From: Austin Clements <aclements@csail.mit.edu> This exposes the committed database revision to library users along with a UUID that can be used to detect when revision numbers are no longer comparable (e.g., because the database has been replaced). --- lib/database-private.h | 1 + lib/database.cc | 11 +++++++++++ lib/notmuch.h | 18 ++++++++++++++++++ test/T570-revision-tracking.sh | 37 +++++++++++++++++++++++++++++++++++++ 4 files changed, 67 insertions(+) create mode 100755 test/T570-revision-tracking.sh diff --git a/lib/database-private.h b/lib/database-private.h index 5c5a2bb..4e93257 100644 --- a/lib/database-private.h +++ b/lib/database-private.h @@ -170,6 +170,7 @@ struct _notmuch_database { * under a higher revision number, which can be generated with * notmuch_database_new_revision. */ unsigned long revision; + const char *uuid; Xapian::QueryParser *query_parser; Xapian::TermGenerator *term_gen; diff --git a/lib/database.cc b/lib/database.cc index 4378979..f88bdb3 100644 --- a/lib/database.cc +++ b/lib/database.cc @@ -978,6 +978,8 @@ notmuch_database_open_verbose (const char *path, notmuch->revision = 0; else notmuch->revision = Xapian::sortable_unserialise (last_mod); + notmuch->uuid = talloc_strdup ( + notmuch, notmuch->xapian_db->get_uuid ().c_str ()); notmuch->query_parser = new Xapian::QueryParser; notmuch->term_gen = new Xapian::TermGenerator; @@ -1651,6 +1653,15 @@ DONE: return NOTMUCH_STATUS_SUCCESS; } +unsigned long +notmuch_database_get_revision (notmuch_database_t *notmuch, + const char **uuid) +{ + if (uuid) + *uuid = notmuch->uuid; + return notmuch->revision; +} + /* We allow the user to use arbitrarily long paths for directories. But * we have a term-length limit. So if we exceed that, we'll use the * SHA-1 of the path for the database term. diff --git a/lib/notmuch.h b/lib/notmuch.h index 20c4e01..b6be727 100644 --- a/lib/notmuch.h +++ b/lib/notmuch.h @@ -461,6 +461,24 @@ notmuch_status_t notmuch_database_end_atomic (notmuch_database_t *notmuch); /** + * Return the committed database revision and UUID. + * + * The database revision number increases monotonically with each + * commit to the database. Hence, all messages and message changes + * committed to the database (that is, visible to readers) have a last + * modification revision <= the committed database revision. Any + * messages committed in the future will be assigned a modification + * revision > the committed database revision. + * + * The UUID is a NUL-terminated opaque string that uniquely identifies + * this database. Two revision numbers are only comparable if they + * have the same database UUID. + */ +unsigned long +notmuch_database_get_revision (notmuch_database_t *notmuch, + const char **uuid); + +/** * Retrieve a directory object from the database for 'path'. * * Here, 'path' should be a path relative to the path of 'database' diff --git a/test/T570-revision-tracking.sh b/test/T570-revision-tracking.sh new file mode 100755 index 0000000..8c12740 --- /dev/null +++ b/test/T570-revision-tracking.sh @@ -0,0 +1,37 @@ +#!/usr/bin/env bash +test_description="database revision tracking" + +. ./test-lib.sh + +add_email_corpus + +test_begin_subtest "notmuch_database_get_revision" +test_C ${MAIL_DIR} <<'EOF' +#include <stdio.h> +#include <string.h> +#include <notmuch.h> +int main (int argc, char** argv) +{ + notmuch_database_t *db; + notmuch_status_t stat; + long revision; + const char *uuid; + + unsigned long rev; + + stat = notmuch_database_open (argv[1], NOTMUCH_DATABASE_MODE_READ_ONLY, &db); + if (stat) + fputs ("open failed\n", stderr); + revision = notmuch_database_get_revision (db, &uuid); + printf("revision=%d\nuuid_len=%d\n", revision, strlen (uuid)); +} +EOF +cat <<'EOF' >EXPECTED +== stdout == +revision=53 +uuid_len=36 +== stderr == +EOF +test_expect_equal_file OUTPUT EXPECTED + +test_done -- 2.1.4