Suricata

Why is the MD5 of the file calculated in the AppendData function?

static int AppendData(File *file, const uint8_t *data, uint32_t data_len)
{
    if (StreamingBufferAppendNoTrack(file->sb, data, data_len) != 0) {
        SCReturnInt(-1);
    }

#ifdef HAVE_NSS
    if (file->md5_ctx) {
        HASH_Update(file->md5_ctx, data, data_len);
    }
    if (file->sha1_ctx) {
        HASH_Update(file->sha1_ctx, data, data_len);
    }
    if (file->sha256_ctx) {
        HASH_Update(file->sha256_ctx, data, data_len);
    }
#endif
    SCReturnInt(0);
}

In this way, MD5 must be calculated for each packet, and there are many thread lock conflicts.

Is it not possible to calculate the MD5 when the file is closed?