113 lines
3.2 KiB
Go
113 lines
3.2 KiB
Go
// 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 update 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)
|
|
}
|