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Commit 48733910 authored by Shai Barack's avatar Shai Barack
Browse files

Aggregate prepared statement cache stats from individual connections. 

Previously, prepared statement cache statistics were tracked globally within `SQLiteConnectionPool`. This change moves the tracking to individual `SQLiteConnection` instances and aggregates these statistics when `collectDbStats` is called on the pool. This provides more accurate per-connection stats and a better overall picture of cache usage across all connections in the pool.

This also corrects the definition of prepared statement cache.

Bug: 440440268
Flag: EXEMPT refactor
Change-Id: Ic2a399a8d033a5a9ca1a02a7ab9ce0598ac44ae8
parent 3bd6739d

apct-tests/perftests/core/src/android/database/SQLiteDatabasePerfTest.java

+0 −5
Original line number Diff line number Diff line
@@ -141,11 +141,6 @@ public class SQLiteDatabasePerfTest { 
            }

        }



        Log.d("testSelectMemory",

                "cacheMissRate: " + mDatabase.getStatementCacheMissRate()

                        + "Total Statements: " + mDatabase.getTotalPreparedStatements()

                        + ". Misses: " + mDatabase.getTotalStatementCacheMisses());



        // Make sure caching is working and our miss rate should definitely be less than 100%

        // however, we would expect this number to be actually closer to 0.

        assertTrue(mDatabase.getStatementCacheMissRate() < 1);

core/java/android/database/sqlite/SQLiteConnection.java

+15 −5
Original line number Diff line number Diff line
@@ -1080,7 +1080,6 @@ public final class SQLiteConnection implements CancellationSignal.OnCancelListen 
     * Return a {@link #PreparedStatement}, possibly from the cache.

     */

    private PreparedStatement acquirePreparedStatementLI(String sql) {

        ++mPool.mTotalPrepareStatements;

        PreparedStatement statement = mPreparedStatementCache.getStatement(sql);

        long seqNum = mPreparedStatementCache.getLastSeqNum();
@@ -1105,7 +1104,6 @@ public final class SQLiteConnection implements CancellationSignal.OnCancelListen 
                skipCache = true;

            }

        }

        ++mPool.mTotalPrepareStatementCacheMiss;

        final long statementPtr = mPreparedStatementCache.createStatement(sql);

        seqNum = mPreparedStatementCache.getLastSeqNum();

        try {
@@ -1441,9 +1439,21 @@ public final class SQLiteConnection implements CancellationSignal.OnCancelListen 
        } else {

            label = mConfiguration.path + " (" + mConnectionId + ")";

        }

        return new DbStats(label, pageCount, pageSize, lookaside,

                mPreparedStatementCache.hitCount(), mPreparedStatementCache.missCount(),

                mPreparedStatementCache.size(), false);

        DbStats dbStats = new DbStats(label, pageCount, pageSize, lookaside, 0, 0, 0, false);

        dbStats.addCacheStatsFrom(this);

        return dbStats;

    }



    int getPreparedStatementCacheHitCount() {

        return mPreparedStatementCache.hitCount();

    }



    int getPreparedStatementCacheMissCount() {

        return mPreparedStatementCache.missCount();

    }



    int getPreparedStatementCacheSize() {

        return mPreparedStatementCache.size();

    }



    @Override

core/java/android/database/sqlite/SQLiteConnectionPool.java

+22 −10
Original line number Diff line number Diff line
@@ -109,10 +109,6 @@ public final class SQLiteConnectionPool implements Closeable { 
            new ArrayList<SQLiteConnection>();

    private SQLiteConnection mAvailablePrimaryConnection;



    // Prepare statement cache statistics

    public int mTotalPrepareStatementCacheMiss = 0;

    public int mTotalPrepareStatements = 0;



    @GuardedBy("mLock")

    private IdleConnectionHandler mIdleConnectionHandler;
@@ -528,9 +524,15 @@ public final class SQLiteConnectionPool implements Closeable { 
            }



            // Global pool stats

            DbStats poolStats = new DbStats(mConfiguration.path, 0, 0, 0,

                    mTotalPrepareStatements - mTotalPrepareStatementCacheMiss,

                    mTotalPrepareStatementCacheMiss, mTotalPrepareStatements, true);

            DbStats poolStats = new DbStats(mConfiguration.path, 0, 0, 0, 0, 0, 0, true);



            if (mAvailablePrimaryConnection != null) {

                poolStats.addCacheStatsFrom(mAvailablePrimaryConnection);

            }

            for (SQLiteConnection connection : mAvailableNonPrimaryConnections) {

                poolStats.addCacheStatsFrom(connection);

            }



            dbStatsList.add(poolStats);

        }

    }
@@ -1246,11 +1248,21 @@ public final class SQLiteConnectionPool implements Closeable { 
    /** @hide */

    @NeverCompile

    public double getStatementCacheMissRate() {

        if (mTotalPrepareStatements == 0) {

            // no statements executed thus no miss rate.

        int cacheHits = 0;

        int cacheMisses = 0;



        if (mAvailablePrimaryConnection != null) {

            cacheHits += mAvailablePrimaryConnection.getPreparedStatementCacheHitCount();

            cacheMisses += mAvailablePrimaryConnection.getPreparedStatementCacheMissCount();

        }

        for (SQLiteConnection connection : mAvailableNonPrimaryConnections) {

            cacheHits += connection.getPreparedStatementCacheHitCount();

            cacheMisses += connection.getPreparedStatementCacheMissCount();

        }

        if (cacheMisses == 0) {

            return 0;

        }

        return (double) mTotalPrepareStatementCacheMiss / (double) mTotalPrepareStatements;

        return (double) cacheMisses / (double) (cacheHits + cacheMisses);

    }



    public long getTotalStatementsTime() {

core/java/android/database/sqlite/SQLiteDatabase.java

+0 −16
Original line number Diff line number Diff line
@@ -2725,22 +2725,6 @@ public final class SQLiteDatabase extends SQLiteClosable { 
        return connectionPools;

    }



    /** @hide */

    @NeverCompile

    public int getTotalPreparedStatements() {

        throwIfNotOpenLocked();



        return mConnectionPoolLocked.mTotalPrepareStatements;

    }



    /** @hide */

    @NeverCompile

    public int getTotalStatementCacheMisses() {

        throwIfNotOpenLocked();



        return mConnectionPoolLocked.mTotalPrepareStatementCacheMiss;

    }



    /**

     * Dump detailed information about all open databases in the current process.

     * Used by bug report.

core/java/android/database/sqlite/SQLiteDebug.java

+9 −3
Original line number Diff line number Diff line
@@ -182,11 +182,11 @@ public final class SQLiteDebug { 
        public int lookaside;



        /** @hide */

        final public int cacheHits;

        public int cacheHits;

        /** @hide */

        final public int cacheMisses;

        public int cacheMisses;

        /** @hide */

        final public int cacheSize;

        public int cacheSize;



        /** true if connection specific stats or whole connection pool if false */

        public final boolean arePoolStats;
@@ -202,6 +202,12 @@ public final class SQLiteDebug { 
            this.cacheSize = cachesize;

            this.arePoolStats = arePoolStats;

        }



        void addCacheStatsFrom(SQLiteConnection connection) {

            cacheHits += connection.getPreparedStatementCacheHitCount();

            cacheMisses += connection.getPreparedStatementCacheMissCount();

            cacheSize += connection.getPreparedStatementCacheSize();

        }

    }



    /**