Fix predict c api (apache#4537)

* Fix predict c api

* Update comm.h

example/image-classification/predict-cpp/Makefile

@@ -14,7 +14,7 @@ LDFLAGS+=`pkg-config --libs opencv`
 # Added for mxnet
 export MXNET_ROOT=`pwd`/../../../../mxnet
 
-CFLAGS+= -I$(MXNET_ROOT)/include 
+CFLAGS+=-Wall -I$(MXNET_ROOT)/include
 LDFLAGS+=$(MXNET_ROOT)/lib/libmxnet.so
 
 image-classification-predict: image-classification-predict.o

example/image-classification/predict-cpp/README.md

@@ -9,8 +9,8 @@ It uses opencv for image reading
 1. Edit image-classification-predict.cc file, change the following lines to your model paths:
   ```bash
     // Models path for your model, you have to modify it
-    std::string json_file = "model/Inception/Inception_BN-symbol.json";
-    std::string param_file = "model/Inception/Inception_BN-0039.params";
+    std::string json_file = "model/Inception/Inception-BN-symbol.json";
+    std::string param_file = "model/Inception/Inception-BN-0126.params";
     std::string synset_file = "model/Inception/synset.txt";
     std::string nd_file = "model/Inception/mean_224.nd";
   ```

example/image-classification/predict-cpp/image-classification-predict.cc

@@ -20,15 +20,16 @@
 // Path for c_predict_api
 #include <mxnet/c_predict_api.h>
 
-#include <opencv2/core/core.hpp>
-#include <opencv2/contrib/contrib.hpp>
-#include <opencv2/highgui/highgui.hpp>
-
 #include <iostream>
 #include <fstream>
 #include <string>
 #include <vector>
 
+#include <opencv2/core/core.hpp>
+#include <opencv2/contrib/contrib.hpp>
+#include <opencv2/highgui/highgui.hpp>
+
+
 const mx_float DEFAULT_MEAN = 117.0;
 
 // Read file to buffer
@@ -44,7 +45,9 @@ class BufferFile {
         std::ifstream ifs(file_path.c_str(), std::ios::in | std::ios::binary);
         if (!ifs) {
             std::cerr << "Can't open the file. Please check " << file_path << ". \n";
-            assert(false);
+            length_ = 0;
+            buffer_ = NULL;
+            return;
         }
 
         ifs.seekg(0, std::ios::end);
@@ -65,8 +68,10 @@ class BufferFile {
     }
 
     ~BufferFile() {
-        delete[] buffer_;
-        buffer_ = NULL;
+        if (buffer_) {
+          delete[] buffer_;
+          buffer_ = NULL;
+        }
     }
 };
 
@@ -98,7 +103,7 @@ void GetImageFile(const std::string image_file,
         uchar* data = im.ptr<uchar>(i);
 
         for (int j = 0; j < im.cols; j++) {
-            if (image_data) {
+            if (mean_data) {
                 mean_r = *mean_data;
                 if (channels > 1) {
                     mean_g = *(mean_data + size / 3);
@@ -112,7 +117,6 @@ void GetImageFile(const std::string image_file,
             }
 
             *ptr_image_r++ = static_cast<mx_float>(*data++) - mean_r;;
-
         }
     }
 }
@@ -172,8 +176,8 @@ int main(int argc, char* argv[]) {
     test_file = std::string(argv[1]);
 
     // Models path for your model, you have to modify it
-    std::string json_file = "model/Inception/Inception_BN-symbol.json";
-    std::string param_file = "model/Inception/Inception_BN-0039.params";
+    std::string json_file = "model/Inception/Inception-BN-symbol.json";
+    std::string param_file = "model/Inception/Inception-BN-0126.params";
     std::string synset_file = "model/Inception/synset.txt";
     std::string nd_file = "model/Inception/mean_224.nd";
 
@@ -199,7 +203,12 @@ int main(int argc, char* argv[]) {
                                         static_cast<mx_uint>(height) };
     PredictorHandle pred_hnd = 0;
 
-    //-- Create Predictor
+    if (json_data.GetLength() == 0 ||
+        param_data.GetLength() == 0) {
+        return -1;
+    }
+
+    // Create Predictor
     MXPredCreate((const char*)json_data.GetBuffer(),
                  (const char*)param_data.GetBuffer(),
                  static_cast<size_t>(param_data.GetLength()),
@@ -210,45 +219,47 @@ int main(int argc, char* argv[]) {
                  input_shape_indptr,
                  input_shape_data,
                  &pred_hnd);
+    assert(pred_hnd);
 
     int image_size = width * height * channels;
 
-    //-- Read Mean Data
+    // Read Mean Data
+    const mx_float* nd_data = NULL;
+    NDListHandle nd_hnd = 0;
     BufferFile nd_buf(nd_file);
 
-    NDListHandle nd_hnd;
-
-    mx_uint nd_index = 0;
-    mx_uint nd_len;
-    const mx_uint* nd_shape = 0;
-    const char* nd_key = 0;
-    const mx_float* nd_data = 0;
-    mx_uint nd_ndim = 0;
+    if (nd_buf.GetLength() > 0) {
+        mx_uint nd_index = 0;
+        mx_uint nd_len;
+        const mx_uint* nd_shape = 0;
+        const char* nd_key = 0;
+        mx_uint nd_ndim = 0;
 
-    MXNDListCreate((const char*)nd_buf.GetBuffer(),
+        MXNDListCreate((const char*)nd_buf.GetBuffer(),
                    nd_buf.GetLength(),
                    &nd_hnd, &nd_len);
 
-    MXNDListGet(nd_hnd, nd_index, &nd_key, &nd_data, &nd_shape, &nd_ndim);
+        MXNDListGet(nd_hnd, nd_index, &nd_key, &nd_data, &nd_shape, &nd_ndim);
+    }
 
-    //-- Read Image Data
+    // Read Image Data
     std::vector<mx_float> image_data = std::vector<mx_float>(image_size);
 
     GetImageFile(test_file, image_data.data(),
                  channels, cv::Size(width, height), nd_data);
 
-    //-- Set Input Image
+    // Set Input Image
     MXPredSetInput(pred_hnd, "data", image_data.data(), image_size);
 
-    //-- Do Predict Forward
+    // Do Predict Forward
     MXPredForward(pred_hnd);
 
     mx_uint output_index = 0;
 
     mx_uint *shape = 0;
     mx_uint shape_len;
 
-    //-- Get Output Result
+    // Get Output Result
     MXPredGetOutputShape(pred_hnd, output_index, &shape, &shape_len);
 
     size_t size = 1;
@@ -258,18 +269,17 @@ int main(int argc, char* argv[]) {
 
     MXPredGetOutput(pred_hnd, output_index, &(data[0]), size);
 
-    //-- Release
-
     // Release NDList
-    MXNDListFree(nd_hnd);
+    if (nd_hnd)
+      MXNDListFree(nd_hnd);
 
     // Release Predictor
     MXPredFree(pred_hnd);
 
     // Synset path for your model, you have to modify it
     std::vector<std::string> synset = LoadSynset(synset_file);
 
-    //-- Print Output Data
+    // Print Output Data
     PrintOutputResult(data, synset);
 
     return 0;

src/c_api/c_predict_api.cc

@@ -81,10 +81,17 @@ int MXPredCreatePartialOut(const char* symbol_json_str,
   MXAPIPredictor* ret = new MXAPIPredictor();
   API_BEGIN();
   Symbol sym;
+  // make sure symbols are registered
+  {
+  mx_uint outSize;
+  const char **outArray;
+  MXListAllOpNames(&outSize, &outArray);
+  }
   // load in the symbol.
   {
-    std::string json = symbol_json_str;
-    sym.outputs = nnvm::pass::LoadJSON(json).outputs;
+    nnvm::Graph g;
+    g.attrs["json"] = std::make_shared<nnvm::any>(std::string(symbol_json_str));
+    sym.outputs = nnvm::ApplyPass(g, "LoadLegacyJSON").outputs;
   }
   // looks likely to output the internal results
   if (num_output_nodes != 0) {
@@ -206,6 +213,7 @@ int MXPredCreatePartialOut(const char* symbol_json_str,
                                    arg_arrays,
                                    grad_store, grad_req,
                                    aux_arrays));
+    ret->out_shapes = out_shapes;
     ret->out_arrays = ret->exec->outputs();
   }
   *out = ret;

src/kvstore/comm.h

@@ -49,6 +49,7 @@ class Comm {
   Context pinned_ctx() const {
     return pinned_ctx_;
   }
+
  protected:
   Context pinned_ctx_;
 };