[db] charting of JSON values was mistakenly limited to very short values

src/base/intern_string.hh

@@ -138,6 +138,23 @@ struct string_fragment {
         return *prefix == '\0';
     }
 
+    bool endswith(const char* suffix) const
+    {
+        auto suffix_len = strlen(suffix);
+
+        if (suffix_len > this->length()) {
+            return false;
+        }
+
+        const auto* curr = this->end() - suffix_len;
+        while (*suffix != '\0' && *curr == *suffix) {
+            suffix += 1;
+            curr += 1;
+        }
+
+        return *suffix == '\0';
+    }
+
     string_fragment substr(int begin) const
     {
         return string_fragment{

src/db_sub_source.cc

@@ -40,6 +40,7 @@
 const char* db_label_source::NULL_STR = "<NULL>";
 
 constexpr size_t MAX_COLUMN_WIDTH = 120;
+constexpr size_t MAX_JSON_WIDTH = 16 * 1024;
 
 void
 db_label_source::text_value_for_line(textview_curses& tc,
@@ -134,7 +135,7 @@ db_label_source::text_attrs_for_line(textview_curses& tc,
                     tc, left, this->dls_headers[lpc].hm_name, num_value, sa);
             }
         }
-        if (row_len > 2 && row_len < MAX_COLUMN_WIDTH
+        if (row_len > 2 && row_len < MAX_JSON_WIDTH
             && ((row_value[0] == '{' && row_value[row_len - 1] == '}')
                 || (row_value[0] == '[' && row_value[row_len - 1] == ']')))
         {
@@ -143,7 +144,7 @@ db_label_source::text_attrs_for_line(textview_curses& tc,
             if (jpw.parse(row_value, row_len) == yajl_status_ok
                 && jpw.complete_parse() == yajl_status_ok)
             {
-                for (auto& jpw_value : jpw.jpw_values) {
+                for (const auto& jpw_value : jpw.jpw_values) {
                     double num_value;
 
                     if (jpw_value.wt_type == yajl_t_number

src/hist_source.hh

@@ -203,7 +203,7 @@ public:
 
         lr.lr_start = left;
 
-        const struct chart_ident& ci = this->sbc_idents[ident_index];
+        const auto& ci = this->sbc_idents[ident_index];
         int amount;
 
         if (value == 0.0) {
@@ -240,8 +240,9 @@ public:
 
     struct bucket_stats_t {
         bucket_stats_t()
-            : bs_min_value(std::numeric_limits<double>::max()),
-              bs_max_value(0){};
+            : bs_min_value(std::numeric_limits<double>::max()), bs_max_value(0)
+        {
+        }
 
         void merge(const bucket_stats_t& rhs, bool do_stacking)
         {
@@ -252,18 +253,18 @@ public:
                 this->bs_max_value
                     = std::max(this->bs_max_value, rhs.bs_max_value);
             }
-        };
+        }
 
         double width() const
         {
             return std::fabs(this->bs_max_value - this->bs_min_value);
-        };
+        }
 
         void update(double value)
         {
             this->bs_max_value = std::max(this->bs_max_value, value);
             this->bs_min_value = std::min(this->bs_min_value, value);
-        };
+        }
 
         double bs_min_value;
         double bs_max_value;
@@ -278,7 +279,7 @@ public:
 
 protected:
     struct chart_ident {
-        chart_ident(const T& ident) : ci_ident(ident) {}
+        explicit chart_ident(const T& ident) : ci_ident(ident) {}
 
         T ci_ident;
         int ci_attrs{0};
@@ -287,12 +288,10 @@ protected:
 
     struct chart_ident& find_ident(const T& ident)
     {
-        typename std::map<T, unsigned int>::iterator iter;
-
-        iter = this->sbc_ident_lookup.find(ident);
+        auto iter = this->sbc_ident_lookup.find(ident);
         if (iter == this->sbc_ident_lookup.end()) {
             this->sbc_ident_lookup[ident] = this->sbc_idents.size();
-            this->sbc_idents.push_back(ident);
+            this->sbc_idents.emplace_back(ident);
             return this->sbc_idents.back();
         }
         return this->sbc_idents[iter->second];

src/json-extension-functions.cc

@@ -517,7 +517,7 @@ json_concat(nonstd::optional<const char*> json_in,
                     array.gen(sqlite3_value_double(val));
                     break;
                 case SQLITE3_TEXT: {
-                    auto text_val = sqlite3_value_text(val);
+                    const auto* text_val = sqlite3_value_text(val);
 
                     if (sqlite3_value_subtype(val) == JSON_SUBTYPE) {
                         concat_gen_elements(
@@ -534,6 +534,47 @@ json_concat(nonstd::optional<const char*> json_in,
     return json_string(gen);
 }
 
+#if 0
+static flattened_json_string
+sql_flatten_json_object(string_fragment sf)
+{
+    yajlpp_gen gen;
+
+    {
+        json_ptr jp("/");
+        json_op jo(jp);
+        auto_mem<yajl_handle_t> handle(yajl_free);
+
+        jo.jo_ptr_data = gen.get_handle();
+        yajl_gen_config(gen, yajl_gen_beautify, false);
+        handle.reset(yajl_alloc(&json_op::gen_callbacks, nullptr, &jo));
+        switch (yajl_parse(
+            handle.in(), (const unsigned char*) sf.data(), sf.length())) {
+            case yajl_status_error:
+            case yajl_status_client_canceled:
+                throw yajlpp_error(handle.in(), sf.data(), sf.length());
+            case yajl_status_ok:
+                break;
+        }
+        switch (yajl_complete_parse(handle.in())) {
+            case yajl_status_error:
+            case yajl_status_client_canceled:
+                throw yajlpp_error(handle.in(), sf.data(), sf.length());
+            case yajl_status_ok:
+                break;
+        }
+    }
+
+    auto result = gen.to_string_fragment();
+    if (!result.startswith("{") || !result.endswith("}")) {
+        throw std::runtime_error(
+            "flatten_json_object() requires a JSON object");
+    }
+
+    return flattened_json_string(gen);
+}
+#endif
+
 struct json_agg_context {
     yajl_gen_t* jac_yajl_gen;
 };
@@ -797,6 +838,14 @@ json_extension_functions(struct FuncDef** basic_funcs,
                 }),
         },
 
+#if 0
+        sqlite_func_adapter<decltype(&sql_flatten_json_object),
+                            sql_flatten_json_object>::
+            builder(help_text("flatten_json_object", "hello")
+                        .sql_function()
+                        .with_parameter({"json", "The JSON"})),
+#endif
+
         {nullptr},
     };
 

src/vtab_module.hh

@@ -282,7 +282,8 @@ to_sqlite(sqlite3_context* ctx, double val)
     sqlite3_result_double(ctx, val);
 }
 
-#define JSON_SUBTYPE 74 /* Ascii for "J" */
+#define JSON_SUBTYPE    74 /* Ascii for "J" */
+#define FLATTEN_SUBTYPE 0x5f
 
 template<typename T>
 inline void

src/vtab_module_json.hh

@@ -35,6 +35,18 @@
 #include "vtab_module.hh"
 #include "yajlpp/yajlpp.hh"
 
+struct flattened_json_string : json_string {
+    explicit flattened_json_string(yajl_gen_t* gen) : json_string(gen) {}
+};
+
+inline void
+to_sqlite(sqlite3_context* ctx, flattened_json_string& val)
+{
+    sqlite3_result_text(
+        ctx, (const char*) val.js_content.release(), val.js_len, free);
+    sqlite3_result_subtype(ctx, FLATTEN_SUBTYPE);
+}
+
 inline void
 to_sqlite(sqlite3_context* ctx, json_string& val)
 {

src/yajlpp/json_op.hh

@@ -59,7 +59,9 @@ public:
     const static yajl_callbacks ptr_callbacks;
 
     explicit json_op(const json_ptr& ptr)
-        : jo_ptr(ptr), jo_ptr_callbacks(gen_callbacks){};
+        : jo_ptr(ptr), jo_ptr_callbacks(gen_callbacks)
+    {
+    }
 
     bool check_index(bool primitive = true)
     {