Demonstrator completed

README.md

@@ -0,0 +1,9 @@
+# Function Shipping Example
+
+The purpose is to foster discussion of capabilities.
+
+The library in ./emulation provides a development kit for function shipping.
+In test/ there is test code showing
+  - how a reduction happens traditionally in the client.
+  - how reduction could be executed on the server (that uses the emulation/dev kit)
+The run.sh script contains everything to build and run the both test applications.

emulation/ngi.c

@@ -1,5 +1,33 @@
 #include <ngi.h>
+#include <assert.h>
+#include <float.h>
+#include <math.h>
 
-void server_reduce(FILE * file, size_t off, size_t size){
+int server_reduce(FILE * file, ngi_op_t op, ngi_type_t type, void * out_buff, size_t off, size_t size){
+  fseek(file, off, SEEK_SET);
 
+  assert(type == NGI_TYPE_FLOAT);
+  assert(op == NGI_OP_MAX);
+
+  float * data = malloc(size);
+  fread(data, size, 1, file);
+
+  float mx = -INFINITY;
+  for(size_t i=0; i < size/sizeof(float); i++){
+    mx = data[i] > mx ? data[i]: mx;
+  }
+  *(float*) out_buff = mx;
+
+  free(data);
+  return 0;
+}
+
+int server_reduce_any_func(FILE * file, void (*func)(int8_t * data, void * out_buff, size_t off, size_t size), void * out_buff, size_t max_out_data_size, size_t off, size_t size){
+  fseek(file, off, SEEK_SET);
+
+  int8_t * data = malloc(size);
+  fread(data, size, 1, file);
+  func(data, out_buff, off, size);
+  free(data);
+  return 0;
 }

emulation/ngi.h

@@ -4,6 +4,27 @@
 #include <stdlib.h>
 #include <stdio.h>
 
-void server_reduce(FILE * file, size_t off, size_t size);
+typedef enum NGI_OP{
+  NGI_OP_MAX
+} ngi_op_t;
+
+typedef enum NGI_TYPE{
+  NGI_TYPE_FLOAT
+} ngi_type_t;
+
+/*
+ * This function invoces a well known reduction operation on data of a well known type
+ * Return 0 upon success, any other code, if e.g., short read
+ */
+int server_reduce(FILE * file, ngi_op_t op, ngi_type_t type, void * out_buff, size_t off, size_t size);
+
+/*
+ * This function runs any type of function on the data
+ * It assumes that the output buffer was initialized accordingly and that it is of max_out_data_size
+ * func must be associative and needs to read/output the output buffer as intermediate storage
+ * Return 0 upon success, any other code, if e.g., short read
+ */
+int server_reduce_any_func(FILE * file, void (*func)(int8_t * data, void * out_buff, size_t off, size_t size), void * out_buff, size_t max_out_data_size, size_t off, size_t size);
+
 
 #endif

test/reduce-ngi.c

@@ -5,6 +5,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <float.h>
+#include <math.h>
 
 #include <ngi.h>
 
@@ -14,26 +15,54 @@
 
 // read the data and reduce it
 void reduce_data(int size){
-  float * data = malloc(size * sizeof(float));
   FILE * file = fopen("data.bin", "rb");
-  fread(data, size*sizeof(float), 1, file);
-  fclose(file);
-
-  server_reduce(file, 0, size*sizeof(float));
-
-  float mx = FLT_MIN;
-  for(int i=0; i < size; i++){
-    mx = data[i] > mx ? data[i]: mx;
-  }
-  free(data);
-
+  float mx;
+  server_reduce(file, NGI_OP_MAX, NGI_TYPE_FLOAT, & mx, 0, size*sizeof(float));
   printf("Maximum: %f\n", mx);
+  fclose(file);
 }
 
+void reduce_min_func(int8_t * data_i, void * out_buff, size_t off, size_t size){
+  float * outf = (float*) out_buff;
+  float mx = *outf;
+  float * data = (float*) data_i;
+  for(size_t i=0; i < size/sizeof(float); i++){
+    mx = data[i] > mx ? data[i]: mx;
+  }
+  *outf = mx;
+}
+
+void reduce_minmax_func(int8_t * data_i, void * out_buff, size_t off, size_t size){
+  float * outf = (float*) out_buff;
+  float mi = outf[0];
+  float mx = outf[1];
+  float * data = (float*) data_i;
+  for(size_t i=0; i < size/sizeof(float); i++){
+    mx = data[i] > mx ? data[i]: mx;
+    mi = data[i] < mi ? data[i]: mi;
+  }
+  outf[0] = mi;
+  outf[1] = mx;
+}
+
+// alternative using an external function
+void reduce_data_func(int size){
+  FILE * file = fopen("data.bin", "rb");
+  float mx;
+  mx = -INFINITY;
+  server_reduce_any_func(file, reduce_min_func, &mx, sizeof(float), 0, size*sizeof(float));
+  printf("Maximum: %f\n", mx);
+
+  float minmax[2] = {INFINITY, -INFINITY};
+  server_reduce_any_func(file, reduce_minmax_func, minmax, 2* sizeof(float), 0, size*sizeof(float));
+  printf("Min/Max: %f - %f\n", minmax[0], minmax[1]);
+  fclose(file);
+}
 
 
 int main(){
   int size = 100;
   reduce_data(size);
+  reduce_data_func(size);
   return 0;
 }

test/reduce-traditional.c

@@ -5,6 +5,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <float.h>
+#include <math.h>
 
 
 /*
@@ -18,7 +19,7 @@ void reduce_data(int size){
   fread(data, size*sizeof(float), 1, file);
   fclose(file);
 
-  float mx = FLT_MIN;
+  float mx = -INFINITY;
   for(int i=0; i < size; i++){
     mx = data[i] > mx ? data[i]: mx;
   }