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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #define LOG_TAG "SQLiteGlobal"
     18 
     19 #include <jni.h>
     20 #include <JNIHelp.h>
     21 #include <android_runtime/AndroidRuntime.h>
     22 
     23 #include <sqlite3.h>
     24 #include <sqlite3_android.h>
     25 
     26 #include "android_database_SQLiteCommon.h"
     27 #include "android_util_Log.h"
     28 
     29 namespace android {
     30 
     31 // Limit heap to 8MB for now.  This is 4 times the maximum cursor window
     32 // size, as has been used by the original code in SQLiteDatabase for
     33 // a long time.
     34 static const int SOFT_HEAP_LIMIT = 8 * 1024 * 1024;
     35 
     36 
     37 // Called each time a message is logged.
     38 static void sqliteLogCallback(void* data, int iErrCode, const char* zMsg) {
     39     bool verboseLog = !!data;
     40     if (iErrCode == 0 || iErrCode == SQLITE_CONSTRAINT || iErrCode == SQLITE_SCHEMA) {
     41         if (verboseLog) {
     42             ALOG(LOG_VERBOSE, SQLITE_LOG_TAG, "(%d) %s\n", iErrCode, zMsg);
     43         }
     44     } else {
     45         ALOG(LOG_ERROR, SQLITE_LOG_TAG, "(%d) %s\n", iErrCode, zMsg);
     46     }
     47 }
     48 
     49 // Sets the global SQLite configuration.
     50 // This must be called before any other SQLite functions are called.
     51 static void sqliteInitialize() {
     52     // Enable multi-threaded mode.  In this mode, SQLite is safe to use by multiple
     53     // threads as long as no two threads use the same database connection at the same
     54     // time (which we guarantee in the SQLite database wrappers).
     55     sqlite3_config(SQLITE_CONFIG_MULTITHREAD);
     56 
     57     // Redirect SQLite log messages to the Android log.
     58     bool verboseLog = android_util_Log_isVerboseLogEnabled(SQLITE_LOG_TAG);
     59     sqlite3_config(SQLITE_CONFIG_LOG, &sqliteLogCallback, verboseLog ? (void*)1 : NULL);
     60 
     61     // The soft heap limit prevents the page cache allocations from growing
     62     // beyond the given limit, no matter what the max page cache sizes are
     63     // set to. The limit does not, as of 3.5.0, affect any other allocations.
     64     sqlite3_soft_heap_limit(SOFT_HEAP_LIMIT);
     65 
     66     // Initialize SQLite.
     67     sqlite3_initialize();
     68 }
     69 
     70 static jint nativeReleaseMemory(JNIEnv* env, jclass clazz) {
     71     return sqlite3_release_memory(SOFT_HEAP_LIMIT);
     72 }
     73 
     74 static JNINativeMethod sMethods[] =
     75 {
     76     /* name, signature, funcPtr */
     77     { "nativeReleaseMemory", "()I",
     78             (void*)nativeReleaseMemory },
     79 };
     80 
     81 int register_android_database_SQLiteGlobal(JNIEnv *env)
     82 {
     83     sqliteInitialize();
     84 
     85     return AndroidRuntime::registerNativeMethods(env, "android/database/sqlite/SQLiteGlobal",
     86             sMethods, NELEM(sMethods));
     87 }
     88 
     89 } // namespace android
     90