isync

mailbox synchronization program
git clone https://git.code.sf.net/p/isync/isync
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commit be9625725c9db965954cf1c76bd12052e7c9c829
parent 2f4b71c56e3e6caa76a649018681704628405108
Author: Oswald Buddenhagen <ossi@users.sf.net>
Date:   Fri, 10 Dec 2021 21:45:51 +0100

rework maxuid tracking yet again

re-introduce newmaxuid, but now it's not used at all until the state
is committed. this simplifies the new-message loop, esp. in view of a
soon significantly increased number of branches in it.

Diffstat:
Msrc/run-tests.pl | 36+++++++++++++++++++++++++++++++-----
Msrc/sync.c | 55+++++++++++++++++++++++++++++--------------------------
Msrc/sync_p.h | 1+
Msrc/sync_state.c | 12+++++++++---
4 files changed, 70 insertions(+), 34 deletions(-)

diff --git a/src/run-tests.pl b/src/run-tests.pl @@ -939,7 +939,9 @@ sub test($$$$) # Generic syncing tests my @x01 = ( - I, 0, 0, + I, 0, I, + R, "*", "", "", # Skipped/failed messages to prevent maxuid topping + S, "", "", "*", A, "*F", "*", "*", B, "*", "*", "*F", C, "*FS", "*", "*F", @@ -999,7 +1001,7 @@ test("full + expunge near side", \@x01, \@X03, \@O03); my @O04 = ("", "", "Sync Pull\n"); my @X04 = ( - K, 0, 0, + K, 0, I, A, "", "+F", "+F", C, "", "+FS", "+S", E, "", "+T", "+T", @@ -1011,7 +1013,7 @@ test("pull", \@x01, \@X04, \@O04); my @O05 = ("", "", "Sync Flags\n"); my @X05 = ( - I, 0, 0, + I, 0, I, A, "", "+F", "+F", B, "+F", "+F", "", C, "", "+FS", "+S", @@ -1022,7 +1024,7 @@ test("flags", \@x01, \@X05, \@O05); my @O06 = ("", "", "Sync Delete\n"); my @X06 = ( - I, 0, 0, + I, 0, I, G, "+T", ">", "", I, "", "<", "+T", ); @@ -1038,7 +1040,7 @@ test("new", \@x01, \@X07, \@O07); my @O08 = ("", "", "Sync PushFlags PullDelete\n"); my @X08 = ( - I, 0, 0, + I, 0, I, B, "+F", "+F", "", C, "", "+F", "", I, "", "<", "+T", @@ -1162,6 +1164,30 @@ my @X38 = ( ); test("max messages + expunge", \@x38, \@X38, \@O38); +# Test for legacy/tampered states with inaccurate maxuid tracking + +# Joined post-push & post-pull state to have just one test - +# there is no way how this could have occurred naturally. +my @x60 = ( + 0, C, 0, + A, "*S", "", "_", + B, "*FS", "*FS", "*FS", + C, "*S", "", "_", + D, "*", "*", "*", + E, "*", "*", "*", + F, "*", "", "", + G, "*", "", "", + H, "", "", "*", + I, "", "", "_", + J, "*", "*", "*", +); + +my @O61 = ("", "", "Sync Flags\n"); # Need to fetch old messages +my @X61 = ( + E, C, E, +); +test("maxuid topping", \@x60, \@X61, \@O61); + # Trashing my @x10 = ( diff --git a/src/sync.c b/src/sync.c @@ -968,8 +968,8 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux JLOG( "| %u %u", (svars->uidval[F], svars->uidval[N]), "new UIDVALIDITYs" ); } - svars->oldmaxuid[F] = svars->maxuid[F]; - svars->oldmaxuid[N] = svars->maxuid[N]; + svars->oldmaxuid[F] = svars->newmaxuid[F]; + svars->oldmaxuid[N] = svars->newmaxuid[N]; info( "Synchronizing...\n" ); for (t = 0; t < 2; t++) @@ -1100,16 +1100,22 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux for (t = 0; t < 2; t++) { debug( "synchronizing new messages on %s\n", str_fn[t^1] ); + int topping = 1; for (tmsg = svars->msgs[t^1]; tmsg; tmsg = tmsg->next) { if (tmsg->status & M_DEAD) continue; srec = tmsg->srec; if (srec) { + // This covers legacy (or somehow corrupted) state files which + // failed to track maxuid properly. + // Note that this doesn't work in the presence of skipped or + // failed messages. We could start keeping zombie entries, but + // this wouldn't help with legacy state files. + if (topping && svars->newmaxuid[t^1] < tmsg->uid) + svars->newmaxuid[t^1] = tmsg->uid; + if (srec->status & S_SKIPPED) { // Pre-1.4 legacy only: The message was skipped due to being too big. - // We must have already seen the UID, but we might have been interrupted. - if (svars->maxuid[t^1] < tmsg->uid) - svars->maxuid[t^1] = tmsg->uid; if (!(svars->chan->ops[t] & OP_RENEW)) continue; srec->status = S_PENDING; @@ -1124,27 +1130,18 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux } else { if (!(svars->chan->ops[t] & OP_NEW)) continue; - // This catches messages: - // - that are actually new - // - whose propagation got interrupted - // - whose propagation was completed, but not logged yet - // - that aren't actually new, but a result of syncing, and the instant - // maxuid upping was prevented by the presence of actually new messages - if (svars->maxuid[t^1] < tmsg->uid) - svars->maxuid[t^1] = tmsg->uid; if (!(srec->status & S_PENDING)) continue; // Nothing to do - the message is paired or expired // Propagation was scheduled, but we got interrupted debug( "unpropagated old message %u\n", tmsg->uid ); } - - if ((svars->chan->ops[t] & OP_EXPUNGE) && (tmsg->flags & F_DELETED)) { - JLOG( "- %u %u", (srec->uid[F], srec->uid[N]), "killing - would be expunged anyway" ); - tmsg->srec = NULL; - srec->status = S_DEAD; - continue; - } } else { + // The 1st unknown message which should be known marks the end + // of the synced range; more known messages may follow (from an + // unidirectional sync in the opposite direction). + if (t == F || tmsg->uid > svars->maxxfuid) + topping = 0; + if (!(svars->chan->ops[t] & OP_NEW)) continue; if (tmsg->uid <= svars->maxuid[t^1]) { @@ -1154,14 +1151,8 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux // - ignored, as it would have been expunged anyway => ignore (even if undeleted) continue; } - svars->maxuid[t^1] = tmsg->uid; debug( "new message %u\n", tmsg->uid ); - if ((svars->chan->ops[t] & OP_EXPUNGE) && (tmsg->flags & F_DELETED)) { - debug( "-> ignoring - would be expunged anyway\n" ); - continue; - } - srec = nfzalloc( sizeof(*srec) ); *svars->srecadd = srec; svars->srecadd = &srec->next; @@ -1170,8 +1161,19 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux srec->uid[t^1] = tmsg->uid; srec->msg[t^1] = tmsg; tmsg->srec = srec; + if (svars->newmaxuid[t^1] < tmsg->uid) + svars->newmaxuid[t^1] = tmsg->uid; JLOG( "+ %u %u", (srec->uid[F], srec->uid[N]), "fresh" ); } + if ((svars->chan->ops[t] & OP_EXPUNGE) && (tmsg->flags & F_DELETED)) { + // Yes, we may nuke fresh entries, created only for newmaxuid tracking. + // It would be lighter on the journal to log a (compressed) skip, but + // this rare case does not justify additional complexity. + JLOG( "- %u %u", (srec->uid[F], srec->uid[N]), "killing - would be expunged anyway" ); + tmsg->srec = NULL; + srec->status = S_DEAD; + continue; + } if (!(tmsg->flags & F_FLAGGED) && tmsg->size > svars->chan->stores[t]->max_size && !(srec->status & (S_DUMMY(F) | S_DUMMY(N) | S_UPGRADE))) { srec->status |= S_DUMMY(t); @@ -1760,6 +1762,7 @@ box_closed_p2( sync_vars_t *svars, int t ) // ensure that all pending messages are still loaded next time in case // of interruption - in particular skipping messages would otherwise // up the limit too early. + svars->maxuid[t] = svars->newmaxuid[t]; if (svars->maxuid[t] != svars->oldmaxuid[t]) PC_JLOG( "N %d %u", (t, svars->maxuid[t]), "up maxuid of %s", str_fn[t] ); } diff --git a/src/sync_p.h b/src/sync_p.h @@ -57,6 +57,7 @@ typedef struct { uint new_pending[2], flags_pending[2], trash_pending[2]; uint maxuid[2]; // highest UID that was already propagated uint oldmaxuid[2]; // highest UID that was already propagated before this run + uint newmaxuid[2]; // highest UID that is currently being propagated uint uidval[2]; // UID validity value uint newuidval[2]; // UID validity obtained from driver uint finduid[2]; // TUID lookup makes sense only for UIDs >= this diff --git a/src/sync_state.c b/src/sync_state.c @@ -255,6 +255,8 @@ load_state( sync_vars_t *svars ) svars->maxxfuid = minwuid - 1; } + svars->newmaxuid[F] = svars->maxuid[F]; + svars->newmaxuid[N] = svars->maxuid[N]; int line = 0; if ((jfp = fopen( svars->jname, "r" ))) { if (!lock_state( svars )) @@ -319,7 +321,7 @@ load_state( sync_vars_t *svars ) goto jbail; } if (c == 'N') { - svars->maxuid[t1] = t2; + svars->maxuid[t1] = svars->newmaxuid[t1] = t2; debug( " maxuid of %s now %u\n", str_fn[t1], t2 ); } else if (c == 'F') { svars->finduid[t1] = t2; @@ -335,6 +337,10 @@ load_state( sync_vars_t *svars ) srec = nfzalloc( sizeof(*srec) ); srec->uid[F] = t1; srec->uid[N] = t2; + if (svars->newmaxuid[F] < t1) + svars->newmaxuid[F] = t1; + if (svars->newmaxuid[N] < t2) + svars->newmaxuid[N] = t2; debug( " new entry(%u,%u)\n", t1, t2 ); srec->status = S_PENDING; *svars->srecadd = srec; @@ -508,8 +514,8 @@ void assign_uid( sync_vars_t *svars, sync_rec_t *srec, int t, uint uid ) { srec->uid[t] = uid; - if (uid == svars->maxuid[t] + 1) - svars->maxuid[t] = uid; + if (uid == svars->newmaxuid[t] + 1) + svars->newmaxuid[t] = uid; srec->status &= ~(S_PENDING | S_UPGRADE); srec->tuid[0] = 0; }