android_translation_layer/src/api-impl/android/database/sqlite/SQLiteDebug.java

/*
 * Copyright (C) 2007 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.
 */
/*
** Modified to support SQLite extensions by the SQLite developers: 
** sqlite-dev@sqlite.org.
*/

package android.database.sqlite;

import java.util.ArrayList;

import android.util.Log;
import android.util.Printer;

/**
 * Provides debugging info about all SQLite databases running in the current process.
 *
 * {@hide}
 */
public final class SQLiteDebug {
	private static native void nativeGetPagerStats(PagerStats stats);

	/**
	 * Controls the printing of informational SQL log messages.
	 *
	 * Enable using "adb shell setprop log.tag.SQLiteLog VERBOSE".
	 */
	public static final boolean DEBUG_SQL_LOG =
			Log.isLoggable("SQLiteLog", Log.VERBOSE);

	/**
	 * Controls the printing of SQL statements as they are executed.
	 *
	 * Enable using "adb shell setprop log.tag.SQLiteStatements VERBOSE".
	 */
	public static final boolean DEBUG_SQL_STATEMENTS =
			Log.isLoggable("SQLiteStatements", Log.VERBOSE);

	/**
	 * Controls the printing of wall-clock time taken to execute SQL statements
	 * as they are executed.
	 *
	 * Enable using "adb shell setprop log.tag.SQLiteTime VERBOSE".
	 */
	public static final boolean DEBUG_SQL_TIME =
			Log.isLoggable("SQLiteTime", Log.VERBOSE);

	/**
	 * True to enable database performance testing instrumentation.
	 * @hide
	 */
	public static final boolean DEBUG_LOG_SLOW_QUERIES = false;

	private SQLiteDebug() {
	}

	/**
	 * Determines whether a query should be logged.
	 *
	 * Reads the "db.log.slow_query_threshold" system property, which can be changed
	 * by the user at any time.  If the value is zero, then all queries will
	 * be considered slow.  If the value does not exist or is negative, then no queries will
	 * be considered slow.
	 *
	 * This value can be changed dynamically while the system is running.
	 * For example, "adb shell setprop db.log.slow_query_threshold 200" will
	 * log all queries that take 200ms or longer to run.
	 * @hide
	 */
	public static final boolean shouldLogSlowQuery(long elapsedTimeMillis) {
		int slowQueryMillis = Integer.parseInt(
			System.getProperty("db.log.slow_query_threshold", "10000")
		);
		return slowQueryMillis >= 0 && elapsedTimeMillis >= slowQueryMillis;
	}

	/**
	 * Contains statistics about the active pagers in the current process.
	 *
	 * @see #nativeGetPagerStats(PagerStats)
	 */
	public static class PagerStats {
		/** the current amount of memory checked out by sqlite using sqlite3_malloc().
		 * documented at http://www.sqlite.org/c3ref/c_status_malloc_size.html
		 */
		public int memoryUsed;

		/** the number of bytes of page cache allocation which could not be sattisfied by the
		 * SQLITE_CONFIG_PAGECACHE buffer and where forced to overflow to sqlite3_malloc().
		 * The returned value includes allocations that overflowed because they where too large
		 * (they were larger than the "sz" parameter to SQLITE_CONFIG_PAGECACHE) and allocations
		 * that overflowed because no space was left in the page cache.
		 * documented at http://www.sqlite.org/c3ref/c_status_malloc_size.html
		 */
		public int pageCacheOverflow;

		/** records the largest memory allocation request handed to sqlite3.
		 * documented at http://www.sqlite.org/c3ref/c_status_malloc_size.html
		 */
		public int largestMemAlloc;

		/** a list of {@link DbStats} - one for each main database opened by the applications
		 * running on the android device
		 */
		public ArrayList<DbStats> dbStats;
	}

	/**
	 * contains statistics about a database
	 */
	public static class DbStats {
		/** name of the database */
		public String dbName;

		/** the page size for the database */
		public long pageSize;

		/** the database size */
		public long dbSize;

		/** documented here http://www.sqlite.org/c3ref/c_dbstatus_lookaside_used.html */
		public int lookaside;

		/** statement cache stats: hits/misses/cachesize */
		public String cache;

		public DbStats(String dbName, long pageCount, long pageSize, int lookaside,
			int hits, int misses, int cachesize) {
			this.dbName = dbName;
			this.pageSize = pageSize / 1024;
			dbSize = (pageCount * pageSize) / 1024;
			this.lookaside = lookaside;
			this.cache = hits + "/" + misses + "/" + cachesize;
		}
	}

	/**
	 * return all pager and database stats for the current process.
	 * @return {@link PagerStats}
	 */
	public static PagerStats getDatabaseInfo() {
		PagerStats stats = new PagerStats();
		nativeGetPagerStats(stats);
		stats.dbStats = SQLiteDatabase.getDbStats();
		return stats;
	}

	/**
	 * Dumps detailed information about all databases used by the process.
	 * @param printer The printer for dumping database state.
	 * @param args Command-line arguments supplied to dumpsys dbinfo
	 */
	public static void dump(Printer printer, String[] args) {
		boolean verbose = false;
		for (String arg : args) {
			if (arg.equals("-v")) {
				verbose = true;
			}
		}

		SQLiteDatabase.dumpAll(printer, verbose);
	}
}