Skip to content

Commit

Permalink
vere: refactors event log metadata reading to avoid the loom (#547)
Browse files Browse the repository at this point in the history 
This PR resolves a bug that I introduced in #531. I added stronger
validation during event log initialization by checking for the presence
of metadata, but that was allocating on the loom (in the case of 32-bit
or greater ships and/or lives). There are various chicken-and-egg
problems with initializing old event logs for replay, so it seems best
to just remove this whole operation from the loom.
  • Loading branch information
@joemfb
joemfb authored Nov 8, 2023
2 parents 2b024e9 + a85aa21 commit 78ea546
Show file tree
Hide file tree
Showing 3 changed files with 95 additions and 53 deletions.
8 changes: 4 additions & 4 deletions pkg/vere/db/lmdb.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -414,7 +414,7 @@ void
u3_lmdb_read_meta(MDB_env* env_u,
void* ptr_v,
const c3_c* key_c,
void (*read_f)(void*, size_t, void*))
void (*read_f)(void*, ssize_t, void*))
{
MDB_txn* txn_u;
MDB_dbi mdb_u;
Expand All @@ -424,15 +424,15 @@ u3_lmdb_read_meta(MDB_env* env_u,
//
if ( (ret_w = mdb_txn_begin(env_u, 0, MDB_RDONLY, &txn_u)) ) {
mdb_logerror(stderr, ret_w, "lmdb: meta read: txn_begin fail");
return read_f(ptr_v, 0, 0);
return read_f(ptr_v, -1, 0);
}

// open the database in the transaction
//
if ( (ret_w = mdb_dbi_open(txn_u, "META", 0, &mdb_u)) ) {
mdb_logerror(stderr, ret_w, "lmdb: meta read: dbi_open fail");
mdb_txn_abort(txn_u);
return read_f(ptr_v, 0, 0);
return read_f(ptr_v, -1, 0);
}

// read by string key, invoking callback with result
Expand All @@ -443,7 +443,7 @@ u3_lmdb_read_meta(MDB_env* env_u,
if ( (ret_w = mdb_get(txn_u, mdb_u, &key_u, &val_u)) ) {
mdb_logerror(stderr, ret_w, "lmdb: read failed");
mdb_txn_abort(txn_u);
return read_f(ptr_v, 0, 0);
return read_f(ptr_v, -1, 0);
}
else {
read_f(ptr_v, val_u.mv_size, val_u.mv_data);
Expand Down
2 changes: 1 addition & 1 deletion pkg/vere/db/lmdb.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@
u3_lmdb_read_meta(MDB_env* env_u,
void* ptr_v,
const c3_c* key_c,
void (*read_f)(void*, size_t, void*));
void (*read_f)(void*, ssize_t, void*));

/* u3_lmdb_save_meta(): save by string into the META db.
*/
Expand Down
138 changes: 90 additions & 48 deletions pkg/vere/disk.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -662,26 +662,26 @@ u3_disk_save_meta(MDB_env* mdb_u,
return c3y;
}

typedef struct {
ssize_t hav_i;
c3_y buf_y[16];
} _mdb_val;


/* _disk_meta_read_cb(): copy [val_p] to atom [ptr_v] if present.
*/
static void
_disk_meta_read_cb(void* ptr_v, size_t val_i, void* val_p)
_disk_meta_read_cb(void* ptr_v, ssize_t val_i, void* val_v)
{
u3_weak* mat = ptr_v;
_mdb_val* val_u = ptr_v;
c3_y* dat_y = (c3_y*)val_v;

if ( val_p ) {
*mat = u3i_bytes(val_i, val_p);
}
}
memset(val_u->buf_y, 0, sizeof(val_u->buf_y));
val_u->hav_i = val_i;

/* _disk_read_meta(): read metadata at [key_c], deserialize.
*/
static u3_weak
_disk_read_meta(MDB_env* mdb_u, const c3_c* key_c)
{
u3_weak dat = u3_none;
u3_lmdb_read_meta(mdb_u, &dat, key_c, _disk_meta_read_cb);
return dat;
if ( 0 < val_i ) {
memcpy(val_u->buf_y, dat_y, c3_min(val_i, sizeof(val_u->buf_y)));
}
}

/* u3_disk_read_meta(): read metadata.
Expand All @@ -692,60 +692,102 @@ u3_disk_read_meta(MDB_env* mdb_u,
c3_o* fak_o,
c3_w* lif_w)
{
u3_weak ver, who, fak, lif;
_mdb_val val_u;

if ( u3_none == (ver = _disk_read_meta(mdb_u, "version")) ) {
// version
//
u3_lmdb_read_meta(mdb_u, &val_u, "version", _disk_meta_read_cb);

if ( 0 > val_u.hav_i ) {
fprintf(stderr, "disk: read meta: no version\r\n");
return c3n;
}
if ( u3_none == (who = _disk_read_meta(mdb_u, "who")) ) {
fprintf(stderr, "disk: read meta: no indentity\r\n");
else if ( (1 != val_u.hav_i) || (1 != *val_u.buf_y) ) {
fprintf(stderr, "disk: read meta: unknown version %u\r\n", *val_u.buf_y);
return c3n;
}
if ( u3_none == (fak = _disk_read_meta(mdb_u, "fake")) ) {
fprintf(stderr, "disk: read meta: no fake bit\r\n");

// identity
//
u3_lmdb_read_meta(mdb_u, &val_u, "who", _disk_meta_read_cb);

if ( 0 > val_u.hav_i ) {
fprintf(stderr, "disk: read meta: no identity\r\n");
return c3n;
}
if ( u3_none == (lif = _disk_read_meta(mdb_u, "life")) ) {
fprintf(stderr, "disk: read meta: no lifecycle length\r\n");
return c3n;
else if ( 16 < val_u.hav_i ) {
// NB: non-fatal
//
fprintf(stderr, "disk: read meta: strange identity\r\n");
}

{
c3_o val_o = c3y;

if ( 1 != ver ) {
fprintf(stderr, "disk: read meta: unknown version %u\r\n", ver);
val_o = c3n;
}
else if ( !((c3y == fak ) || (c3n == fak )) ) {
fprintf(stderr, "disk: read meta: invalid fake bit\r\n");
val_o = c3n;
}
else if ( c3n == u3a_is_cat(lif) ) {
fprintf(stderr, "disk: read meta: invalid lifecycle length\r\n");
val_o = c3n;
}
if ( who_d ) {
c3_y* byt_y = val_u.buf_y;

who_d[0] = (c3_d)byt_y[0]
| (c3_d)byt_y[1] << 8
| (c3_d)byt_y[2] << 16
| (c3_d)byt_y[3] << 24
| (c3_d)byt_y[4] << 32
| (c3_d)byt_y[5] << 40
| (c3_d)byt_y[6] << 48
| (c3_d)byt_y[7] << 56;

byt_y += 8;
who_d[1] = (c3_d)byt_y[0]
| (c3_d)byt_y[1] << 8
| (c3_d)byt_y[2] << 16
| (c3_d)byt_y[3] << 24
| (c3_d)byt_y[4] << 32
| (c3_d)byt_y[5] << 40
| (c3_d)byt_y[6] << 48
| (c3_d)byt_y[7] << 56;
}

// fake bit
//
u3_lmdb_read_meta(mdb_u, &val_u, "fake", _disk_meta_read_cb);

if ( c3n == val_o ) {
u3z(ver); u3z(who); u3z(fak); u3z(lif);
return c3n;
if ( 0 > val_u.hav_i ) {
fprintf(stderr, "disk: read meta: no fake bit\r\n");
return c3n;
}
else if ( 0 == val_u.hav_i ) {
if ( fak_o ) {
*fak_o = 0;
}
}

if ( who_d ) {
u3r_chubs(0, 2, who_d, who);
else if ( (1 == val_u.hav_i) || !((*val_u.buf_y) >> 1) ) {
*fak_o = (*val_u.buf_y) & 1;
}
else {
fprintf(stderr, "disk: read meta: invalid fake bit %u %zd\r\n",
*val_u.buf_y, val_u.hav_i);
return c3n;
}

// life
//
u3_lmdb_read_meta(mdb_u, &val_u, "life", _disk_meta_read_cb);

if ( fak_o ) {
*fak_o = fak;
if ( 0 > val_u.hav_i ) {
fprintf(stderr, "disk: read meta: no lifecycle length\r\n");
return c3n;
}
else if ( 4 < val_u.hav_i ) {
// NB: non-fatal
//
fprintf(stderr, "disk: read meta: strange life\r\n");
}

if ( lif_w ) {
*lif_w = lif;
c3_y* byt_y = val_u.buf_y;
*lif_w = (c3_w)byt_y[0]
| (c3_w)byt_y[1] << 8
| (c3_w)byt_y[2] << 16
| (c3_w)byt_y[3] << 24;
}

u3z(who);
return c3y;
}

Expand Down

0 comments on commit 78ea546

Please sign in to comment.