feat: Statistics - Export to CSV/TSV

src/app.cpp

@@ -16,6 +16,7 @@ void App::init(SDL_Window* window) {
     TRACE_FUNCTION_CAT("app");
     window_ = window;
     toolbar_.set_window(window);
+    stats_.set_window(window);
     load_settings();
     if (platform::supports_vsync()) {
         SDL_GL_SetSwapInterval(vsync_ ? 1 : 0);

src/platform/INDEX.md

@@ -13,6 +13,7 @@ void run_main_loop(void (*step)(), bool* running);
 std::string settings_path();
 bool supports_vsync();
 void open_file_dialog(SDL_Window*);
+void save_file_dialog(SDL_Window*, const std::string& default_name, const std::string& content);
 void handle_file_drop(const char* path);
 bool has_pending_file();
 PendingFile take_pending_file();

src/platform/platform.h

@@ -27,8 +27,9 @@ void run_main_loop(void (*step)(), bool* running);
 std::string settings_path();  // empty = no persistence
 bool supports_vsync();
 
-// File dialog
+// File dialogs
 void open_file_dialog(SDL_Window* window);
+void save_file_dialog(SDL_Window* window, const std::string& default_name, const std::string& content);
 
 // File drop handling (called from SDL event loop)
 void handle_file_drop(const char* path);

src/platform/platform_desktop.cpp

@@ -12,6 +12,19 @@ static void file_dialog_callback(void* /*userdata*/, const char* const* filelist
     }
 }
 
+static std::string g_save_content;
+
+static void save_dialog_callback(void* /*userdata*/, const char* const* filelist, int /*filter*/) {
+    if (filelist && filelist[0]) {
+        SDL_IOStream* io = SDL_IOFromFile(filelist[0], "w");
+        if (io) {
+            SDL_WriteIO(io, g_save_content.data(), g_save_content.size());
+            SDL_CloseIO(io);
+        }
+        g_save_content.clear();
+    }
+}
+
 void platform::set_gl_attributes() {
     TRACE_FUNCTION_CAT("platform");
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
@@ -67,6 +80,17 @@ void platform::open_file_dialog(SDL_Window* window) {
     SDL_ShowOpenFileDialog(file_dialog_callback, nullptr, window, filters, 2, nullptr, false);
 }
 
+void platform::save_file_dialog(SDL_Window* window, const std::string& default_name, const std::string& content) {
+    if (!window) return;
+    static const SDL_DialogFileFilter filters[] = {
+        {"CSV Files", "csv"},
+        {"TSV Files", "tsv"},
+        {"All Files", "*"},
+    };
+    g_save_content = content;
+    SDL_ShowSaveFileDialog(save_dialog_callback, nullptr, window, filters, 3, default_name.c_str());
+}
+
 void platform::handle_file_drop(const char* path) {
     TRACE_FUNCTION_CAT("platform");
     g_pending.path = path;

src/platform/platform_wasm.cpp

@@ -69,6 +69,28 @@ bool platform::supports_vsync() {
     return false;
 }
 
+void platform::save_file_dialog(SDL_Window* /*window*/, const std::string& default_name, const std::string& content) {
+    // Trigger browser download via JS blob
+    EM_ASM(
+        {
+            var name = UTF8ToString($0);
+            var data = UTF8ToString($1);
+            var blob = new Blob([data], {
+                type:
+                    'text/plain'
+            });
+            var url = URL.createObjectURL(blob);
+            var a = document.createElement('a');
+            a.href = url;
+            a.download = name;
+            document.body.appendChild(a);
+            a.click();
+            document.body.removeChild(a);
+            URL.revokeObjectURL(url);
+        },
+        default_name.c_str(), content.c_str());
+}
+
 void platform::open_file_dialog(SDL_Window* /*window*/) {
     trigger_file_input();
 }

src/ui/INDEX.md

@@ -81,16 +81,22 @@ void on_model_changed();
 void render(const TraceModel&, ViewState&);
 ```
 
-## stats_panel.h / stats_panel.cpp — SQL editor + result table + visual query builder; tabs serialized to JSON
+## stats_panel.h / stats_panel.cpp — SQL editor + result table + visual query builder; tabs serialized to JSON; CSV/TSV export
 ```
 void render(const TraceModel&, QueryDb&, ViewState&);
+void set_window(SDL_Window*);
 nlohmann::json save_tabs() const;
 void load_tabs(const nlohmann::json&);
 // QueryBuilderState
 void reset();
 std::string build_sql(const char* const* columns, int num_columns) const;
 ```
 
+## export_utils.h — export query results to CSV or TSV format
+```
+std::string export_result(const QueryDb::QueryResult&, char delimiter);
+```
+
 ## flame_graph_panel.h / flame_graph_panel.cpp — per-thread icicle charts with flat node pool; filterable sidebar, zoom, search highlighting, context menu
 ```
 void render(const TraceModel&, ViewState&);

src/ui/export_utils.h

@@ -0,0 +1,41 @@
+#pragma once
+#include "model/query_db.h"
+#include <sstream>
+#include <string>
+
+// Export query results as delimited text (CSV with ',' or TSV with '\t').
+// CSV quoting follows RFC 4180: fields containing the delimiter, quotes, or
+// newlines are wrapped in double-quotes with internal quotes escaped.
+inline std::string export_result(const QueryDb::QueryResult& result, char delimiter) {
+    auto needs_quoting = [&](const std::string& s) {
+        if (delimiter != ',') return false;
+        return s.find_first_of(",\"\n") != std::string::npos;
+    };
+    auto write_field = [&](std::ostringstream& out, const std::string& s) {
+        if (needs_quoting(s)) {
+            out << '"';
+            for (char ch : s) {
+                if (ch == '"') out << '"';
+                out << ch;
+            }
+            out << '"';
+        } else {
+            out << s;
+        }
+    };
+
+    std::ostringstream out;
+    for (size_t c = 0; c < result.columns.size(); c++) {
+        if (c > 0) out << delimiter;
+        write_field(out, result.columns[c]);
+    }
+    out << '\n';
+    for (const auto& row : result.rows) {
+        for (size_t c = 0; c < row.size(); c++) {
+            if (c > 0) out << delimiter;
+            write_field(out, row[c]);
+        }
+        out << '\n';
+    }
+    return out.str();
+}

src/ui/stats_panel.cpp

@@ -1,7 +1,9 @@
 #include "stats_panel.h"
+#include "export_utils.h"
 #include "format_time.h"
 #include "sort_utils.h"
 #include "tracing.h"
+#include "platform/platform.h"
 #include "imgui.h"
 #include <nlohmann/json.hpp>
 #include <algorithm>
@@ -400,6 +402,16 @@ void StatsPanel::render_tab(QueryTab& tab, const TraceModel& model, QueryDb& db,
     if (!tab.result.ok || tab.result.columns.empty()) return;
 
     ImGui::Text("%zu rows", tab.result.rows.size());
+    ImGui::SameLine();
+    if (ImGui::SmallButton("Export CSV")) {
+        std::string content = export_result(tab.result, ',');
+        platform::save_file_dialog(window_, tab.title + ".csv", content);
+    }
+    ImGui::SameLine();
+    if (ImGui::SmallButton("Export TSV")) {
+        std::string content = export_result(tab.result, '\t');
+        platform::save_file_dialog(window_, tab.title + ".tsv", content);
+    }
 
     // Find the "name" column index for click-to-browse
     int name_col = -1;

src/ui/stats_panel.h

@@ -6,6 +6,8 @@
 #include <string>
 #include <nlohmann/json_fwd.hpp>
 
+struct SDL_Window;
+
 struct QueryTab {
     std::string title = "Query";
     std::string query;
@@ -72,6 +74,7 @@ struct QueryBuilderState {
 class StatsPanel {
 public:
     void render(const TraceModel& model, QueryDb& db, ViewState& view);
+    void set_window(SDL_Window* window) { window_ = window; }
 
     nlohmann::json save_tabs() const;
     void load_tabs(const nlohmann::json& j);
@@ -89,6 +92,8 @@ class StatsPanel {
     int active_tab_ = 0;
     float sql_height_ = 0.0f;  // draggable SQL editor height (0 = use default)
 
+    SDL_Window* window_ = nullptr;
+
     bool show_schema_ = false;
     bool show_builder_ = false;
     QueryBuilderState builder_;

tests/test_export_utils.cpp

@@ -0,0 +1,58 @@
+#include <gtest/gtest.h>
+#include "ui/export_utils.h"
+
+static QueryDb::QueryResult make_result(std::vector<std::string> cols, std::vector<std::vector<std::string>> rows) {
+    QueryDb::QueryResult r;
+    r.columns = std::move(cols);
+    r.rows = std::move(rows);
+    r.ok = true;
+    return r;
+}
+
+TEST(ExportUtils, CsvBasic) {
+    auto r = make_result({"name", "count"}, {{"foo", "3"}, {"bar", "7"}});
+    std::string csv = export_result(r, ',');
+    EXPECT_EQ(csv, "name,count\nfoo,3\nbar,7\n");
+}
+
+TEST(ExportUtils, TsvBasic) {
+    auto r = make_result({"name", "count"}, {{"foo", "3"}, {"bar", "7"}});
+    std::string tsv = export_result(r, '\t');
+    EXPECT_EQ(tsv, "name\tcount\nfoo\t3\nbar\t7\n");
+}
+
+TEST(ExportUtils, CsvQuotesFieldsWithCommas) {
+    auto r = make_result({"val"}, {{"hello, world"}, {"plain"}});
+    std::string csv = export_result(r, ',');
+    EXPECT_EQ(csv, "val\n\"hello, world\"\nplain\n");
+}
+
+TEST(ExportUtils, CsvQuotesFieldsWithQuotes) {
+    auto r = make_result({"val"}, {{"say \"hi\""}});
+    std::string csv = export_result(r, ',');
+    EXPECT_EQ(csv, "val\n\"say \"\"hi\"\"\"\n");
+}
+
+TEST(ExportUtils, CsvQuotesFieldsWithNewlines) {
+    auto r = make_result({"val"}, {{"line1\nline2"}});
+    std::string csv = export_result(r, ',');
+    EXPECT_EQ(csv, "val\n\"line1\nline2\"\n");
+}
+
+TEST(ExportUtils, TsvNoQuoting) {
+    // TSV should not quote fields even if they contain commas or quotes
+    auto r = make_result({"val"}, {{"hello, world"}, {"say \"hi\""}});
+    std::string tsv = export_result(r, '\t');
+    EXPECT_EQ(tsv, "val\nhello, world\nsay \"hi\"\n");
+}
+
+TEST(ExportUtils, EmptyResult) {
+    auto r = make_result({"a", "b"}, {});
+    EXPECT_EQ(export_result(r, ','), "a,b\n");
+    EXPECT_EQ(export_result(r, '\t'), "a\tb\n");
+}
+
+TEST(ExportUtils, SingleColumn) {
+    auto r = make_result({"x"}, {{"1"}, {"2"}});
+    EXPECT_EQ(export_result(r, ','), "x\n1\n2\n");
+}