nicer API

Author: kripken

Makefile

@@ -7,7 +7,7 @@ CFLAGS=-DSQLITE_OMIT_LOAD_EXTENSION
 all: sql.js benchmark.html benchmark
 
 sql.js: sqlite3.c
-	$(EMCC) $(CFLAGS) sqlite3.c main.c --post-js bindings.js -o sql.js -s EXPORTED_FUNCTIONS="['_sqlite3_open', '_sqlite3_close', '_sqlite3_exec']"
+	$(EMCC) $(CFLAGS) sqlite3.c main.c --pre-js pre.js --post-js post.js -o sql.js -s EXPORTED_FUNCTIONS="['_sqlite3_open', '_sqlite3_close', '_sqlite3_exec']"
 
 benchmark.html: sqlite3.c benchmark.c
 	$(EMCC) $(CFLAGS) sqlite3.c benchmark.c -o benchmark.html

benchmark.js

@@ -7,14 +7,14 @@ function TIME(msg) {
   then = now;
 }
 
-var db = SQL.open(":memory:");
+var db = SQL.open();
 function report(data) {
   for (var i = 0; i < data.length; i++) {
     print(data[i].column + ' = ' + data[i].value + '\n');
   }
 }
 function RUN(cmd) {
-  SQL.exec(db, cmd, report);
+  db.exec(cmd, report);
 }
 
 TIME("'startup'");
@@ -53,5 +53,5 @@ RUN("SELECT count(*) FROM t1 WHERE a == 4");
 RUN("SELECT count(*) FROM t1 WHERE b > 20000 AND b < 50000;");
 TIME("selects with indexes");
 
-SQL.close(db);
+db.close();
 

bindings.js

@@ -0,0 +1,44 @@
+var apiTemp = Runtime.stackAlloc(4);
+var callbackTemp = FUNCTION_TABLE.length;
+FUNCTION_TABLE.push(0, 0);
+
+Module['open'] = function(filename) {
+  filename = filename || ":memory:";
+  var ret = Module['ccall']('sqlite3_open', 'number', ['string', 'number'], [filename, apiTemp]);
+  if (ret) throw 'SQLite exception: ' + ret;
+  return {
+    ptr: getValue(apiTemp, 'i32'),
+
+    'close': function() {
+      var ret = Module['ccall']('sqlite3_close', 'number', ['number'], [this.ptr]);
+      if (ret) throw 'SQLite exception: ' + ret;
+    },
+
+    'exec': function(sql, callback) {
+      setValue(apiTemp, 0, 'i32');
+      if (callback) {
+        FUNCTION_TABLE[callbackTemp] = function(notUsed, argc, argv, colNames) {
+          var data = [];
+          for (var i = 0; i < argc; i++) {
+            data.push({
+              'column': Pointer_stringify(getValue(colNames + i*Runtime.QUANTUM_SIZE, 'i32')),
+              'value': Pointer_stringify(getValue(argv + i*Runtime.QUANTUM_SIZE, 'i32'))
+            });
+          }
+          callback(data);
+        };
+      }
+      var ret = Module['ccall']('sqlite3_exec', 'number', ['number', 'string', 'number', 'number', 'number'],
+                                [this.ptr, sql, callback ? callbackTemp : 0, 0, apiTemp]);
+      var errPtr = getValue(apiTemp, 'i32');
+      if (ret || errPtr) {
+        var msg = 'SQLite exception: ' + ret + ', ' + (errPtr ? Pointer_stringify(errPtr) : '');
+        if (errPtr) _sqlite3_free(errPtr);
+        throw msg;
+      }
+    }
+  };
+};
+
+this['SQL'] = Module;
+

post.js

@@ -0,0 +1,2 @@
+// This is sql.js, a port of SQLite to JavaScript using Emscripten
+

pre.js

@@ -1,28 +1,28 @@
 // js -m -n -e "load('sql.js')" test.js
 
-var db = SQL.open(":memory:");
+var db = SQL.open();
 
 print('created db');
 
-SQL.exec(db, "CREATE TABLE my_table(a INTEGER, b INTEGER, c VARCHAR(100));");
+db.exec("CREATE TABLE my_table(a INTEGER, b INTEGER, c VARCHAR(100));");
 
 print('executed one command');
 
-SQL.exec(db, "INSERT INTO my_table VALUES(1,13153,'thirteen thousand one hundred fifty three');");
-SQL.exec(db, "INSERT INTO my_table VALUES(1,987,'some other number');");
+db.exec("INSERT INTO my_table VALUES(1,13153,'thirteen thousand one hundred fifty three');");
+db.exec("INSERT INTO my_table VALUES(1,987,'some other number');");
 
 function report(data) {
   print(JSON.stringify(data, null, '  '));
 }
 
-SQL.exec(db, "SELECT count(*) FROM my_table;", report);
+db.exec("SELECT count(*) FROM my_table;", report);
 // prints [{ "column": "count(*)", "value": "2" }]
 
 print('printed one report');
 
-SQL.exec(db, "SELECT a, b, c FROM my_table;", report);
+db.exec("SELECT a, b, c FROM my_table;", report);
 // prints [{ "column": "a", "value": "1" }, { "column": "b", "value": "13153" }, { "column": "c", "value": "thirteen thousand one hundred fifty three" }]
 //        [{ "column": "a", "value": "1" }, { "column": "b", "value": "987"   }, { "column": "c", "value": "some other number" }]
 
-SQL.close(db);
+db.close();