Optimize startup, HTTP/SSE streaming, and fix macOS libedit bindings

session.cpp

@@ -1,5 +1,6 @@
 /* session.cpp — session persistence, loading, compaction. */
 #include "bantam.hpp"
+#include <algorithm>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
@@ -24,6 +25,29 @@ static std::string sessions_dir() {
   return d;
 }
 
+static bool load_session_file(const std::string &full, Session &s) {
+  std::string buf;
+  if (!read_file_str(full, buf)) return false;
+  Json root_mut;
+  if (!Json::parse(buf, root_mut) || !root_mut.is_object()) return false;
+  const Json &root = root_mut;
+  s = Session{};
+  s.id = root["id"].str();
+  s.created = root["created"].str();
+  s.summary = root["summary"].str();
+  const Json &marr = root["messages"];
+  if (marr.is_array()) {
+    s.messages.items.reserve(marr.aval.size());
+    for (auto &mo : marr.aval) {
+      Message m;
+      parse_message_json(mo, m);
+      s.messages.items.push_back(std::move(m));
+    }
+  }
+  if (s.summary.empty()) s.summary = "(no summary)";
+  return true;
+}
+
 void save_session(const Messages &msgs, std::string_view sid,
                   std::string *out_id, std::string *out_summary) {
   std::string id = (!sid.empty()) ? std::string(sid) : project_id();
@@ -40,6 +64,7 @@ void save_session(const Messages &msgs, std::string_view sid,
   std::string sum = summary_of(msgs);
   root["summary"] = sum;
   Json arr = Json::array();
+  arr.aval.reserve(msgs.items.size());
   for (auto &m : msgs.items) {
     Json mo;
     serialize_message_json(mo, m);
@@ -63,63 +88,46 @@ std::vector<Session> sessions_load() {
         std::string nm = de->d_name;
         if (nm == "." || nm == "..") continue;
         if (nm.size() < 5 || nm.substr(nm.size() - 5) != ".json") continue;
-        files.push_back(nm);
+        files.push_back(std::move(nm));
       }
       closedir(dir);
     }
   }
-  for (size_t i = 1; i < files.size(); i++) {
-    for (size_t j = i; j > 0 && files[j - 1] > files[j]; j--) {
-      std::swap(files[j - 1], files[j]);
-    }
-  }
+  std::sort(files.begin(), files.end());
+  ss.reserve(files.size());
   for (auto &nm : files) {
     std::string full = d + "/" + nm;
-    std::string buf;
-    if (!read_file_str(full, buf)) continue;
-    Json root_mut;
-    if (!Json::parse(buf, root_mut) || !root_mut.is_object()) continue;
-    const Json &root = root_mut;
     Session s;
-    s.id = root["id"].str();
-    s.created = root["created"].str();
-    s.summary = root["summary"].str();
-    const Json &marr = root["messages"];
-    if (marr.is_array()) {
-      for (auto &mo : marr.aval) {
-        Message m;
-        parse_message_json(mo, m);
-        s.messages.items.push_back(std::move(m));
-      }
+    if (load_session_file(full, s)) {
+      ss.push_back(std::move(s));
     }
-    if (s.summary.empty()) s.summary = "(no summary)";
-    ss.push_back(std::move(s));
   }
   /* sort by id descending (newest first) */
-  for (size_t i = 1; i < ss.size(); i++) {
-    for (size_t j = i; j > 0 && ss[j - 1].id < ss[j].id; j--) {
-      std::swap(ss[j - 1], ss[j]);
-    }
-  }
+  std::sort(ss.begin(), ss.end(), [](const Session &a, const Session &b) {
+    return a.id > b.id;
+  });
   return ss;
 }
 
 std::unique_ptr<Messages> load_session(std::string_view sid, std::string *err) {
+  if (!sid.empty() && sid.find('/') == std::string_view::npos) {
+    std::string exact = sessions_dir() + "/" + std::string(sid) + ".json";
+    Session s;
+    if (load_session_file(exact, s) && s.id == sid) {
+      return std::make_unique<Messages>(std::move(s.messages));
+    }
+  }
   auto ss = sessions_load();
   for (auto &s : ss) {
     if (s.id == sid) {
-      auto res = std::make_unique<Messages>();
-      for (auto &m : s.messages.items) res->items.push_back(m);
-      return res;
+      return std::make_unique<Messages>(std::move(s.messages));
     }
   }
   /* prefix match */
   std::vector<Session *> pref;
-  for (auto &s : ss) if (s.id.rfind(sid, 0) == 0) pref.push_back(&s);
+  for (auto &s : ss) if (s.id.starts_with(sid)) pref.push_back(&s);
   if (pref.size() == 1) {
-    auto res = std::make_unique<Messages>();
-    for (auto &m : pref[0]->messages.items) res->items.push_back(m);
-    return res;
+    return std::make_unique<Messages>(std::move(pref[0]->messages));
   }
   if (pref.size() > 1) {
     std::string names;
@@ -134,13 +142,10 @@ std::unique_ptr<Messages> load_session(std::string_view sid, std::string *err) {
 
 std::unique_ptr<Session> find_project_session() {
   std::string pid = project_id();
-  auto ss = sessions_load();
-  for (auto &s : ss) {
-    if (s.id == pid) {
-      auto found = std::make_unique<Session>();
-      *found = std::move(s);
-      return found;
-    }
+  std::string path = sessions_dir() + "/" + pid + ".json";
+  auto found = std::make_unique<Session>();
+  if (load_session_file(path, *found) && found->id == pid) {
+    return found;
   }
   return nullptr;
 }