[PATCH 4/6] cli/count: add --output=modifications

[David Bremner]

We need some way to extract the uuid/revision of the database, and
count seems like the least bad choice of current commands.
The (perhaps weak) argument for count over search is that count
already reports statistics about the entire database.
---
 notmuch-count.c                | 18 +++++++++++++++++-
 test/T570-revision-tracking.sh | 12 ++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/notmuch-count.c b/notmuch-count.c
index 57a88a8..7c61ccb 100644
--- a/notmuch-count.c
+++ b/notmuch-count.c
@@ -25,6 +25,7 @@ enum {
     OUTPUT_THREADS,
     OUTPUT_MESSAGES,
     OUTPUT_FILES,
+    OUTPUT_LASTMOD,
 };
 
 /* The following is to allow future options to be added more easily */
@@ -71,6 +72,9 @@ print_count (notmuch_database_t *notmuch, const char *query_str,
 {
     notmuch_query_t *query;
     size_t i;
+    unsigned long revision;
+    const char *uuid;
+    int ret = 0;
 
     query = notmuch_query_create (notmuch, query_str);
     if (query == NULL) {
@@ -91,11 +95,22 @@ print_count (notmuch_database_t *notmuch, const char *query_str,
     case OUTPUT_FILES:
 	printf ("%u\n", count_files (query));
 	break;
+    case OUTPUT_LASTMOD:
+	if (strcmp (notmuch_query_get_query_string (query), "*") != 0) {
+	    fprintf (stderr, "Error: Only '*' is currently supported "
+		     " with output=modifications\n");
+	    ret = 1;
+	    goto DONE;
+	}
+
+	revision = notmuch_database_get_revision (notmuch, &uuid);
+	printf ("%s\t%lu\n", uuid, revision);
     }
 
+ DONE:
     notmuch_query_destroy (query);
 
-    return 0;
+    return ret;
 }
 
 static int
@@ -139,6 +154,7 @@ notmuch_count_command (notmuch_config_t *config, int argc, char *argv[])
 	  (notmuch_keyword_t []){ { "threads", OUTPUT_THREADS },
 				  { "messages", OUTPUT_MESSAGES },
 				  { "files", OUTPUT_FILES },
+				  { "modifications", OUTPUT_LASTMOD },
 				  { 0, 0 } } },
 	{ NOTMUCH_OPT_KEYWORD, &exclude, "exclude", 'x',
 	  (notmuch_keyword_t []){ { "true", EXCLUDE_TRUE },
diff --git a/test/T570-revision-tracking.sh b/test/T570-revision-tracking.sh
index 74a7c49..062fd59 100755
--- a/test/T570-revision-tracking.sh
+++ b/test/T570-revision-tracking.sh
@@ -34,4 +34,16 @@ UUID	53
 EOF
 test_expect_equal_file EXPECTED CLEAN
 
+grep '^[0-9a-f]' OUTPUT > INITIAL_OUTPUT
+
+test_begin_subtest "output of count matches test code"
+notmuch count --output=modifications '*' > OUTPUT
+test_expect_equal_file INITIAL_OUTPUT OUTPUT
+
+test_begin_subtest "modification count increases"
+before=$(notmuch count --output=modifications '*' | cut -f2)
+notmuch tag +a-random-tag-8743632 '*'
+after=$(notmuch count --output=modifications '*' | cut -f2)
+result=$(($before < $after))
+test_expect_equal 1 ${result}
 test_done
-- 
2.1.4