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Diffstat (limited to 'src/com/android/providers/downloads/StorageManager.java')
| -rw-r--r-- | src/com/android/providers/downloads/StorageManager.java | 472 |
1 files changed, 0 insertions, 472 deletions
diff --git a/src/com/android/providers/downloads/StorageManager.java b/src/com/android/providers/downloads/StorageManager.java deleted file mode 100644 index b8cd6c79..00000000 --- a/src/com/android/providers/downloads/StorageManager.java +++ /dev/null @@ -1,472 +0,0 @@ -/* - * Copyright (C) 2010 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 com.android.providers.downloads; - -import static com.android.providers.downloads.Constants.LOGV; -import static com.android.providers.downloads.Constants.TAG; - -import android.content.ContentUris; -import android.content.Context; -import android.content.res.Resources; -import android.database.Cursor; -import android.database.sqlite.SQLiteException; -import android.net.Uri; -import android.os.Environment; -import android.os.StatFs; -import android.provider.Downloads; -import android.text.TextUtils; -import android.util.Log; - -import com.android.internal.R; - -import java.io.File; -import java.util.ArrayList; -import java.util.Arrays; -import java.util.List; - -import android.system.ErrnoException; -import android.system.Os; -import android.system.StructStat; - -/** - * Manages the storage space consumed by Downloads Data dir. When space falls below - * a threshold limit (set in resource xml files), starts cleanup of the Downloads data dir - * to free up space. - */ -class StorageManager { - /** the max amount of space allowed to be taken up by the downloads data dir */ - private static final long sMaxdownloadDataDirSize = - Resources.getSystem().getInteger(R.integer.config_downloadDataDirSize) * 1024 * 1024; - - /** threshold (in bytes) beyond which the low space warning kicks in and attempt is made to - * purge some downloaded files to make space - */ - private static final long sDownloadDataDirLowSpaceThreshold = - Resources.getSystem().getInteger( - R.integer.config_downloadDataDirLowSpaceThreshold) - * sMaxdownloadDataDirSize / 100; - - /** see {@link Environment#getExternalStorageDirectory()} */ - private final File mExternalStorageDir; - - /** see {@link Environment#getDownloadCacheDirectory()} */ - private final File mSystemCacheDir; - - /** The downloaded files are saved to this dir. it is the value returned by - * {@link Context#getCacheDir()}. - */ - private final File mDownloadDataDir; - - /** how often do we need to perform checks on space to make sure space is available */ - private static final int FREQUENCY_OF_CHECKS_ON_SPACE_AVAILABILITY = 1024 * 1024; // 1MB - private int mBytesDownloadedSinceLastCheckOnSpace = 0; - - /** misc members */ - private final Context mContext; - - public StorageManager(Context context) { - mContext = context; - mDownloadDataDir = getDownloadDataDirectory(context); - mExternalStorageDir = Environment.getExternalStorageDirectory(); - mSystemCacheDir = Environment.getDownloadCacheDirectory(); - startThreadToCleanupDatabaseAndPurgeFileSystem(); - } - - /** How often should database and filesystem be cleaned up to remove spurious files - * from the file system and - * The value is specified in terms of num of downloads since last time the cleanup was done. - */ - private static final int FREQUENCY_OF_DATABASE_N_FILESYSTEM_CLEANUP = 250; - private int mNumDownloadsSoFar = 0; - - synchronized void incrementNumDownloadsSoFar() { - if (++mNumDownloadsSoFar % FREQUENCY_OF_DATABASE_N_FILESYSTEM_CLEANUP == 0) { - startThreadToCleanupDatabaseAndPurgeFileSystem(); - } - } - /* start a thread to cleanup the following - * remove spurious files from the file system - * remove excess entries from the database - */ - private Thread mCleanupThread = null; - private synchronized void startThreadToCleanupDatabaseAndPurgeFileSystem() { - if (mCleanupThread != null && mCleanupThread.isAlive()) { - return; - } - mCleanupThread = new Thread() { - @Override public void run() { - removeSpuriousFiles(); - trimDatabase(); - } - }; - mCleanupThread.start(); - } - - void verifySpaceBeforeWritingToFile(int destination, String path, long length) - throws StopRequestException { - // do this check only once for every 1MB of downloaded data - if (incrementBytesDownloadedSinceLastCheckOnSpace(length) < - FREQUENCY_OF_CHECKS_ON_SPACE_AVAILABILITY) { - return; - } - verifySpace(destination, path, length); - } - - void verifySpace(int destination, String path, long length) throws StopRequestException { - resetBytesDownloadedSinceLastCheckOnSpace(); - File dir = null; - if (Constants.LOGV) { - Log.i(Constants.TAG, "in verifySpace, destination: " + destination + - ", path: " + path + ", length: " + length); - } - if (path == null) { - throw new IllegalArgumentException("path can't be null"); - } - switch (destination) { - case Downloads.Impl.DESTINATION_CACHE_PARTITION: - case Downloads.Impl.DESTINATION_CACHE_PARTITION_NOROAMING: - case Downloads.Impl.DESTINATION_CACHE_PARTITION_PURGEABLE: - dir = mDownloadDataDir; - break; - case Downloads.Impl.DESTINATION_EXTERNAL: - dir = mExternalStorageDir; - break; - case Downloads.Impl.DESTINATION_SYSTEMCACHE_PARTITION: - dir = mSystemCacheDir; - break; - case Downloads.Impl.DESTINATION_FILE_URI: - if (path.startsWith(mExternalStorageDir.getPath())) { - dir = mExternalStorageDir; - } else if (path.startsWith(mDownloadDataDir.getPath())) { - dir = mDownloadDataDir; - } else if (path.startsWith(mSystemCacheDir.getPath())) { - dir = mSystemCacheDir; - } - break; - } - if (dir == null) { - throw new IllegalStateException("invalid combination of destination: " + destination + - ", path: " + path); - } - findSpace(dir, length, destination); - } - - /** - * finds space in the given filesystem (input param: root) to accommodate # of bytes - * specified by the input param(targetBytes). - * returns true if found. false otherwise. - */ - private synchronized void findSpace(File root, long targetBytes, int destination) - throws StopRequestException { - if (targetBytes == 0) { - return; - } - if (destination == Downloads.Impl.DESTINATION_FILE_URI || - destination == Downloads.Impl.DESTINATION_EXTERNAL) { - if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) { - throw new StopRequestException(Downloads.Impl.STATUS_DEVICE_NOT_FOUND_ERROR, - "external media not mounted"); - } - } - // is there enough space in the file system of the given param 'root'. - long bytesAvailable = getAvailableBytesInFileSystemAtGivenRoot(root); - if (bytesAvailable < sDownloadDataDirLowSpaceThreshold) { - /* filesystem's available space is below threshold for low space warning. - * threshold typically is 10% of download data dir space quota. - * try to cleanup and see if the low space situation goes away. - */ - discardPurgeableFiles(destination, sDownloadDataDirLowSpaceThreshold); - removeSpuriousFiles(); - bytesAvailable = getAvailableBytesInFileSystemAtGivenRoot(root); - if (bytesAvailable < sDownloadDataDirLowSpaceThreshold) { - /* - * available space is still below the threshold limit. - * - * If this is system cache dir, print a warning. - * otherwise, don't allow downloading until more space - * is available because downloadmanager shouldn't end up taking those last - * few MB of space left on the filesystem. - */ - if (root.equals(mSystemCacheDir)) { - Log.w(Constants.TAG, "System cache dir ('/cache') is running low on space." + - "space available (in bytes): " + bytesAvailable); - } else { - throw new StopRequestException(Downloads.Impl.STATUS_INSUFFICIENT_SPACE_ERROR, - "space in the filesystem rooted at: " + root + - " is below 10% availability. stopping this download."); - } - } - } - if (root.equals(mDownloadDataDir)) { - // this download is going into downloads data dir. check space in that specific dir. - bytesAvailable = getAvailableBytesInDownloadsDataDir(mDownloadDataDir); - if (bytesAvailable < sDownloadDataDirLowSpaceThreshold) { - // print a warning - Log.w(Constants.TAG, "Downloads data dir: " + root + - " is running low on space. space available (in bytes): " + bytesAvailable); - } - if (bytesAvailable < targetBytes) { - // Insufficient space; make space. - discardPurgeableFiles(destination, sDownloadDataDirLowSpaceThreshold); - removeSpuriousFiles(); - bytesAvailable = getAvailableBytesInDownloadsDataDir(mDownloadDataDir); - } - } - if (bytesAvailable < targetBytes) { - throw new StopRequestException(Downloads.Impl.STATUS_INSUFFICIENT_SPACE_ERROR, - "not enough free space in the filesystem rooted at: " + root + - " and unable to free any more"); - } - } - - /** - * returns the number of bytes available in the downloads data dir - * TODO this implementation is too slow. optimize it. - */ - private long getAvailableBytesInDownloadsDataDir(File root) { - File[] files = root.listFiles(); - long space = sMaxdownloadDataDirSize; - if (files == null) { - return space; - } - int size = files.length; - for (int i = 0; i < size; i++) { - space -= files[i].length(); - } - if (Constants.LOGV) { - Log.i(Constants.TAG, "available space (in bytes) in downloads data dir: " + space); - } - return space; - } - - private long getAvailableBytesInFileSystemAtGivenRoot(File root) { - StatFs stat = new StatFs(root.getPath()); - // put a bit of margin (in case creating the file grows the system by a few blocks) - long availableBlocks = (long) stat.getAvailableBlocks() - 4; - long size = stat.getBlockSize() * availableBlocks; - if (Constants.LOGV) { - Log.i(Constants.TAG, "available space (in bytes) in filesystem rooted at: " + - root.getPath() + " is: " + size); - } - return size; - } - - File locateDestinationDirectory(String mimeType, int destination, long contentLength) - throws StopRequestException { - switch (destination) { - case Downloads.Impl.DESTINATION_CACHE_PARTITION: - case Downloads.Impl.DESTINATION_CACHE_PARTITION_PURGEABLE: - case Downloads.Impl.DESTINATION_CACHE_PARTITION_NOROAMING: - return mDownloadDataDir; - case Downloads.Impl.DESTINATION_SYSTEMCACHE_PARTITION: - return mSystemCacheDir; - case Downloads.Impl.DESTINATION_EXTERNAL: - File base = new File(mExternalStorageDir.getPath() + Constants.DEFAULT_DL_SUBDIR); - if (!base.isDirectory() && !base.mkdir()) { - // Can't create download directory, e.g. because a file called "download" - // already exists at the root level, or the SD card filesystem is read-only. - throw new StopRequestException(Downloads.Impl.STATUS_FILE_ERROR, - "unable to create external downloads directory " + base.getPath()); - } - return base; - default: - throw new IllegalStateException("unexpected value for destination: " + destination); - } - } - - File getDownloadDataDirectory() { - return mDownloadDataDir; - } - - public static File getDownloadDataDirectory(Context context) { - return context.getCacheDir(); - } - - /** - * Deletes purgeable files from the cache partition. This also deletes - * the matching database entries. Files are deleted in LRU order until - * the total byte size is greater than targetBytes - */ - private long discardPurgeableFiles(int destination, long targetBytes) { - if (true || Constants.LOGV) { - Log.i(Constants.TAG, "discardPurgeableFiles: destination = " + destination + - ", targetBytes = " + targetBytes); - } - String destStr = (destination == Downloads.Impl.DESTINATION_SYSTEMCACHE_PARTITION) ? - String.valueOf(destination) : - String.valueOf(Downloads.Impl.DESTINATION_CACHE_PARTITION_PURGEABLE); - String[] bindArgs = new String[]{destStr}; - Cursor cursor = mContext.getContentResolver().query( - Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, - null, - "( " + - Downloads.Impl.COLUMN_STATUS + " = '" + Downloads.Impl.STATUS_SUCCESS + "' AND " + - Downloads.Impl.COLUMN_DESTINATION + " = ? )", - bindArgs, - Downloads.Impl.COLUMN_LAST_MODIFICATION); - if (cursor == null) { - return 0; - } - long totalFreed = 0; - try { - final int dataIndex = cursor.getColumnIndex(Downloads.Impl._DATA); - while (cursor.moveToNext() && totalFreed < targetBytes) { - final String data = cursor.getString(dataIndex); - if (TextUtils.isEmpty(data)) continue; - - File file = new File(data); - if (Constants.LOGV) { - Log.d(Constants.TAG, "purging " + file.getAbsolutePath() + " for " - + file.length() + " bytes"); - } - totalFreed += file.length(); - file.delete(); - long id = cursor.getLong(cursor.getColumnIndex(Downloads.Impl._ID)); - mContext.getContentResolver().delete( - ContentUris.withAppendedId(Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, id), - null, null); - } - } finally { - cursor.close(); - } - if (true || Constants.LOGV) { - Log.i(Constants.TAG, "Purged files, freed " + totalFreed + " for " + - targetBytes + " requested"); - } - return totalFreed; - } - - /** - * Removes files in the systemcache and downloads data dir without corresponding entries in - * the downloads database. - * This can occur if a delete is done on the database but the file is not removed from the - * filesystem (due to sudden death of the process, for example). - * This is not a very common occurrence. So, do this only once in a while. - */ - private void removeSpuriousFiles() { - if (Constants.LOGV) { - Log.i(Constants.TAG, "in removeSpuriousFiles"); - } - // get a list of all files in system cache dir and downloads data dir - List<File> files = new ArrayList<File>(); - File[] listOfFiles = mSystemCacheDir.listFiles(); - if (listOfFiles != null) { - files.addAll(Arrays.asList(listOfFiles)); - } - listOfFiles = mDownloadDataDir.listFiles(); - if (listOfFiles != null) { - files.addAll(Arrays.asList(listOfFiles)); - } - if (files.size() == 0) { - return; - } - Cursor cursor = mContext.getContentResolver().query( - Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, - new String[] { Downloads.Impl._DATA }, null, null, null); - try { - if (cursor != null) { - while (cursor.moveToNext()) { - String filename = cursor.getString(0); - if (!TextUtils.isEmpty(filename)) { - if (LOGV) { - Log.i(Constants.TAG, "in removeSpuriousFiles, preserving file " + - filename); - } - files.remove(new File(filename)); - } - } - } - } finally { - if (cursor != null) { - cursor.close(); - } - } - - // delete files owned by us, but that don't appear in our database - final int myUid = android.os.Process.myUid(); - for (File file : files) { - final String path = file.getAbsolutePath(); - try { - final StructStat stat = Os.stat(path); - if (stat.st_uid == myUid) { - if (Constants.LOGVV) { - Log.d(TAG, "deleting spurious file " + path); - } - file.delete(); - } - } catch (ErrnoException e) { - Log.w(TAG, "stat(" + path + ") result: " + e); - } - } - } - - /** - * Drops old rows from the database to prevent it from growing too large - * TODO logic in this method needs to be optimized. maintain the number of downloads - * in memory - so that this method can limit the amount of data read. - */ - private void trimDatabase() { - if (Constants.LOGV) { - Log.i(Constants.TAG, "in trimDatabase"); - } - Cursor cursor = null; - try { - cursor = mContext.getContentResolver().query(Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, - new String[] { Downloads.Impl._ID }, - Downloads.Impl.COLUMN_STATUS + " >= '200'", null, - Downloads.Impl.COLUMN_LAST_MODIFICATION); - if (cursor == null) { - // This isn't good - if we can't do basic queries in our database, - // nothing's gonna work - Log.e(Constants.TAG, "null cursor in trimDatabase"); - return; - } - if (cursor.moveToFirst()) { - int numDelete = cursor.getCount() - Constants.MAX_DOWNLOADS; - int columnId = cursor.getColumnIndexOrThrow(Downloads.Impl._ID); - while (numDelete > 0) { - Uri downloadUri = ContentUris.withAppendedId( - Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, cursor.getLong(columnId)); - mContext.getContentResolver().delete(downloadUri, null, null); - if (!cursor.moveToNext()) { - break; - } - numDelete--; - } - } - } catch (SQLiteException e) { - // trimming the database raised an exception. alright, ignore the exception - // and return silently. trimming database is not exactly a critical operation - // and there is no need to propagate the exception. - Log.w(Constants.TAG, "trimDatabase failed with exception: " + e.getMessage()); - return; - } finally { - if (cursor != null) { - cursor.close(); - } - } - } - - private synchronized int incrementBytesDownloadedSinceLastCheckOnSpace(long val) { - mBytesDownloadedSinceLastCheckOnSpace += val; - return mBytesDownloadedSinceLastCheckOnSpace; - } - - private synchronized void resetBytesDownloadedSinceLastCheckOnSpace() { - mBytesDownloadedSinceLastCheckOnSpace = 0; - } -} |