From adb34a7af2b775f8831c047c6a026d8038b97cc4 Mon Sep 17 00:00:00 2001
From: Igor Vytyaz <vytyaz@google.com>
Date: Fri, 13 Sep 2019 10:49:12 -0700
Subject: [PATCH] Making metadata block in DRC files deterministic.

---
 src/draco/metadata/metadata.h               | 10 +++++-----
 src/draco/metadata/metadata_encoder.cc      |  7 +++----
 src/draco/metadata/metadata_encoder_test.cc |  6 +++---
 3 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/draco/metadata/metadata.h b/src/draco/metadata/metadata.h
index c483949..bf0be36 100644
--- a/src/draco/metadata/metadata.h
+++ b/src/draco/metadata/metadata.h
@@ -18,7 +18,7 @@
 #include <cstring>
 #include <memory>
 #include <string>
-#include <unordered_map>
+#include <map>
 #include <vector>
 
 #include "draco/core/hash_utils.h"
@@ -150,10 +150,10 @@ class Metadata {
   void RemoveEntry(const std::string &name);
 
   int num_entries() const { return static_cast<int>(entries_.size()); }
-  const std::unordered_map<std::string, EntryValue> &entries() const {
+  const std::map<std::string, EntryValue> &entries() const {
     return entries_;
   }
-  const std::unordered_map<std::string, std::unique_ptr<Metadata>>
+  const std::map<std::string, std::unique_ptr<Metadata>>
       &sub_metadatas() const {
     return sub_metadatas_;
   }
@@ -178,8 +178,8 @@ class Metadata {
     return itr->second.GetValue(entry_value);
   }
 
-  std::unordered_map<std::string, EntryValue> entries_;
-  std::unordered_map<std::string, std::unique_ptr<Metadata>> sub_metadatas_;
+  std::map<std::string, EntryValue> entries_;
+  std::map<std::string, std::unique_ptr<Metadata>> sub_metadatas_;
 
   friend struct MetadataHasher;
 };
diff --git a/src/draco/metadata/metadata_encoder.cc b/src/draco/metadata/metadata_encoder.cc
index c98a334..6e85ce6 100644
--- a/src/draco/metadata/metadata_encoder.cc
+++ b/src/draco/metadata/metadata_encoder.cc
@@ -20,8 +20,7 @@ namespace draco {
 
 bool MetadataEncoder::EncodeMetadata(EncoderBuffer *out_buffer,
                                      const Metadata *metadata) {
-  const std::unordered_map<std::string, EntryValue> &entries =
-      metadata->entries();
+  const std::map<std::string, EntryValue> &entries = metadata->entries();
   // Encode number of entries.
   EncodeVarint(static_cast<uint32_t>(metadata->num_entries()), out_buffer);
   // Encode all entries.
@@ -33,8 +32,8 @@ bool MetadataEncoder::EncodeMetadata(EncoderBuffer *out_buffer,
     EncodeVarint(data_size, out_buffer);
     out_buffer->Encode(entry_value.data(), data_size);
   }
-  const std::unordered_map<std::string, std::unique_ptr<Metadata>>
-      &sub_metadatas = metadata->sub_metadatas();
+  const std::map<std::string, std::unique_ptr<Metadata>> &sub_metadatas =
+      metadata->sub_metadatas();
   // Encode number of sub-metadata
   EncodeVarint(static_cast<uint32_t>(sub_metadatas.size()), out_buffer);
   // Encode each sub-metadata
diff --git a/src/draco/metadata/metadata_encoder_test.cc b/src/draco/metadata/metadata_encoder_test.cc
index fbda613..d8f7f2f 100644
--- a/src/draco/metadata/metadata_encoder_test.cc
+++ b/src/draco/metadata/metadata_encoder_test.cc
@@ -75,9 +75,9 @@ class MetadataEncoderTest : public ::testing::Test {
   void CheckMetadatasAreEqual(const draco::Metadata &metadata0,
                               const draco::Metadata &metadata1) {
     ASSERT_EQ(metadata0.num_entries(), metadata1.num_entries());
-    const std::unordered_map<std::string, draco::EntryValue> &entries0 =
+    const std::map<std::string, draco::EntryValue> &entries0 =
         metadata0.entries();
-    const std::unordered_map<std::string, draco::EntryValue> &entries1 =
+    const std::map<std::string, draco::EntryValue> &entries1 =
         metadata1.entries();
     for (const auto &entry : entries0) {
       const std::string &entry_name = entry.first;
@@ -90,7 +90,7 @@ class MetadataEncoderTest : public ::testing::Test {
     // Check nested metadata.
     ASSERT_EQ(metadata0.sub_metadatas().size(),
               metadata1.sub_metadatas().size());
-    const std::unordered_map<std::string, std::unique_ptr<draco::Metadata>>
+    const std::map<std::string, std::unique_ptr<draco::Metadata>>
         &sub_metadatas0 = metadata0.sub_metadatas();
     // Encode each sub-metadata
     for (auto &&sub_metadata_entry0 : sub_metadatas0) {