1/* 2 * Copyright (C) 2009 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.os; 18 19import android.util.Log; 20 21import com.android.internal.os.IDropBoxManagerService; 22 23import java.io.ByteArrayInputStream; 24import java.io.Closeable; 25import java.io.File; 26import java.io.FileInputStream; 27import java.io.IOException; 28import java.io.InputStream; 29import java.util.zip.GZIPInputStream; 30 31/** 32 * Enqueues chunks of data (from various sources -- application crashes, kernel 33 * log records, etc.). The queue is size bounded and will drop old data if the 34 * enqueued data exceeds the maximum size. You can think of this as a 35 * persistent, system-wide, blob-oriented "logcat". 36 * 37 * <p>You can obtain an instance of this class by calling 38 * {@link android.content.Context#getSystemService} 39 * with {@link android.content.Context#DROPBOX_SERVICE}. 40 * 41 * <p>DropBoxManager entries are not sent anywhere directly, but other system 42 * services and debugging tools may scan and upload entries for processing. 43 */ 44public class DropBoxManager { 45 private static final String TAG = "DropBoxManager"; 46 private final IDropBoxManagerService mService; 47 48 /** Flag value: Entry's content was deleted to save space. */ 49 public static final int IS_EMPTY = 1; 50 51 /** Flag value: Content is human-readable UTF-8 text (can be combined with IS_GZIPPED). */ 52 public static final int IS_TEXT = 2; 53 54 /** Flag value: Content can be decompressed with {@link java.util.zip.GZIPOutputStream}. */ 55 public static final int IS_GZIPPED = 4; 56 57 /** Flag value for serialization only: Value is a byte array, not a file descriptor */ 58 private static final int HAS_BYTE_ARRAY = 8; 59 60 /** 61 * A single entry retrieved from the drop box. 62 * This may include a reference to a stream, so you must call 63 * {@link #close()} when you are done using it. 64 */ 65 public static class Entry implements Parcelable, Closeable { 66 private final String mTag; 67 private final long mTimeMillis; 68 69 private final byte[] mData; 70 private final ParcelFileDescriptor mFileDescriptor; 71 private final int mFlags; 72 73 /** Create a new empty Entry with no contents. */ 74 public Entry(String tag, long millis) { 75 if (tag == null) throw new NullPointerException("tag == null"); 76 77 mTag = tag; 78 mTimeMillis = millis; 79 mData = null; 80 mFileDescriptor = null; 81 mFlags = IS_EMPTY; 82 } 83 84 /** Create a new Entry with plain text contents. */ 85 public Entry(String tag, long millis, String text) { 86 if (tag == null) throw new NullPointerException("tag == null"); 87 if (text == null) throw new NullPointerException("text == null"); 88 89 mTag = tag; 90 mTimeMillis = millis; 91 mData = text.getBytes(); 92 mFileDescriptor = null; 93 mFlags = IS_TEXT; 94 } 95 96 /** 97 * Create a new Entry with byte array contents. 98 * The data array must not be modified after creating this entry. 99 */ 100 public Entry(String tag, long millis, byte[] data, int flags) { 101 if (tag == null) throw new NullPointerException("tag == null"); 102 if (((flags & IS_EMPTY) != 0) != (data == null)) { 103 throw new IllegalArgumentException("Bad flags: " + flags); 104 } 105 106 mTag = tag; 107 mTimeMillis = millis; 108 mData = data; 109 mFileDescriptor = null; 110 mFlags = flags; 111 } 112 113 /** 114 * Create a new Entry with streaming data contents. 115 * Takes ownership of the ParcelFileDescriptor. 116 */ 117 public Entry(String tag, long millis, ParcelFileDescriptor data, int flags) { 118 if (tag == null) throw new NullPointerException("tag == null"); 119 if (((flags & IS_EMPTY) != 0) != (data == null)) { 120 throw new IllegalArgumentException("Bad flags: " + flags); 121 } 122 123 mTag = tag; 124 mTimeMillis = millis; 125 mData = null; 126 mFileDescriptor = data; 127 mFlags = flags; 128 } 129 130 /** 131 * Create a new Entry with the contents read from a file. 132 * The file will be read when the entry's contents are requested. 133 */ 134 public Entry(String tag, long millis, File data, int flags) throws IOException { 135 if (tag == null) throw new NullPointerException("tag == null"); 136 if ((flags & IS_EMPTY) != 0) throw new IllegalArgumentException("Bad flags: " + flags); 137 138 mTag = tag; 139 mTimeMillis = millis; 140 mData = null; 141 mFileDescriptor = ParcelFileDescriptor.open(data, ParcelFileDescriptor.MODE_READ_ONLY); 142 mFlags = flags; 143 } 144 145 /** Close the input stream associated with this entry. */ 146 public void close() { 147 try { if (mFileDescriptor != null) mFileDescriptor.close(); } catch (IOException e) { } 148 } 149 150 /** @return the tag originally attached to the entry. */ 151 public String getTag() { return mTag; } 152 153 /** @return time when the entry was originally created. */ 154 public long getTimeMillis() { return mTimeMillis; } 155 156 /** @return flags describing the content returned by {@link #getInputStream()}. */ 157 public int getFlags() { return mFlags & ~IS_GZIPPED; } // getInputStream() decompresses. 158 159 /** 160 * @param maxBytes of string to return (will truncate at this length). 161 * @return the uncompressed text contents of the entry, null if the entry is not text. 162 */ 163 public String getText(int maxBytes) { 164 if ((mFlags & IS_TEXT) == 0) return null; 165 if (mData != null) return new String(mData, 0, Math.min(maxBytes, mData.length)); 166 167 InputStream is = null; 168 try { 169 is = getInputStream(); 170 if (is == null) return null; 171 byte[] buf = new byte[maxBytes]; 172 return new String(buf, 0, Math.max(0, is.read(buf))); 173 } catch (IOException e) { 174 return null; 175 } finally { 176 try { if (is != null) is.close(); } catch (IOException e) {} 177 } 178 } 179 180 /** @return the uncompressed contents of the entry, or null if the contents were lost */ 181 public InputStream getInputStream() throws IOException { 182 InputStream is; 183 if (mData != null) { 184 is = new ByteArrayInputStream(mData); 185 } else if (mFileDescriptor != null) { 186 is = new ParcelFileDescriptor.AutoCloseInputStream(mFileDescriptor); 187 } else { 188 return null; 189 } 190 return (mFlags & IS_GZIPPED) != 0 ? new GZIPInputStream(is) : is; 191 } 192 193 public static final Parcelable.Creator<Entry> CREATOR = new Parcelable.Creator() { 194 public Entry[] newArray(int size) { return new Entry[size]; } 195 public Entry createFromParcel(Parcel in) { 196 String tag = in.readString(); 197 long millis = in.readLong(); 198 int flags = in.readInt(); 199 if ((flags & HAS_BYTE_ARRAY) != 0) { 200 return new Entry(tag, millis, in.createByteArray(), flags & ~HAS_BYTE_ARRAY); 201 } else { 202 return new Entry(tag, millis, in.readFileDescriptor(), flags); 203 } 204 } 205 }; 206 207 public int describeContents() { 208 return mFileDescriptor != null ? Parcelable.CONTENTS_FILE_DESCRIPTOR : 0; 209 } 210 211 public void writeToParcel(Parcel out, int flags) { 212 out.writeString(mTag); 213 out.writeLong(mTimeMillis); 214 if (mFileDescriptor != null) { 215 out.writeInt(mFlags & ~HAS_BYTE_ARRAY); // Clear bit just to be safe 216 mFileDescriptor.writeToParcel(out, flags); 217 } else { 218 out.writeInt(mFlags | HAS_BYTE_ARRAY); 219 out.writeByteArray(mData); 220 } 221 } 222 } 223 224 /** {@hide} */ 225 public DropBoxManager(IDropBoxManagerService service) { mService = service; } 226 227 /** 228 * Create a dummy instance for testing. All methods will fail unless 229 * overridden with an appropriate mock implementation. To obtain a 230 * functional instance, use {@link android.content.Context#getSystemService}. 231 */ 232 protected DropBoxManager() { mService = null; } 233 234 /** 235 * Stores human-readable text. The data may be discarded eventually (or even 236 * immediately) if space is limited, or ignored entirely if the tag has been 237 * blocked (see {@link #isTagEnabled}). 238 * 239 * @param tag describing the type of entry being stored 240 * @param data value to store 241 */ 242 public void addText(String tag, String data) { 243 try { mService.add(new Entry(tag, 0, data)); } catch (RemoteException e) {} 244 } 245 246 /** 247 * Stores binary data, which may be ignored or discarded as with {@link #addText}. 248 * 249 * @param tag describing the type of entry being stored 250 * @param data value to store 251 * @param flags describing the data 252 */ 253 public void addData(String tag, byte[] data, int flags) { 254 if (data == null) throw new NullPointerException("data == null"); 255 try { mService.add(new Entry(tag, 0, data, flags)); } catch (RemoteException e) {} 256 } 257 258 /** 259 * Stores the contents of a file, which may be ignored or discarded as with 260 * {@link #addText}. 261 * 262 * @param tag describing the type of entry being stored 263 * @param file to read from 264 * @param flags describing the data 265 * @throws IOException if the file can't be opened 266 */ 267 public void addFile(String tag, File file, int flags) throws IOException { 268 if (file == null) throw new NullPointerException("file == null"); 269 Entry entry = new Entry(tag, 0, file, flags); 270 try { 271 mService.add(entry); 272 } catch (RemoteException e) { 273 // ignore 274 } finally { 275 entry.close(); 276 } 277 } 278 279 /** 280 * Checks any blacklists (set in system settings) to see whether a certain 281 * tag is allowed. Entries with disabled tags will be dropped immediately, 282 * so you can save the work of actually constructing and sending the data. 283 * 284 * @param tag that would be used in {@link #addText} or {@link #addFile} 285 * @return whether events with that tag would be accepted 286 */ 287 public boolean isTagEnabled(String tag) { 288 try { return mService.isTagEnabled(tag); } catch (RemoteException e) { return false; } 289 } 290 291 /** 292 * Gets the next entry from the drop box <em>after</em> the specified time. 293 * Requires <code>android.permission.READ_LOGS</code>. You must always call 294 * {@link Entry#close()} on the return value! 295 * 296 * @param tag of entry to look for, null for all tags 297 * @param msec time of the last entry seen 298 * @return the next entry, or null if there are no more entries 299 */ 300 public Entry getNextEntry(String tag, long msec) { 301 try { return mService.getNextEntry(tag, msec); } catch (RemoteException e) { return null; } 302 } 303 304 // TODO: It may be useful to have some sort of notification mechanism 305 // when data is added to the dropbox, for demand-driven readers -- 306 // for now readers need to poll the dropbox to find new data. 307} 308