Modify Pybind LoDTensor API according to length-based LoD (#11106)

* add lod_tensor util and modify pybind

* refind pybind LoDTensor API and modify LoDTensor and DataFeeder test

* fix test error

* fix detection map op test

* fix reorder_lod_tensor test

* fix seq_concat_op

* fix chunk evel op test

* fix target assign op

* fix warp ctc op

* address comments step 1: reverse reset_lod op

* step 2: modify op test

* add warning message

* remove has_valid_lod

* add back has_valid_lod

* address comments

* add exception catching trial

benchmark/fluid/models/machine_translation.py

@@ -173,21 +173,6 @@ def simple_attention(encoder_vec, encoder_proj, decoder_state):
         return avg_cost, feeding_list
 
 
-def to_lodtensor(data, place):
-    seq_lens = [len(seq) for seq in data]
-    cur_len = 0
-    lod = [cur_len]
-    for l in seq_lens:
-        cur_len += l
-        lod.append(cur_len)
-    flattened_data = np.concatenate(data, axis=0).astype("int64")
-    flattened_data = flattened_data.reshape([len(flattened_data), 1])
-    lod_t = core.LoDTensor()
-    lod_t.set(flattened_data, place)
-    lod_t.set_lod([lod])
-    return lod_t, lod[-1]
-
-
 def lodtensor_to_ndarray(lod_tensor):
     dims = lod_tensor.get_dims()
     ndarray = np.zeros(shape=dims).astype('float32')

benchmark/fluid/models/stacked_dynamic_lstm.py

@@ -125,18 +125,3 @@ def gate_common(
         batch_size=args.batch_size)
 
     return loss, inference_program, adam, train_reader, test_reader, batch_acc
-
-
-def to_lodtensor(data, place):
-    seq_lens = [len(seq) for seq in data]
-    cur_len = 0
-    lod = [cur_len]
-    for l in seq_lens:
-        cur_len += l
-        lod.append(cur_len)
-    flattened_data = numpy.concatenate(data, axis=0).astype("int64")
-    flattened_data = flattened_data.reshape([len(flattened_data), 1])
-    res = fluid.LoDTensor()
-    res.set(flattened_data, place)
-    res.set_lod([lod])
-    return res

paddle/fluid/framework/lod_tensor.cc

@@ -410,5 +410,38 @@ void LoDTensor::MergeLoDTensor(
   }
 }
 
+LoD ConvertToLengthBasedLoD(const LoD &offset_lod) {
+  LoD length_lod;
+  length_lod.reserve(offset_lod.size());
+  for (size_t lvl = 0; lvl < offset_lod.size(); ++lvl) {
+    std::vector<size_t> level;
+    if (offset_lod[lvl].size() > 0) {
+      level.reserve(offset_lod[lvl].size() - 1);
+    }
+    for (size_t idx = 0; idx < offset_lod[lvl].size() - 1; ++idx) {
+      level.push_back(offset_lod[lvl][idx + 1] - offset_lod[lvl][idx]);
+    }
+    length_lod.push_back(level);
+  }
+  return length_lod;
+}
+
+LoD ConvertToOffsetBasedLoD(const LoD &length_lod) {
+  LoD offset_lod;
+  offset_lod.reserve(length_lod.size());
+  for (size_t lvl = 0; lvl < length_lod.size(); ++lvl) {
+    std::vector<size_t> level;
+    level.reserve(length_lod[lvl].size() + 1);
+    size_t tmp = 0;
+    level.push_back(tmp);
+    for (size_t idx = 0; idx < length_lod[lvl].size(); ++idx) {
+      tmp += length_lod[lvl][idx];
+      level.push_back(tmp);
+    }
+    offset_lod.push_back(level);
+  }
+  return offset_lod;
+}
+
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/framework/lod_tensor.h

@@ -226,5 +226,19 @@ extern void WriteToRecordIO(recordio::Writer* writer,
 extern std::vector<LoDTensor> ReadFromRecordIO(
     recordio::Scanner* scanner, const platform::DeviceContext& dev_ctx);
 
+/*
+ * Convert between length-based LoD and offset-based LoD.
+ * The implementation of LoDTensor class use offset-based LoD.
+ * However, we want to expose the more user-friendly length-based
+ * LoD to the Python side instead.
+ *
+ * Example:
+ * If offset_lod = [[0, 2, 3],[0, 3, 5, 9]]
+ * then length_lod = [[2, 1], [3, 2, 4]]
+ */
+LoD ConvertToLengthBasedLoD(const LoD& offset_lod);
+
+LoD ConvertToOffsetBasedLoD(const LoD& length_lod);
+
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/framework/lod_tensor_test.cc

@@ -228,6 +228,38 @@ TEST(LoD, CheckAbsLoD) {
   ASSERT_FALSE(CheckAbsLoD(abs_lod0));
 }
 
+TEST(LoD, ConvertToLengthBasedLoD) {
+  LoD offset_lod;
+  offset_lod.push_back(std::vector<size_t>({0, 2}));
+  offset_lod.push_back(std::vector<size_t>({0, 1, 3}));
+  offset_lod.push_back(std::vector<size_t>({0, 2, 4, 5}));
+
+  LoD length_lod = ConvertToLengthBasedLoD(offset_lod);
+
+  LoD expected;
+  expected.push_back(std::vector<size_t>({2}));
+  expected.push_back(std::vector<size_t>({1, 2}));
+  expected.push_back(std::vector<size_t>({2, 2, 1}));
+
+  EXPECT_EQ(length_lod, expected);
+}
+
+TEST(LoD, ConvertToOffsetBasedLoD) {
+  LoD length_lod;
+  length_lod.push_back(std::vector<size_t>({2}));
+  length_lod.push_back(std::vector<size_t>({1, 2}));
+  length_lod.push_back(std::vector<size_t>({2, 2, 1}));
+
+  LoD offset_lod = ConvertToOffsetBasedLoD(length_lod);
+
+  LoD expected;
+  expected.push_back(std::vector<size_t>({0, 2}));
+  expected.push_back(std::vector<size_t>({0, 1, 3}));
+  expected.push_back(std::vector<size_t>({0, 2, 4, 5}));
+
+  EXPECT_EQ(offset_lod, expected);
+}
+
 template <typename T>
 static void TestRecordIO() {
   LoDTensor tensor;

paddle/fluid/pybind/pybind.cc

@@ -144,28 +144,74 @@ PYBIND11_PLUGIN(core) {
   py::class_<LoDTensor, Tensor>(m, "LoDTensor")
       .def_buffer(
           [](Tensor &self) -> py::buffer_info { return CastToPyBuffer(self); })
-      .def(
-          "__init__",
-          [](LoDTensor &instance, const std::vector<std::vector<size_t>> &lod) {
-            LoD new_lod;
-            new_lod.reserve(lod.size());
-            std::copy(lod.begin(), lod.end(), std::back_inserter(new_lod));
-            new (&instance) LoDTensor(new_lod);
-          })
+      .def("__init__",
+           [](LoDTensor &instance, const std::vector<std::vector<size_t>>
+                                       &recursive_sequence_lengths) {
+             LoD new_lod;
+             new_lod.reserve(recursive_sequence_lengths.size());
+             std::copy(recursive_sequence_lengths.begin(),
+                       recursive_sequence_lengths.end(),
+                       std::back_inserter(new_lod));
+             LoD new_offset_lod = ConvertToOffsetBasedLoD(new_lod);
+             PADDLE_ENFORCE(
+                 CheckLoD(new_offset_lod, -1),
+                 "the provided recursive_sequence_lengths info is invalid");
+             new (&instance) LoDTensor(new_offset_lod);
+           })
       .def("__init__", [](LoDTensor &instance) { new (&instance) LoDTensor(); })
       .def("set_lod",
            [](LoDTensor &self, const std::vector<std::vector<size_t>> &lod) {
+             // the input lod is offset-based level-of-detail info
+             LOG(WARNING)
+                 << "set_lod is deprecated and will be removed by 9.2018, "
+                    "please switch to set_recursive_sequence_lengths.";
              LoD new_lod;
              new_lod.reserve(lod.size());
              std::copy(lod.begin(), lod.end(), std::back_inserter(new_lod));
+             PADDLE_ENFORCE(CheckLoD(new_lod, vectorize(self.dims()).front()),
+                            "the provided lod info is invalid");
              self.set_lod(new_lod);
            })
-      .def("lod", [](LoDTensor &self) -> std::vector<std::vector<size_t>> {
-        auto lod = self.lod();
-        std::vector<std::vector<size_t>> new_lod;
-        new_lod.reserve(lod.size());
-        std::copy(lod.begin(), lod.end(), std::back_inserter(new_lod));
-        return new_lod;
+      .def("set_recursive_sequence_lengths",
+           [](LoDTensor &self, const std::vector<std::vector<size_t>>
+                                   &recursive_sequence_lengths) {
+             // the input recursive_sequence_lengths is length-based
+             // level-of-detail info
+             LoD new_lod;
+             new_lod.reserve(recursive_sequence_lengths.size());
+             std::copy(recursive_sequence_lengths.begin(),
+                       recursive_sequence_lengths.end(),
+                       std::back_inserter(new_lod));
+             LoD new_offset_lod = ConvertToOffsetBasedLoD(new_lod);
+             PADDLE_ENFORCE(
+                 CheckLoD(new_offset_lod, vectorize(self.dims()).front()),
+                 "the provided recursive_sequence_lengths info is invalid");
+             self.set_lod(new_offset_lod);
+           })
+      .def("lod",
+           [](LoDTensor &self) -> std::vector<std::vector<size_t>> {
+             // output the offset-based lod info
+             LOG(WARNING) << "lod is deprecated and will be removed by 9.2018, "
+                             "please switch to recursive_sequence_lengths.";
+             LoD lod = self.lod();
+             std::vector<std::vector<size_t>> new_lod;
+             new_lod.reserve(lod.size());
+             std::copy(lod.begin(), lod.end(), std::back_inserter(new_lod));
+             return new_lod;
+           })
+      .def("recursive_sequence_lengths",
+           [](LoDTensor &self) -> std::vector<std::vector<size_t>> {
+             // output the length-based lod info
+             LoD lod = ConvertToLengthBasedLoD(self.lod());
+             std::vector<std::vector<size_t>> new_lod;
+             new_lod.reserve(lod.size());
+             std::copy(lod.begin(), lod.end(), std::back_inserter(new_lod));
+             return new_lod;
+           })
+      .def("has_valid_recursive_sequence_lengths", [](LoDTensor &self) -> bool {
+        // Check that the lod info is valid and match the outermost
+        // dimension of the LoDTensor data
+        return CheckLoD(self.lod(), vectorize(self.dims()).front());
       });
 
   py::class_<SelectedRows>(m, "SelectedRows")

python/paddle/fluid/data_feeder.py

@@ -47,7 +47,7 @@ def __init__(self, place, lod_level, shape, dtype):
         self.lod = []
 
         for i in six.range(lod_level):
-            self.lod.append([0])
+            self.lod.append([])
 
     def feed(self, data):
         self._feed_impl_(data, self.lod, self.lod_level)
@@ -56,8 +56,7 @@ def _feed_impl_(self, data, lod, lod_level):
         if lod_level == 0:
             self.data.append(data)
         else:
-            cur_lod_len = len(data)
-            lod[0].append(lod[0][-1] + cur_lod_len)
+            lod[0].append(len(data))
             for each_data in data:
                 self._feed_impl_(each_data, lod[1:], lod_level - 1)
 
@@ -66,7 +65,7 @@ def done(self):
         t = core.LoDTensor()
         t.set(arr, self.place)
         if self.lod_level > 0:
-            t.set_lod(self.lod)
+            t.set_recursive_sequence_lengths(self.lod)
         return t
 
 

python/paddle/fluid/lod_tensor.py

@@ -18,80 +18,6 @@
 __all__ = ['create_lod_tensor', 'create_random_int_lodtensor']
 
 
-def _validate_lod(lod, tensor_height=-1):
-    """Check whether the input length-based lod info is valid.
-
-    There are several things to check:
-    1. lod should be a list of lists. Empty list is fine.
-    2. The length of each sublist (a lod level) should be at least one.
-    3. Each element in each lod level should be an integer greater than 0.
-    4. The sum of one lod level should be equal to the length of the next lod level.
-    5. The sum of the last lod level should be equal to the tensor height. 
-       Bypass this check if user does not provide tensor_height as input.
-
-    Args:
-        lod: the length-based lod info, e.g., [[2, 3], [2, 1, 2, 3, 4]].
-        tensor_height: the outermost dimension of the tensor with which the input 
-            lod is associated with. 
-
-    Returns:
-        A boolean indicating whether the input lod is valid or not.
-    """
-    assert isinstance(lod, list), "lod should be a list"
-    # Empty lod is fine
-    if len(lod) == 0:
-        return True
-
-    lod_sum = []
-    for level in lod:
-        assert isinstance(level, list), "each item in lod should be a list"
-        # Each level of lod should have at least one length info
-        if len(level) < 1:
-            return False
-        level_sum = 0
-        for lod_len in level:
-            # Each length in a level should be > 0
-            if lod_len <= 0:
-                return False
-            level_sum += lod_len
-        lod_sum.append(level_sum)
-
-    for idx, val in enumerate(lod_sum[:-1]):
-        # Each level's sum should be equal to 
-        # the number of items in the next level
-        if val != len(lod[idx + 1]):
-            return False
-
-    if tensor_height == -1:
-        return True
-    else:
-        # Last level's sum should be equal to the tensor height
-        return lod_sum[-1] == tensor_height
-
-
-def _convert_lod(lod):
-    """Convert a length-based lod to a offset-based lod.
-
-    If the length-based lod is [[2, 3], [2, 1, 2, 3, 4]],
-    then the offset-based lod is [[0, 2, 5], [0, 2, 3, 5, 8, 12]].
-
-    Args:
-        lod: a length-based lod info. 
-
-    Returns:
-        A list of lists as the offset-based lod converted to from the input lod.
-    """
-    new_lod = []
-    for level in lod:
-        cur_len = 0
-        new_level = [cur_len]
-        for lod_len in level:
-            cur_len += lod_len
-            new_level.append(cur_len)
-        new_lod.append(new_level)
-    return new_lod
-
-
 def create_lod_tensor(data, lod, place):
     """Create a lod tensor from a numpy array, a list, or an existing lod tensor.
 
@@ -139,11 +65,11 @@ def create_lod_tensor(data, lod, place):
         flattened_data = flattened_data.reshape([len(flattened_data), 1])
         return create_lod_tensor(flattened_data, lod, place)
     elif isinstance(data, np.ndarray):
-        assert _validate_lod(lod,
-                             data.shape[0]), "the provided lod info is invalid"
         tensor = core.LoDTensor()
         tensor.set(data, place)
-        tensor.set_lod(_convert_lod(lod))
+        tensor.set_recursive_sequence_lengths(lod)
+        assert tensor.has_valid_recursive_sequence_lengths(
+        ), "the provided lod info is invalid"
         return tensor
     else:
         raise TypeError(
@@ -181,9 +107,8 @@ def create_random_int_lodtensor(lod, base_shape, place, low, high):
         A fluid LoDTensor object with tensor data and lod info. 
     """
     assert isinstance(base_shape, list), "base_shape should be a list"
-    converted_lod = _convert_lod(lod)
     # append the total number of basic elements to the front of its shape
-    overall_shape = [converted_lod[-1][-1]] + base_shape
+    overall_shape = [sum(lod[-1])] + base_shape
     # the range of integer data elements is [low, high]    
     data = np.random.random_integers(low, high, overall_shape).astype("int64")
     return create_lod_tensor(data, lod, place)