watch for file updates

main.cpp

@@ -15,6 +15,7 @@
 #include <ranges>
 #include <stack>
 #include <map>
+#include <thread>
 
 #include <json.hpp>
 #include <date.h>
@@ -98,6 +99,9 @@ class builder {
     std::map<std::string, std::string> properties;
     templater *templr;
 
+    std::map<fs::path, time_t> last_build;
+
+
     const std::set<std::string> apply_templates_exts {"md","html", "txt", "markdown", "xml", "atom", "rss"};
 
 
@@ -438,6 +442,7 @@ class builder {
                 {new rss_feed_plugin{}, new microblog_plugin{}});
 
         add_default_templates();
+        update_file_dates();
     }
 
     ~builder() {delete templr;}
@@ -463,11 +468,13 @@ class builder {
     void
     write_build(std::map<fs::path, blog_item> &compile_jobs) 
     {
+        time_t now = to_time_t(std::chrono::system_clock::now());
 
         // make directory structure
         for (auto &e: compile_jobs) {
             if (job_type::MAKE_DIR & e.second.type) {
                 fs::create_directories(e.first);
+                last_build[e.second.src] = now;
             }
         }
 
@@ -477,6 +484,7 @@ class builder {
             auto dest = e.first;
             if (job_type::COPY_FILE & e.second.type) {
                 fs::copy(src, dest, fs::copy_options::update_existing); 
+                last_build[e.second.src] = now;
             }
 
             if (job_type::DELETE_FILE & e.second.type) {
@@ -497,17 +505,17 @@ class builder {
             }
         }
 
-        for (auto &e: compile_jobs) {
-        }
-
         for (auto &e: compile_jobs) {
             if ((job_type::MARKDOWN | job_type::TEMPLATE) & e.second.type) {
                 write_file(e.first.string(), e.second.properties.at("body"));
+                last_build[e.second.src] = now;
             }
+
         }
     }
 
 
+
     void 
     build() 
     {
@@ -560,7 +568,58 @@ class builder {
         // stage 2 build
 
         write_build(compile_jobs);
+    }
 
+    void update_file_dates() {
+        for (auto e = fs::recursive_directory_iterator(properties.at("source_root"));
+                e != fs::recursive_directory_iterator();
+                ++e)
+        {
+            // skip hidden files
+            std::string filename = e->path().filename().string();
+            if (filename.length() > 0 && filename.at(0) == '.') {
+                e.disable_recursion_pending();
+                continue;
+            }
+            
+            time_t last_modification = to_time_t(fs::last_write_time(e->path()));
+            last_build[e->path()] = last_modification; 
+        }
+    }
+
+    void rebuild_if_newer() {
+        bool rebuild = false;
+//        for (auto &e: fs::directory_iterator(properties.at("source_root"))) {
+        for (auto e = fs::recursive_directory_iterator(properties.at("source_root"));
+                e != fs::recursive_directory_iterator();
+                ++e)
+        {
+            // skip hidden files
+            std::string filename = e->path().filename().string();
+            if (filename.length() > 0 && filename.at(0) == '.') {
+                e.disable_recursion_pending();
+                continue;
+            }
+
+            if (this->last_build.count(e->path())) {
+
+                time_t last_modification = to_time_t(fs::last_write_time(e->path()));
+
+                if (std::difftime(last_modification, last_build.at(e->path())) > 0) {
+                    rebuild = true;
+                    spdlog::info("Rebuilding with updated file: {}", e->path().string());
+                    break;
+                }
+
+            } else {
+                rebuild = true;
+                spdlog::info("Rebuilding with new file: {}", e->path().string());
+                break;
+            }
+        }
+
+        if (rebuild)
+            build();
     }
 
     void dump_stgen_json() {
@@ -771,9 +830,9 @@ int main(int argc, char **argv) {
          * compiled in rather than fork and exec'd
          */
         while (continue_running) {
-            b.build();
-            spdlog::info("Built site.");
-            sleep(5);
+            b.rebuild_if_newer();
+            std::this_thread::sleep_for(std::chrono::milliseconds(200));
+
         }
         s.stop_serving();
     }