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Merge "unittests for DatabaseConnectionPool (and fix bugs)"

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This commit is contained in:
Vasu Nori
2010-07-07 14:27:43 -07:00
committed by Android (Google) Code Review
parent c9880beb2d 6ac21d30be
commit 7fbee2f73e
2 changed files with 449 additions and 33 deletions
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118
core/java/android/database/sqlite/DatabaseConnectionPool.java
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@@ -48,6 +48,9 @@ import java.util.Random;
/** the main database connection to which this connection pool is attached */
private final SQLiteDatabase mParentDbObj;
/** Random number generator used to pick a free connection out of the pool */
private Random rand; // lazily initialized
/* package */ DatabaseConnectionPool(SQLiteDatabase db) {
this.mParentDbObj = db;
if (Log.isLoggable(TAG, Log.DEBUG)) {
@@ -75,50 +78,67 @@ import java.util.Random;
* @return the Database connection that the caller can use
*/
/* package */ SQLiteDatabase get(String sql) {
if (Log.isLoggable(TAG, Log.DEBUG)) {
doAsserts();
}
SQLiteDatabase db = null;
PoolObj poolObj = null;
synchronized(mParentDbObj) {
int poolSize = mPool.size();
if (Log.isLoggable(TAG, Log.DEBUG)) {
assert sql != null;
doAsserts();
}
if (getFreePoolSize() == 0) {
if (mMaxPoolSize == mPool.size()) {
// no free ( = available) connections
if (mMaxPoolSize == poolSize) {
// maxed out. can't open any more connections.
// let the caller wait on one of the pooled connections
// preferably a connection caching the pre-compiled statement of the given SQL
if (mMaxPoolSize == 1) {
poolObj = mPool.get(0);
} else {
// get a random number between 0 and (mMaxPoolSize-1)
poolObj = mPool.get(
new Random(SystemClock.elapsedRealtime()).nextInt(mMaxPoolSize-1));
for (int i = 0; i < mMaxPoolSize; i++) {
if (mPool.get(i).mDb.isSqlInStatementCache(sql)) {
poolObj = mPool.get(i);
break;
}
}
if (poolObj == null) {
// there are no database connections with the given SQL pre-compiled.
// ok to return any of the connections.
if (rand == null) {
rand = new Random(SystemClock.elapsedRealtime());
}
poolObj = mPool.get(rand.nextInt(mMaxPoolSize));
}
}
db = poolObj.mDb;
} else {
// create a new connection and add it to the pool, since we haven't reached
// max pool size allowed
int poolSize = getPoolSize();
db = mParentDbObj.createPoolConnection((short)(poolSize + 1));
poolObj = new PoolObj(db);
mPool.add(poolSize, poolObj);
}
} else {
// there are free connections available. pick one
for (int i = mPool.size() - 1; i >= 0; i--) {
poolObj = mPool.get(i);
if (!poolObj.isFree()) {
continue;
}
// it is free - but does its database object already have the given sql in its
// statement-cache?
db = poolObj.mDb;
if (sql == null || db.isSqlInStatementCache(sql)) {
// found a free connection we can use
// preferably a connection caching the pre-compiled statement of the given SQL
for (int i = 0; i < poolSize; i++) {
if (mPool.get(i).isFree() && mPool.get(i).mDb.isSqlInStatementCache(sql)) {
poolObj = mPool.get(i);
break;
}
// haven't found a database object which has the given sql in its
// statement-cache
}
if (poolObj == null) {
// didn't find a free database connection with the given SQL already
// pre-compiled. return a free connection (this means, the same SQL could be
// pre-compiled on more than one database connection. potential wasted memory.)
for (int i = 0; i < poolSize; i++) {
if (mPool.get(i).isFree()) {
poolObj = mPool.get(i);
break;
}
}
}
db = poolObj.mDb;
}
assert poolObj != null;
@@ -181,13 +201,10 @@ import java.util.Random;
return list;
}
/* package */ int getPoolSize() {
synchronized(mParentDbObj) {
return mPool.size();
}
}
private int getFreePoolSize() {
/**
* package level access for testing purposes only. otherwise, private should be sufficient.
*/
/* package */ int getFreePoolSize() {
int count = 0;
for (int i = mPool.size() - 1; i >= 0; i--) {
if (mPool.get(i).isFree()) {
@@ -197,12 +214,29 @@ import java.util.Random;
return count++;
}
/**
* only for testing purposes
*/
/* package */ ArrayList<PoolObj> getPool() {
return mPool;
}
@Override
public String toString() {
return "db: " + mParentDbObj.getPath() +
", threadid = " + Thread.currentThread().getId() +
", totalsize = " + mPool.size() + ", #free = " + getFreePoolSize() +
", maxpoolsize = " + mMaxPoolSize;
StringBuilder buff = new StringBuilder();
buff.append("db: ");
buff.append(mParentDbObj.getPath());
buff.append(", totalsize = ");
buff.append(mPool.size());
buff.append(", #free = ");
buff.append(getFreePoolSize());
buff.append(", maxpoolsize = ");
buff.append(mMaxPoolSize);
for (PoolObj p : mPool) {
buff.append("\n");
buff.append(p.toString());
}
return buff.toString();
}
private void doAsserts() {
@@ -224,10 +258,21 @@ import java.util.Random;
}
}
/** only used for testing purposes. */
/* package */ boolean isDatabaseObjFree(SQLiteDatabase db) {
return mPool.get(db.mConnectionNum - 1).isFree();
}
/** only used for testing purposes. */
/* package */ int getSize() {
return mPool.size();
}
/**
* represents objects in the connection pool.
* package-level access for testing purposes only.
*/
private static class PoolObj {
/* package */ static class PoolObj {
private final SQLiteDatabase mDb;
private boolean mFreeBusyFlag = FREE;
@@ -289,6 +334,13 @@ import java.util.Random;
}
}
/**
* only for testing purposes
*/
/* package */ synchronized int getNumHolders() {
return mNumHolders;
}
@Override
public String toString() {
StringBuilder buff = new StringBuilder();