common : throttle download progress output to reduce IO flush (#17427)

This change limits progress updates to approximately every 0.1% of the
file size to minimize stdio overhead.

Also fixes compiler warnings regarding __func__ in lambdas.

Signed-off-by: Adrien Gallouët <angt@huggingface.co>

common/download.cpp

@@ -517,16 +517,18 @@ static bool common_pull_file(httplib::Client & cli,
         headers.emplace("Range", "bytes=" + std::to_string(existing_size) + "-");
     }
 
-    std::atomic<size_t> downloaded{existing_size};
+    const char * func = __func__; // avoid __func__ inside a lambda
+    size_t downloaded = existing_size;
+    size_t progress_step = 0;
 
     auto res = cli.Get(resolve_path, headers,
         [&](const httplib::Response &response) {
             if (existing_size > 0 && response.status != 206) {
-                LOG_WRN("%s: server did not respond with 206 Partial Content for a resume request. Status: %d\n", __func__, response.status);
+                LOG_WRN("%s: server did not respond with 206 Partial Content for a resume request. Status: %d\n", func, response.status);
                 return false;
             }
             if (existing_size == 0 && response.status != 200) {
-                LOG_WRN("%s: download received non-successful status code: %d\n", __func__, response.status);
+                LOG_WRN("%s: download received non-successful status code: %d\n", func, response.status);
                 return false;
             }
             if (total_size == 0 && response.has_header("Content-Length")) {
@@ -534,7 +536,7 @@ static bool common_pull_file(httplib::Client & cli,
                     size_t content_length = std::stoull(response.get_header_value("Content-Length"));
                     total_size = existing_size + content_length;
                 } catch (const std::exception &e) {
-                    LOG_WRN("%s: invalid Content-Length header: %s\n", __func__, e.what());
+                    LOG_WRN("%s: invalid Content-Length header: %s\n", func, e.what());
                 }
             }
             return true;
@@ -542,11 +544,16 @@ static bool common_pull_file(httplib::Client & cli,
         [&](const char *data, size_t len) {
             ofs.write(data, len);
             if (!ofs) {
-                LOG_ERR("%s: error writing to file: %s\n", __func__, path_tmp.c_str());
+                LOG_ERR("%s: error writing to file: %s\n", func, path_tmp.c_str());
                 return false;
             }
             downloaded += len;
-            print_progress(downloaded, total_size);
+            progress_step += len;
+
+            if (progress_step >= total_size / 1000 || downloaded == total_size) {
+                print_progress(downloaded, total_size);
+                progress_step = 0;
+            }
             return true;
         },
         nullptr