DropBoxManager.java revision b247536aa3d458750edbc6b45b2348a994d83426
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.File; 25import java.io.FileInputStream; 26import java.io.IOException; 27import java.io.InputStream; 28import java.util.zip.GZIPInputStream; 29 30/** 31 * Enqueues chunks of data (from various sources -- application crashes, kernel 32 * log records, etc.). The queue is size bounded and will drop old data if the 33 * enqueued data exceeds the maximum size. You can think of this as a 34 * persistent, system-wide, blob-oriented "logcat". 35 * 36 * <p>You can obtain an instance of this class by calling 37 * {@link android.content.Context#getSystemService} 38 * with {@link android.content.Context#DROPBOX_SERVICE}. 39 * 40 * <p>DropBoxManager entries are not sent anywhere directly, but other system 41 * services and debugging tools may scan and upload entries for processing. 42 */ 43public class DropBoxManager { 44 private static final String TAG = "DropBoxManager"; 45 private final IDropBoxManagerService mService; 46 47 /** Flag value: Entry's content was deleted to save space. */ 48 public static final int IS_EMPTY = 1; 49 50 /** Flag value: Content is human-readable UTF-8 text (can be combined with IS_GZIPPED). */ 51 public static final int IS_TEXT = 2; 52 53 /** Flag value: Content can be decompressed with {@link java.util.zip.GZIPOutputStream}. */ 54 public static final int IS_GZIPPED = 4; 55 56 /** 57 * Broadcast Action: This is broadcast when a new entry is added in the dropbox. 58 * You must hold the {@link android.Manifest.permission#READ_LOGS} permission 59 * in order to receive this broadcast. 60 * 61 * <p class="note">This is a protected intent that can only be sent 62 * by the system. 63 */ 64 public static final String ACTION_DROPBOX_ENTRY_ADDED = 65 "android.intent.action.DROPBOX_ENTRY_ADDED"; 66 67 /** 68 * Extra for {@link android.os.DropBoxManager#ACTION_DROPBOX_ENTRY_ADDED}: 69 * string containing the dropbox tag. 70 */ 71 public static final String EXTRA_TAG = "tag"; 72 73 /** 74 * Extra for {@link android.os.DropBoxManager#ACTION_DROPBOX_ENTRY_ADDED}: 75 * long integer value containing time (in milliseconds since January 1, 1970 00:00:00 UTC) 76 * when the entry was created. 77 */ 78 public static final String EXTRA_TIME = "time"; 79 80 /** 81 * A single entry retrieved from the drop box. 82 * This may include a reference to a stream, so you must call 83 * {@link #close()} when you are done using it. 84 */ 85 public static class Entry implements Parcelable { 86 private final String mTag; 87 private final long mTimeMillis; 88 89 private final byte[] mData; 90 private final ParcelFileDescriptor mFileDescriptor; 91 private final int mFlags; 92 93 /** Create a new empty Entry with no contents. */ 94 public Entry(String tag, long millis) { 95 this(tag, millis, (Object) null, IS_EMPTY); 96 } 97 98 /** Create a new Entry with plain text contents. */ 99 public Entry(String tag, long millis, String text) { 100 this(tag, millis, (Object) text.getBytes(), IS_TEXT); 101 } 102 103 /** 104 * Create a new Entry with byte array contents. 105 * The data array must not be modified after creating this entry. 106 */ 107 public Entry(String tag, long millis, byte[] data, int flags) { 108 this(tag, millis, (Object) data, flags); 109 } 110 111 /** 112 * Create a new Entry with streaming data contents. 113 * Takes ownership of the ParcelFileDescriptor. 114 */ 115 public Entry(String tag, long millis, ParcelFileDescriptor data, int flags) { 116 this(tag, millis, (Object) data, flags); 117 } 118 119 /** 120 * Create a new Entry with the contents read from a file. 121 * The file will be read when the entry's contents are requested. 122 */ 123 public Entry(String tag, long millis, File data, int flags) throws IOException { 124 this(tag, millis, (Object) ParcelFileDescriptor.open( 125 data, ParcelFileDescriptor.MODE_READ_ONLY), flags); 126 } 127 128 /** Internal constructor for CREATOR.createFromParcel(). */ 129 private Entry(String tag, long millis, Object value, int flags) { 130 if (tag == null) throw new NullPointerException(); 131 if (((flags & IS_EMPTY) != 0) != (value == null)) throw new IllegalArgumentException(); 132 133 mTag = tag; 134 mTimeMillis = millis; 135 mFlags = flags; 136 137 if (value == null) { 138 mData = null; 139 mFileDescriptor = null; 140 } else if (value instanceof byte[]) { 141 mData = (byte[]) value; 142 mFileDescriptor = null; 143 } else if (value instanceof ParcelFileDescriptor) { 144 mData = null; 145 mFileDescriptor = (ParcelFileDescriptor) value; 146 } else { 147 throw new IllegalArgumentException(); 148 } 149 } 150 151 /** Close the input stream associated with this entry. */ 152 public void close() { 153 try { if (mFileDescriptor != null) mFileDescriptor.close(); } catch (IOException e) { } 154 } 155 156 /** @return the tag originally attached to the entry. */ 157 public String getTag() { return mTag; } 158 159 /** @return time when the entry was originally created. */ 160 public long getTimeMillis() { return mTimeMillis; } 161 162 /** @return flags describing the content returned by @{link #getInputStream()}. */ 163 public int getFlags() { return mFlags & ~IS_GZIPPED; } // getInputStream() decompresses. 164 165 /** 166 * @param maxBytes of string to return (will truncate at this length). 167 * @return the uncompressed text contents of the entry, null if the entry is not text. 168 */ 169 public String getText(int maxBytes) { 170 if ((mFlags & IS_TEXT) == 0) return null; 171 if (mData != null) return new String(mData, 0, Math.min(maxBytes, mData.length)); 172 173 InputStream is = null; 174 try { 175 is = getInputStream(); 176 byte[] buf = new byte[maxBytes]; 177 int readBytes = 0; 178 int n = 0; 179 while (n >= 0 && (readBytes += n) < maxBytes) { 180 n = is.read(buf, readBytes, maxBytes - readBytes); 181 } 182 return new String(buf, 0, readBytes); 183 } catch (IOException e) { 184 return null; 185 } finally { 186 try { if (is != null) is.close(); } catch (IOException e) {} 187 } 188 } 189 190 /** @return the uncompressed contents of the entry, or null if the contents were lost */ 191 public InputStream getInputStream() throws IOException { 192 InputStream is; 193 if (mData != null) { 194 is = new ByteArrayInputStream(mData); 195 } else if (mFileDescriptor != null) { 196 is = new ParcelFileDescriptor.AutoCloseInputStream(mFileDescriptor); 197 } else { 198 return null; 199 } 200 return (mFlags & IS_GZIPPED) != 0 ? new GZIPInputStream(is) : is; 201 } 202 203 public static final Parcelable.Creator<Entry> CREATOR = new Parcelable.Creator() { 204 public Entry[] newArray(int size) { return new Entry[size]; } 205 public Entry createFromParcel(Parcel in) { 206 return new Entry( 207 in.readString(), in.readLong(), in.readValue(null), in.readInt()); 208 } 209 }; 210 211 public int describeContents() { 212 return mFileDescriptor != null ? Parcelable.CONTENTS_FILE_DESCRIPTOR : 0; 213 } 214 215 public void writeToParcel(Parcel out, int flags) { 216 out.writeString(mTag); 217 out.writeLong(mTimeMillis); 218 if (mFileDescriptor != null) { 219 out.writeValue(mFileDescriptor); 220 } else { 221 out.writeValue(mData); 222 } 223 out.writeInt(mFlags); 224 } 225 } 226 227 /** {@hide} */ 228 public DropBoxManager(IDropBoxManagerService service) { mService = service; } 229 230 /** 231 * Create a dummy instance for testing. All methods will fail unless 232 * overridden with an appropriate mock implementation. To obtain a 233 * functional instance, use {@link android.content.Context#getSystemService}. 234 */ 235 protected DropBoxManager() { mService = null; } 236 237 /** 238 * Stores human-readable text. The data may be discarded eventually (or even 239 * immediately) if space is limited, or ignored entirely if the tag has been 240 * blocked (see {@link #isTagEnabled}). 241 * 242 * @param tag describing the type of entry being stored 243 * @param data value to store 244 */ 245 public void addText(String tag, String data) { 246 try { mService.add(new Entry(tag, 0, data)); } catch (RemoteException e) {} 247 } 248 249 /** 250 * Stores binary data, which may be ignored or discarded as with {@link #addText}. 251 * 252 * @param tag describing the type of entry being stored 253 * @param data value to store 254 * @param flags describing the data 255 */ 256 public void addData(String tag, byte[] data, int flags) { 257 if (data == null) throw new NullPointerException(); 258 try { mService.add(new Entry(tag, 0, data, flags)); } catch (RemoteException e) {} 259 } 260 261 /** 262 * Stores the contents of a file, which may be ignored or discarded as with 263 * {@link #addText}. 264 * 265 * @param tag describing the type of entry being stored 266 * @param file to read from 267 * @param flags describing the data 268 * @throws IOException if the file can't be opened 269 */ 270 public void addFile(String tag, File file, int flags) throws IOException { 271 if (file == null) throw new NullPointerException(); 272 Entry entry = new Entry(tag, 0, file, flags); 273 try { 274 mService.add(new Entry(tag, 0, file, flags)); 275 } catch (RemoteException e) { 276 // ignore 277 } finally { 278 entry.close(); 279 } 280 } 281 282 /** 283 * Checks any blacklists (set in system settings) to see whether a certain 284 * tag is allowed. Entries with disabled tags will be dropped immediately, 285 * so you can save the work of actually constructing and sending the data. 286 * 287 * @param tag that would be used in {@link #addText} or {@link #addFile} 288 * @return whether events with that tag would be accepted 289 */ 290 public boolean isTagEnabled(String tag) { 291 try { return mService.isTagEnabled(tag); } catch (RemoteException e) { return false; } 292 } 293 294 /** 295 * Gets the next entry from the drop box *after* the specified time. 296 * Requires android.permission.READ_LOGS. You must always call 297 * {@link Entry#close()} on the return value! 298 * 299 * @param tag of entry to look for, null for all tags 300 * @param msec time of the last entry seen 301 * @return the next entry, or null if there are no more entries 302 */ 303 public Entry getNextEntry(String tag, long msec) { 304 try { return mService.getNextEntry(tag, msec); } catch (RemoteException e) { return null; } 305 } 306 307 // TODO: It may be useful to have some sort of notification mechanism 308 // when data is added to the dropbox, for demand-driven readers -- 309 // for now readers need to poll the dropbox to find new data. 310} 311