Add github.com/mattn/go-sqlite3

This can be used to implement the `database/sql` interface from the Go
standard library for sqlite databases. This is the currently preferred
method to store user data for Ceres.

1 files changed, 112 insertions, 0 deletions

diff --git a/vendor/github.com/mattn/go-sqlite3/sqlite3_opt_preupdate_hook.go b/vendor/github.com/mattn/go-sqlite3/sqlite3_opt_preupdate_hook.go
new file mode 100644
index 0000000..b43e482
--- /dev/null
+++ b/vendor/github.com/mattn/go-sqlite3/sqlite3_opt_preupdate_hook.go
@@ -0,0 +1,112 @@
+// Copyright (C) 2019 G.J.R. Timmer <gjr.timmer@gmail.com>.
+// Copyright (C) 2018 segment.com <friends@segment.com>
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+// +build sqlite_preupdate_hook
+
+package sqlite3
+
+/*
+#cgo CFLAGS: -DSQLITE_ENABLE_PREUPDATE_HOOK
+#cgo LDFLAGS: -lm
+
+#ifndef USE_LIBSQLITE3
+#include "sqlite3-binding.h"
+#else
+#include <sqlite3.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+
+void preUpdateHookTrampoline(void*, sqlite3 *, int, char *, char *, sqlite3_int64, sqlite3_int64);
+*/
+import "C"
+import (
+	"errors"
+	"unsafe"
+)
+
+// RegisterPreUpdateHook sets the pre-update hook for a connection.
+//
+// The callback is passed a SQLitePreUpdateData struct with the data for
+// the update, as well as methods for fetching copies of impacted data.
+//
+// If there is an existing preupdate hook for this connection, it will be
+// removed. If callback is nil the existing hook (if any) will be removed
+// without creating a new one.
+func (c *SQLiteConn) RegisterPreUpdateHook(callback func(SQLitePreUpdateData)) {
+	if callback == nil {
+		C.sqlite3_preupdate_hook(c.db, nil, nil)
+	} else {
+		C.sqlite3_preupdate_hook(c.db, (*[0]byte)(unsafe.Pointer(C.preUpdateHookTrampoline)), unsafe.Pointer(newHandle(c, callback)))
+	}
+}
+
+// Depth returns the source path of the write, see sqlite3_preupdate_depth()
+func (d *SQLitePreUpdateData) Depth() int {
+	return int(C.sqlite3_preupdate_depth(d.Conn.db))
+}
+
+// Count returns the number of columns in the row
+func (d *SQLitePreUpdateData) Count() int {
+	return int(C.sqlite3_preupdate_count(d.Conn.db))
+}
+
+func (d *SQLitePreUpdateData) row(dest []interface{}, new bool) error {
+	for i := 0; i < d.Count() && i < len(dest); i++ {
+		var val *C.sqlite3_value
+		var src interface{}
+
+		// Initially I tried making this just a function pointer argument, but
+		// it's absurdly complicated to pass C function pointers.
+		if new {
+			C.sqlite3_preupdate_new(d.Conn.db, C.int(i), &val)
+		} else {
+			C.sqlite3_preupdate_old(d.Conn.db, C.int(i), &val)
+		}
+
+		switch C.sqlite3_value_type(val) {
+		case C.SQLITE_INTEGER:
+			src = int64(C.sqlite3_value_int64(val))
+		case C.SQLITE_FLOAT:
+			src = float64(C.sqlite3_value_double(val))
+		case C.SQLITE_BLOB:
+			len := C.sqlite3_value_bytes(val)
+			blobptr := C.sqlite3_value_blob(val)
+			src = C.GoBytes(blobptr, len)
+		case C.SQLITE_TEXT:
+			len := C.sqlite3_value_bytes(val)
+			cstrptr := unsafe.Pointer(C.sqlite3_value_text(val))
+			src = C.GoBytes(cstrptr, len)
+		case C.SQLITE_NULL:
+			src = nil
+		}
+
+		err := convertAssign(&dest[i], src)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Old populates dest with the row data to be replaced. This works similar to
+// database/sql's Rows.Scan()
+func (d *SQLitePreUpdateData) Old(dest ...interface{}) error {
+	if d.Op == SQLITE_INSERT {
+		return errors.New("There is no old row for INSERT operations")
+	}
+	return d.row(dest, false)
+}
+
+// New populates dest with the replacement row data. This works similar to
+// database/sql's Rows.Scan()
+func (d *SQLitePreUpdateData) New(dest ...interface{}) error {
+	if d.Op == SQLITE_DELETE {
+		return errors.New("There is no new row for DELETE operations")
+	}
+	return d.row(dest, true)
+}