block buffer_manager::read(string table_name, FILE_TYPE t, int offset)
{
for (int i = 0; i < BUFFER_SIZE; i++)
{
if (m_block_age[i] >= 0)
{
if (block_equal(i, table_name, t, offset) == true)
{
age_plus_1();
m_block_age[i] = 0;
return m_block[i];
}
}
}
block b;
FILE* fp = NULL;
if (t == FILE_TYPE::RECORD)
fp = fopen((table_name + ".blo").c_str(), "rb");
else if (t == FILE_TYPE::INDEX)
fp = fopen((table_name + ".ind").c_str(), "rb");
if (fp == NULL)
{
error e(1, "", "", "");
throw e;
}
fseek(fp, offset * 4096, SEEK_SET);
fread(b.m_data, sizeof(BYTE), 4096, fp);
fclose(fp);
b.m_offset = offset;
b.m_table_name = table_name;
b.m_file_type = t;
refresh_block_to_buffer(b);
return b;
}
/** Verifies and decrypts a packet */
static bool method_decrypt(fastd_peer_t *peer, fastd_method_session_state_t *session, fastd_buffer_t *out, fastd_buffer_t in, bool *reordered) {
if (in.len < COMMON_HEADBYTES+sizeof(fastd_block128_t))
return false;
if (!method_session_is_valid(session))
return false;
uint8_t in_nonce[COMMON_NONCEBYTES];
uint8_t flags;
int64_t age;
if (!fastd_method_handle_common_header(&session->common, &in, in_nonce, &flags, &age))
return false;
if (flags)
return false;
uint8_t nonce[session->method->cipher_info->iv_length] __attribute__((aligned(8)));
fastd_method_expand_nonce(nonce, in_nonce, sizeof(nonce));
size_t tail_len = alignto(in.len, sizeof(fastd_block128_t))-in.len;
*out = fastd_buffer_alloc(in.len, 0, tail_len);
int n_blocks = block_count(in.len, sizeof(fastd_block128_t));
fastd_block128_t *inblocks = in.data;
fastd_block128_t *outblocks = out->data;
fastd_block128_t tag;
bool ok = session->cipher->crypt(session->cipher_state, outblocks, inblocks, n_blocks*sizeof(fastd_block128_t), nonce);
if (ok) {
if (tail_len)
memset(in.data+in.len, 0, tail_len);
put_size(&inblocks[n_blocks], in.len-sizeof(fastd_block128_t));
ok = session->ghash->digest(session->ghash_state, &tag, inblocks+1, n_blocks*sizeof(fastd_block128_t));
}
if (!ok || !block_equal(&tag, &outblocks[0])) {
fastd_buffer_free(*out);
return false;
}
fastd_buffer_free(in);
fastd_buffer_push_head(out, sizeof(fastd_block128_t));
fastd_tristate_t reorder_check = fastd_method_reorder_check(peer, &session->common, in_nonce, age);
if (reorder_check.set) {
*reordered = reorder_check.state;
}
else {
fastd_buffer_free(*out);
*out = fastd_buffer_alloc(0, 0, 0);
}
return true;
}
void buffer_manager::refresh_block_to_buffer(block b)
{
for (int i = 0; i < BUFFER_SIZE; i++)
{
if (m_block_age[i] >= 0)
{
if (block_equal(i, b.m_table_name, b.m_file_type, b.m_offset) == true)
{
age_plus_1();
m_block_age[i] = 0;
m_block[i] = b;
return;
}
}
}
for (int i = 0; i < BUFFER_SIZE; i++)
{
if (m_block_age[i] < 0)
{
age_plus_1();
m_block_age[i] = 0;
m_block[i] = b;
return;
}
}
int max_age = 0;
int max_index = 0;
for (int i = 0; i < BUFFER_SIZE; i++)
{
if (m_block_age[i]>max_age)
{
max_age = m_block_age[i];
max_index = i;
}
}
FILE* fp = NULL;
if (m_block[max_index].m_file_type == FILE_TYPE::RECORD)
fp = fopen((m_block[max_index].m_table_name + ".blo").c_str(), "rb+");
else if (m_block[max_index].m_file_type == FILE_TYPE::INDEX)
fp = fopen((m_block[max_index].m_table_name + ".ind").c_str(), "rb+");
if (fp == NULL)
{
error e;
throw e;
}
fseek(fp, m_block[max_index].m_offset * 4096, SEEK_SET);
fwrite(m_block[max_index].m_data, sizeof(BYTE), 4096, fp);
fclose(fp);
age_plus_1();
m_block_age[max_index] = 0;
m_block[max_index] = b;
return;
}
void chunk_block_set(Chunk *chunk, Vector3i *pos, Block *block)
{
int index = pos->x+(pos->y*16)+(pos->z*256);
chunk->changed = !block_equal(chunk->blocks[index], block);
chunk->blocks[index] = block;
if(block == NULL) {
chunk->empty = true;
for(int i=0;i<4096;++i) {
if(chunk->blocks[i] != NULL) {
chunk->empty = false;
break;
}
}
} else {
chunk->empty = false;
}
}
