Moved tensorflow::StringPiece::Hasher out of tensorflow::StringPiece and renamed it tensorflow::StringPieceHasher. This allows tensorflow::StringPiece to be more easily replaced with absl::string_view (which does not contain a Hasher struct).

PiperOrigin-RevId: 175563786

15 files changed, 128 insertions, 47 deletions

diff --git a/tensorflow/cc/framework/cc_op_gen.cc b/tensorflow/cc/framework/cc_op_gen.cc
index 38a17598b8..7a1b2a012d 100644
--- a/tensorflow/cc/framework/cc_op_gen.cc
+++ b/tensorflow/cc/framework/cc_op_gen.cc
@@ -297,7 +297,7 @@ string ToCamelCase(const string& str) {
 // argument to a function.
 std::pair<const char*, bool> AttrTypeName(StringPiece attr_type) {
   static const std::unordered_map<StringPiece, std::pair<const char*, bool>,
-                                  StringPiece::Hasher>
+                                  StringPieceHasher>
       attr_type_map{
           {"string", {"StringPiece", false}},
           {"list(string)", {"gtl::ArraySlice<string>", true}},
@@ -325,29 +325,112 @@ std::pair<const char*, bool> AttrTypeName(StringPiece attr_type) {
 }
 
 bool IsCPPKeyword(StringPiece name) {
-  static const std::unordered_set<StringPiece, StringPiece::Hasher>
+  static const std::unordered_set<StringPiece, StringPieceHasher>
       // Keywords obtained from http://en.cppreference.com/w/cpp/keyword
       kCPPReserved{
-          "alignas", "alignof", "and", "and_eq", "asm", "atomic_cancel",
-          "atomic_commit", "atomic_noexcept", "auto", "bitand", "bitor", "bool",
-          "break", "case", "catch", "char", "char16_t", "char32_t", "class",
-          "compl", "concept", "const", "const_cast", "constexpr", "continue",
-          "decltype", "default", "delete", "do", "double", "dynamic_cast",
-          "else", "enum", "explicit", "export", "extern", "false", "final",
-          "float", "for", "friend", "goto", "if", "import", "inline", "int",
-          "long", "module", "mutable", "namespace", "new", "noexcept", "not",
-          "not_eq", "nullptr", "operator", "or", "or_eq", "override", "private",
-          "protected", "public", "register", "reinterpret_cast", "requires",
-          "return", "short", "signed", "sizeof", "static", "static_assert",
-          "static_cast", "struct", "switch", "synchronized", "template", "this",
-          "thread_local", "throw", "true", "try", "typedef", "typeid",
-          "typename", "union", "unsigned", "using", "virtual", "void",
-          "volatile", "wchar_t", "while", "xor", "xor_eq",
+          "alignas",
+          "alignof",
+          "and",
+          "and_eq",
+          "asm",
+          "atomic_cancel",
+          "atomic_commit",
+          "atomic_noexcept",
+          "auto",
+          "bitand",
+          "bitor",
+          "bool",
+          "break",
+          "case",
+          "catch",
+          "char",
+          "char16_t",
+          "char32_t",
+          "class",
+          "compl",
+          "concept",
+          "const",
+          "const_cast",
+          "constexpr",
+          "continue",
+          "decltype",
+          "default",
+          "delete",
+          "do",
+          "double",
+          "dynamic_cast",
+          "else",
+          "enum",
+          "explicit",
+          "export",
+          "extern",
+          "false",
+          "final",
+          "float",
+          "for",
+          "friend",
+          "goto",
+          "if",
+          "import",
+          "inline",
+          "int",
+          "long",
+          "module",
+          "mutable",
+          "namespace",
+          "new",
+          "noexcept",
+          "not",
+          "not_eq",
+          "nullptr",
+          "operator",
+          "or",
+          "or_eq",
+          "override",
+          "private",
+          "protected",
+          "public",
+          "register",
+          "reinterpret_cast",
+          "requires",
+          "return",
+          "short",
+          "signed",
+          "sizeof",
+          "static",
+          "static_assert",
+          "static_cast",
+          "struct",
+          "switch",
+          "synchronized",
+          "template",
+          "this",
+          "thread_local",
+          "throw",
+          "true",
+          "try",
+          "typedef",
+          "typeid",
+          "typename",
+          "union",
+          "unsigned",
+          "using",
+          "virtual",
+          "void",
+          "volatile",
+          "wchar_t",
+          "while",
+          "xor",
+          "xor_eq",
 
           // The following are not C++ keywords, but names of local variables
           // and parameters used in the op constructor. Treating them as
           // keywords, so that other parameter names don't conflict with these.
-          "builder", "node", "ret", "scope", "unique_name",
+          "builder",
+          "node",
+          "ret",
+          "scope",
+          "unique_name",
       };
   return kCPPReserved.count(name) > 0;
 }
diff --git a/tensorflow/core/common_runtime/device_mgr.h b/tensorflow/core/common_runtime/device_mgr.h
index d16681ac59..cd93f76324 100644
--- a/tensorflow/core/common_runtime/device_mgr.h
+++ b/tensorflow/core/common_runtime/device_mgr.h
@@ -68,7 +68,7 @@ class DeviceMgr {
 
   StringPiece CopyToBackingStore(StringPiece s);
 
-  std::unordered_map<StringPiece, Device*, StringPiece::Hasher> device_map_;
+  std::unordered_map<StringPiece, Device*, StringPieceHasher> device_map_;
   core::Arena name_backing_store_;  // Storage for keys in device_map_
   std::unordered_map<string, int> device_type_counts_;
 
diff --git a/tensorflow/core/common_runtime/direct_session.cc b/tensorflow/core/common_runtime/direct_session.cc
index 316fb0ac16..d1dc826a6e 100644
--- a/tensorflow/core/common_runtime/direct_session.cc
+++ b/tensorflow/core/common_runtime/direct_session.cc
@@ -1135,7 +1135,7 @@ Status DirectSession::GetOrCreateExecutors(
 
   if (run_state_args->is_partial_run) {
     ek->graph = std::move(run_state_args->graph);
-    std::unordered_set<StringPiece, StringPiece::Hasher> names;
+    std::unordered_set<StringPiece, StringPieceHasher> names;
     for (const string& input : inputs) {
       TensorId id(ParseTensorName(input));
       names.emplace(id.first);
diff --git a/tensorflow/core/common_runtime/direct_session.h b/tensorflow/core/common_runtime/direct_session.h
index 7fbabf6d81..780d0b46a8 100644
--- a/tensorflow/core/common_runtime/direct_session.h
+++ b/tensorflow/core/common_runtime/direct_session.h
@@ -64,8 +64,7 @@ class DirectSession : public Session {
   ~DirectSession() override;
 
   typedef std::vector<std::pair<string, Tensor>> NamedTensorList;
-  typedef std::unordered_map<StringPiece, Node*, StringPiece::Hasher>
-      NameNodeMap;
+  typedef std::unordered_map<StringPiece, Node*, StringPieceHasher> NameNodeMap;
 
   ::tensorflow::Status Create(const GraphDef& graph) override;
   ::tensorflow::Status Extend(const GraphDef& graph) override;
diff --git a/tensorflow/core/common_runtime/placer.cc b/tensorflow/core/common_runtime/placer.cc
index 73fdf60fd5..54f082e823 100644
--- a/tensorflow/core/common_runtime/placer.cc
+++ b/tensorflow/core/common_runtime/placer.cc
@@ -129,7 +129,7 @@ class ColocationGraph {
     // 'string' values stored in NodeDef attribute lists, as well as StringPiece
     // values that refer to 'string' values from NodeDef::name(), without
     // performing any string allocations.
-    std::unordered_map<StringPiece, const Node*, StringPiece::Hasher>
+    std::unordered_map<StringPiece, const Node*, StringPieceHasher>
         colocation_group_root;
 
     for (Node* node : graph_->nodes()) {
@@ -171,7 +171,7 @@ class ColocationGraph {
   }
 
   Status ColocateNodeToGroup(
-      std::unordered_map<StringPiece, const Node*, StringPiece::Hasher>*
+      std::unordered_map<StringPiece, const Node*, StringPieceHasher>*
           colocation_group_root,
       Node* node, StringPiece colocation_group) {
     const Node*& root_node = (*colocation_group_root)[colocation_group];
diff --git a/tensorflow/core/common_runtime/step_stats_collector.cc b/tensorflow/core/common_runtime/step_stats_collector.cc
index e6403df97f..ba8e555f36 100644
--- a/tensorflow/core/common_runtime/step_stats_collector.cc
+++ b/tensorflow/core/common_runtime/step_stats_collector.cc
@@ -139,7 +139,7 @@ void StepStatsCollector::BuildCostModel(
     const DeviceStepStats* hardware_stats;
   };
 
-  std::unordered_map<StringPiece, DeviceStats, StringPiece::Hasher>
+  std::unordered_map<StringPiece, DeviceStats, StringPieceHasher>
       per_device_stats;
   std::unordered_map<int, const DeviceStepStats*> gpu_hardware_stats;
 
@@ -179,7 +179,7 @@ void StepStatsCollector::BuildCostModel(
     CostModel* cm = cost_model_manager->FindOrCreateCostModel(graph);
     cm->IncrementUpdateTimes();
 
-    std::unordered_map<StringPiece, Node*, StringPiece::Hasher> name_to_node;
+    std::unordered_map<StringPiece, Node*, StringPieceHasher> name_to_node;
     for (Node* n : graph->nodes()) {
       name_to_node.emplace(n->name(), n);
     }
diff --git a/tensorflow/core/distributed_runtime/master_session.cc b/tensorflow/core/distributed_runtime/master_session.cc
index f7fce1d0ec..7617158d66 100644
--- a/tensorflow/core/distributed_runtime/master_session.cc
+++ b/tensorflow/core/distributed_runtime/master_session.cc
@@ -208,7 +208,7 @@ class MasterSession::ReffedClientGraph : public core::RefCounted {
   const bool is_partial_;
   const DebugOptions& debug_opts_;
   WorkerCacheInterface* const worker_cache_;  // Not owned.
-  std::unordered_map<StringPiece, Node*, StringPiece::Hasher> name_to_node_;
+  std::unordered_map<StringPiece, Node*, StringPieceHasher> name_to_node_;
 
   // Graph partitioned into per-location subgraphs.
   struct Part {
@@ -486,7 +486,7 @@ Status MasterSession::ReffedClientGraph::RunPartitions(
   VLOG(2) << "RunPartitions step_id " << step_id << " execution_count "
           << execution_count;
   // Maps the names of fed tensors to their index in `req`.
-  std::unordered_map<StringPiece, size_t, StringPiece::Hasher> feeds(3);
+  std::unordered_map<StringPiece, size_t, StringPieceHasher> feeds(3);
 
   for (size_t i = 0; i < req.num_feeds(); ++i) {
     if (!feeds.insert({req.feed_name(i), i}).second) {
diff --git a/tensorflow/core/framework/variant_op_registry.h b/tensorflow/core/framework/variant_op_registry.h
index 831dbd3dff..13f6908cae 100644
--- a/tensorflow/core/framework/variant_op_registry.h
+++ b/tensorflow/core/framework/variant_op_registry.h
@@ -145,9 +145,8 @@ class UnaryVariantOpRegistry {
   static std::unordered_set<string>* PersistentStringStorage();
 
  private:
-  std::unordered_map<StringPiece, VariantShapeFn, StringPiece::Hasher>
-      shape_fns;
-  std::unordered_map<StringPiece, VariantDecodeFn, StringPiece::Hasher>
+  std::unordered_map<StringPiece, VariantShapeFn, StringPieceHasher> shape_fns;
+  std::unordered_map<StringPiece, VariantDecodeFn, StringPieceHasher>
       decode_fns;
 
   // Map std::pair<Direction, type_name> to function.
@@ -159,7 +158,7 @@ class UnaryVariantOpRegistry {
       ret = Hash64Combine(ret, sp_hasher_(std::get<1>(x)));
       return ret;
     }
-    StringPiece::Hasher sp_hasher_;
+    StringPieceHasher sp_hasher_;
   };
 
   std::unordered_map<std::pair<VariantDeviceCopyDirection, StringPiece>,
@@ -177,7 +176,7 @@ class UnaryVariantOpRegistry {
       ret = Hash64Combine(ret, sp_hasher_(std::get<2>(x)));
       return ret;
     }
-    StringPiece::Hasher sp_hasher_;
+    StringPieceHasher sp_hasher_;
   };
   std::unordered_map<std::tuple<VariantUnaryOp, StringPiece, StringPiece>,
                      VariantUnaryOpFn, TupleHash>
diff --git a/tensorflow/core/graph/costmodel.h b/tensorflow/core/graph/costmodel.h
index a908a4843c..8afa4971ad 100644
--- a/tensorflow/core/graph/costmodel.h
+++ b/tensorflow/core/graph/costmodel.h
@@ -30,7 +30,7 @@ limitations under the License.
 #include "tensorflow/core/platform/protobuf.h"
 
 namespace tensorflow {
-typedef std::unordered_map<StringPiece, int32, StringPiece::Hasher>
+typedef std::unordered_map<StringPiece, int32, StringPieceHasher>
     NodeNameToCostIdMap;
 
 class StepStats;
diff --git a/tensorflow/core/graph/graph_constructor.cc b/tensorflow/core/graph/graph_constructor.cc
index 2ee409768b..ebaffeb50e 100644
--- a/tensorflow/core/graph/graph_constructor.cc
+++ b/tensorflow/core/graph/graph_constructor.cc
@@ -241,13 +241,13 @@ class GraphConstructor {
   };
   // TODO(vrv): Profile this data structure to see if we should use an
   // alternative implementation of std::unordered_map.
-  std::unordered_map<StringPiece, NodeInfo, StringPiece::Hasher> gdef_nodes_;
+  std::unordered_map<StringPiece, NodeInfo, StringPieceHasher> gdef_nodes_;
 
   // Mapping from node name to the existing node in g_.
-  std::unordered_map<StringPiece, Node*, StringPiece::Hasher> existing_nodes_;
+  std::unordered_map<StringPiece, Node*, StringPieceHasher> existing_nodes_;
 
   // Prefixes already used in the graph.
-  std::unordered_set<StringPiece, StringPiece::Hasher> existing_prefixes_;
+  std::unordered_set<StringPiece, StringPieceHasher> existing_prefixes_;
 
   // Imported node names that have been uniquified. The key is the original
   // name, the value is the new unique name.
diff --git a/tensorflow/core/graph/quantize_training.cc b/tensorflow/core/graph/quantize_training.cc
index d9cb55f448..cb0fc8a154 100644
--- a/tensorflow/core/graph/quantize_training.cc
+++ b/tensorflow/core/graph/quantize_training.cc
@@ -42,7 +42,7 @@ const float kEMADecay = 0.999;
 
 // Node types to rewrite. Insert quantize_and_dequantize op for their inputs.
 const auto* nodes_to_rewrite =
-    new std::unordered_set<string, StringPiece::Hasher>{"MatMul", "Conv2D"};
+    new std::unordered_set<string, StringPieceHasher>{"MatMul", "Conv2D"};
 
 // Contains necessary parameters to convert an edge.
 struct EdgeToConvert {
@@ -563,7 +563,7 @@ Status ProcessTargetEdges(Graph* graph, const string& quant_op_type,
                           const std::vector<EdgeToConvert>& target_edges) {
   // Remember previously converted ops to avoid duplicated conversion on the
   // same input.
-  std::unordered_map<string, Node*, StringPiece::Hasher> name_index;
+  std::unordered_map<string, Node*, StringPieceHasher> name_index;
   std::vector<Node*> added_variables;
   for (const EdgeToConvert edge : target_edges) {
     Node* convert_node;
diff --git a/tensorflow/core/graph/subgraph.h b/tensorflow/core/graph/subgraph.h
index 8ccc27914b..3c1f8870f5 100644
--- a/tensorflow/core/graph/subgraph.h
+++ b/tensorflow/core/graph/subgraph.h
@@ -71,7 +71,7 @@ Status RewriteGraphForExecution(
     const DeviceAttributes& device_info, bool use_function_convention,
     RewriteGraphMetadata* out_metadata);
 
-typedef std::unordered_map<StringPiece, Node*, StringPiece::Hasher> NameIndex;
+typedef std::unordered_map<StringPiece, Node*, StringPieceHasher> NameIndex;
 
 // Augment "*g" by adding special "fetch" nodes that connect to the
 // tensor outputs specified in "fetch_outputs" to retrieve the output
diff --git a/tensorflow/core/lib/core/stringpiece.cc b/tensorflow/core/lib/core/stringpiece.cc
index 984f4404ce..29b727fc44 100644
--- a/tensorflow/core/lib/core/stringpiece.cc
+++ b/tensorflow/core/lib/core/stringpiece.cc
@@ -21,7 +21,7 @@ limitations under the License.
 
 namespace tensorflow {
 
-size_t StringPiece::Hasher::operator()(StringPiece s) const {
+size_t StringPieceHasher::operator()(StringPiece s) const {
   return Hash64(s.data(), s.size());
 }
 
diff --git a/tensorflow/core/lib/core/stringpiece.h b/tensorflow/core/lib/core/stringpiece.h
index 94f4a377f1..53af116465 100644
--- a/tensorflow/core/lib/core/stringpiece.h
+++ b/tensorflow/core/lib/core/stringpiece.h
@@ -103,10 +103,6 @@ class StringPiece {
 
   StringPiece substr(size_t pos, size_t n = npos) const;
 
-  struct Hasher {
-    size_t operator()(StringPiece arg) const;
-  };
-
   // Return a string that contains the copy of the referenced data.
   std::string ToString() const { return std::string(data_, size_); }
 
@@ -133,6 +129,10 @@ class StringPiece {
   // Intentionally copyable
 };
 
+struct StringPieceHasher {
+  size_t operator()(StringPiece s) const;
+};
+
 inline bool operator==(StringPiece x, StringPiece y) {
   return ((x.size() == y.size()) &&
           (memcmp(x.data(), y.data(), x.size()) == 0));
diff --git a/tensorflow/tools/graph_transforms/fold_constants_lib.cc b/tensorflow/tools/graph_transforms/fold_constants_lib.cc
index f2934a79bd..250f54e20f 100644
--- a/tensorflow/tools/graph_transforms/fold_constants_lib.cc
+++ b/tensorflow/tools/graph_transforms/fold_constants_lib.cc
@@ -39,9 +39,9 @@ limitations under the License.
 namespace tensorflow {
 namespace graph_transforms {
 namespace {
-using StringPieceSet = std::unordered_set<StringPiece, StringPiece::Hasher>;
+using StringPieceSet = std::unordered_set<StringPiece, StringPieceHasher>;
 template <typename T>
-using StringPieceMap = std::unordered_map<StringPiece, T, StringPiece::Hasher>;
+using StringPieceMap = std::unordered_map<StringPiece, T, StringPieceHasher>;
 }  // namespace
 
 Status ReplaceSendRecvs(const GraphDef& original_graph_def,