add python-d example.

.gitignore

@@ -24,3 +24,4 @@ download/
 *.pb
 *.dll
 *.lib
+tmp.bin

README.md

@@ -28,13 +28,16 @@ with (newGraph)
 }
 ```
 
+And more:
+- [save/load TF graphs between Python and D](example/graph_import)
+
 ## Features
 
 - [x] Setup CI
 - [x] Wrap tensor and session for basic usages (see `tfd.session` unittests).
 - [x] mir.ndslice.Slice `s` <=> tfd.tensor.Tensor `t` integration by `s.tensor`, `t.slicedAs(s)`.
+- [x] [Example](example/graph_import) to save/load TF graphs.
 - [ ] Use [pbd](https://github.com/ShigekiKarita/pbd) to save/load proto files.
-- [ ] Example using C API to save/load TF graphs.
 - [ ] Parse `ops.pbtxt` to generate typed ops bindings.
 - [ ] Rewrite C API example with typed bindings.
 - [ ] Implement autograd, and simple training APIs in D.

example/graph_import/graph_export.d

@@ -0,0 +1,20 @@
+#!/usr/bin/env dub
+/+ dub.json:
+{
+  "dependencies": {
+     "tfd": {"path": "../.."}
+  }
+}
++/
+import tfd : newGraph;
+
+void main()
+{
+  with (newGraph) {
+    auto a = placeholder!int("a");
+    auto b = constant(3, "b");
+    // TODO(karita): provide name "add" by identity
+    auto add = a + b;
+    write("add-d.bin");
+  }
+}

example/graph_import/graph_export.py

@@ -0,0 +1,7 @@
+import tensorflow.compat.v1 as tf
+
+with tf.Session() as sess:
+  a = tf.placeholder(tf.int32, (), "a")
+  b = tf.constant(3)
+  c = tf.identity(a + b, "add")
+  tf.io.write_graph(sess.graph_def, ".", "add-py.bin", as_text=False)

example/graph_import/graph_import.d

@@ -0,0 +1,25 @@
+#!/usr/bin/env dub
+/+ dub.json:
+{
+  "dependencies": {
+     "tfd": {"path": "../.."}
+  }
+}
++/
+import std.stdio : writeln;
+import std.file : read;
+import tfd : newGraph, tensor;
+
+void main()
+{
+  with (newGraph) {
+    // TODO(karita): pbtxt support.
+    load(read("add-py.bin"));
+    auto a = operationByName("a");
+    auto add = operationByName("add");
+
+    const t = session.run([add], [a: 1.tensor])[0].tensor;
+    assert(t.scalar!int == 1 + 3);
+    writeln(t.scalar!int);
+  }
+}

example/graph_import/graph_import.py

@@ -0,0 +1,17 @@
+import tensorflow.compat.v1 as tf
+
+with tf.Session() as sess:
+  with open("add-d.bin", "rb") as f:
+    graph_def = tf.GraphDef()
+    graph_def.ParseFromString(f.read())
+
+  tf.import_graph_def(graph_def)
+  graph = tf.get_default_graph()
+  for op in graph.get_operations():
+    print(op.name)
+
+  a = graph.get_tensor_by_name("import/a:0")
+  add = graph.get_tensor_by_name("import/add:0")
+  result = sess.run(add, {a: 1})
+  print(result)
+  assert(result == 4)

source/tfd/c_api/linux.d

@@ -1,4 +1,4 @@
-module tfd.c_api.linux_;
+module tfd.c_api.linux;
 version (linux):
 
         import core.stdc.config;

source/tfd/c_api/linux.dpp

@@ -1,5 +1,5 @@
 /// Tensorflow C API header generated by dpp.
 /// NOTE: module name linux will be " 1" (https://github.com/atilaneves/dpp/issues/258)
-module tfd.c_api.linux_;
+module tfd.c_api.linux;
 version (linux):
 #include <tensorflow/c/c_api.h>

source/tfd/c_api/package.d

@@ -7,7 +7,7 @@ version (Windows)
 }
 else version (linux)
 {
-  public import tfd.c_api.linux_;
+  public import tfd.c_api.linux;
 }
 else
 {

source/tfd/graph.d

@@ -169,6 +169,37 @@ struct GraphOwner
     TF_DeleteGraph(this.ptr);
     TF_DeleteStatus(this.status);
   }
+
+  /// Loads serialized graph (GraphDef proto).
+  @nogc nothrow @trusted
+  void load(const(void)[] proto)
+  {
+    auto buffer = TF_NewBufferFromString(proto.ptr, proto.length);
+    auto opts = TF_NewImportGraphDefOptions;
+    TF_GraphImportGraphDef(this.ptr, buffer, opts, this.status);
+    assertStatus(this.status);
+  }
+
+  /// Returns serialized bytes (GraphDef proto).
+  @nogc nothrow @trusted
+  TF_Buffer* serialize()
+  {
+    auto buffer = TF_NewBuffer;
+    TF_GraphToGraphDef(this.ptr, buffer, this.status);
+    assertStatus(this.status);
+    return buffer;
+  }
+
+  /// Writes serialized bytes (GraphDef proto) to a given file.
+  @nogc nothrow @trusted
+  void write(const(char)* fileName)
+  {
+    import core.stdc.stdio;
+
+    auto buffer = this.serialize();
+    auto fp = fopen(fileName, "wb");
+    fwrite(buffer.data, 1, buffer.length, fp); 
+  }
 }
 
 /// TF_Operation wrapper used in Graph.
@@ -199,6 +230,15 @@ struct Graph
   /// Base reference counted pointer.
   SlimRCPtr!GraphOwner base;
   alias base this;
+  /// Get an operation by name
+
+  @nogc nothrow @trusted
+  Operation operationByName(const(char)* name)
+  {
+    auto opr = TF_GraphOperationByName(this.ptr, name);
+    assert(opr);
+    return Operation(opr, this);
+  }
 
   /// Creates a placeholder in this graph.
   Operation placeholder(T, size_t N)(
@@ -245,7 +285,7 @@ unittest
 {
   import tfd.tensor;
 
-  auto buffer = TF_NewBuffer;
+  TF_Buffer* buffer;
   scope (exit) TF_DeleteBuffer(buffer);
   {
     auto graph = newGraph;
@@ -259,22 +299,16 @@ unittest
       auto add = a + b;
       assert(TF_GraphOperationByName(graph, "add"));
     }
-    // Export to a GraphDef (protobuf)
-    TF_GraphToGraphDef(graph, buffer, graph.status);
-    assertStatus(graph.status);
+    buffer = graph.serialize;
+    // for coverage
+    graph.write("tmp.bin");
   }
-  {
+  with (newGraph) {
     // Import from the GraphDef (protobuf)
-    auto graph = newGraph;
-    auto opts = TF_NewImportGraphDefOptions;
-    TF_GraphImportGraphDef(graph, buffer, opts, graph.status);
-    assertStatus(graph.status);
-
-    auto a = TF_GraphOperationByName(graph, "a");
-    assert(a);
-    auto add = TF_GraphOperationByName(graph, "add");
-    assert(add);
-    const t = TensorOwner(graph.session.run([add], [a: 1.tensor])[0]);
+    load(buffer.data[0 .. buffer.length]);
+    auto a = operationByName("a");
+    auto add = operationByName("add");
+    const t = session.run([add], [a: 1.tensor])[0].tensor;
     assert(t.scalar!int == 1 + 3);
   }
 }

source/tfd/tensor.d

@@ -260,6 +260,12 @@ Tensor tensor(Args ...)(Args args)
   return createSlimRC!TensorOwner(makeTF_Tensor(forward!args));
 }
 
+@trusted
+Tensor tensor(TF_Tensor* t)
+{
+  return createSlimRC!TensorOwner(t);
+}
+
 /// Make a scalar RCTensor.
 @nogc nothrow @safe
 unittest