examples/server/main.cpp

@@ -269,18 +269,6 @@ struct LoraEntry {
     std::string fullpath;
 };
 
-void free_results(sd_image_t* result_images, int num_results) {
-    if (result_images) {
-        for (int i = 0; i < num_results; ++i) {
-            if (result_images[i].data) {
-                stbi_image_free(result_images[i].data);
-                result_images[i].data = nullptr;
-            }
-        }
-    }
-    free(result_images);
-}
-
 int main(int argc, const char** argv) {
     if (argc > 1 && std::string(argv[1]) == "--version") {
         std::cout << version_string() << "\n";
@@ -549,7 +537,6 @@ int main(int argc, const char** argv) {
                 item["b64_json"] = b64;
                 out["data"].push_back(item);
             }
-            free_results(results, num_results);
 
             res.set_content(out.dump(), "application/json");
             res.status = 200;
@@ -794,7 +781,6 @@ int main(int argc, const char** argv) {
                 item["b64_json"] = b64;
                 out["data"].push_back(item);
             }
-            free_results(results, num_results);
 
             res.set_content(out.dump(), "application/json");
             res.status = 200;
@@ -1115,7 +1101,6 @@ int main(int argc, const char** argv) {
                 std::string b64 = base64_encode(image_bytes);
                 out["images"].push_back(b64);
             }
-            free_results(results, num_results);
 
             res.set_content(out.dump(), "application/json");
             res.status = 200;

src/ucache.hpp

@@ -19,7 +19,6 @@ struct UCacheConfig {
     bool adaptive_threshold     = true;
     float early_step_multiplier = 0.5f;
     float late_step_multiplier  = 1.5f;
-    float relative_norm_gain    = 1.6f;
     bool reset_error_on_compute = true;
 };
 
@@ -46,16 +45,14 @@ struct UCacheState {
     bool has_output_prev_norm             = false;
     bool has_relative_transformation_rate = false;
     float relative_transformation_rate    = 0.0f;
+    float cumulative_change_rate          = 0.0f;
     float last_input_change               = 0.0f;
     bool has_last_input_change            = false;
-    float output_change_ema               = 0.0f;
-    bool has_output_change_ema            = false;
     int total_steps_skipped               = 0;
     int current_step_index                = -1;
     int steps_computed_since_active       = 0;
-    int expected_total_steps              = 0;
-    int consecutive_skipped_steps         = 0;
     float accumulated_error               = 0.0f;
+    float reference_output_norm           = 0.0f;
 
     struct BlockMetrics {
         float sum_transformation_rate = 0.0f;
@@ -109,16 +106,14 @@ struct UCacheState {
         has_output_prev_norm             = false;
         has_relative_transformation_rate = false;
         relative_transformation_rate     = 0.0f;
+        cumulative_change_rate           = 0.0f;
         last_input_change                = 0.0f;
         has_last_input_change            = false;
-        output_change_ema                = 0.0f;
-        has_output_change_ema            = false;
         total_steps_skipped              = 0;
         current_step_index               = -1;
         steps_computed_since_active      = 0;
-        expected_total_steps             = 0;
-        consecutive_skipped_steps        = 0;
         accumulated_error                = 0.0f;
+        reference_output_norm            = 0.0f;
         block_metrics.reset();
         total_active_steps = 0;
     }
@@ -138,8 +133,7 @@ struct UCacheState {
         if (!initialized || sigmas.size() < 2) {
             return;
         }
-        size_t n_steps       = sigmas.size() - 1;
-        expected_total_steps = static_cast<int>(n_steps);
+        size_t n_steps = sigmas.size() - 1;
 
         size_t start_step = static_cast<size_t>(config.start_percent * n_steps);
         size_t end_step   = static_cast<size_t>(config.end_percent * n_steps);
@@ -213,15 +207,11 @@ struct UCacheState {
         }
 
         int effective_total = estimated_total_steps;
-        if (effective_total <= 0) {
-            effective_total = expected_total_steps;
-        }
         if (effective_total <= 0) {
             effective_total = std::max(20, steps_computed_since_active * 2);
         }
 
         float progress = (effective_total > 0) ? (static_cast<float>(steps_computed_since_active) / effective_total) : 0.0f;
-        progress       = std::max(0.0f, std::min(1.0f, progress));
 
         float multiplier = 1.0f;
         if (progress < 0.2f) {
@@ -319,31 +309,17 @@ struct UCacheState {
 
         if (has_output_prev_norm && has_relative_transformation_rate &&
             last_input_change > 0.0f && output_prev_norm > 0.0f) {
-            float approx_output_change = relative_transformation_rate * last_input_change;
-            float approx_output_change_rate;
-            if (config.use_relative_threshold) {
-                float base_scale          = std::max(output_prev_norm, 1e-6f);
-                float dyn_scale           = has_output_change_ema
-                                                ? std::max(output_change_ema * std::max(1.0f, config.relative_norm_gain), 1e-6f)
-                                                : base_scale;
-                float scale               = std::sqrt(base_scale * dyn_scale);
-                approx_output_change_rate = approx_output_change / scale;
-            } else {
-                approx_output_change_rate = approx_output_change;
-            }
-            // Increase estimated error with skip horizon to avoid long extrapolation streaks
-            approx_output_change_rate *= (1.0f + 0.50f * consecutive_skipped_steps);
-            accumulated_error = accumulated_error * config.error_decay_rate + approx_output_change_rate;
+            float approx_output_change_rate = (relative_transformation_rate * last_input_change) / output_prev_norm;
+            accumulated_error               = accumulated_error * config.error_decay_rate + approx_output_change_rate;
 
             float effective_threshold = get_adaptive_threshold();
-            if (!config.use_relative_threshold && output_prev_norm > 0.0f) {
-                effective_threshold = effective_threshold * output_prev_norm;
+            if (config.use_relative_threshold && reference_output_norm > 0.0f) {
+                effective_threshold = effective_threshold * reference_output_norm;
             }
 
             if (accumulated_error < effective_threshold) {
                 skip_current_step = true;
                 total_steps_skipped++;
-                consecutive_skipped_steps++;
                 apply_cache(cond, input, output);
                 return true;
             } else if (config.reset_error_on_compute) {
@@ -364,8 +340,6 @@ struct UCacheState {
         if (cond != anchor_condition) {
             return;
         }
-        steps_computed_since_active++;
-        consecutive_skipped_steps = 0;
 
         size_t ne      = static_cast<size_t>(ggml_nelements(input));
         float* in_data = (float*)input->data;
@@ -385,14 +359,6 @@ struct UCacheState {
                 output_change /= static_cast<float>(ne);
             }
         }
-        if (std::isfinite(output_change) && output_change > 0.0f) {
-            if (!has_output_change_ema) {
-                output_change_ema     = output_change;
-                has_output_change_ema = true;
-            } else {
-                output_change_ema = 0.8f * output_change_ema + 0.2f * output_change;
-            }
-        }
 
         prev_output.resize(ne);
         for (size_t i = 0; i < ne; ++i) {
@@ -407,6 +373,10 @@ struct UCacheState {
         output_prev_norm     = (ne > 0) ? (mean_abs / static_cast<float>(ne)) : 0.0f;
         has_output_prev_norm = output_prev_norm > 0.0f;
 
+        if (reference_output_norm == 0.0f) {
+            reference_output_norm = output_prev_norm;
+        }
+
         if (has_last_input_change && last_input_change > 0.0f && output_change > 0.0f) {
             float rate = output_change / last_input_change;
             if (std::isfinite(rate)) {