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for memory databases, don't set journal_mode and don't allow WAL

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WAL and journal_mode are not applicable to memory databases

Change-Id: I06fcbfe9ce76878c57d1542efe9cc060598262ff
This commit is contained in:
Vasu Nori
2010-06-22 13:16:35 -07:00
parent 5666170c1e
commit a98cb2632d
1 changed files with 30 additions and 26 deletions
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56
core/java/android/database/sqlite/SQLiteDatabase.java
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@@ -341,6 +341,8 @@ public class SQLiteDatabase extends SQLiteClosable {
*/
/* package */ final short mConnectionNum;
private static final String MEMORY_DB_PATH = ":memory:";
/**
* @param closable
*/
@@ -955,16 +957,7 @@ public class SQLiteDatabase extends SQLiteClosable {
sBlockSize = new StatFs("/data").getBlockSize();
}
sqliteDatabase.setPageSize(sBlockSize);
// set journal_mode to truncate for non-memory databases
if (!path.equalsIgnoreCase(":memory:")) {
String s = DatabaseUtils.stringForQuery(sqliteDatabase, "PRAGMA journal_mode=TRUNCATE",
null);
if (!s.equalsIgnoreCase("TRUNCATE")) {
Log.e(TAG, "setting journal_mode to TRUNCATE failed for db: " + path +
" (on pragma set journal_mode, sqlite returned:" + s);
}
}
sqliteDatabase.setJournalMode(path, "TRUNCATE");
// add this database to the list of databases opened in this process
ActiveDatabases.addActiveDatabase(sqliteDatabase);
@@ -1017,6 +1010,17 @@ public class SQLiteDatabase extends SQLiteClosable {
return openDatabase(path, factory, CREATE_IF_NECESSARY, errorHandler);
}
private void setJournalMode(final String dbPath, final String mode) {
// journal mode can be set only for non-memory databases
if (!dbPath.equalsIgnoreCase(MEMORY_DB_PATH)) {
String s = DatabaseUtils.stringForQuery(this, "PRAGMA journal_mode=" + mode, null);
if (!s.equalsIgnoreCase(mode)) {
Log.e(TAG, "setting journal_mode to " + mode + " failed for db: " + dbPath +
" (on pragma set journal_mode, sqlite returned:" + s);
}
}
}
/**
* Create a memory backed SQLite database. Its contents will be destroyed
* when the database is closed.
@@ -1030,7 +1034,7 @@ public class SQLiteDatabase extends SQLiteClosable {
*/
public static SQLiteDatabase create(CursorFactory factory) {
// This is a magic string with special meaning for SQLite.
return openDatabase(":memory:", factory, CREATE_IF_NECESSARY);
return openDatabase(MEMORY_DB_PATH, factory, CREATE_IF_NECESSARY);
}
/**
@@ -2300,10 +2304,12 @@ public class SQLiteDatabase extends SQLiteClosable {
* <p>
* If a query is part of a transaction, then it is executed on the same database handle the
* transaction was begun.
*
* <p>
* If the database has any attached databases, then execution of queries in paralel is NOT
* possible. In such cases, {@link IllegalStateException} is thrown.
* possible. In such cases, a message is printed to logcat and false is returned.
* <p>
* This feature is not available for :memory: databases. In such cases,
* a message is printed to logcat and false is returned.
* <p>
* A typical way to use this method is the following:
* <pre>
@@ -2318,27 +2324,25 @@ public class SQLiteDatabase extends SQLiteClosable {
* Non-exclusive mode allows database file to be in readable by threads executing queries.
* </p>
*
* @throws IllegalStateException thrown if the database has any attached databases.
* @return true if write-ahead-logging is set. false otherwise
*/
public synchronized void enableWriteAheadLogging() {
if (mConnectionPool != null) {
// connection pool already setup.
return;
public synchronized boolean enableWriteAheadLogging() {
if (mPath.equalsIgnoreCase(MEMORY_DB_PATH)) {
Log.i(TAG, "can't enable WAL for memory databases.");
return false;
}
// make sure this database has NO attached databases because sqlite's write-ahead-logging
// doesn't work for databases with attached databases
if (getAttachedDbs().size() > 1) {
throw new IllegalStateException("this database: " + mPath +
" has attached databases. can't do execution of of queries in parallel.");
Log.i(TAG, "this database: " + mPath + " has attached databases. can't enable WAL.");
return false;
}
mConnectionPool = new DatabaseConnectionPool(this);
// set journal_mode to WAL
String s = DatabaseUtils.stringForQuery(this, "PRAGMA journal_mode=WAL", null);
if (!s.equalsIgnoreCase("WAL")) {
Log.e(TAG, "setting journal_mode to WAL failed");
if (mConnectionPool == null) {
mConnectionPool = new DatabaseConnectionPool(this);
setJournalMode(mPath, "WAL");
}
return true;
}
/**