added ability to receive updates from sqlite3_update_hook

examples/simple-chaining.js

@@ -9,8 +9,15 @@ var db;
 function createDb() {
     console.log("createDb chain");
     db = new sqlite3.Database('chain.sqlite3', createTable);
+
+    listenDatabaseUpdates();
 }
 
+function listenDatabaseUpdates() {
+    db.addListener('change', function(eventType, database, table, rowId) {
+        console.log("database was changed", eventType, database, table, rowId);
+    });
+}
 
 function createTable() {
     console.log("createTable lorem");

lib/sqlite3.js

@@ -146,7 +146,7 @@ Statement.prototype.map = function() {
 
 var isVerbose = false;
 
-var supportedEvents = [ 'trace', 'profile', 'insert', 'update', 'delete' ];
+var supportedEvents = [ 'trace', 'profile', 'change' ];
 
 Database.prototype.addListener = Database.prototype.on = function(type) {
     var val = EventEmitter.prototype.addListener.apply(this, arguments);

src/database.cc

@@ -344,6 +344,11 @@ NAN_METHOD(Database::Configure) {
         baton->status = Nan::To<int>(info[1]).FromJust();
         db->Schedule(SetBusyTimeout, baton);
     }
+    else if (Nan::Equals(info[0], Nan::New("change").ToLocalChecked()).FromJust()) {
+        Local<Function> handle;
+        Baton* baton = new Baton(db, handle);
+        db->Schedule(RegisterUpdateCallback, baton);
+    }
     else {
         return Nan::ThrowError(Exception::Error(String::Concat(
 #if V8_MAJOR_VERSION > 6
@@ -499,12 +504,13 @@ void Database::UpdateCallback(Database *db, UpdateInfo* info) {
     Nan::HandleScope scope;
 
     Local<Value> argv[] = {
+        Nan::New("change").ToLocalChecked(),
         Nan::New(sqlite_authorizer_string(info->type)).ToLocalChecked(),
         Nan::New(info->database.c_str()).ToLocalChecked(),
         Nan::New(info->table.c_str()).ToLocalChecked(),
         Nan::New<Number>(info->rowid),
     };
-    EMIT_EVENT(db->handle(), 4, argv);
+    EMIT_EVENT(db->handle(), 5, argv);
     delete info;
 }
 

test/update_hook.test.js

@@ -0,0 +1,76 @@
+var sqlite3 = require('..');
+var assert = require('assert');
+
+describe('update_hook', function() {
+    var db;
+
+    beforeEach(function(done) {
+        db = new sqlite3.Database(':memory:', function(err) {
+            if (err) return done(err);
+
+            db.run("CREATE TABLE update_hooks_test (id int PRIMARY KEY, value text)", done);
+        });
+    });
+
+    it('emits insert event on inserting data to table', function(done) {
+        db.addListener('change', function(eventType, database, table, rowId) {
+            assert.equal(eventType, 'insert');
+            assert.equal(database, 'main');
+            assert.equal(table, 'update_hooks_test');
+            assert.equal(rowId, 1);
+
+            return done();
+        });
+
+        db.run("INSERT INTO update_hooks_test VALUES (1, 'value')", function(err) {
+            if (err) return done(err);
+
+        });
+    });
+
+    it('emits update event on row modification in table', function(done) {
+        db.run("INSERT INTO update_hooks_test VALUES (2, 'value'), (3, 'value4')", function(err) {
+            if (err) return done(err);
+
+            db.addListener('change', function(eventType, database, table, rowId) {
+                assert.equal(eventType, 'update');
+                assert.equal(database, 'main');
+                assert.equal(table, 'update_hooks_test');
+                assert.equal(rowId, 1);
+
+                db.all("SELECT * FROM update_hooks_test WHERE rowid = ?", rowId, function(err, rows) {
+                    assert.deepEqual(rows, [{ id: 2, value: 'new_val' }]);
+
+                    return done(err);
+                });
+            });
+
+            db.run("UPDATE update_hooks_test SET value = 'new_val' WHERE id = 2", function(err) {
+                if (err) return done(err);
+            });
+        });
+    });
+
+    it('emits delete event on row was deleted from table', function(done) {
+        db.run("INSERT INTO update_hooks_test VALUES (2, 'value')", function(err) {
+            if (err) return done(err);
+
+            db.addListener('change', function(eventType, database, table, rowId) {
+                assert.equal(eventType, 'delete');
+                assert.equal(database, 'main');
+                assert.equal(table, 'update_hooks_test');
+                assert.equal(rowId, 1);
+
+                return done();
+            });
+
+            db.run("DELETE FROM update_hooks_test WHERE id = 2", function(err) {
+                if (err) return done(err);
+            });
+        });
+    });
+
+    afterEach(function(done) {
+        db.close(done);
+    });
+});