unless
* overridden with an appropriate mock implementation. To obtain a
* functional instance, use {@link android.content.Context#getSystemService}.
*/
protected DropBoxManager() { mService = null; }
/**
* Stores human-readable text. The data may be discarded eventually (or even
* immediately) if space is limited, or ignored entirely if the tag has been
* blocked (see {@link #isTagEnabled}).
*
* @param tag describing the type of entry being stored
* @param data value to store
*/
public void addText(String tag, String data) {
try { mService.add(new Entry(tag, 0, data)); } catch (RemoteException e) {}
}
/**
* Stores binary data, which may be ignored or discarded as with {@link #addText}.
*
* @param tag describing the type of entry being stored
* @param data value to store
* @param flags describing the data
*/
public void addData(String tag, byte[] data, int flags) {
if (data == null) throw new NullPointerException("data == null");
try { mService.add(new Entry(tag, 0, data, flags)); } catch (RemoteException e) {}
}
/**
* Stores the contents of a file, which may be ignored or discarded as with
* {@link #addText}.
*
* @param tag describing the type of entry being stored
* @param file to read from
* @param flags describing the data
* @throws IOException if the file can't be opened
*/
public void addFile(String tag, File file, int flags) throws IOException {
if (file == null) throw new NullPointerException("file == null");
Entry entry = new Entry(tag, 0, file, flags);
try {
mService.add(entry);
} catch (RemoteException e) {
// ignore
} finally {
entry.close();
}
}
/**
* Checks any blacklists (set in system settings) to see whether a certain
* tag is allowed. Entries with disabled tags will be dropped immediately,
* so you can save the work of actually constructing and sending the data.
*
* @param tag that would be used in {@link #addText} or {@link #addFile}
* @return whether events with that tag would be accepted
*/
public boolean isTagEnabled(String tag) {
try { return mService.isTagEnabled(tag); } catch (RemoteException e) { return false; }
}
/**
* Gets the next entry from the drop box <em>after</em> the specified time.
* Requires <code>android.permission.READ_LOGS</code>. You must always call
* {@link Entry#close()} on the return value!
*
* @param tag of entry to look for, null for all tags
* @param msec time of the last entry seen
* @return the next entry, or null if there are no more entries
*/
public Entry getNextEntry(String tag, long msec) {
try { return mService.getNextEntry(tag, msec); } catch (RemoteException e) { return null; }
}
// TODO: It may be useful to have some sort of notification mechanism
// when data is added to the dropbox, for demand-driven readers --
// for now readers need to poll the dropbox to find new data.
}
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