escape.go

package gocosmosdb

// escapeSQL takes a string and escapes all special characters for JSON marshaling
func escapeSQL(sql string) string {
	return escapeSpecialChars(sql)
}

// reserveBuffer checks cap(buf) and expand buffer to len(buf) + appendSize.
// If cap(buf) is not enough, reallocate new buffer.
func reserveBuffer(buf []byte, appendSize int) []byte {
	newSize := len(buf) + appendSize
	if cap(buf) < newSize {
		// Grow buffer exponentially
		newBuf := make([]byte, len(buf)*2+appendSize)
		copy(newBuf, buf)
		buf = newBuf
	}
	return buf[:newSize]
}

// escapeSpecialChars removes all special chars from a query string
func escapeSpecialChars(v string) string {
	buf := make([]byte, 0)
	pos := len(buf)
	buf = reserveBuffer(buf, len(v)*2)

	for i := 0; i < len(v); i++ {
		c := v[i]
		switch c {
		case '\x00':
			buf[pos] = '\\'
			buf[pos+1] = '0'
			pos += 2
		case '\n':
			buf[pos] = '\\'
			buf[pos+1] = 'n'
			pos += 2
		case '\r':
			buf[pos] = '\\'
			buf[pos+1] = 'r'
			pos += 2
		case '\x1a':
			buf[pos] = '\\'
			buf[pos+1] = 'Z'
			pos += 2
		/*case '\'':
		buf[pos] = '\\'
		buf[pos+1] = '\''
		pos += 2*/
		case '"':
			buf[pos] = '\\'
			buf[pos+1] = '"'
			pos += 2
		case '\\':
			buf[pos] = '\\'
			buf[pos+1] = '\\'
			pos += 2
		default:
			buf[pos] = c
			pos++
		}
	}

	return string(buf[:pos])
}