public boolean onStringValue(Object base, long offset, int size) {
            if (curRowIsTagField) {
                boolean ok = false;
                for (byte[] tag : acceptTags) {
                    if (UTF8Util.containsCommaSep(base, offset, size, tag)) {
                        ok = true;
                        break;
                    }
                }
                if (!ok) {
                    curRowIgnore = true;
                }
                return true;
            }

            int rawValueOffset = curRowRawValueBytes;
            putValue(curRowIndex, (((long) rawValueOffset) << 32) | (long) size);

            Platform.copyMemory(
                    base, offset,
                    rawValuesBuffer, BYTE_ARRAY_OFFSET + rawValueOffset,
                    size);

            curRowRawValueBytes += size;
            return true;
        }
Take size of bytes from buffer and move forward pos.
indexr-segment/src/main/java/io/indexr/segment/rt/UTF8Row.java