cli/count: add --lastmod

In the short term we need a way to get lastmod information e.g. for
the test suite. In the long term we probably want to add lastmod
information to at least the structured output for several other
clients (e.g. show, search).

doc/man1/notmuch-count.rst

@@ -47,6 +47,11 @@ Supported options for **count** include
         (or threads) in the database will be output. This option is not
         compatible with specifying search terms on the command line.
 
+    ``--lastmod``
+	Append lastmod (counter for number of database updates) and UUID
+	to the output. lastmod values are only comparable between databases
+	with the same UUID.
+
     ``--input=``\ <filename>
         Read input from given file, instead of from stdin. Implies
         ``--batch``.

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 */
@@ -67,10 +68,13 @@ count_files (notmuch_query_t *query)
 
 static int
 print_count (notmuch_database_t *notmuch, const char *query_str,
-	     const char **exclude_tags, size_t exclude_tags_length, int output)
+	     const char **exclude_tags, size_t exclude_tags_length, int output, int print_lastmod)
 {
     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) {
@@ -83,24 +87,31 @@ print_count (notmuch_database_t *notmuch, const char *query_str,
 
     switch (output) {
     case OUTPUT_MESSAGES:
-	printf ("%u\n", notmuch_query_count_messages (query));
+	printf ("%u", notmuch_query_count_messages (query));
 	break;
     case OUTPUT_THREADS:
-	printf ("%u\n", notmuch_query_count_threads (query));
+	printf ("%u", notmuch_query_count_threads (query));
 	break;
     case OUTPUT_FILES:
-	printf ("%u\n", count_files (query));
+	printf ("%u", count_files (query));
 	break;
     }
 
+    if (print_lastmod) {
+	revision = notmuch_database_get_revision (notmuch, &uuid);
+	printf ("\t%s\t%lu\n", uuid, revision);
+    } else {
+	fputs ("\n", stdout);
+    }
+
     notmuch_query_destroy (query);
 
-    return 0;
+    return ret;
 }
 
 static int
 count_file (notmuch_database_t *notmuch, FILE *input, const char **exclude_tags,
-	    size_t exclude_tags_length, int output)
+	    size_t exclude_tags_length, int output, int print_lastmod)
 {
     char *line = NULL;
     ssize_t line_len;
@@ -110,7 +121,7 @@ count_file (notmuch_database_t *notmuch, FILE *input, const char **exclude_tags,
     while (!ret && (line_len = getline (&line, &line_size, input)) != -1) {
 	chomp_newline (line);
 	ret = print_count (notmuch, line, exclude_tags, exclude_tags_length,
-			   output);
+			   output, print_lastmod);
     }
 
     if (line)
@@ -130,6 +141,7 @@ notmuch_count_command (notmuch_config_t *config, int argc, char *argv[])
     const char **search_exclude_tags = NULL;
     size_t search_exclude_tags_length = 0;
     notmuch_bool_t batch = FALSE;
+    notmuch_bool_t print_lastmod = FALSE;
     FILE *input = stdin;
     char *input_file_name = NULL;
     int ret;
@@ -139,11 +151,13 @@ 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 },
 				  { "false", EXCLUDE_FALSE },
 				  { 0, 0 } } },
+	{ NOTMUCH_OPT_BOOLEAN, &print_lastmod, "lastmod", 'l', 0 },
 	{ NOTMUCH_OPT_BOOLEAN, &batch, "batch", 0, 0 },
 	{ NOTMUCH_OPT_STRING, &input_file_name, "input", 'i', 0 },
 	{ NOTMUCH_OPT_INHERIT, (void *) &notmuch_shared_options, NULL, 0, 0 },
@@ -188,10 +202,10 @@ notmuch_count_command (notmuch_config_t *config, int argc, char *argv[])
 
     if (batch)
 	ret = count_file (notmuch, input, search_exclude_tags,
-			  search_exclude_tags_length, output);
+			  search_exclude_tags_length, output, print_lastmod);
     else
 	ret = print_count (notmuch, query_str, search_exclude_tags,
-			   search_exclude_tags_length, output);
+			   search_exclude_tags_length, output, print_lastmod);
 
     notmuch_database_destroy (notmuch);
 

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 --lastmod '*' | cut -f2-3 > OUTPUT
+test_expect_equal_file INITIAL_OUTPUT OUTPUT
+
+test_begin_subtest "modification count increases"
+before=$(notmuch count --lastmod '*' | cut -f3)
+notmuch tag +a-random-tag-8743632 '*'
+after=$(notmuch count --lastmod '*' | cut -f3)
+result=$(($before < $after))
+test_expect_equal 1 ${result}
 test_done