Fix optional fields in ObjectMetadata. (#951)

This is part of the fixes for #934. It fixes CommonMetadata and
ObjectMetadata.

Author: coryan

google/cloud/storage/bucket_metadata.cc

@@ -193,10 +193,14 @@ std::ostream& operator<<(std::ostream& os, BucketMetadata const& rhs) {
   }
 
   os << ", location=" << rhs.location() << ", logging=" << rhs.logging()
-     << ", metageneration=" << rhs.metageneration() << ", name=" << rhs.name()
-     << ", owner.entity=" << rhs.owner().entity
-     << ", owner.entity_id=" << rhs.owner().entity_id
-     << ", self_link=" << rhs.self_link()
+     << ", metageneration=" << rhs.metageneration() << ", name=" << rhs.name();
+
+  if (rhs.has_owner()) {
+    os << ", owner.entity=" << rhs.owner().entity
+       << ", owner.entity_id=" << rhs.owner().entity_id;
+  }
+
+  os << ", self_link=" << rhs.self_link()
      << ", storage_class=" << rhs.storage_class()
      << ", time_created=" << rhs.time_created().time_since_epoch().count()
      << ", updated=" << rhs.updated().time_since_epoch().count();

google/cloud/storage/internal/common_metadata.h

@@ -15,6 +15,7 @@
 #ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_INTERNAL_COMMON_METADATA_H_
 #define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_STORAGE_INTERNAL_COMMON_METADATA_H_
 
+#include "google/cloud/internal/optional.h"
 #include "google/cloud/storage/internal/metadata_parser.h"
 #include "google/cloud/storage/internal/nljson.h"
 #include <chrono>
@@ -31,6 +32,32 @@ struct Owner {
   std::string entity_id;
 };
 
+inline bool operator==(Owner const& lhs, Owner const& rhs) {
+  return std::tie(lhs.entity, lhs.entity_id) ==
+         std::tie(rhs.entity, rhs.entity_id);
+}
+
+inline bool operator<(Owner const& lhs, Owner const& rhs) {
+  return std::tie(lhs.entity, lhs.entity_id) <
+         std::tie(rhs.entity, rhs.entity_id);
+}
+
+inline bool operator!=(Owner const& lhs, Owner const& rhs) {
+  return std::rel_ops::operator!=(lhs, rhs);
+}
+
+inline bool operator>(Owner const& lhs, Owner const& rhs) {
+  return std::rel_ops::operator>(lhs, rhs);
+}
+
+inline bool operator<=(Owner const& lhs, Owner const& rhs) {
+  return std::rel_ops::operator<=(lhs, rhs);
+}
+
+inline bool operator>=(Owner const& lhs, Owner const& rhs) {
+  return std::rel_ops::operator>=(lhs, rhs);
+}
+
 namespace internal {
 /**
  * Refactor common functionality in BucketMetadata and ObjectMetadata.
@@ -43,7 +70,7 @@ namespace internal {
 template <typename Derived>
 class CommonMetadata {
  public:
-  CommonMetadata() : metageneration_(0) {}
+  CommonMetadata() : metageneration_(0), owner_() {}
 
   static CommonMetadata<Derived> ParseFromJson(internal::nl::json const& json) {
     CommonMetadata<Derived> result{};
@@ -53,8 +80,10 @@ class CommonMetadata {
     result.metageneration_ = ParseLongField(json, "metageneration");
     result.name_ = json.value("name", "");
     if (json.count("owner") != 0) {
-      result.owner_.entity = json["owner"].value("entity", "");
-      result.owner_.entity_id = json["owner"].value("entityId", "");
+      Owner o;
+      o.entity = json["owner"].value("entity", "");
+      o.entity_id = json["owner"].value("entityId", "");
+      result.owner_ = std::move(o);
     }
     result.self_link_ = json.value("selfLink", "");
     result.storage_class_ = json.value("storageClass", "");
@@ -78,7 +107,9 @@ class CommonMetadata {
     return *static_cast<Derived*>(this);
   }
 
-  Owner const& owner() const { return owner_; }
+  bool has_owner() const { return owner_.has_value(); }
+  Owner const& owner() const { return owner_.value(); }
+
   std::string const& self_link() const { return self_link_; }
 
   std::string const& storage_class() const { return storage_class_; }
@@ -112,7 +143,7 @@ class CommonMetadata {
   std::string kind_;
   std::int64_t metageneration_;
   std::string name_;
-  Owner owner_;
+  google::cloud::internal::optional<Owner> owner_;
   std::string self_link_;
   std::string storage_class_;
   std::chrono::system_clock::time_point time_created_;

google/cloud/storage/object_metadata.cc

@@ -41,9 +41,10 @@ ObjectMetadata ObjectMetadata::ParseFromJson(internal::nl::json const& json) {
   result.crc32c_ = json.value("crc32c", "");
   if (json.count("customerEncryption") != 0) {
     auto field = json["customerEncryption"];
-    result.customer_encryption_.encryption_algorithm =
-        field.value("encryptionAlgorithm", "");
-    result.customer_encryption_.key_sha256 = field.value("keySha256", "");
+    CustomerEncryption e;
+    e.encryption_algorithm = field.value("encryptionAlgorithm", "");
+    e.key_sha256 = field.value("keySha256", "");
+    result.customer_encryption_ = std::move(e);
   }
   result.generation_ = internal::ParseLongField(json, "generation");
   result.kms_key_name_ = json.value("kmsKeyName", "");
@@ -76,10 +77,7 @@ bool ObjectMetadata::operator==(ObjectMetadata const& rhs) const {
          content_encoding_ == rhs.content_encoding_ and
          content_language_ == rhs.content_language_ and
          content_type_ == rhs.content_type_ and crc32c_ == rhs.crc32c_ and
-         customer_encryption_.encryption_algorithm ==
-             rhs.customer_encryption_.encryption_algorithm and
-         customer_encryption_.key_sha256 ==
-             rhs.customer_encryption_.key_sha256 and
+         customer_encryption_ == customer_encryption_ and
          generation_ == rhs.generation_ and
          kms_key_name_ == rhs.kms_key_name_ and md5_hash_ == rhs.md5_hash_ and
          media_link_ == rhs.media_link_ and metadata_ == rhs.metadata_ and
@@ -102,23 +100,32 @@ std::ostream& operator<<(std::ostream& os, ObjectMetadata const& rhs) {
      << ", content_disposition=" << rhs.content_disposition()
      << ", content_encoding=" << rhs.content_encoding()
      << ", content_language=" << rhs.content_language()
-     << ", content_type=" << rhs.content_type() << ", crc32c=" << rhs.crc32c()
-     << ", customer_encryption.encryption_algorithm="
-     << rhs.customer_encryption().encryption_algorithm
-     << ", customer_encryption.key_sha256="
-     << rhs.customer_encryption().key_sha256 << ", etag=" << rhs.etag()
-     << ", generation=" << rhs.generation() << ", id=" << rhs.id()
-     << ", kind=" << rhs.kind() << ", kms_key_name=" << rhs.kms_key_name()
+     << ", content_type=" << rhs.content_type() << ", crc32c=" << rhs.crc32c();
+
+  if (rhs.has_customer_encryption()) {
+    os << ", customer_encryption.encryption_algorithm="
+       << rhs.customer_encryption().encryption_algorithm
+       << ", customer_encryption.key_sha256="
+       << rhs.customer_encryption().key_sha256;
+  }
+
+  os << ", etag=" << rhs.etag() << ", generation=" << rhs.generation()
+     << ", id=" << rhs.id() << ", kind=" << rhs.kind()
+     << ", kms_key_name=" << rhs.kms_key_name()
      << ", md5_hash=" << rhs.md5_hash() << ", media_link=" << rhs.media_link();
   sep = "metadata.";
   for (auto const& kv : rhs.metadata_) {
     os << sep << kv.first << "=" << kv.second;
     sep = ", metadata.";
   }
-  os << ", metageneration=" << rhs.metageneration() << ", name=" << rhs.name()
-     << ", owner.entity=" << rhs.owner().entity
-     << ", owner.entity_id=" << rhs.owner().entity_id
-     << ", self_link=" << rhs.self_link() << ", size=" << rhs.size()
+  os << ", metageneration=" << rhs.metageneration() << ", name=" << rhs.name();
+
+  if (rhs.has_owner()) {
+    os << ", owner.entity=" << rhs.owner().entity
+       << ", owner.entity_id=" << rhs.owner().entity_id;
+  }
+
+  os << ", self_link=" << rhs.self_link() << ", size=" << rhs.size()
      << ", storage_class=" << rhs.storage_class()
      << ", time_created=" << rhs.time_created().time_since_epoch().count()
      << ", time_deleted=" << rhs.time_deleted().time_since_epoch().count()

google/cloud/storage/object_metadata.h

@@ -31,6 +31,38 @@ struct CustomerEncryption {
   std::string key_sha256;
 };
 
+inline bool operator==(CustomerEncryption const& lhs,
+                       CustomerEncryption const& rhs) {
+  return std::tie(lhs.encryption_algorithm, lhs.key_sha256) ==
+         std::tie(rhs.encryption_algorithm, lhs.key_sha256);
+}
+
+inline bool operator<(CustomerEncryption const& lhs,
+                      CustomerEncryption const& rhs) {
+  return std::tie(lhs.encryption_algorithm, lhs.key_sha256) <
+         std::tie(rhs.encryption_algorithm, lhs.key_sha256);
+}
+
+inline bool operator!=(CustomerEncryption const& lhs,
+                       CustomerEncryption const& rhs) {
+  return std::rel_ops::operator!=(lhs, rhs);
+}
+
+inline bool operator>(CustomerEncryption const& lhs,
+                      CustomerEncryption const& rhs) {
+  return std::rel_ops::operator>(lhs, rhs);
+}
+
+inline bool operator<=(CustomerEncryption const& lhs,
+                       CustomerEncryption const& rhs) {
+  return std::rel_ops::operator<=(lhs, rhs);
+}
+
+inline bool operator>=(CustomerEncryption const& lhs,
+                       CustomerEncryption const& rhs) {
+  return std::rel_ops::operator>=(lhs, rhs);
+}
+
 /**
  * Represents the metadata for a Google Cloud Storage Object.
  */
@@ -85,8 +117,12 @@ class ObjectMetadata : private internal::CommonMetadata<ObjectMetadata> {
   }
 
   std::string const& crc32c() const { return crc32c_; }
+
+  bool has_customer_encryption() const {
+    return customer_encryption_.has_value();
+  }
   CustomerEncryption const& customer_encryption() const {
-    return customer_encryption_;
+    return customer_encryption_.value();
   }
 
   using CommonMetadata::etag;
@@ -167,7 +203,7 @@ class ObjectMetadata : private internal::CommonMetadata<ObjectMetadata> {
   std::string content_language_;
   std::string content_type_;
   std::string crc32c_;
-  CustomerEncryption customer_encryption_;
+  google::cloud::internal::optional<CustomerEncryption> customer_encryption_;
   std::int64_t generation_;
   std::string kms_key_name_;
   std::string md5_hash_;