[sql] fix joins on some vtables

src/fstat_vtab.cc

@@ -104,11 +104,10 @@ CREATE TABLE fstat (
         sqlite3_vtab_cursor base;
         string c_pattern;
         static_root_mem<glob_t, globfree> c_glob;
-        size_t c_path_index;
+        size_t c_path_index{0};
         struct stat c_stat;
 
-        cursor(sqlite3_vtab *vt)
-                : base({vt}), c_path_index(0) {
+        cursor(sqlite3_vtab *vt) : base({vt}) {
             memset(&this->c_stat, 0, sizeof(this->c_stat));
         };
 
@@ -129,6 +128,10 @@ CREATE TABLE fstat (
             return SQLITE_OK;
         };
 
+        int reset() {
+            return SQLITE_OK;
+        }
+
         int eof() {
             return this->c_path_index >= this->c_glob->gl_pathc;
         };

src/regexp_vtab.cc

@@ -103,6 +103,10 @@ CREATE TABLE regexp_capture (
             this->c_context.set_count(0);
         };
 
+        int reset() {
+            return SQLITE_OK;
+        };
+
         int next() {
             if (this->c_index >= (this->c_context.get_count() - 1)) {
                 this->c_input->pi_offset = this->c_input->pi_next_offset;

src/views_vtab.cc

@@ -542,8 +542,8 @@ CREATE TABLE lnav_view_filters (
 struct lnav_view_filter_stats : public tvt_iterator_cursor<lnav_view_filter_stats>,
     public lnav_view_filter_base {
     static constexpr const char *CREATE_STMT = R"(
--- Access lnav's filters through this table.
-CREATE TABLE lnav_view_filters (
+-- Access statistics for filters through this table.
+CREATE TABLE lnav_view_filter_stats (
     view_name TEXT,     -- The name of the view.
     filter_id INTEGER,  -- The filter identifier.
     hits      INTEGER   -- The number of lines that matched this filter.
@@ -574,6 +574,11 @@ CREATE TABLE lnav_view_filters (
     }
 };
 
+static const char *CREATE_FILTER_VIEW = R"(
+CREATE VIEW lnav_view_filters_and_stats AS
+  SELECT * FROM lnav_view_filters LEFT NATURAL JOIN lnav_view_filter_stats
+)";
+
 int register_views_vtab(sqlite3 *db)
 {
     static vtab_module<lnav_views> LNAV_VIEWS_MODULE;
@@ -595,5 +600,11 @@ int register_views_vtab(sqlite3 *db)
     rc = LNAV_VIEW_FILTER_STATS_MODULE.create(db, "lnav_view_filter_stats");
     assert(rc == SQLITE_OK);
 
+    char *errmsg;
+    if (sqlite3_exec(db, CREATE_FILTER_VIEW, nullptr, nullptr, &errmsg) != SQLITE_OK) {
+        log_error("Unable to create filter view: %s", errmsg);
+
+    }
+
     return rc;
 }

src/vtab_module.hh

@@ -610,7 +610,9 @@ struct vtab_module {
     static int vt_filter(sqlite3_vtab_cursor *p_vtc,
                          int idxNum, const char *idxStr,
                          int argc, sqlite3_value **argv) {
-        return SQLITE_OK;
+        auto *p_cur = (typename T::cursor *) p_vtc;
+
+        return p_cur->reset();
     }
 
     static int tvt_update(sqlite3_vtab *tab,
@@ -698,6 +700,14 @@ struct tvt_iterator_cursor {
             this->iter = handler.begin();
         };
 
+        int reset() {
+            T handler;
+
+            this->iter = handler.begin();
+
+            return SQLITE_OK;
+        };
+
         int next()
         {
             T handler;

test/test_sql.sh

@@ -666,7 +666,7 @@ EOF
 
 
 schema_dump() {
-    ${lnav_test} -n -c ';.schema' ${test_dir}/logfile_access_log.0 | head -n15
+    ${lnav_test} -n -c ';.schema' ${test_dir}/logfile_access_log.0 | head -n17
 }
 
 run_test schema_dump
@@ -678,6 +678,8 @@ CREATE VIRTUAL TABLE lnav_views USING lnav_views_impl();
 CREATE VIRTUAL TABLE lnav_view_stack USING lnav_view_stack_impl();
 CREATE VIRTUAL TABLE lnav_view_filters USING lnav_view_filters_impl();
 CREATE VIRTUAL TABLE lnav_view_filter_stats USING lnav_view_filter_stats_impl();
+CREATE VIEW lnav_view_filters_and_stats AS
+  SELECT * FROM lnav_view_filters LEFT NATURAL JOIN lnav_view_filter_stats;
 CREATE VIRTUAL TABLE lnav_file USING lnav_file_impl();
 CREATE VIRTUAL TABLE regexp_capture USING regexp_capture_impl();
 CREATE VIRTUAL TABLE fstat USING fstat_impl();