1 files changed, 218 insertions, 7 deletions

diff --git a/vendor/modernc.org/sqlite/sqlite.go b/vendor/modernc.org/sqlite/sqlite.go
index f8c696f6..7fce68ee 100644
--- a/vendor/modernc.org/sqlite/sqlite.go
+++ b/vendor/modernc.org/sqlite/sqlite.go
@@ -1090,14 +1090,18 @@ func (c *conn) bindText(pstmt uintptr, idx1 int, value string) (uintptr, error)
 
 // int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
 func (c *conn) bindBlob(pstmt uintptr, idx1 int, value []byte) (uintptr, error) {
+	if len(value) == 0 {
+		if rc := sqlite3.Xsqlite3_bind_zeroblob(c.tls, pstmt, int32(idx1), 0); rc != sqlite3.SQLITE_OK {
+			return 0, c.errstr(rc)
+		}
+		return 0, nil
+	}
+
 	p, err := c.malloc(len(value))
 	if err != nil {
 		return 0, err
 	}
-
-	if len(value) != 0 {
-		copy((*libc.RawMem)(unsafe.Pointer(p))[:len(value):len(value)], value)
-	}
+	copy((*libc.RawMem)(unsafe.Pointer(p))[:len(value):len(value)], value)
 	if rc := sqlite3.Xsqlite3_bind_blob(c.tls, pstmt, int32(idx1), p, int32(len(value)), 0); rc != sqlite3.SQLITE_OK {
 		c.free(p)
 		return 0, c.errstr(rc)
@@ -1307,6 +1311,7 @@ func (c *conn) Close() error {
 
 		c.db = 0
 	}
+
 	if c.tls != nil {
 		c.tls.Close()
 		c.tls = nil
@@ -1323,6 +1328,32 @@ func (c *conn) closeV2(db uintptr) error {
 	return nil
 }
 
+type userDefinedFunction struct {
+	zFuncName uintptr
+	nArg      int32
+	eTextRep  int32
+	xFunc     func(*libc.TLS, uintptr, int32, uintptr)
+
+	freeOnce sync.Once
+}
+
+func (c *conn) createFunctionInternal(fun *userDefinedFunction) error {
+	if rc := sqlite3.Xsqlite3_create_function(
+		c.tls,
+		c.db,
+		fun.zFuncName,
+		fun.nArg,
+		fun.eTextRep,
+		0,
+		*(*uintptr)(unsafe.Pointer(&fun.xFunc)),
+		0,
+		0,
+	); rc != sqlite3.SQLITE_OK {
+		return c.errstr(rc)
+	}
+	return nil
+}
+
 // Execer is an optional interface that may be implemented by a Conn.
 //
 // If a Conn does not implement Execer, the sql package's DB.Exec will first
@@ -1388,9 +1419,14 @@ func (c *conn) query(ctx context.Context, query string, args []driver.NamedValue
 }
 
 // Driver implements database/sql/driver.Driver.
-type Driver struct{}
+type Driver struct {
+	// user defined functions that are added to every new connection on Open
+	udfs map[string]*userDefinedFunction
+}
+
+var d = &Driver{udfs: make(map[string]*userDefinedFunction)}
 
-func newDriver() *Driver { return &Driver{} }
+func newDriver() *Driver { return d }
 
 // Open returns a new connection to the database.  The name is a string in a
 // driver-specific format.
@@ -1422,5 +1458,180 @@ func newDriver() *Driver { return &Driver{} }
 // available at
 // https://www.sqlite.org/lang_transaction.html#deferred_immediate_and_exclusive_transactions
 func (d *Driver) Open(name string) (driver.Conn, error) {
-	return newConn(name)
+	c, err := newConn(name)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, udf := range d.udfs {
+		if err = c.createFunctionInternal(udf); err != nil {
+			c.Close()
+			return nil, err
+		}
+	}
+	return c, nil
+}
+
+// FunctionContext represents the context user defined functions execute in.
+// Fields and/or methods of this type may get addedd in the future.
+type FunctionContext struct{}
+
+const sqliteValPtrSize = unsafe.Sizeof(&sqlite3.Sqlite3_value{})
+
+// RegisterScalarFunction registers a scalar function named zFuncName with nArg
+// arguments. Passing -1 for nArg indicates the function is variadic.
+//
+// The new function will be available to all new connections opened after
+// executing RegisterScalarFunction.
+func RegisterScalarFunction(
+	zFuncName string,
+	nArg int32,
+	xFunc func(ctx *FunctionContext, args []driver.Value) (driver.Value, error),
+) error {
+	return registerScalarFunction(zFuncName, nArg, sqlite3.SQLITE_UTF8, xFunc)
+}
+
+// MustRegisterScalarFunction is like RegisterScalarFunction but panics on
+// error.
+func MustRegisterScalarFunction(
+	zFuncName string,
+	nArg int32,
+	xFunc func(ctx *FunctionContext, args []driver.Value) (driver.Value, error),
+) {
+	if err := RegisterScalarFunction(zFuncName, nArg, xFunc); err != nil {
+		panic(err)
+	}
+}
+
+// MustRegisterDeterministicScalarFunction is like
+// RegisterDeterministicScalarFunction but panics on error.
+func MustRegisterDeterministicScalarFunction(
+	zFuncName string,
+	nArg int32,
+	xFunc func(ctx *FunctionContext, args []driver.Value) (driver.Value, error),
+) {
+	if err := RegisterDeterministicScalarFunction(zFuncName, nArg, xFunc); err != nil {
+		panic(err)
+	}
+}
+
+// RegisterDeterministicScalarFunction registers a deterministic scalar
+// function named zFuncName with nArg arguments. Passing -1 for nArg indicates
+// the function is variadic. A deterministic function means that the function
+// always gives the same output when the input parameters are the same.
+//
+// The new function will be available to all new connections opened after
+// executing RegisterDeterministicScalarFunction.
+func RegisterDeterministicScalarFunction(
+	zFuncName string,
+	nArg int32,
+	xFunc func(ctx *FunctionContext, args []driver.Value) (driver.Value, error),
+) error {
+	return registerScalarFunction(zFuncName, nArg, sqlite3.SQLITE_UTF8|sqlite3.SQLITE_DETERMINISTIC, xFunc)
+}
+
+func registerScalarFunction(
+	zFuncName string,
+	nArg int32,
+	eTextRep int32,
+	xFunc func(ctx *FunctionContext, args []driver.Value) (driver.Value, error),
+) error {
+
+	if _, ok := d.udfs[zFuncName]; ok {
+		return fmt.Errorf("a function named %q is already registered", zFuncName)
+	}
+
+	// dont free, functions registered on the driver live as long as the program
+	name, err := libc.CString(zFuncName)
+	if err != nil {
+		return err
+	}
+
+	udf := &userDefinedFunction{
+		zFuncName: name,
+		nArg:      nArg,
+		eTextRep:  eTextRep,
+		xFunc: func(tls *libc.TLS, ctx uintptr, argc int32, argv uintptr) {
+			setErrorResult := func(res error) {
+				errmsg, cerr := libc.CString(res.Error())
+				if cerr != nil {
+					panic(cerr)
+				}
+				defer libc.Xfree(tls, errmsg)
+				sqlite3.Xsqlite3_result_error(tls, ctx, errmsg, -1)
+				sqlite3.Xsqlite3_result_error_code(tls, ctx, sqlite3.SQLITE_ERROR)
+			}
+
+			args := make([]driver.Value, argc)
+			for i := int32(0); i < argc; i++ {
+				valPtr := *(*uintptr)(unsafe.Pointer(argv + uintptr(i)*sqliteValPtrSize))
+
+				switch valType := sqlite3.Xsqlite3_value_type(tls, valPtr); valType {
+				case sqlite3.SQLITE_TEXT:
+					args[i] = libc.GoString(sqlite3.Xsqlite3_value_text(tls, valPtr))
+				case sqlite3.SQLITE_INTEGER:
+					args[i] = sqlite3.Xsqlite3_value_int64(tls, valPtr)
+				case sqlite3.SQLITE_FLOAT:
+					args[i] = sqlite3.Xsqlite3_value_double(tls, valPtr)
+				case sqlite3.SQLITE_NULL:
+					args[i] = nil
+				case sqlite3.SQLITE_BLOB:
+					size := sqlite3.Xsqlite3_value_bytes(tls, valPtr)
+					blobPtr := sqlite3.Xsqlite3_value_blob(tls, valPtr)
+					v := make([]byte, size)
+					copy(v, (*libc.RawMem)(unsafe.Pointer(blobPtr))[:size:size])
+					args[i] = v
+				default:
+					panic(fmt.Sprintf("unexpected argument type %q passed by sqlite", valType))
+				}
+			}
+
+			res, err := xFunc(&FunctionContext{}, args)
+			if err != nil {
+				setErrorResult(err)
+				return
+			}
+
+			switch resTyped := res.(type) {
+			case nil:
+				sqlite3.Xsqlite3_result_null(tls, ctx)
+			case int64:
+				sqlite3.Xsqlite3_result_int64(tls, ctx, resTyped)
+			case float64:
+				sqlite3.Xsqlite3_result_double(tls, ctx, resTyped)
+			case bool:
+				sqlite3.Xsqlite3_result_int(tls, ctx, libc.Bool32(resTyped))
+			case time.Time:
+				sqlite3.Xsqlite3_result_int64(tls, ctx, resTyped.Unix())
+			case string:
+				size := int32(len(resTyped))
+				cstr, err := libc.CString(resTyped)
+				if err != nil {
+					panic(err)
+				}
+				defer libc.Xfree(tls, cstr)
+				sqlite3.Xsqlite3_result_text(tls, ctx, cstr, size, sqlite3.SQLITE_TRANSIENT)
+			case []byte:
+				size := int32(len(resTyped))
+				if size == 0 {
+					sqlite3.Xsqlite3_result_zeroblob(tls, ctx, 0)
+					return
+				}
+				p := libc.Xmalloc(tls, types.Size_t(size))
+				if p == 0 {
+					panic(fmt.Sprintf("unable to allocate space for blob: %d", size))
+				}
+				defer libc.Xfree(tls, p)
+				copy((*libc.RawMem)(unsafe.Pointer(p))[:size:size], resTyped)
+
+				sqlite3.Xsqlite3_result_blob(tls, ctx, p, size, sqlite3.SQLITE_TRANSIENT)
+			default:
+				setErrorResult(fmt.Errorf("function did not return a valid driver.Value: %T", resTyped))
+				return
+			}
+		},
+	}
+	d.udfs[zFuncName] = udf
+
+	return nil
 }