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Add support for update/commit/rollback event notifications (#350)
Using sqlite3_commit_hook, sqlite3_rollback_hook, and sqlite3_update_hook Co-authored-by: Moxie Marlinspike <[email protected]>
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+412
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lines changed

7 files changed

+412
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lines changed

‎src/main/java/org/sqlite/SQLiteCommitListener.java

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package org.sqlite;
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/**
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* https://www.sqlite.org/c3ref/commit_hook.html
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*/
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public interface SQLiteCommitListener {
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void onCommit();
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void onRollback();
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}

‎src/main/java/org/sqlite/SQLiteConnection.java

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@@ -417,6 +417,42 @@ public void rollback() throws SQLException {
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db.exec(connectionConfig.transactionPrefix(), getAutoCommit());
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}
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/**
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* Add a listener for DB update events, see https://www.sqlite.org/c3ref/update_hook.html
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*
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* @param listener The listener to receive update events
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*/
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public void addUpdateListener(SQLiteUpdateListener listener) {
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db.addUpdateListener(listener);
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}
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/**
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* Remove a listener registered for DB update events.
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*
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* @param listener The listener to no longer receive update events
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*/
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public void removeUpdateListener(SQLiteUpdateListener listener) {
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db.removeUpdateListener(listener);
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}
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/**
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* Add a listener for DB commit/rollback events, see https://www.sqlite.org/c3ref/commit_hook.html
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*
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* @param listener The listener to receive commit events
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*/
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public void addCommitListener(SQLiteCommitListener listener) {
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db.addCommitListener(listener);
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}
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/**
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* Remove a listener registered for DB commit/rollback events.
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*
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* @param listener The listener to no longer receive commit/rollback events.
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*/
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public void removeCommitListener(SQLiteCommitListener listener) {
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db.removeCommitListener(listener);
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}
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/**
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* Extracts PRAGMA values from the filename and sets them into the Properties

‎src/main/java/org/sqlite/SQLiteUpdateListener.java

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package org.sqlite;
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/**
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* https://www.sqlite.org/c3ref/update_hook.html
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*/
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public interface SQLiteUpdateListener {
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public enum Type {
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INSERT, DELETE, UPDATE
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}
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void onUpdate(Type type, String database, String table, long rowId);
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}

‎src/main/java/org/sqlite/core/DB.java

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@@ -18,15 +18,19 @@
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import org.sqlite.BusyHandler;
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import org.sqlite.Function;
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import org.sqlite.ProgressHandler;
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import org.sqlite.SQLiteCommitListener;
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import org.sqlite.SQLiteConfig;
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import org.sqlite.SQLiteErrorCode;
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import org.sqlite.SQLiteException;
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import org.sqlite.SQLiteUpdateListener;
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import java.sql.BatchUpdateException;
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import java.sql.SQLException;
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import java.util.HashMap;
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import java.util.HashSet;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.Set;
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import java.util.concurrent.atomic.AtomicBoolean;
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/*
@@ -55,6 +59,9 @@ public abstract class DB implements Codes
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/** Tracer for statements to avoid unfinalized statements on db close. */
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private final Map<Long, CoreStatement> stmts = new HashMap<Long, CoreStatement>();
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private final Set<SQLiteUpdateListener> updateListeners = new HashSet<SQLiteUpdateListener>();
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private final Set<SQLiteCommitListener> commitListeners = new HashSet<SQLiteCommitListener>();
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public DB(String url, String fileName, SQLiteConfig config)
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throws SQLException
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{
@@ -901,6 +908,68 @@ public final synchronized int executeUpdate(CoreStatement stmt, Object[] vals) t
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return changes();
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}
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abstract void set_commit_listener(boolean enabled);
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abstract void set_update_listener(boolean enabled);
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public synchronized void addUpdateListener(SQLiteUpdateListener listener) {
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if (updateListeners.add(listener) && updateListeners.size() == 1) {
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set_update_listener(true);
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}
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}
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public synchronized void addCommitListener(SQLiteCommitListener listener) {
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if (commitListeners.add(listener) && commitListeners.size() == 1) {
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set_commit_listener(true);
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}
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}
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public synchronized void removeUpdateListener(SQLiteUpdateListener listener) {
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if (updateListeners.remove(listener) && updateListeners.isEmpty()) {
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set_update_listener(false);
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}
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}
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public synchronized void removeCommitListener(SQLiteCommitListener listener) {
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if (commitListeners.remove(listener) && commitListeners.isEmpty()) {
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set_commit_listener(false);
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}
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}
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void onUpdate(int type, String database, String table, long rowId) {
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Set<SQLiteUpdateListener> listeners;
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synchronized (this) {
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listeners = new HashSet<SQLiteUpdateListener>(updateListeners);
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}
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for (SQLiteUpdateListener listener : listeners) {
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SQLiteUpdateListener.Type operationType;
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switch (type) {
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case 18: operationType = SQLiteUpdateListener.Type.INSERT; break;
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case 9: operationType = SQLiteUpdateListener.Type.DELETE; break;
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case 23: operationType = SQLiteUpdateListener.Type.UPDATE; break;
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default: throw new AssertionError("Unknown type: " + type);
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}
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listener.onUpdate(operationType, database, table, rowId);
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}
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}
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void onCommit(boolean commit) {
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Set<SQLiteCommitListener> listeners;
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synchronized (this) {
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listeners = new HashSet<SQLiteCommitListener>(commitListeners);
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}
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for (SQLiteCommitListener listener : listeners) {
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if (commit) listener.onCommit();
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else listener.onRollback();
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}
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}
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/**
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* Throws SQLException with error message.
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* @throws SQLException

‎src/main/java/org/sqlite/core/NativeDB.c

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@@ -1328,7 +1328,6 @@ JNIEXPORT void JNICALL Java_org_sqlite_core_NativeDB_free_1functions(
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}
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}
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// COMPOUND FUNCTIONS ///////////////////////////////////////////////
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JNIEXPORT jobjectArray JNICALL Java_org_sqlite_core_NativeDB_column_1metadata(
@@ -1607,3 +1606,76 @@ JNIEXPORT void JNICALL Java_org_sqlite_core_NativeDB_clear_1progress_1handler(
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sqlite3_progress_handler(gethandle(env, this), 0, NULL, NULL);
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(*env)->DeleteGlobalRef(env, progress_handler_context.phandler);
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}
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// Update hook
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struct UpdateHandlerContext {
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JavaVM *vm;
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jmethodID method;
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jobject handler;
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};
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static struct UpdateHandlerContext update_handler_context;
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void update_hook(void *context, int type, char const *database, char const *table, sqlite3_int64 row) {
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JNIEnv *env = 0;
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(*update_handler_context.vm)->AttachCurrentThread(update_handler_context.vm, (void **)&env, 0);
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jstring databaseString = (*env)->NewStringUTF(env, database);
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jstring tableString = (*env)->NewStringUTF(env, table);
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(*env)->CallVoidMethod(env, update_handler_context.handler, update_handler_context.method, type, databaseString, tableString, row);
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(*env)->DeleteLocalRef(env, databaseString);
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(*env)->DeleteLocalRef(env, tableString);
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}
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JNIEXPORT void JNICALL Java_org_sqlite_core_NativeDB_set_1update_1listener(JNIEnv *env, jobject this, jboolean enabled) {
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if (enabled) {
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update_handler_context.method = (*env)->GetMethodID(env, dbclass, "onUpdate", "(ILjava/lang/String;Ljava/lang/String;J)V");
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update_handler_context.handler = (*env)->NewGlobalRef(env, this);
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(*env)->GetJavaVM(env, &update_handler_context.vm);
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sqlite3_update_hook(gethandle(env, this), &update_hook, NULL);
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} else {
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sqlite3_update_hook(gethandle(env, this), NULL, NULL);
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(*env)->DeleteGlobalRef(env, update_handler_context.handler);
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}
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}
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// Commit hook
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struct CommitHandlerContext {
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JavaVM *vm;
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jmethodID method;
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jobject handler;
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};
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static struct CommitHandlerContext commit_handler_context;
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int commit_hook(void *context) {
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JNIEnv *env = 0;
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(*commit_handler_context.vm)->AttachCurrentThread(commit_handler_context.vm, (void **)&env, 0);
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(*env)->CallVoidMethod(env, commit_handler_context.handler, commit_handler_context.method, 1);
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return 0;
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}
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void rollback_hook(void *context) {
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JNIEnv *env = 0;
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(*commit_handler_context.vm)->AttachCurrentThread(commit_handler_context.vm, (void **)&env, 0);
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(*env)->CallVoidMethod(env, commit_handler_context.handler, commit_handler_context.method, 0);
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}
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JNIEXPORT void JNICALL Java_org_sqlite_core_NativeDB_set_1commit_1listener(JNIEnv *env, jobject this, jboolean enabled) {
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if (enabled) {
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commit_handler_context.method = (*env)->GetMethodID(env, dbclass, "onCommit", "(Z)V");
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commit_handler_context.handler = (*env)->NewGlobalRef(env, this);
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(*env)->GetJavaVM(env, &commit_handler_context.vm);
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sqlite3_commit_hook(gethandle(env, this), &commit_hook, NULL);
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sqlite3_rollback_hook(gethandle(env, this), &rollback_hook, NULL);
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} else {
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sqlite3_commit_hook(gethandle(env, this), NULL, NULL);
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sqlite3_update_hook(gethandle(env, this), NULL, NULL);
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(*env)->DeleteGlobalRef(env, commit_handler_context.handler);
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}
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}

‎src/main/java/org/sqlite/core/NativeDB.java

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@@ -469,6 +469,12 @@ native synchronized int restore(byte[] dbNameUtf8, byte[] sourceFileName,
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@Override
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native synchronized boolean[][] column_metadata(long stmt);
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@Override
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native synchronized void set_commit_listener(boolean enabled);
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@Override
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native synchronized void set_update_listener(boolean enabled);
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/**
473479
* Throws an SQLException
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* @param msg Message for the SQLException.

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