[ovs-dev] [PATCH v2 1/2] table: Create method for resetting table formatting.

Mark Michelson mmichels at redhat.com
Mon Oct 8 18:49:07 UTC 2018


Table formatting has a local static integer that is intended to insert
line breaks between tables. This works exactly as intended, as long as
each call to table_format() is done as a single unit within the run of a
process.

When ovn-nbctl is run in daemon mode, it is a long-running process that
makes multiple calls to table_format() throughout its lifetime. After
the first call, this results in an unexpected newline prepended to table
output on each subsequent ovn-nbctl invocation.

The solution is to introduce a function to reset table formatting. This
way, the first time after resetting table formatting, no newline is
prepended.

Signed-off-by: Mark Michelson <mmichels at redhat.com>
---
 lib/table.c               | 23 +++++++++++++++++------
 lib/table.h               |  1 +
 ovn/utilities/ovn-nbctl.c |  1 +
 tests/ovn-nbctl.at        | 13 +++++++++++++
 4 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/lib/table.c b/lib/table.c
index ab72668c7..48d18b651 100644
--- a/lib/table.c
+++ b/lib/table.c
@@ -236,15 +236,18 @@ table_print_timestamp__(const struct table *table, struct ds *s)
     }
 }
 
+static bool first_table = true;
+
 static void
 table_print_table__(const struct table *table, const struct table_style *style,
                     struct ds *s)
 {
-    static int n = 0;
     int *widths;
     size_t x, y;
 
-    if (n++ > 0) {
+    if (first_table) {
+        first_table = false;
+    } else {
         ds_put_char(s, '\n');
     }
 
@@ -318,10 +321,11 @@ static void
 table_print_list__(const struct table *table, const struct table_style *style,
                    struct ds *s)
 {
-    static int n = 0;
     size_t x, y;
 
-    if (n++ > 0) {
+    if (first_table) {
+        first_table = false;
+    } else {
         ds_put_char(s, '\n');
     }
 
@@ -469,10 +473,11 @@ static void
 table_print_csv__(const struct table *table, const struct table_style *style,
                   struct ds *s)
 {
-    static int n = 0;
     size_t x, y;
 
-    if (n++ > 0) {
+    if (first_table) {
+        first_table = false;
+    } else {
         ds_put_char(s, '\n');
     }
 
@@ -614,6 +619,12 @@ table_format(const struct table *table, const struct table_style *style,
     }
 }
 
+void
+table_format_reset(void)
+{
+    first_table = true;
+}
+
 /* Outputs 'table' on stdout in the specified 'style'. */
 void
 table_print(const struct table *table, const struct table_style *style)
diff --git a/lib/table.h b/lib/table.h
index 76e65bb70..33263e2a2 100644
--- a/lib/table.h
+++ b/lib/table.h
@@ -133,6 +133,7 @@ void table_parse_cell_format(struct table_style *, const char *format);
 void table_print(const struct table *, const struct table_style *);
 void table_format(const struct table *, const struct table_style *,
                   struct ds *);
+void table_format_reset(void);
 void table_usage(void);
 
 #endif /* table.h */
diff --git a/ovn/utilities/ovn-nbctl.c b/ovn/utilities/ovn-nbctl.c
index eabd30308..d65a9ba08 100644
--- a/ovn/utilities/ovn-nbctl.c
+++ b/ovn/utilities/ovn-nbctl.c
@@ -5311,6 +5311,7 @@ server_cmd_run(struct unixctl_conn *conn, int argc, const char **argv_,
     }
 
     struct ds output = DS_EMPTY_INITIALIZER;
+    table_format_reset();
     for (struct ctl_command *c = commands; c < &commands[n_commands]; c++) {
         if (c->table) {
             table_format(c->table, &table_style, &output);
diff --git a/tests/ovn-nbctl.at b/tests/ovn-nbctl.at
index a599b1bf7..7d627cdc0 100644
--- a/tests/ovn-nbctl.at
+++ b/tests/ovn-nbctl.at
@@ -1517,3 +1517,16 @@ AT_CHECK([ovn-nbctl create Port_Group name=pg0], [0], [ignore])
 AT_CHECK([ovn-nbctl get Port_Group pg0 name], [0], [dnl
 "pg0"
 ])])
+
+
+OVN_NBCTL_TEST([ovn_nbctl_extra_newlines], [extra newlines], [
+dnl This test addresses a specific issue seen when running ovn-nbctl in
+dnl daemon mode. All we have to do is ensure that each time we list database
+dnl information, there is not an extra newline at the beginning of the output.
+AT_CHECK([ovn-nbctl ls-add sw1], [0], [ignore])
+AT_CHECK([ovn-nbctl --columns=name list logical_switch sw1], [0], [dnl
+name                : "sw1"
+])
+AT_CHECK([ovn-nbctl --columns=name list logical_switch sw1], [0], [dnl
+name                : "sw1"
+])])
-- 
2.14.4



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