db-ctl-base: Give better error messages for ambiguous abbreviations.

Tables and columns may be abbreviated to unique prefixes, but until now the error messages have just said there's more than one match. This commit makes the error messages list the possibilities. Reviewed-by: Yifeng Sun <[email protected]> Signed-off-by: Ben Pfaff <[email protected]>
shqyang · Sep 18, 2019 · cf0e423 · cf0e423
1 parent 3ae9a07
commit cf0e423
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Showing 2 changed files with 41 additions and 22 deletions.
diff --git a/lib/db-ctl-base.c b/lib/db-ctl-base.c
@@ -430,31 +430,39 @@ static char *
 get_column(const struct ovsdb_idl_table_class *table, const char *column_name,
            const struct ovsdb_idl_column **columnp)
 {
+    struct sset best_matches = SSET_INITIALIZER(&best_matches);
     const struct ovsdb_idl_column *best_match = NULL;
     unsigned int best_score = 0;
-    size_t i;
 
-    for (i = 0; i < table->n_columns; i++) {
+    for (size_t i = 0; i < table->n_columns; i++) {
         const struct ovsdb_idl_column *column = &table->columns[i];
         unsigned int score = score_partial_match(column->name, column_name);
-        if (score > best_score) {
+        if (score && score >= best_score) {
+            if (score > best_score) {
+                sset_clear(&best_matches);
+            }
+            sset_add(&best_matches, column->name);
             best_match = column;
             best_score = score;
-        } else if (score == best_score) {
-            best_match = NULL;
         }
     }
 
-    *columnp = best_match;
-    if (best_match) {
-        return NULL;
-    } else if (best_score) {
-        return xasprintf("%s contains more than one column whose name "
-                         "matches \"%s\"", table->name, column_name);
+    char *error = NULL;
+    *columnp = NULL;
+    if (!best_match) {
+        error = xasprintf("%s does not contain a column whose name matches "
+                          "\"%s\"", table->name, column_name);
+    } else if (sset_count(&best_matches) == 1) {
+        *columnp = best_match;
     } else {
-        return xasprintf("%s does not contain a column whose name matches "
-                         "\"%s\"", table->name, column_name);
+        char *matches = sset_join(&best_matches, ", ", "");
+        error = xasprintf("%s contains more than one column "
+                          "whose name matches \"%s\": %s",
+                          table->name, column_name, matches);
+        free(matches);
     }
+    sset_destroy(&best_matches);
+    return error;
 }
 
 static char * OVS_WARN_UNUSED_RESULT
@@ -1207,27 +1215,35 @@ cmd_list(struct ctl_context *ctx)
 static char * OVS_WARN_UNUSED_RESULT
 get_table(const char *table_name, const struct ovsdb_idl_table_class **tablep)
 {
+    struct sset best_matches = SSET_INITIALIZER(&best_matches);
     const struct ovsdb_idl_table_class *best_match = NULL;
     unsigned int best_score = 0;
-    char *error = NULL;
 
     for (const struct ovsdb_idl_table_class *table = idl_classes;
          table < &idl_classes[n_classes]; table++) {
         unsigned int score = score_partial_match(table->name, table_name);
-        if (score > best_score) {
+        if (score && score >= best_score) {
+            if (score > best_score) {
+                sset_clear(&best_matches);
+            }
+            sset_add(&best_matches, table->name);
             best_match = table;
             best_score = score;
-        } else if (score == best_score) {
-            best_match = NULL;
         }
     }
-    if (best_match) {
+
+    char *error = NULL;
+    if (!best_match) {
+        error = xasprintf("unknown table \"%s\"", table_name);
+    } else if (sset_count(&best_matches) == 1) {
         *tablep = best_match;
-    } else if (best_score) {
-        error = xasprintf("multiple table names match \"%s\"", table_name);
     } else {
-        error = xasprintf("unknown table \"%s\"", table_name);
+        char *matches = sset_join(&best_matches, ", ", "");
+        error = xasprintf("\"%s\" matches multiple table names: %s",
+                          table_name, matches);
+        free(matches);
     }
+    sset_destroy(&best_matches);
     return error;
 }
 

diff --git a/tests/ovs-vsctl.at b/tests/ovs-vsctl.at
@@ -848,14 +848,17 @@ targets             : ["1.2.3.4:567"]
 AT_CHECK([RUN_OVS_VSCTL([list interx x])],
   [1], [], [ovs-vsctl: unknown table "interx"
 ])
+AT_CHECK([RUN_OVS_VSCTL([list c x])],
+  [1], [], [ovs-vsctl: "c" matches multiple table names: CT_Timeout_Policy, CT_Zone, Controller
+])
 AT_CHECK([RUN_OVS_VSCTL([list bridge x])],
   [1], [], [ovs-vsctl: no row "x" in table Bridge
 ])
 AT_CHECK([RUN_OVS_VSCTL([get bridge x datapath_id])],
   [1], [], [ovs-vsctl: no row "x" in table Bridge
 ])
 AT_CHECK([RUN_OVS_VSCTL([get bridge br0 d])],
-  [1], [], [ovs-vsctl: Bridge contains more than one column whose name matches "d"
+  [1], [], [ovs-vsctl: Bridge contains more than one column whose name matches "d": datapath_id, datapath_type, datapath_version
 ])
 AT_CHECK([RUN_OVS_VSCTL([get bridge br0 x])],
   [1], [], [ovs-vsctl: Bridge does not contain a column whose name matches "x"