xref: /frameworks/base/core/jni/android_database_SQLiteConnection.cpp

/*
 * 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.
 */

#define LOG_TAG "SQLiteConnection"

#include <jni.h>
#include <JNIHelp.h>
#include <android_runtime/AndroidRuntime.h>
#include <android_runtime/Log.h>

#include <utils/Log.h>
#include <utils/String8.h>
#include <utils/String16.h>
#include <cutils/ashmem.h>
#include <sys/mman.h>

#include <string.h>
#include <unistd.h>

#include <androidfw/CursorWindow.h>

#include <sqlite3.h>
#include <sqlite3_android.h>

#include "android_database_SQLiteCommon.h"

#include "core_jni_helpers.h"

// Set to 1 to use UTF16 storage for localized indexes.
#define UTF16_STORAGE 0

namespace android {

/* Busy timeout in milliseconds.
 * If another connection (possibly in another process) has the database locked for
 * longer than this amount of time then SQLite will generate a SQLITE_BUSY error.
 * The SQLITE_BUSY error is then raised as a SQLiteDatabaseLockedException.
 *
 * In ordinary usage, busy timeouts are quite rare.  Most databases only ever
 * have a single open connection at a time unless they are using WAL.  When using
 * WAL, a timeout could occur if one connection is busy performing an auto-checkpoint
 * operation.  The busy timeout needs to be long enough to tolerate slow I/O write
 * operations but not so long as to cause the application to hang indefinitely if
 * there is a problem acquiring a database lock.
 */
static const int BUSY_TIMEOUT_MS = 2500;

static struct {
    jfieldID name;
    jfieldID numArgs;
    jmethodID dispatchCallback;
} gSQLiteCustomFunctionClassInfo;

static struct {
    jclass clazz;
} gStringClassInfo;

struct SQLiteConnection {
    // Open flags.
    // Must be kept in sync with the constants defined in SQLiteDatabase.java.
    enum {
        OPEN_READWRITE          = 0x00000000,
        OPEN_READONLY           = 0x00000001,
        OPEN_READ_MASK          = 0x00000001,
        NO_LOCALIZED_COLLATORS  = 0x00000010,
        CREATE_IF_NECESSARY     = 0x10000000,
    };

    sqlite3* const db;
    const int openFlags;
    const String8 path;
    const String8 label;

    volatile bool canceled;

    SQLiteConnection(sqlite3* db, int openFlags, const String8& path, const String8& label) :
        db(db), openFlags(openFlags), path(path), label(label), canceled(false) { }
};

// Called each time a statement begins execution, when tracing is enabled.
static void sqliteTraceCallback(void *data, const char *sql) {