isync

mailbox synchronization program
git clone https://git.code.sf.net/p/isync/isync
Log | Files | Refs | README | LICENSE

commit 68a412115a75223fb9561f0a467970d2a4af65bf
parent 0e5046e14afbaee599387cbbdc997c9669b8879c
Author: Oswald Buddenhagen <ossi@users.sf.net>
Date:   Mon, 25 Nov 2019 20:55:41 +0100

don't rewrite state gratuitously

delay the creation of the new state and journal until there is actually
something interesting to write. this saves some cpu cycles and prolongs
ssd life a whee bit.

Diffstat:
Msrc/run-tests.pl | 5+++--
Msrc/sync.c | 71++++++++++++++++++++++++++++++++++++++++++++++++++---------------------
2 files changed, 53 insertions(+), 23 deletions(-)

diff --git a/src/run-tests.pl b/src/run-tests.pl @@ -702,7 +702,7 @@ sub test($$$@) rmtree "far"; my $njl = (@nj - 1) * 2; - for (my $l = 2; $l < $njl; $l++) { + for (my $l = 1; $l <= $njl; $l++) { mkchan($$sx[0], $$sx[1], @{ $$sx[2] }); my ($nxc, @nret) = runsync("-J$l", "4-interrupt.log"); @@ -721,7 +721,8 @@ sub test($$$@) print "Options:\n"; print " [ ".join(", ", map('"'.qm($_).'"', @sfx))." ]\n"; my @nnj = readfile("near/.mbsyncstate.journal"); - print "Journal:\n".join("", @nnj[0..($l / 2 - 1)])."-------\n".join("", @nnj[($l / 2)..$#nnj])."\n"; + my $ln = int($l / 2); + print "Journal:\n".join("", @nnj[0..$ln])."-------\n".join("", @nnj[($ln + 1)..$#nnj])."\n"; print "Full journal:\n".join("", @nj)."\n"; if (!$nxc) { print "Expected result:\n"; diff --git a/src/sync.c b/src/sync.c @@ -39,6 +39,8 @@ # define fdatasync fsync #endif +#define JOURNAL_VERSION "4" + channel_conf_t global_conf; channel_conf_t *channels; group_conf_t *groups; @@ -167,10 +169,12 @@ typedef struct { uint ref_count, nsrecs, opts[2]; 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 uidval[2]; // UID validity value uint newuidval[2]; // UID validity obtained from driver uint finduid[2]; // TUID lookup makes sense only for UIDs >= this uint maxxfuid; // highest expired UID on far side + uint oldmaxxfuid; // highest expired UID on far side before this run uchar good_flags[2], bad_flags[2]; } sync_vars_t; @@ -218,6 +222,15 @@ static int check_cancel( sync_vars_t *svars ); #define ST_SENDING_NEW (1<<15) +static void +create_state( sync_vars_t *svars ) +{ + if (!(svars->nfp = fopen( svars->nname, "w" ))) { + sys_error( "Error: cannot create new sync state %s", svars->nname ); + exit( 1 ); + } +} + static void ATTR_PRINTFLIKE(2, 3) jFprintf( sync_vars_t *svars, const char *msg, ... ) { @@ -225,6 +238,16 @@ jFprintf( sync_vars_t *svars, const char *msg, ... ) if (JLimit && !--JLimit) exit( 101 ); + if (!svars->jfp) { + create_state( svars ); + if (!(svars->jfp = fopen( svars->jname, svars->replayed ? "a" : "w" ))) { + sys_error( "Error: cannot create journal %s", svars->jname ); + exit( 1 ); + } + setlinebuf( svars->jfp ); + if (!svars->replayed) + Fprintf( svars->jfp, JOURNAL_VERSION "\n" ); + } va_start( va, msg ); vFprintf( svars->jfp, msg, va ); va_end( va ); @@ -625,8 +648,6 @@ clean_strdup( const char *s ) } -#define JOURNAL_VERSION "4" - static int prepare_state( sync_vars_t *svars ) { @@ -704,6 +725,12 @@ save_state( sync_vars_t *svars ) sync_rec_t *srec; char fbuf[16]; /* enlarge when support for keywords is added */ + // If no change was made, the state is also unmodified. + if (!svars->jfp && !svars->replayed) + return; + + if (!svars->nfp) + create_state( svars ); Fprintf( svars->nfp, "FarUidValidity %u\nNearUidValidity %u\nMaxPulledUid %u\nMaxPushedUid %u\n", svars->uidval[F], svars->uidval[N], svars->maxuid[F], svars->maxuid[N] ); @@ -719,7 +746,8 @@ save_state( sync_vars_t *svars ) } Fclose( svars->nfp, 1 ); - Fclose( svars->jfp, 0 ); + if (svars->jfp) + Fclose( svars->jfp, 0 ); if (!(DFlags & KEEPJOURNAL)) { /* order is important! */ if (rename( svars->nname, svars->dname )) @@ -1234,18 +1262,6 @@ box_opened2( sync_vars_t *svars, int t ) if (!lock_state( svars )) goto bail; - if (!(svars->nfp = fopen( svars->nname, "w" ))) { - sys_error( "Error: cannot create new sync state %s", svars->nname ); - goto bail; - } - if (!(svars->jfp = fopen( svars->jname, "a" ))) { - sys_error( "Error: cannot create journal %s", svars->jname ); - fclose( svars->nfp ); - goto bail; - } - setlinebuf( svars->jfp ); - if (!svars->replayed) - jFprintf( svars, JOURNAL_VERSION "\n" ); opts[F] = opts[N] = 0; if (fails) @@ -1495,10 +1511,16 @@ 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->oldmaxxfuid = svars->maxxfuid; + info( "Synchronizing...\n" ); for (t = 0; t < 2; t++) svars->good_flags[t] = (uchar)svars->drv[t]->get_supported_flags( svars->ctx[t] ); + int any_new[2] = { 0, 0 }; + debug( "synchronizing old entries\n" ); for (srec = svars->srecs; srec; srec = srec->next) { if (srec->status & S_DEAD) @@ -1643,6 +1665,7 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux srec->status = S_PENDING; JLOG( "~ %u %u %u", (srec->uid[F], srec->uid[N], srec->status), "was too big" ); } + any_new[t] = 1; } else { if (srec->status == S_SKIPPED) { debug( "-> still too big\n" ); @@ -1825,12 +1848,16 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux } debug( "propagating new messages\n" ); - if (UseFSync) + if (UseFSync && svars->jfp) fdatasync( fileno( svars->jfp ) ); for (t = 0; t < 2; t++) { - svars->finduid[t] = svars->drv[t]->get_uidnext( svars->ctx[t] ); - JLOG( "F %d %u", (t, svars->finduid[t]), "save UIDNEXT of %s", str_fn[t] ); - svars->new_msgs[t] = svars->msgs[1-t]; + if (any_new[t]) { + svars->finduid[t] = svars->drv[t]->get_uidnext( svars->ctx[t] ); + JLOG( "F %d %u", (t, svars->finduid[t]), "save UIDNEXT of %s", str_fn[t] ); + svars->new_msgs[t] = svars->msgs[1-t]; + } else { + svars->state[t] |= ST_SENT_NEW; + } msgs_copied( svars, t ); if (check_cancel( svars )) goto out; @@ -2164,7 +2191,8 @@ 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 big messages would otherwise // up the limit too early. - JLOG( "N %d %u", (t, svars->maxuid[t]), "up maxuid of %s", str_fn[t] ); + if (svars->maxuid[t] != svars->oldmaxuid[t]) + JLOG( "N %d %u", (t, svars->maxuid[t]), "up maxuid of %s", str_fn[t] ); } if (((svars->state[F] | svars->state[N]) & ST_DID_EXPUNGE) || svars->chan->max_messages) { @@ -2191,7 +2219,8 @@ box_closed_p2( sync_vars_t *svars, int t ) // This is just an optimization, so it needs no journaling of intermediate states. // However, doing it before the entry purge would require ensuring that the // exception list includes all relevant messages. - JLOG( "! %u", svars->maxxfuid, "max expired UID on far side" ); + if (svars->maxxfuid != svars->oldmaxxfuid) + JLOG( "! %u", svars->maxxfuid, "max expired UID on far side" ); save_state( svars );