/*
* Copyright (C) 2011 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.database.sqlite;
import dalvik.system.BlockGuard;
import dalvik.system.CloseGuard;
import android.database.Cursor;
import android.database.CursorWindow;
import android.database.DatabaseUtils;
import android.database.sqlite.SQLiteDebug.DbStats;
import android.os.CancellationSignal;
import android.os.OperationCanceledException;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.util.LruCache;
import android.util.Printer;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Map;
import java.util.regex.Pattern;
/**
* Represents a SQLite database connection.
* Each connection wraps an instance of a native <code>sqlite3</code> object.
* <p>
* When database connection pooling is enabled, there can be multiple active
* connections to the same database. Otherwise there is typically only one
* connection per database.
* </p><p>
* When the SQLite WAL feature is enabled, multiple readers and one writer
* can concurrently access the database. Without WAL, readers and writers
* are mutually exclusive.
* </p>
*
* <h2>Ownership and concurrency guarantees</h2>
* <p>
* Connection objects are not thread-safe. They are acquired as needed to
* perform a database operation and are then returned to the pool. At any
* given time, a connection is either owned and used by a {@link SQLiteSession}
* object or the {@link SQLiteConnectionPool}. Those classes are
* responsible for serializing operations to guard against concurrent
* use of a connection.
* </p><p>
* The guarantee of having a single owner allows this class to be implemented
* without locks and greatly simplifies resource management.
* </p>
*
* <h2>Encapsulation guarantees</h2>
* <p>
* The connection object object owns *all* of the SQLite related native
* objects that are associated with the connection. What's more, there are
* no other objects in the system that are capable of obtaining handles to
* those native objects. Consequently, when the connection is closed, we do
* not have to worry about what other components might have references to
* its associated SQLite state -- there are none.
* </p><p>
* Encapsulation is what ensures that the connection object's
* lifecycle does not become a tortured mess of finalizers and reference
* queues.
* </p>
*
* <h2>Reentrance</h2>
* <p>
* This class must tolerate reentrant execution of SQLite operations because
* triggers may call custom SQLite functions that perform additional queries.
* </p>
*
* @hide
*/
public final class SQLiteConnection implements CancellationSignal.OnCancelListener {
private static final String TAG = "SQLiteConnection";
private static final boolean DEBUG = false;
private static final String[] EMPTY_STRING_ARRAY = new String[0];
private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
private static final Pattern TRIM_SQL_PATTERN = Pattern.compile("[\\s]*\\n+[\\s]*");
private final CloseGuard mCloseGuard = CloseGuard.get();
private final SQLiteConnectionPool mPool;
private final SQLiteDatabaseConfiguration mConfiguration;
private final int mConnectionId;
private final boolean mIsPrimaryConnection;
private final boolean mIsReadOnlyConnection;
private final PreparedStatementCache mPreparedStatementCache;
private PreparedStatement mPreparedStatementPool;
// The recent operations log.
private final OperationLog mRecentOperations = new OperationLog();
// The native SQLiteConnection pointer. (FOR INTERNAL USE ONLY)
private long mConnectionPtr;
private boolean mOnlyAllowReadOnlyOperations;
// The number of times attachCancellationSignal has been called.
// Because SQLite statement execution can be reentrant, we keep track of how many
// times we have attempted to attach a cancellation signal to the connection so that
// we can ensure that we detach the signal at the right time.
private int mCancellationSignalAttachCount;
private static native long nativeOpen(String path, int openFlags, String label,
boolean enableTrace, boolean enableProfile);
private static native void nativeClose(long connectionPtr);
private static native void nativeRegisterCustomFunction(long connectionPtr,
SQLiteCustomFunction function);
private static native void nativeRegisterLocalizedCollators(long connectionPtr, String locale);
private static native long nativePrepareStatement(long connectionPtr, String sql);
private static native void nativeFinalizeStatement(long connectionPtr, long statementPtr);
private static native int nativeGetParameterCount(long connectionPtr, long statementPtr);
private static native boolean nativeIsReadOnly(long connectionPtr, long statementPtr);
private static native int nativeGetColumnCount(long connectionPtr, long statementPtr);
private static native String nativeGetColumnName(long connectionPtr, long statementPtr,
int index);
private static native void nativeBindNull(long connectionPtr, long statementPtr,
int index);
private static native void nativeBindLong(long connectionPtr, long statementPtr,
int index, long value);
private static native void nativeBindDouble(long connectionPtr, long statementPtr,
int index, double value);
private static native void nativeBindString(long connectionPtr, long statementPtr,
int index, String value);
private static native void nativeBindBlob(long connectionPtr, long statementPtr,
int index, byte[] value);
private static native void nativeResetStatementAndClearBindings(
long connectionPtr, long statementPtr);
private static native void nativeExecute(long connectionPtr, long statementPtr);
private static native long nativeExecuteForLong(long connectionPtr, long statementPtr);
private static native String nativeExecuteForString(long connectionPtr, long statementPtr);
private static native int nativeExecuteForBlobFileDescriptor(
long connectionPtr, long statementPtr);
private static native int nativeExecuteForChangedRowCount(long connectionPtr, long statementPtr);
private static native long nativeExecuteForLastInsertedRowId(
long connectionPtr, long statementPtr);
private static native long nativeExecuteForCursorWindow(
long connectionPtr, long statementPtr, long windowPtr,
int startPos, int requiredPos, boolean countAllRows);
private static native int nativeGetDbLookaside(long connectionPtr);
private static native void nativeCancel(long connectionPtr);
private static native void nativeResetCancel(long connectionPtr, boolean cancelable);
private SQLiteConnection(SQLiteConnectionPool pool,
SQLiteDatabaseConfiguration configuration,
int connectionId, boolean primaryConnection) {
mPool = pool;
mConfiguration = new SQLiteDatabaseConfiguration(configuration);
mConnectionId = connectionId;
mIsPrimaryConnection = primaryConnection;
mIsReadOnlyConnection = (configuration.openFlags & SQLiteDatabase.OPEN_READONLY) != 0;
mPreparedStatementCache = new PreparedStatementCache(
mConfiguration.maxSqlCacheSize);
mCloseGuard.open("close");
}
@Override
protected void finalize() throws Throwable {
try {
if (mPool != null && mConnectionPtr != 0) {
mPool.onConnectionLeaked();
}
dispose(true);
} finally {
super.finalize();
}
}
// Called by SQLiteConnectionPool only.
static SQLiteConnection open(SQLiteConnectionPool pool,
SQLiteDatabaseConfiguration configuration,
int connectionId, boolean primaryConnection) {
SQLiteConnection connection = new SQLiteConnection(pool, configuration,
connectionId, primaryConnection);
try {
connection.open();
return connection;
} catch (SQLiteException ex) {
connection.dispose(false);
throw ex;
}
}
// Called by SQLiteConnectionPool only.
// Closes the database closes and releases all of its associated resources.
// Do not call methods on the connection after it is closed. It will probably crash.
void close() {
dispose(false);
}
private void open() {
mConnectionPtr = nativeOpen(mConfiguration.path, mConfiguration.openFlags,
mConfiguration.label,
SQLiteDebug.DEBUG_SQL_STATEMENTS, SQLiteDebug.DEBUG_SQL_TIME);
setPageSize();
setForeignKeyModeFromConfiguration();
setWalModeFromConfiguration();
setJournalSizeLimit();
setAutoCheckpointInterval();
setLocaleFromConfiguration();
// Register custom functions.
final int functionCount = mConfiguration.customFunctions.size();
for (int i = 0; i < functionCount; i++) {
SQLiteCustomFunction function = mConfiguration.customFunctions.get(i);
nativeRegisterCustomFunction(mConnectionPtr, function);
}
}
private void dispose(boolean finalized) {
if (mCloseGuard != null) {
if (finalized) {
mCloseGuard.warnIfOpen();
}
mCloseGuard.close();
}
if (mConnectionPtr != 0) {
final int cookie = mRecentOperations.beginOperation("close", null, null);
try {
mPreparedStatementCache.evictAll();
nativeClose(mConnectionPtr);
mConnectionPtr = 0;
} finally {
mRecentOperations.endOperation(cookie);
}
}
}
private void setPageSize() {
if (!mConfiguration.isInMemoryDb() && !mIsReadOnlyConnection) {
final long newValue = SQLiteGlobal.getDefaultPageSize();
long value = executeForLong("PRAGMA page_size", null, null);
if (value != newValue) {
execute("PRAGMA page_size=" + newValue, null, null);
}
}
}
private void setAutoCheckpointInterval() {
if (!mConfiguration.isInMemoryDb() && !mIsReadOnlyConnection) {
final long newValue = SQLiteGlobal.getWALAutoCheckpoint();
long value = executeForLong("PRAGMA wal_autocheckpoint", null, null);
if (value != newValue) {
executeForLong("PRAGMA wal_autocheckpoint=" + newValue, null, null);
}
}
}
private void setJournalSizeLimit() {
if (!mConfiguration.isInMemoryDb() && !mIsReadOnlyConnection) {
final long newValue = SQLiteGlobal.getJournalSizeLimit();
long value = executeForLong("PRAGMA journal_size_limit", null, null);
if (value != newValue) {
executeForLong("PRAGMA journal_size_limit=" + newValue, null, null);
}
}
}
private void setForeignKeyModeFromConfiguration() {
if (!mIsReadOnlyConnection) {
final long newValue = mConfiguration.foreignKeyConstraintsEnabled ? 1 : 0;
long value = executeForLong("PRAGMA foreign_keys", null, null);
if (value != newValue) {
execute("PRAGMA foreign_keys=" + newValue, null, null);
}
}
}
private void setWalModeFromConfiguration() {
if (!mConfiguration.isInMemoryDb() && !mIsReadOnlyConnection) {
if ((mConfiguration.openFlags & SQLiteDatabase.ENABLE_WRITE_AHEAD_LOGGING) != 0) {
setJournalMode("WAL");
setSyncMode(SQLiteGlobal.getWALSyncMode());
} else {
setJournalMode(SQLiteGlobal.getDefaultJournalMode());
setSyncMode(SQLiteGlobal.getDefaultSyncMode());
}
}
}
private void setSyncMode(String newValue) {
String value = executeForString("PRAGMA synchronous", null, null);
if (!canonicalizeSyncMode(value).equalsIgnoreCase(
canonicalizeSyncMode(newValue))) {
execute("PRAGMA synchronous=" + newValue, null, null);
}
}
private static String canonicalizeSyncMode(String value) {
if (value.equals("0")) {
return "OFF";
} else if (value.equals("1")) {
return "NORMAL";
} else if (value.equals("2")) {
return "FULL";
}
return value;
}
private void setJournalMode(String newValue) {
String value = executeForString("PRAGMA journal_mode", null, null);
if (!value.equalsIgnoreCase(newValue)) {
try {
String result = executeForString("PRAGMA journal_mode=" + newValue, null, null);
if (result.equalsIgnoreCase(newValue)) {
return;
}
// PRAGMA journal_mode silently fails and returns the original journal
// mode in some cases if the journal mode could not be changed.
} catch (SQLiteDatabaseLockedException ex) {
// This error (SQLITE_BUSY) occurs if one connection has the database
// open in WAL mode and another tries to change it to non-WAL.
}
// Because we always disable WAL mode when a database is first opened
// (even if we intend to re-enable it), we can encounter problems if
// there is another open connection to the database somewhere.
// This can happen for a variety of reasons such as an application opening
// the same database in multiple processes at the same time or if there is a
// crashing content provider service that the ActivityManager has
// removed from its registry but whose process hasn't quite died yet
// by the time it is restarted in a new process.
//
// If we don't change the journal mode, nothing really bad happens.
// In the worst case, an application that enables WAL might not actually
// get it, although it can still use connection pooling.
Log.w(TAG, "Could not change the database journal mode of '"
+ mConfiguration.label + "' from '" + value + "' to '" + newValue
+ "' because the database is locked. This usually means that "
+ "there are other open connections to the database which prevents "
+ "the database from enabling or disabling write-ahead logging mode. "
+ "Proceeding without changing the journal mode.");
}
}
private void setLocaleFromConfiguration() {
if ((mConfiguration.openFlags & SQLiteDatabase.NO_LOCALIZED_COLLATORS) != 0) {
return;
}
// Register the localized collators.
final String newLocale = mConfiguration.locale.toString();
nativeRegisterLocalizedCollators(mConnectionPtr, newLocale);
// If the database is read-only, we cannot modify the android metadata table
// or existing indexes.
if (mIsReadOnlyConnection) {
return;
}
try {
// Ensure the android metadata table exists.
execute("CREATE TABLE IF NOT EXISTS android_metadata (locale TEXT)", null, null);
// Check whether the locale was actually changed.
final String oldLocale = executeForString("SELECT locale FROM android_metadata "
+ "UNION SELECT NULL ORDER BY locale DESC LIMIT 1", null, null);
if (oldLocale != null && oldLocale.equals(newLocale)) {
return;
}
// Go ahead and update the indexes using the new locale.
execute("BEGIN", null, null);
boolean success = false;
try {
execute("DELETE FROM android_metadata", null, null);
execute("INSERT INTO android_metadata (locale) VALUES(?)",
new Object[] { newLocale }, null);
execute("REINDEX LOCALIZED", null, null);
success = true;
} finally {
execute(success ? "COMMIT" : "ROLLBACK", null, null);
}
} catch (RuntimeException ex) {
throw new SQLiteException("Failed to change locale for db '" + mConfiguration.label
+ "' to '" + newLocale + "'.", ex);
}
}
// Called by SQLiteConnectionPool only.
void reconfigure(SQLiteDatabaseConfiguration configuration) {
mOnlyAllowReadOnlyOperations = false;
// Register custom functions.
final int functionCount = configuration.customFunctions.size();
for (int i = 0; i < functionCount; i++) {
SQLiteCustomFunction function = configuration.customFunctions.get(i);
if (!mConfiguration.customFunctions.contains(function)) {
nativeRegisterCustomFunction(mConnectionPtr, function);
}
}
// Remember what changed.
boolean foreignKeyModeChanged = configuration.foreignKeyConstraintsEnabled
!= mConfiguration.foreignKeyConstraintsEnabled;
boolean walModeChanged = ((configuration.openFlags ^ mConfiguration.openFlags)
& SQLiteDatabase.ENABLE_WRITE_AHEAD_LOGGING) != 0;
boolean localeChanged = !configuration.locale.equals(mConfiguration.locale);
// Update configuration parameters.
mConfiguration.updateParametersFrom(configuration);
// Update prepared statement cache size.
mPreparedStatementCache.resize(configuration.maxSqlCacheSize);
// Update foreign key mode.
if (foreignKeyModeChanged) {
setForeignKeyModeFromConfiguration();
}
// Update WAL.
if (walModeChanged) {
setWalModeFromConfiguration();
}
// Update locale.
if (localeChanged) {
setLocaleFromConfiguration();
}
}
// Called by SQLiteConnectionPool only.
// When set to true, executing write operations will throw SQLiteException.
// Preparing statements that might write is ok, just don't execute them.
void setOnlyAllowReadOnlyOperations(boolean readOnly) {
mOnlyAllowReadOnlyOperations = readOnly;
}
// Called by SQLiteConnectionPool only.
// Returns true if the prepared statement cache contains the specified SQL.
boolean isPreparedStatementInCache(String sql) {
return mPreparedStatementCache.get(sql) != null;
}
/**
* Gets the unique id of this connection.
* @return The connection id.
*/
public int getConnectionId() {
return mConnectionId;
}
/**
* Returns true if this is the primary database connection.
* @return True if this is the primary database connection.
*/
public boolean isPrimaryConnection() {
return mIsPrimaryConnection;
}
/**
* Prepares a statement for execution but does not bind its parameters or execute it.
* <p>
* This method can be used to check for syntax errors during compilation
* prior to execution of the statement. If the {@code outStatementInfo} argument
* is not null, the provided {@link SQLiteStatementInfo} object is populated
* with information about the statement.
* </p><p>
* A prepared statement makes no reference to the arguments that may eventually
* be bound to it, consequently it it possible to cache certain prepared statements
* such as SELECT or INSERT/UPDATE statements. If the statement is cacheable,
* then it will be stored in the cache for later.
* </p><p>
* To take advantage of this behavior as an optimization, the connection pool
* provides a method to acquire a connection that already has a given SQL statement
* in its prepared statement cache so that it is ready for execution.
* </p>
*
* @param sql The SQL statement to prepare.
* @param outStatementInfo The {@link SQLiteStatementInfo} object to populate
* with information about the statement, or null if none.
*
* @throws SQLiteException if an error occurs, such as a syntax error.
*/
public void prepare(String sql, SQLiteStatementInfo outStatementInfo) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
final int cookie = mRecentOperations.beginOperation("prepare", sql, null);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
if (outStatementInfo != null) {
outStatementInfo.numParameters = statement.mNumParameters;
outStatementInfo.readOnly = statement.mReadOnly;
final int columnCount = nativeGetColumnCount(
mConnectionPtr, statement.mStatementPtr);
if (columnCount == 0) {
outStatementInfo.columnNames = EMPTY_STRING_ARRAY;
} else {
outStatementInfo.columnNames = new String[columnCount];
for (int i = 0; i < columnCount; i++) {
outStatementInfo.columnNames[i] = nativeGetColumnName(
mConnectionPtr, statement.mStatementPtr, i);
}
}
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
mRecentOperations.endOperation(cookie);
}
}
/**
* Executes a statement that does not return a result.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
public void execute(String sql, Object[] bindArgs,
CancellationSignal cancellationSignal) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
final int cookie = mRecentOperations.beginOperation("execute", sql, bindArgs);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
throwIfStatementForbidden(statement);
bindArguments(statement, bindArgs);
applyBlockGuardPolicy(statement);
attachCancellationSignal(cancellationSignal);
try {
nativeExecute(mConnectionPtr, statement.mStatementPtr);
} finally {
detachCancellationSignal(cancellationSignal);
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
mRecentOperations.endOperation(cookie);
}
}
/**
* Executes a statement that returns a single <code>long</code> result.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return The value of the first column in the first row of the result set
* as a <code>long</code>, or zero if none.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
public long executeForLong(String sql, Object[] bindArgs,
CancellationSignal cancellationSignal) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
final int cookie = mRecentOperations.beginOperation("executeForLong", sql, bindArgs);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
throwIfStatementForbidden(statement);
bindArguments(statement, bindArgs);
applyBlockGuardPolicy(statement);
attachCancellationSignal(cancellationSignal);
try {
return nativeExecuteForLong(mConnectionPtr, statement.mStatementPtr);
} finally {
detachCancellationSignal(cancellationSignal);
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
mRecentOperations.endOperation(cookie);
}
}
/**
* Executes a statement that returns a single {@link String} result.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return The value of the first column in the first row of the result set
* as a <code>String</code>, or null if none.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
public String executeForString(String sql, Object[] bindArgs,
CancellationSignal cancellationSignal) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
final int cookie = mRecentOperations.beginOperation("executeForString", sql, bindArgs);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
throwIfStatementForbidden(statement);
bindArguments(statement, bindArgs);
applyBlockGuardPolicy(statement);
attachCancellationSignal(cancellationSignal);
try {
return nativeExecuteForString(mConnectionPtr, statement.mStatementPtr);
} finally {
detachCancellationSignal(cancellationSignal);
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
mRecentOperations.endOperation(cookie);
}
}
/**
* Executes a statement that returns a single BLOB result as a
* file descriptor to a shared memory region.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return The file descriptor for a shared memory region that contains
* the value of the first column in the first row of the result set as a BLOB,
* or null if none.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
public ParcelFileDescriptor executeForBlobFileDescriptor(String sql, Object[] bindArgs,
CancellationSignal cancellationSignal) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
final int cookie = mRecentOperations.beginOperation("executeForBlobFileDescriptor",
sql, bindArgs);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
throwIfStatementForbidden(statement);
bindArguments(statement, bindArgs);
applyBlockGuardPolicy(statement);
attachCancellationSignal(cancellationSignal);
try {
int fd = nativeExecuteForBlobFileDescriptor(
mConnectionPtr, statement.mStatementPtr);
return fd >= 0 ? ParcelFileDescriptor.adoptFd(fd) : null;
} finally {
detachCancellationSignal(cancellationSignal);
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
mRecentOperations.endOperation(cookie);
}
}
/**
* Executes a statement that returns a count of the number of rows
* that were changed. Use for UPDATE or DELETE SQL statements.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return The number of rows that were changed.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
public int executeForChangedRowCount(String sql, Object[] bindArgs,
CancellationSignal cancellationSignal) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
int changedRows = 0;
final int cookie = mRecentOperations.beginOperation("executeForChangedRowCount",
sql, bindArgs);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
throwIfStatementForbidden(statement);
bindArguments(statement, bindArgs);
applyBlockGuardPolicy(statement);
attachCancellationSignal(cancellationSignal);
try {
changedRows = nativeExecuteForChangedRowCount(
mConnectionPtr, statement.mStatementPtr);
return changedRows;
} finally {
detachCancellationSignal(cancellationSignal);
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
if (mRecentOperations.endOperationDeferLog(cookie)) {
mRecentOperations.logOperation(cookie, "changedRows=" + changedRows);
}
}
}
/**
* Executes a statement that returns the row id of the last row inserted
* by the statement. Use for INSERT SQL statements.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return The row id of the last row that was inserted, or 0 if none.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
public long executeForLastInsertedRowId(String sql, Object[] bindArgs,
CancellationSignal cancellationSignal) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
final int cookie = mRecentOperations.beginOperation("executeForLastInsertedRowId",
sql, bindArgs);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
throwIfStatementForbidden(statement);
bindArguments(statement, bindArgs);
applyBlockGuardPolicy(statement);
attachCancellationSignal(cancellationSignal);
try {
return nativeExecuteForLastInsertedRowId(
mConnectionPtr, statement.mStatementPtr);
} finally {
detachCancellationSignal(cancellationSignal);
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
mRecentOperations.endOperation(cookie);
}
}
/**
* Executes a statement and populates the specified {@link CursorWindow}
* with a range of results. Returns the number of rows that were counted
* during query execution.
*
* @param sql The SQL statement to execute.
* @param bindArgs The arguments to bind, or null if none.
* @param window The cursor window to clear and fill.
* @param startPos The start position for filling the window.
* @param requiredPos The position of a row that MUST be in the window.
* If it won't fit, then the query should discard part of what it filled
* so that it does. Must be greater than or equal to <code>startPos</code>.
* @param countAllRows True to count all rows that the query would return
* regagless of whether they fit in the window.
* @param cancellationSignal A signal to cancel the operation in progress, or null if none.
* @return The number of rows that were counted during query execution. Might
* not be all rows in the result set unless <code>countAllRows</code> is true.
*
* @throws SQLiteException if an error occurs, such as a syntax error
* or invalid number of bind arguments.
* @throws OperationCanceledException if the operation was canceled.
*/
public int executeForCursorWindow(String sql, Object[] bindArgs,
CursorWindow window, int startPos, int requiredPos, boolean countAllRows,
CancellationSignal cancellationSignal) {
if (sql == null) {
throw new IllegalArgumentException("sql must not be null.");
}
if (window == null) {
throw new IllegalArgumentException("window must not be null.");
}
window.acquireReference();
try {
int actualPos = -1;
int countedRows = -1;
int filledRows = -1;
final int cookie = mRecentOperations.beginOperation("executeForCursorWindow",
sql, bindArgs);
try {
final PreparedStatement statement = acquirePreparedStatement(sql);
try {
throwIfStatementForbidden(statement);
bindArguments(statement, bindArgs);
applyBlockGuardPolicy(statement);
attachCancellationSignal(cancellationSignal);
try {
final long result = nativeExecuteForCursorWindow(
mConnectionPtr, statement.mStatementPtr, window.mWindowPtr,
startPos, requiredPos, countAllRows);
actualPos = (int)(result >> 32);
countedRows = (int)result;
filledRows = window.getNumRows();
window.setStartPosition(actualPos);
return countedRows;
} finally {
detachCancellationSignal(cancellationSignal);
}
} finally {
releasePreparedStatement(statement);
}
} catch (RuntimeException ex) {
mRecentOperations.failOperation(cookie, ex);
throw ex;
} finally {
if (mRecentOperations.endOperationDeferLog(cookie)) {
mRecentOperations.logOperation(cookie, "window='" + window
+ "', startPos=" + startPos
+ ", actualPos=" + actualPos
+ ", filledRows=" + filledRows
+ ", countedRows=" + countedRows);
}
}
} finally {
window.releaseReference();
}
}
private PreparedStatement acquirePreparedStatement(String sql) {
PreparedStatement statement = mPreparedStatementCache.get(sql);
boolean skipCache = false;
if (statement != null) {
if (!statement.mInUse) {
return statement;
}
// The statement is already in the cache but is in use (this statement appears
// to be not only re-entrant but recursive!). So prepare a new copy of the
// statement but do not cache it.
skipCache = true;
}
final long statementPtr = nativePrepareStatement(mConnectionPtr, sql);
try {
final int numParameters = nativeGetParameterCount(mConnectionPtr, statementPtr);
final int type = DatabaseUtils.getSqlStatementType(sql);
final boolean readOnly = nativeIsReadOnly(mConnectionPtr, statementPtr);
statement = obtainPreparedStatement(sql, statementPtr, numParameters, type, readOnly);
if (!skipCache && isCacheable(type)) {
mPreparedStatementCache.put(sql, statement);
statement.mInCache = true;
}
} catch (RuntimeException ex) {
// Finalize the statement if an exception occurred and we did not add
// it to the cache. If it is already in the cache, then leave it there.
if (statement == null || !statement.mInCache) {
nativeFinalizeStatement(mConnectionPtr, statementPtr);
}
throw ex;
}
statement.mInUse = true;
return statement;
}
private void releasePreparedStatement(PreparedStatement statement) {
statement.mInUse = false;
if (statement.mInCache) {
try {
nativeResetStatementAndClearBindings(mConnectionPtr, statement.mStatementPtr);
} catch (SQLiteException ex) {
// The statement could not be reset due to an error. Remove it from the cache.
// When remove() is called, the cache will invoke its entryRemoved() callback,
// which will in turn call finalizePreparedStatement() to finalize and
// recycle the statement.
if (DEBUG) {
Log.d(TAG, "Could not reset prepared statement due to an exception. "
+ "Removing it from the cache. SQL: "
+ trimSqlForDisplay(statement.mSql), ex);
}
mPreparedStatementCache.remove(statement.mSql);
}
} else {
finalizePreparedStatement(statement);
}
}
private void finalizePreparedStatement(PreparedStatement statement) {
nativeFinalizeStatement(mConnectionPtr, statement.mStatementPtr);
recyclePreparedStatement(statement);
}
private void attachCancellationSignal(CancellationSignal cancellationSignal) {
if (cancellationSignal != null) {
cancellationSignal.throwIfCanceled();
mCancellationSignalAttachCount += 1;
if (mCancellationSignalAttachCount == 1) {
// Reset cancellation flag before executing the statement.
nativeResetCancel(mConnectionPtr, true /*cancelable*/);
// After this point, onCancel() may be called concurrently.
cancellationSignal.setOnCancelListener(this);
}
}
}
private void detachCancellationSignal(CancellationSignal cancellationSignal) {
if (cancellationSignal != null) {
assert mCancellationSignalAttachCount > 0;
mCancellationSignalAttachCount -= 1;
if (mCancellationSignalAttachCount == 0) {
// After this point, onCancel() cannot be called concurrently.
cancellationSignal.setOnCancelListener(null);
// Reset cancellation flag after executing the statement.
nativeResetCancel(mConnectionPtr, false /*cancelable*/);
}
}
}
// CancellationSignal.OnCancelListener callback.
// This method may be called on a different thread than the executing statement.
// However, it will only be called between calls to attachCancellationSignal and
// detachCancellationSignal, while a statement is executing. We can safely assume
// that the SQLite connection is still alive.
@Override
public void onCancel() {
nativeCancel(mConnectionPtr);
}
private void bindArguments(PreparedStatement statement, Object[] bindArgs) {
final int count = bindArgs != null ? bindArgs.length : 0;
if (count != statement.mNumParameters) {
throw new SQLiteBindOrColumnIndexOutOfRangeException(
"Expected " + statement.mNumParameters + " bind arguments but "
+ count + " were provided.");
}
if (count == 0) {
return;
}
final long statementPtr = statement.mStatementPtr;
for (int i = 0; i < count; i++) {
final Object arg = bindArgs[i];
switch (DatabaseUtils.getTypeOfObject(arg)) {
case Cursor.FIELD_TYPE_NULL:
nativeBindNull(mConnectionPtr, statementPtr, i + 1);
break;
case Cursor.FIELD_TYPE_INTEGER:
nativeBindLong(mConnectionPtr, statementPtr, i + 1,
((Number)arg).longValue());
break;
case Cursor.FIELD_TYPE_FLOAT:
nativeBindDouble(mConnectionPtr, statementPtr, i + 1,
((Number)arg).doubleValue());
break;
case Cursor.FIELD_TYPE_BLOB:
nativeBindBlob(mConnectionPtr, statementPtr, i + 1, (byte[])arg);
break;
case Cursor.FIELD_TYPE_STRING:
default:
if (arg instanceof Boolean) {
// Provide compatibility with legacy applications which may pass
// Boolean values in bind args.
nativeBindLong(mConnectionPtr, statementPtr, i + 1,
((Boolean)arg).booleanValue() ? 1 : 0);
} else {
nativeBindString(mConnectionPtr, statementPtr, i + 1, arg.toString());
}
break;
}
}
}
private void throwIfStatementForbidden(PreparedStatement statement) {
if (mOnlyAllowReadOnlyOperations && !statement.mReadOnly) {
throw new SQLiteException("Cannot execute this statement because it "
+ "might modify the database but the connection is read-only.");
}
}
private static boolean isCacheable(int statementType) {
if (statementType == DatabaseUtils.STATEMENT_UPDATE
|| statementType == DatabaseUtils.STATEMENT_SELECT) {
return true;
}
return false;
}
private void applyBlockGuardPolicy(PreparedStatement statement) {
if (!mConfiguration.isInMemoryDb()) {
if (statement.mReadOnly) {
BlockGuard.getThreadPolicy().onReadFromDisk();
} else {
BlockGuard.getThreadPolicy().onWriteToDisk();
}
}
}
/**
* Dumps debugging information about this connection.
*
* @param printer The printer to receive the dump, not null.
* @param verbose True to dump more verbose information.
*/
public void dump(Printer printer, boolean verbose) {
dumpUnsafe(printer, verbose);
}
/**
* Dumps debugging information about this connection, in the case where the
* caller might not actually own the connection.
*
* This function is written so that it may be called by a thread that does not
* own the connection. We need to be very careful because the connection state is
* not synchronized.
*
* At worst, the method may return stale or slightly wrong data, however
* it should not crash. This is ok as it is only used for diagnostic purposes.
*
* @param printer The printer to receive the dump, not null.
* @param verbose True to dump more verbose information.
*/
void dumpUnsafe(Printer printer, boolean verbose) {
printer.println("Connection #" + mConnectionId + ":");
if (verbose) {
printer.println(" connectionPtr: 0x" + Long.toHexString(mConnectionPtr));
}
printer.println(" isPrimaryConnection: " + mIsPrimaryConnection);
printer.println(" onlyAllowReadOnlyOperations: " + mOnlyAllowReadOnlyOperations);
mRecentOperations.dump(printer, verbose);
if (verbose) {
mPreparedStatementCache.dump(printer);
}
}
/**
* Describes the currently executing operation, in the case where the
* caller might not actually own the connection.
*
* This function is written so that it may be called by a thread that does not
* own the connection. We need to be very careful because the connection state is
* not synchronized.
*
* At worst, the method may return stale or slightly wrong data, however
* it should not crash. This is ok as it is only used for diagnostic purposes.
*
* @return A description of the current operation including how long it has been running,
* or null if none.
*/
String describeCurrentOperationUnsafe() {
return mRecentOperations.describeCurrentOperation();
}
/**
* Collects statistics about database connection memory usage.
*
* @param dbStatsList The list to populate.
*/
void collectDbStats(ArrayList<DbStats> dbStatsList) {
// Get information about the main database.
int lookaside = nativeGetDbLookaside(mConnectionPtr);
long pageCount = 0;
long pageSize = 0;
try {
pageCount = executeForLong("PRAGMA page_count;", null, null);
pageSize = executeForLong("PRAGMA page_size;", null, null);
} catch (SQLiteException ex) {
// Ignore.
}
dbStatsList.add(getMainDbStatsUnsafe(lookaside, pageCount, pageSize));
// Get information about attached databases.
// We ignore the first row in the database list because it corresponds to
// the main database which we have already described.
CursorWindow window = new CursorWindow("collectDbStats");
try {
executeForCursorWindow("PRAGMA database_list;", null, window, 0, 0, false, null);
for (int i = 1; i < window.getNumRows(); i++) {
String name = window.getString(i, 1);
String path = window.getString(i, 2);
pageCount = 0;
pageSize = 0;
try {
pageCount = executeForLong("PRAGMA " + name + ".page_count;", null, null);
pageSize = executeForLong("PRAGMA " + name + ".page_size;", null, null);
} catch (SQLiteException ex) {
// Ignore.
}
String label = " (attached) " + name;
if (!path.isEmpty()) {
label += ": " + path;
}
dbStatsList.add(new DbStats(label, pageCount, pageSize, 0, 0, 0, 0));
}
} catch (SQLiteException ex) {
// Ignore.
} finally {
window.close();
}
}
/**
* Collects statistics about database connection memory usage, in the case where the
* caller might not actually own the connection.
*
* @return The statistics object, never null.
*/
void collectDbStatsUnsafe(ArrayList<DbStats> dbStatsList) {
dbStatsList.add(getMainDbStatsUnsafe(0, 0, 0));
}
private DbStats getMainDbStatsUnsafe(int lookaside, long pageCount, long pageSize) {
// The prepared statement cache is thread-safe so we can access its statistics
// even if we do not own the database connection.
String label = mConfiguration.path;
if (!mIsPrimaryConnection) {
label += " (" + mConnectionId + ")";
}
return new DbStats(label, pageCount, pageSize, lookaside,
mPreparedStatementCache.hitCount(),
mPreparedStatementCache.missCount(),
mPreparedStatementCache.size());
}
@Override
public String toString() {
return "SQLiteConnection: " + mConfiguration.path + " (" + mConnectionId + ")";
}
private PreparedStatement obtainPreparedStatement(String sql, long statementPtr,
int numParameters, int type, boolean readOnly) {
PreparedStatement statement = mPreparedStatementPool;
if (statement != null) {
mPreparedStatementPool = statement.mPoolNext;
statement.mPoolNext = null;
statement.mInCache = false;
} else {
statement = new PreparedStatement();
}
statement.mSql = sql;
statement.mStatementPtr = statementPtr;
statement.mNumParameters = numParameters;
statement.mType = type;
statement.mReadOnly = readOnly;
return statement;
}
private void recyclePreparedStatement(PreparedStatement statement) {
statement.mSql = null;
statement.mPoolNext = mPreparedStatementPool;
mPreparedStatementPool = statement;
}
private static String trimSqlForDisplay(String sql) {
return TRIM_SQL_PATTERN.matcher(sql).replaceAll(" ");
}
/**
* Holder type for a prepared statement.
*
* Although this object holds a pointer to a native statement object, it
* does not have a finalizer. This is deliberate. The {@link SQLiteConnection}
* owns the statement object and will take care of freeing it when needed.
* In particular, closing the connection requires a guarantee of deterministic
* resource disposal because all native statement objects must be freed before
* the native database object can be closed. So no finalizers here.
*/
private static final class PreparedStatement {
// Next item in pool.
public PreparedStatement mPoolNext;
// The SQL from which the statement was prepared.
public String mSql;
// The native sqlite3_stmt object pointer.
// Lifetime is managed explicitly by the connection.
public long mStatementPtr;
// The number of parameters that the prepared statement has.
public int mNumParameters;
// The statement type.
public int mType;
// True if the statement is read-only.
public boolean mReadOnly;
// True if the statement is in the cache.
public boolean mInCache;
// True if the statement is in use (currently executing).
// We need this flag because due to the use of custom functions in triggers, it's
// possible for SQLite calls to be re-entrant. Consequently we need to prevent
// in use statements from being finalized until they are no longer in use.
public boolean mInUse;
}
private final class PreparedStatementCache
extends LruCache<String, PreparedStatement> {
public PreparedStatementCache(int size) {
super(size);
}
@Override
protected void entryRemoved(boolean evicted, String key,
PreparedStatement oldValue, PreparedStatement newValue) {
oldValue.mInCache = false;
if (!oldValue.mInUse) {
finalizePreparedStatement(oldValue);
}
}
public void dump(Printer printer) {
printer.println(" Prepared statement cache:");
Map<String, PreparedStatement> cache = snapshot();
if (!cache.isEmpty()) {
int i = 0;
for (Map.Entry<String, PreparedStatement> entry : cache.entrySet()) {
PreparedStatement statement = entry.getValue();
if (statement.mInCache) { // might be false due to a race with entryRemoved
String sql = entry.getKey();
printer.println(" " + i + ": statementPtr=0x"
+ Long.toHexString(statement.mStatementPtr)
+ ", numParameters=" + statement.mNumParameters
+ ", type=" + statement.mType
+ ", readOnly=" + statement.mReadOnly
+ ", sql=\"" + trimSqlForDisplay(sql) + "\"");
}
i += 1;
}
} else {
printer.println(" <none>");
}
}
}
private static final class OperationLog {
private static final int MAX_RECENT_OPERATIONS = 20;
private static final int COOKIE_GENERATION_SHIFT = 8;
private static final int COOKIE_INDEX_MASK = 0xff;
private final Operation[] mOperations = new Operation[MAX_RECENT_OPERATIONS];
private int mIndex;
private int mGeneration;
public int beginOperation(String kind, String sql, Object[] bindArgs) {
synchronized (mOperations) {
final int index = (mIndex + 1) % MAX_RECENT_OPERATIONS;
Operation operation = mOperations[index];
if (operation == null) {
operation = new Operation();
mOperations[index] = operation;
} else {
operation.mFinished = false;
operation.mException = null;
if (operation.mBindArgs != null) {
operation.mBindArgs.clear();
}
}
operation.mStartTime = System.currentTimeMillis();
operation.mKind = kind;
operation.mSql = sql;
if (bindArgs != null) {
if (operation.mBindArgs == null) {
operation.mBindArgs = new ArrayList<Object>();
} else {
operation.mBindArgs.clear();
}
for (int i = 0; i < bindArgs.length; i++) {
final Object arg = bindArgs[i];
if (arg != null && arg instanceof byte[]) {
// Don't hold onto the real byte array longer than necessary.
operation.mBindArgs.add(EMPTY_BYTE_ARRAY);
} else {
operation.mBindArgs.add(arg);
}
}
}
operation.mCookie = newOperationCookieLocked(index);
mIndex = index;
return operation.mCookie;
}
}
public void failOperation(int cookie, Exception ex) {
synchronized (mOperations) {
final Operation operation = getOperationLocked(cookie);
if (operation != null) {
operation.mException = ex;
}
}
}
public void endOperation(int cookie) {
synchronized (mOperations) {
if (endOperationDeferLogLocked(cookie)) {
logOperationLocked(cookie, null);
}
}
}
public boolean endOperationDeferLog(int cookie) {
synchronized (mOperations) {
return endOperationDeferLogLocked(cookie);
}
}
public void logOperation(int cookie, String detail) {
synchronized (mOperations) {
logOperationLocked(cookie, detail);
}
}
private boolean endOperationDeferLogLocked(int cookie) {
final Operation operation = getOperationLocked(cookie);
if (operation != null) {
operation.mEndTime = System.currentTimeMillis();
operation.mFinished = true;
return SQLiteDebug.DEBUG_LOG_SLOW_QUERIES && SQLiteDebug.shouldLogSlowQuery(
operation.mEndTime - operation.mStartTime);
}
return false;
}
private void logOperationLocked(int cookie, String detail) {
final Operation operation = getOperationLocked(cookie);
StringBuilder msg = new StringBuilder();
operation.describe(msg, false);
if (detail != null) {
msg.append(", ").append(detail);
}
Log.d(TAG, msg.toString());
}
private int newOperationCookieLocked(int index) {
final int generation = mGeneration++;
return generation << COOKIE_GENERATION_SHIFT | index;
}
private Operation getOperationLocked(int cookie) {
final int index = cookie & COOKIE_INDEX_MASK;
final Operation operation = mOperations[index];
return operation.mCookie == cookie ? operation : null;
}
public String describeCurrentOperation() {
synchronized (mOperations) {
final Operation operation = mOperations[mIndex];
if (operation != null && !operation.mFinished) {
StringBuilder msg = new StringBuilder();
operation.describe(msg, false);
return msg.toString();
}
return null;
}
}
public void dump(Printer printer, boolean verbose) {
synchronized (mOperations) {
printer.println(" Most recently executed operations:");
int index = mIndex;
Operation operation = mOperations[index];
if (operation != null) {
int n = 0;
do {
StringBuilder msg = new StringBuilder();
msg.append(" ").append(n).append(": [");
msg.append(operation.getFormattedStartTime());
msg.append("] ");
operation.describe(msg, verbose);
printer.println(msg.toString());
if (index > 0) {
index -= 1;
} else {
index = MAX_RECENT_OPERATIONS - 1;
}
n += 1;
operation = mOperations[index];
} while (operation != null && n < MAX_RECENT_OPERATIONS);
} else {
printer.println(" <none>");
}
}
}
}
private static final class Operation {
private static final SimpleDateFormat sDateFormat =
new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
public long mStartTime;
public long mEndTime;
public String mKind;
public String mSql;
public ArrayList<Object> mBindArgs;
public boolean mFinished;
public Exception mException;
public int mCookie;
public void describe(StringBuilder msg, boolean verbose) {
msg.append(mKind);
if (mFinished) {
msg.append(" took ").append(mEndTime - mStartTime).append("ms");
} else {
msg.append(" started ").append(System.currentTimeMillis() - mStartTime)
.append("ms ago");
}
msg.append(" - ").append(getStatus());
if (mSql != null) {
msg.append(", sql=\"").append(trimSqlForDisplay(mSql)).append("\"");
}
if (verbose && mBindArgs != null && mBindArgs.size() != 0) {
msg.append(", bindArgs=[");
final int count = mBindArgs.size();
for (int i = 0; i < count; i++) {
final Object arg = mBindArgs.get(i);
if (i != 0) {
msg.append(", ");
}
if (arg == null) {
msg.append("null");
} else if (arg instanceof byte[]) {
msg.append("<byte[]>");
} else if (arg instanceof String) {
msg.append("\"").append((String)arg).append("\"");
} else {
msg.append(arg);
}
}
msg.append("]");
}
if (mException != null) {
msg.append(", exception=\"").append(mException.getMessage()).append("\"");
}
}
private String getStatus() {
if (!mFinished) {
return "running";
}
return mException != null ? "failed" : "succeeded";
}
private String getFormattedStartTime() {
return sDateFormat.format(new Date(mStartTime));
}
}
}
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