# -*- coding=utf-8 -*- """ # Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """ import paddle.fluid as fluid from paddlerec.core.utils import envs from paddlerec.core.model import Model as ModelBase class Model(ModelBase): def __init__(self, config): ModelBase.__init__(self, config) # tree meta hyper parameters self.max_layers = envs.get_global_env("tree_parameters.max_layers", 4, self._namespace) self.node_nums = envs.get_global_env("tree_parameters.node_nums", 26, self._namespace) self.leaf_node_nums = envs.get_global_env( "tree_parameters.leaf_node_nums", 13, self._namespace) self.output_positive = envs.get_global_env( "tree_parameters.output_positive", True, self._namespace) self.layer_node_num_list = envs.get_global_env( "tree_parameters.layer_node_num_list", [2, 4, 7, 12], self._namespace) self.child_nums = envs.get_global_env("tree_parameters.child_nums", 2, self._namespace) self.tree_layer_path = envs.get_global_env("tree.tree_layer_path", None, "train.startup") # model training hyper parameter self.node_emb_size = envs.get_global_env( "hyper_parameters.node_emb_size", 64, self._namespace) self.input_emb_size = envs.get_global_env( "hyper_parameters.input_emb_size", 768, self._namespace) self.act = envs.get_global_env("hyper_parameters.act", "tanh", self._namespace) self.neg_sampling_list = envs.get_global_env( "hyper_parameters.neg_sampling_list", [1, 2, 3, 4], self._namespace) # model infer hyper parameter self.topK = envs.get_global_env("hyper_parameters.node_nums", 1, self._namespace) self.batch_size = envs.get_global_env("batch_size", 1, "evaluate.reader") def train_net(self): self.train_input() self.tdm_net() self.create_info() self.avg_loss() self.metrics() def infer_net(self): self.infer_input() self.create_first_layer() self.tdm_infer_net() """ -------- Train network detail ------- """ def train_input(self): input_emb = fluid.data( name="input_emb", shape=[None, self.input_emb_size], dtype="float32", ) self._data_var.append(input_emb) item_label = fluid.data( name="item_label", shape=[None, 1], dtype="int64", ) self._data_var.append(item_label) if self._platform != "LINUX": self._data_loader = fluid.io.DataLoader.from_generator( feed_list=self._data_var, capacity=64, use_double_buffer=False, iterable=False) def tdm_net(self): """ tdm训练网络的主要流程部分 """ is_distributed = True if envs.get_trainer() == "CtrTrainer" else False input_emb = self._data_var[0] item_label = self._data_var[1] # 根据输入的item的正样本在给定的树上进行负采样 # sample_nodes 是采样的node_id的结果，包含正负样本 # sample_label 是采样的node_id对应的正负标签 # sample_mask 是为了保持tensor维度一致，padding部分的标签，若为0，则是padding的虚拟node_id sample_nodes, sample_label, sample_mask = fluid.contrib.layers.tdm_sampler( x=item_label, neg_samples_num_list=self.neg_sampling_list, layer_node_num_list=self.layer_node_num_list, leaf_node_num=self.leaf_node_nums, tree_travel_attr=fluid.ParamAttr(name="TDM_Tree_Travel"), tree_layer_attr=fluid.ParamAttr(name="TDM_Tree_Layer"), output_positive=self.output_positive, output_list=True, seed=0, tree_dtype='int64', dtype='int64') # 查表得到每个节点的Embedding sample_nodes_emb = [ fluid.embedding( input=sample_nodes[i], is_sparse=True, size=[self.node_nums, self.node_emb_size], param_attr=fluid.ParamAttr(name="TDM_Tree_Emb")) for i in range(self.max_layers) ] # 此处进行Reshape是为了之后层次化的分类器训练 sample_nodes_emb = [ fluid.layers.reshape(sample_nodes_emb[i], [ -1, self.neg_sampling_list[i] + self.output_positive, self.node_emb_size ]) for i in range(self.max_layers) ] # 对输入的input_emb进行转换，使其维度与node_emb维度一致 input_trans_emb = self.input_trans_layer(input_emb) # 分类器的主体网络，分别训练不同层次的分类器 layer_classifier_res = self.classifier_layer(input_trans_emb, sample_nodes_emb) # 最后的概率判别FC，将所有层次的node分类结果放到一起以相同的标准进行判别 # 考虑到树极大可能不平衡，有些item不在最后一层，所以需要这样的机制保证每个item都有机会被召回 tdm_fc = fluid.layers.fc( input=layer_classifier_res, size=2, act=None, num_flatten_dims=2, param_attr=fluid.ParamAttr(name="tdm.cls_fc.weight"), bias_attr=fluid.ParamAttr(name="tdm.cls_fc.bias")) # 将loss打平，放到一起计算整体网络的loss tdm_fc_re = fluid.layers.reshape(tdm_fc, [-1, 2]) # 若想对各个层次的loss辅以不同的权重，则在此处无需concat # 支持各个层次分别计算loss，再乘相应的权重 sample_label = fluid.layers.concat(sample_label, axis=1) labels_reshape = fluid.layers.reshape(sample_label, [-1, 1]) labels_reshape.stop_gradient = True # 计算整体的loss并得到softmax的输出 cost, softmax_prob = fluid.layers.softmax_with_cross_entropy( logits=tdm_fc_re, label=labels_reshape, return_softmax=True) # 通过mask过滤掉虚拟节点的loss sample_mask = fluid.layers.concat(sample_mask, axis=1) mask_reshape = fluid.layers.reshape(sample_mask, [-1, 1]) mask_index = fluid.layers.where(mask_reshape != 0) mask_index.stop_gradient = True self.mask_cost = fluid.layers.gather_nd(cost, mask_index) softmax_prob = fluid.layers.unsqueeze(input=softmax_prob, axes=[1]) self.mask_prob = fluid.layers.gather_nd(softmax_prob, mask_index) self.mask_label = fluid.layers.gather_nd(labels_reshape, mask_index) self._predict = self.mask_prob def create_info(self): fluid.default_startup_program().global_block().create_var( name="TDM_Tree_Info", dtype=fluid.core.VarDesc.VarType.INT32, shape=[self.node_nums, 3 + self.child_nums], persistable=True, initializer=fluid.initializer.ConstantInitializer(0)) fluid.default_main_program().global_block().create_var( name="TDM_Tree_Info", dtype=fluid.core.VarDesc.VarType.INT32, shape=[self.node_nums, 3 + self.child_nums], persistable=True) def avg_loss(self): avg_cost = fluid.layers.reduce_mean(self.mask_cost) self._cost = avg_cost def metrics(self): auc, batch_auc, _ = fluid.layers.auc(input=self._predict, label=self.mask_label, num_thresholds=2**12, slide_steps=20) self._metrics["AUC"] = auc self._metrics["BATCH_AUC"] = batch_auc self._metrics["BATCH_LOSS"] = self._cost def input_trans_layer(self, input_emb): """ 输入侧训练组网 """ # 将input映射到与node相同的维度 input_fc_out = fluid.layers.fc( input=input_emb, size=self.node_emb_size, act=None, param_attr=fluid.ParamAttr(name="trans.input_fc.weight"), bias_attr=fluid.ParamAttr(name="trans.input_fc.bias"), ) # 将input_emb映射到各个不同层次的向量表示空间 input_layer_fc_out = [ fluid.layers.fc( input=input_fc_out, size=self.node_emb_size, act=self.act, param_attr=fluid.ParamAttr( name="trans.layer_fc.weight." + str(i)), bias_attr=fluid.ParamAttr( name="trans.layer_fc.bias." + str(i)), ) for i in range(self.max_layers) ] return input_layer_fc_out def _expand_layer(self, input_layer, node, layer_idx): # 扩展input的输入，使数量与node一致， # 也可以以其他broadcast的操作进行代替 # 同时兼容了训练组网与预测组网 input_layer_unsequeeze = fluid.layers.unsqueeze( input=input_layer, axes=[1]) if not isinstance(node, list): input_layer_expand = fluid.layers.expand( input_layer_unsequeeze, expand_times=[1, node.shape[1], 1]) else: input_layer_expand = fluid.layers.expand( input_layer_unsequeeze, expand_times=[1, node[layer_idx].shape[1], 1]) return input_layer_expand def classifier_layer(self, input, node): # 扩展input，使维度与node匹配 input_expand = [ self._expand_layer(input[i], node, i) for i in range(self.max_layers) ] # 将input_emb与node_emb concat到一起过分类器FC input_node_concat = [ fluid.layers.concat( input=[input_expand[i], node[i]], axis=2) for i in range(self.max_layers) ] hidden_states_fc = [ fluid.layers.fc( input=input_node_concat[i], size=self.node_emb_size, num_flatten_dims=2, act=self.act, param_attr=fluid.ParamAttr( name="cls.concat_fc.weight." + str(i)), bias_attr=fluid.ParamAttr(name="cls.concat_fc.bias." + str(i))) for i in range(self.max_layers) ] # 如果将所有层次的node放到一起计算loss，则需要在此处concat # 将分类器结果以batch为准绳concat到一起，而不是layer # 维度形如[batch_size, total_node_num, node_emb_size] hidden_states_concat = fluid.layers.concat(hidden_states_fc, axis=1) return hidden_states_concat """ -------- Infer network detail ------- """ def infer_input(self): input_emb = fluid.layers.data( name="input_emb", shape=[self.input_emb_size], dtype="float32", ) self._infer_data_var.append(input_emb) self._infer_data_loader = fluid.io.DataLoader.from_generator( feed_list=self._infer_data_var, capacity=64, use_double_buffer=False, iterable=False) def get_layer_list(self): """get layer list from layer_list.txt""" layer_list = [] with open(self.tree_layer_path, 'r') as fin: for line in fin.readlines(): l = [] layer = (line.split('\n'))[0].split(',') for node in layer: if node: l.append(node) layer_list.append(l) self.layer_list = layer_list def create_first_layer(self): """decide which layer to start infer""" self.get_layer_list() first_layer_id = 0 for idx, layer_node in enumerate(self.layer_node_num_list): if layer_node >= self.topK: first_layer_id = idx break first_layer_node = self.layer_list[first_layer_id] self.first_layer_idx = first_layer_id node_list = [] mask_list = [] for id in first_layer_node: node_list.append( fluid.layers.fill_constant( [self.batch_size, 1], value=int(id), dtype='int64')) mask_list.append( fluid.layers.fill_constant( [self.batch_size, 1], value=0, dtype='int64')) self.first_layer_node = fluid.layers.concat(node_list, axis=1) self.first_layer_node_mask = fluid.layers.concat(mask_list, axis=1) def tdm_infer_net(self): """ infer的主要流程 infer的基本逻辑是：从上层开始（具体层idx由树结构及TopK值决定） 1、依次通过每一层分类器，得到当前层输入的指定节点的prob 2、根据prob值大小，取topK的节点，取这些节点的孩子节点作为下一层的输入 3、循环1、2步骤，遍历完所有层，得到每一层筛选结果的集合 4、将筛选结果集合中的叶子节点，拿出来再做一次topK，得到最终的召回输出 """ input_emb = self._infer_data_var[0] node_score = [] node_list = [] current_layer_node = self.first_layer_node current_layer_node_mask = self.first_layer_node_mask input_trans_emb = self.input_fc_infer(input_emb) for layer_idx in range(self.first_layer_idx, self.max_layers): # 确定当前层的需要计算的节点数 if layer_idx == self.first_layer_idx: current_layer_node_num = self.first_layer_node.shape[1] else: current_layer_node_num = current_layer_node.shape[1] * \ current_layer_node.shape[2] current_layer_node = fluid.layers.reshape( current_layer_node, [-1, current_layer_node_num]) current_layer_node_mask = fluid.layers.reshape( current_layer_node_mask, [-1, current_layer_node_num]) node_emb = fluid.embedding( input=current_layer_node, size=[self.node_nums, self.node_emb_size], param_attr=fluid.ParamAttr(name="TDM_Tree_Emb")) input_fc_out = self.layer_fc_infer(input_trans_emb, layer_idx) # 过每一层的分类器 layer_classifier_res = self.classifier_layer_infer( input_fc_out, node_emb, layer_idx) # 过最终的判别分类器 tdm_fc = fluid.layers.fc( input=layer_classifier_res, size=2, act=None, num_flatten_dims=2, param_attr=fluid.ParamAttr(name="tdm.cls_fc.weight"), bias_attr=fluid.ParamAttr(name="tdm.cls_fc.bias")) prob = fluid.layers.softmax(tdm_fc) positive_prob = fluid.layers.slice( prob, axes=[2], starts=[1], ends=[2]) prob_re = fluid.layers.reshape(positive_prob, [-1, current_layer_node_num]) # 过滤掉padding产生的无效节点（node_id=0） node_zero_mask = fluid.layers.cast(current_layer_node, 'bool') node_zero_mask = fluid.layers.cast(node_zero_mask, 'float') prob_re = prob_re * node_zero_mask # 在当前层的分类结果中取topK，并将对应的score及node_id保存下来 k = self.topK if current_layer_node_num < self.topK: k = current_layer_node_num _, topk_i = fluid.layers.topk(prob_re, k) # index_sample op根据下标索引tensor对应位置的值 # 若paddle版本>2.0，调用方式为paddle.index_sample top_node = fluid.contrib.layers.index_sample(current_layer_node, topk_i) prob_re_mask = prob_re * current_layer_node_mask # 过滤掉非叶子节点 topk_value = fluid.contrib.layers.index_sample(prob_re_mask, topk_i) node_score.append(topk_value) node_list.append(top_node) # 取当前层topK结果的孩子节点，作为下一层的输入 if layer_idx < self.max_layers - 1: # tdm_child op 根据输入返回其 child 及 child_mask # 若child是叶子节点，则child_mask=1，否则为0 current_layer_node, current_layer_node_mask = \ fluid.contrib.layers.tdm_child(x=top_node, node_nums=self.node_nums, child_nums=self.child_nums, param_attr=fluid.ParamAttr( name="TDM_Tree_Info"), dtype='int64') total_node_score = fluid.layers.concat(node_score, axis=1) total_node = fluid.layers.concat(node_list, axis=1) # 考虑到树可能是不平衡的，计算所有层的叶子节点的topK res_score, res_i = fluid.layers.topk(total_node_score, self.topK) res_layer_node = fluid.contrib.layers.index_sample(total_node, res_i) res_node = fluid.layers.reshape(res_layer_node, [-1, self.topK, 1]) # 利用Tree_info信息，将node_id转换为item_id tree_info = fluid.default_main_program().global_block().var( "TDM_Tree_Info") res_node_emb = fluid.layers.gather_nd(tree_info, res_node) res_item = fluid.layers.slice( res_node_emb, axes=[2], starts=[0], ends=[1]) self.res_item_re = fluid.layers.reshape(res_item, [-1, self.topK]) self._infer_results["item"] = self.res_item_re def input_fc_infer(self, input_emb): """ 输入侧预测组网第一部分，将input转换为node同维度 """ # 组网与训练时保持一致 input_fc_out = fluid.layers.fc( input=input_emb, size=self.node_emb_size, act=None, param_attr=fluid.ParamAttr(name="trans.input_fc.weight"), bias_attr=fluid.ParamAttr(name="trans.input_fc.bias"), ) return input_fc_out def layer_fc_infer(self, input_fc_out, layer_idx): """ 输入侧预测组网第二部分，将input映射到不同层次的向量空间 """ # 组网与训练保持一致，通过layer_idx指定不同层的FC input_layer_fc_out = fluid.layers.fc( input=input_fc_out, size=self.node_emb_size, act=self.act, param_attr=fluid.ParamAttr( name="trans.layer_fc.weight." + str(layer_idx)), bias_attr=fluid.ParamAttr( name="trans.layer_fc.bias." + str(layer_idx)), ) return input_layer_fc_out def classifier_layer_infer(self, input, node, layer_idx): # 为infer组网提供的简化版classifier，通过给定layer_idx调用不同层的分类器 # 同样需要保持input与node的维度匹配 input_expand = self._expand_layer(input, node, layer_idx) # 与训练网络相同的concat逻辑 input_node_concat = fluid.layers.concat( input=[input_expand, node], axis=2) # 根据参数名param_attr调用不同的层的FC hidden_states_fc = fluid.layers.fc( input=input_node_concat, size=self.node_emb_size, num_flatten_dims=2, act=self.act, param_attr=fluid.ParamAttr( name="cls.concat_fc.weight." + str(layer_idx)), bias_attr=fluid.ParamAttr( name="cls.concat_fc.bias." + str(layer_idx))) return hidden_states_fc