Namespace google::cloud::storage (2.30.0)

Contains all the Google Cloud Storage C++ client APIs.

Classes

AlwaysRetryIdempotencyPolicy

A IdempotencyPolicy that always retries all requests.

BucketAccessControl

Wraps the bucketAccessControl resource in Google Cloud Storage.

BucketAccessControlPatchBuilder

Prepares a patch for a BucketAccessControl resource.

BucketMetadata

Represents a Google Cloud Storage Bucket Metadata object.

BucketMetadataPatchBuilder

Prepares a patch for the Bucket resource.

ChannelOptions

Describes the configuration for low-level connection features.

Client

The Google Cloud Storage (GCS) Client.

ClientOptions

Describes the configuration for a storage::Client object.

CustomHeader

An option to inject custom headers into the request.

HashMismatchError

Report checksum mismatches as exceptions.

HmacKeyMetadata

Represents the metadata for a Google Cloud Storage HmacKeyResource.

IdempotencyPolicy

Define the interface for the idempotency policy.

LifecycleRule

Defines objects to read, create, and modify Object Lifecycle Rules.

LimitedErrorCountRetryPolicy

A retry policy based on counting errors.

LimitedTimeRetryPolicy

A retry policy based on elapsed time.

MaxStreams

A parameter type indicating the maximum number of streams to ParallelUploadFile.

MinStreamSize

A parameter type indicating the minimum stream size to ParallelUploadFile.

NativeExpression

Represents a google::type::Expr.

NativeIamBinding

Represents a Binding which associates a member with a particular role which can be used for Identity and Access management for Cloud Platform Resources.

NativeIamPolicy

Represent the result of a GetIamPolicy or SetIamPolicy request.

NotificationMetadata

Represents the metadata for a Google Cloud Storage Notification resource.

ObjectAccessControl

Wraps the objectAccessControl resource in Google Cloud Storage.

ObjectAccessControlPatchBuilder

Prepares a patch for an ObjectAccessControl resource.

ObjectMetadata

Represents the metadata for a Google Cloud Storage Object.

ObjectMetadataPatchBuilder

Prepares a patch for the Bucket resource.

ObjectReadStream

Defines a std::basic_istream<char> to read from a GCS Object.

ObjectRewriter

Complete long running object rewrite operations.

ObjectWriteStream

Defines a std::basic_ostream<char> to write to a GCS object.

PolicyDocumentCondition

Define a condition for a policy document.

RetryPolicy

The base class for the Storage library retry policies.

ServiceAccount

Represents the metadata for a Google Cloud Storage service account.

StrictIdempotencyPolicy

A IdempotencyPolicy that only retries strictly idempotent requests.

Structs

AcceptEncoding

Modify the accepted encodings.

AddExtensionFieldOption

Add a extension header to a POST policy.

AddExtensionHeaderOption

Add a extension header to a signed URL.

AddQueryParameterOption

Add a extension header to a signed URL.

AutoFinalize

Control whether upload streams auto-finalize on destruction.

BackoffPolicyOption

Set the backoff policy for a GCS client.

BucketAutoclass

The autoclass configuration for a Bucket.

BucketBilling

The billing configuration for a Bucket.

BucketBoundHostname

Use domain-named bucket in a V4 signed URL.

BucketCustomPlacementConfig

Configuration for Custom Dual Regions.

BucketEncryption

Describes the default customer managed encryption key for a bucket.

BucketHierarchicalNamespace

Configuration for a bucket's hierarchical namespace feature.

BucketIamConfiguration

The IAM configuration for a Bucket.

BucketLifecycle

The Object Lifecycle configuration for a Bucket.

BucketLogging

The Logging configuration for a Bucket.

BucketObjectRetention

The soft delete policy for a bucket.

BucketRetentionPolicy

The retention policy for a bucket.

BucketSoftDeletePolicy

The soft delete policy for a bucket.

BucketVersioning

The versioning configuration for a Bucket.

BucketWebsite

The website configuration for a Bucket.

ComposeSourceObject

Defines one of the source objects for a compose operation.

ConnectionPoolSizeOption

Set the maximum connection pool size.

ContentEncoding

Sets the contentEncoding option for object uploads.

ContentType

Set the MIME content type of an object.

CopySourceAcl

Applicable only for buckets the don't have uniform bucket-level access enabled.

CorsEntry

An entry in the CORS list.

Crc32cChecksumValue

Provide a pre-computed CRC32C checksum value.

CustomerEncryption

A simple representation for the customerEncryption field.

Deleted

Included deleted HMAC keys in list requests.

Delimiter

Returns results in a directory-like mode.

DestinationKmsKeyName

Configure the Customer-Managed Encryption Key (CMEK) for an rewrite.

DestinationPredefinedAcl

Set the ACL to a predefined value when copying Objects.

DisableCrc32cChecksum

Disable CRC32C checksum computations.

DisableMD5Hash

Disable or enable MD5 Hashing computations.

DownloadBufferSizeOption

Control the formatted I/O download buffer.

DownloadStallMinimumRateOption

The minimum accepted bytes/second download rate.

DownloadStallTimeoutOption

Sets the download stall timeout.

EnableCurlSigpipeHandlerOption

Disables automatic OpenSSL sigpipe handler.

EnableCurlSslLockingOption

Disables automatic OpenSSL locking.

EnableObjectRetention

Set this parameter to true to create buckets with object retention enabled.

EncryptionKey

An optional parameter to set the Customer-Supplied Encryption key.

EncryptionKeyData

A simple wrapper for the encryption key attributes.

EndOffset

Filter results to objects whose names are lexicographically before EndOffset.

ExpirationTime

Define the expiration time for a signed URL.

Fields

Defines the fields query parameter.

Generation

Set the version of an object to operate on.

IamEndpointOption

Configure the IAM endpoint for the GCS client library.

IdempotencyPolicyOption

Set the idempotency policy for a GCS client.

IfGenerationMatch

A pre-condition: the request succeeds only if the object generation matches.

IfGenerationNotMatch

A pre-condition: the request succeeds unless the object generation matches.

IfMatchEtag

A pre-condition: apply this operation only if the HTTP Entity Tag matches.

IfMetagenerationMatch

A pre-condition: the request succeeds if the metadata generation matches.

IfMetagenerationNotMatch

A pre-condition: the request succeeds unless the metadata generation matches.

IfNoneMatchEtag

A pre-condition: apply this operation only if the HTTP Entity Tag does not match.

IfSourceGenerationMatch

A pre-condition: the request succeeds if the source object generation matches.

IfSourceGenerationNotMatch

A pre-condition: the request succeeds unless the source object generation matches.

IfSourceMetagenerationMatch

A pre-condition: the request succeeds if the source object metadata generation matches.

IfSourceMetagenerationNotMatch

A pre-condition: the request succeeds unless the source object metadata generation matches.

IncludeFoldersAsPrefixes

Set this parameter to true to include folders in the Client::ListObjectsAndPrefixes() calls.

IncludeTrailingDelimiter

If true, objects that end in exactly one instance of delimiter have their metadata included in items[] in addition to the relevant part of the object name appearing in prefixes[].

KmsKeyName

Configure the Customer-Managed Encryption Key (CMEK) for an upload.

LifecycleRuleAction

Implement a wrapper for Lifecycle Rules actions.

LifecycleRuleCondition

Implement a wrapper for Lifecycle Conditions.

MatchGlob

Restrict list operations to entries matching a glob pattern.

MaxBytesRewrittenPerCall

Limit the number of bytes rewritten in a Objects: rewrite step.

MaximumCurlSocketRecvSizeOption

Control the maximum socket receive buffer.

MaximumCurlSocketSendSizeOption

Control the maximum socket send buffer.

MaximumSimpleUploadSizeOption

Defines the threshold to switch from simple to resumable uploads for files.

MaxResults

Limit the number of results per page when listing Buckets and Objects.

MD5HashValue

Provide a pre-computed MD5 hash value.

Oauth2CredentialsOption

Configure oauth2::Credentials for the GCS client library.

ObjectRetention

Specifies the retention parameters of an object.

OverrideDefaultProject

Override the default project.

OverrideUnlockedRetention

Set this parameter to true to override the current object's retention.

Owner

A simple wrapper for the owner field in object and bucket metadata.

PolicyDocument

Define a policy document.

PolicyDocumentResult

Define a policy document result.

PolicyDocumentV4

Define a policy document V4.

PolicyDocumentV4Result

Define a policy document result V4.

PredefinedAcl

Set the ACL to predefined values when creating Buckets or Objects.

PredefinedDefaultObjectAcl

Set the default object ACL to a predefined value in a Bucket.

Prefix

Restrict list operations to entries starting with this value.

ProjectIdOption

Set the Google Cloud Platform project id.

Projection

Controls what metadata fields are included in the response.

ProjectTeam

Represents the projectTeam field in *AccessControls.

QuotaUser

Sets the user for this operation for quota enforcement purposes.

ReadFromOffset

Download all the data from the GCS object starting at the given offset.

ReadLast

Read last N bytes from the GCS object.

ReadRange

Request only a portion of the GCS object in a ReadObject operation.

ReadRangeData

RequestedPolicyVersion

Controls the IAM policy version returned by IAM queries.

RestEndpointOption

Configure the REST endpoint for the GCS client library.

RetryPolicyOption

Set the retry policy for a GCS client.

RewriteProgress

Represents the status of a rewrite operation.

Scheme

Use the specified scheme (e.g. "http") in a V4 signed URL.

ServiceAccountFilter

Only list HMAC keys belonging to a specific Service Account.

SignedUrlDuration

Define the duration for a V4 signed URL.

SignedUrlTimestamp

Define the timestamp duration for a V4 signed URL.

SigningAccount

Specify the service account used to sign a blob.

SigningAccountDelegates

Specify the sequence of delegates used to sign a blob.

SoftDeleted

Set this parameter to true to include soft-deleted object in Client::ListObjects() and Client::GetObjectMetadata() calls.

SourceEncryptionKey

An optional parameter to set the Customer-Supplied Encryption key for rewrite source object.

SourceGeneration

Set the generation for the source object in copy operations.

StartOffset

Filter results to objects whose names are lexicographically equal to or after StartOffset.

SubResourceOption

Specify a sub-resource in a signed URL.

TransferStallMinimumRateOption

The minimum accepted bytes/second transfer rate.

TransferStallTimeoutOption

Sets the transfer stall timeout.

UniformBucketLevelAccess

Configure if only the IAM policies are used for access control.

UploadBufferSize

Set the buffer size for a stream created in Client::WriteObject().

UploadBufferSizeOption

Control the formatted I/O upload buffer.

UploadContentLength

Provide an expected final length of an uploaded object.

UploadFromOffset

Upload the local file to GCS server starting at the given offset.

UploadLimit

The maximum length of the local file to upload to GCS server.

UseResumableUploadSession

Request a resumable upload, restoring a previous session if necessary.

UserIp

Sets the user IP on an operation for quota enforcement purposes.

UserProject

Set the project used for billing in "requester pays" Buckets.

Versions

Control if all versions of an object should be included when listing objects.

VirtualHostname

Indicate that the bucket should be a part of hostname in the URL.

WithObjectMetadata

A request option to define the object metadata attributes.

Enums

AutoFinalizeConfig

Functions

PublicAccessPreventionEnforced()

Public Access Prevention helper functions

Returns
Type Description
std::string

PublicAccessPreventionInherited()

Public Access Prevention helper functions

Returns
Type Description
std::string

PublicAccessPreventionUnspecified()

Public Access Prevention helper functions

Returns
Type Description
std::string

TEAM_EDITORS()

Well-known values for the project_team().team field..

The following functions are handy to avoid common typos in the team names.

We use functions instead of enums because enums are not backwards compatible and are brittle to changes in the server-side.

Returns
Type Description
std::string

TEAM_OWNERS()

Well-known values for the project_team().team field..

The following functions are handy to avoid common typos in the team names.

We use functions instead of enums because enums are not backwards compatible and are brittle to changes in the server-side.

Returns
Type Description
std::string

TEAM_VIEWERS()

Well-known values for the project_team().team field..

The following functions are handy to avoid common typos in the team names.

We use functions instead of enums because enums are not backwards compatible and are brittle to changes in the server-side.

Returns
Type Description
std::string

AutoFinalizeEnabled()

Configure a stream to automatically finalize an upload on destruction.

Returns
Type Description
AutoFinalize

AutoFinalizeDisabled()

Configure a stream to leave uploads pending (not finalized) on destruction.

Returns
Type Description
AutoFinalize

RpoDefault()

A helper function to avoid typos in the RPO configuration.

Returns
Type Description
std::string

RpoAsyncTurbo()

A helper function to avoid typos in the RPO configuration.

Returns
Type Description
std::string

CreateRandomPrefixName(std::string const &)

Create a random prefix for object names.

This is useful for operations which require a unique prefix for temporary files.

This is a helper function and it doesn't communicate with GCS, so there is a very small chance that names generated this way aren't unique. The chance should be small enough to fit any error budget.

Given the same prefix, the randomly generated names will have the same length.

Parameter
Name Description
prefix

the prefix of the prefix to be created.

Returns
Type Description
std::string

the random prefix name

DeleteByPrefix(Client &, std::string const &, std::string const &, Options &&...)

Delete objects whose names match a given prefix.

Parameters
Name Description
client

the client on which to perform the operation.

bucket_name

the name of the bucket that will contain the object.

prefix

the prefix of the objects to be deleted.

options

a list of optional query parameters and/or request headers. Valid types for this operation include QuotaUser, UserIp, UserProject and Versions.

typename...
Returns
Type Description
Status

ComposeMany(Client &, std::string const &, std::vector< ComposeSourceObject >, std::string const &, std::string, bool, Options &&...)

Compose existing objects into a new object in the same bucket.

Contrary to Client::ComposeObject, this function doesn't have a limit on the number of source objects.

The implementation may need to perform multiple Client::ComposeObject calls to create intermediate, temporary objects which are then further composed. Due to the lack of atomicity of this series of operations, stray temporary objects might be left over if there are transient failures. In order to allow the user to easily control for such situations, the user is expected to provide a unique prefix parameter, which will become the prefix of all the temporary objects created by this function. Once this function finishes, the user may safely remove all objects with the provided prefix (e.g. via DeleteByPrefix()). We recommend using CreateRandomPrefixName() for selecting a random prefix within a bucket.

Idempotency

This operation is not idempotent. While each request performed by this function is retried based on the client policies, the operation itself stops on the first request that fails.

Example
  namespace gcs = ::google::cloud::storage;
  using ::google::cloud::StatusOr;
  [](gcs::Client client, std::string const& bucket_name,
     std::string const& destination_object_name,
     std::vector<gcs::ComposeSourceObject> const& compose_objects) {
    std::string prefix = gcs::CreateRandomPrefixName(".tmpfiles");
    StatusOr<gcs::ObjectMetadata> composed_object =
        ComposeMany(client, bucket_name, compose_objects, prefix,
                    destination_object_name, false);
    // If this is an effect of some transient unavailability, stray temporary
    // might be left over. You can use `DeleteByPrefix()` with `prefix` as
    // argument to delete them.
    if (!composed_object) throw std::move(composed_object).status();

    std::cout << "Composed new object " << composed_object->name()
              << " in bucket " << composed_object->bucket()
              << "\nFull metadata: " << *composed_object << "\n";
  }
Parameters
Name Description
client

the client on which to perform the operations needed by this function

bucket_name

the name of the bucket used for source object and destination object.

source_objects

objects used to compose destination_object_name.

prefix

prefix for temporary objects created by this function; there should not be any objects with this prefix; in order to avoid race conditions, this function will create an object with this name

destination_object_name

the composed object name.

ignore_cleanup_failures

if the composition succeeds but cleanup of temporary objects fails, depending on this parameter either a success will be returned (true) or the relevant cleanup error (false)

options

a list of optional query parameters and/or request headers. Valid types for this operation include DestinationPredefinedAcl, EncryptionKey, IfGenerationMatch, IfMetagenerationMatchKmsKeyName, QuotaUser, UserIp, UserProject and WithObjectMetadata.

typename...
Returns
Type Description
StatusOr< ObjectMetadata >

MakeGrpcClient(Options)

Create a google::cloud::storage::Client object configured to use gRPC.

Example
void GrpcReadWrite(std::string const& bucket_name) {
  namespace gcs = ::google::cloud::storage;
  auto constexpr kText = R"""(Hello World!)""";

  auto client = gcs::MakeGrpcClient();

  auto object = client.InsertObject(bucket_name, "lorem.txt", kText);
  if (!object) throw std::move(object).status();

  auto input = client.ReadObject(bucket_name, "lorem.txt",
                                 gcs::Generation(object->generation()));
  std::string const actual(std::istreambuf_iterator<char>{input}, {});
  if (input.bad()) throw google::cloud::Status(input.status());
  std::cout << "The contents read back are:\n"
            << actual
            << "\nThe received checksums are: " << input.received_hash()
            << "\nThe computed checksums are: " << input.computed_hash()
            << "\nThe original hashes    are: crc32c=" << object->crc32c()
            << ",md5=" << object->md5_hash() << "\n";
}
Parameter
Name Description
opts

the configuration parameters for the Client.

Returns
Type Description
google::cloud::storage::Client

ComputeMD5Hash(absl::string_view)

Compute the MD5 Hash of a buffer in the format preferred by GCS.

Parameter
Name Description
payload
Returns
Type Description
std::string

ComputeMD5Hash(std::string const &)

Compute the MD5 Hash of a buffer in the format preferred by GCS.

Parameter
Name Description
payload
Returns
Type Description
std::string

ComputeMD5Hash(char const *)

Compute the MD5 Hash of a buffer in the format preferred by GCS.

Parameter
Name Description
payload
Returns
Type Description
std::string

EnableMD5Hash()

Enable MD5 hashes in upload and download operations.

Use this function where the option DisableMD5Hash is expected to enable MD5 hashes.

Returns
Type Description
DisableMD5Hash

ComputeCrc32cChecksum(absl::string_view)

Compute the CRC32C checksum of a buffer in the format preferred by GCS.

Parameter
Name Description
payload
Returns
Type Description
std::string

ComputeCrc32cChecksum(std::string const &)

Compute the CRC32C checksum of a buffer in the format preferred by GCS.

Parameter
Name Description
payload
Returns
Type Description
std::string

ComputeCrc32cChecksum(char const *)

Compute the CRC32C checksum of a buffer in the format preferred by GCS.

Parameter
Name Description
payload
Returns
Type Description
std::string

ObjectRetentionUnlocked()

A helper function to avoid typos in the ObjectRetention configuration.

Returns
Type Description
std::string

ObjectRetentionLocked()

A helper function to avoid typos in the ObjectRetention configuration.

Returns
Type Description
std::string

ParallelUploadFile(Client, std::string, std::string, std::string, std::string, bool, Options &&...)

Perform a parallel upload of a given file.

You can affect how many shards will be created by using the MaxStreams and MinStreamSize options.

Idempotency

This operation is not idempotent. While each request performed by this function is retried based on the client policies, the operation itself stops on the first request that fails.

Example
  namespace gcs = ::google::cloud::storage;
  using ::google::cloud::StatusOr;
  [](gcs::Client client, std::string const& file_name,
     std::string const& bucket_name, std::string const& object_name) {
    // Pick a unique random prefix for the temporary objects created by the
    // parallel upload.
    auto prefix = gcs::CreateRandomPrefixName("");

    auto metadata = gcs::ParallelUploadFile(
        std::move(client), file_name, bucket_name, object_name, prefix, false);
    if (!metadata) throw std::move(metadata).status();

    std::cout << "Uploaded " << file_name << " to object " << metadata->name()
              << " in bucket " << metadata->bucket()
              << "\nFull metadata: " << *metadata << "\n";
  }
Parameters
Name Description
client

the client on which to perform the operation.

file_name

the path to the file to be uploaded

bucket_name

the name of the bucket that will contain the object.

object_name

the uploaded object name.

prefix

the prefix with which temporary objects will be created.

ignore_cleanup_failures

treat failures to cleanup the temporary objects as not fatal.

options

a list of optional query parameters and/or request headers. Valid types for this operation include DestinationPredefinedAcl, EncryptionKey, IfGenerationMatch, IfMetagenerationMatch, KmsKeyName, MaxStreams,MinStreamSize,QuotaUser,UserIp,UserProject,WithObjectMetadata,UseResumableUploadSession`.

typename...
Returns
Type Description
StatusOr< ObjectMetadata >

the metadata of the object created by the upload.

FormatDateForForm(PolicyDocumentV4Result const &)

Format the current date in the format expected by a POST form.

Parameter
Name Description

Returns
Type Description
std::string

AddExtensionHeader(std::string, std::string)

Parameters
Name Description
header
value
Returns
Type Description
AddExtensionHeaderOption

WithGeneration(std::uint64_t)

Parameter
Name Description
generation
Returns
Type Description
AddQueryParameterOption

WithGenerationMarker(std::uint64_t)

Parameter
Name Description
generation
Returns
Type Description
AddQueryParameterOption

WithUserProject(std::string)

Parameter
Name Description
user_project
Returns
Type Description
AddQueryParameterOption

WithMarker(std::string)

Parameter
Name Description
marker
Returns
Type Description
AddQueryParameterOption

WithResponseContentDisposition(std::string)

Parameter
Name Description
disposition
Returns
Type Description
AddQueryParameterOption

WithResponseContentType(std::string const &)

Parameter
Name Description
type
Returns
Type Description
AddQueryParameterOption

WithAcl()

Returns
Type Description
SubResourceOption

WithBilling()

Returns
Type Description
SubResourceOption

WithCompose()

Returns
Type Description
SubResourceOption

WithCors()

Returns
Type Description
SubResourceOption

WithEncryption()

Returns
Type Description
SubResourceOption

WithEncryptionConfig()

Returns
Type Description
SubResourceOption

WithLifecycle()

Returns
Type Description
SubResourceOption

WithLocation()

Returns
Type Description
SubResourceOption

WithLogging()

Returns
Type Description
SubResourceOption

WithStorageClass()

Returns
Type Description
SubResourceOption

WithTagging()

Returns
Type Description
SubResourceOption

AddExtensionField(std::string, std::string)

Parameters
Name Description
field
value
Returns
Type Description
AddExtensionFieldOption

RestoreResumableUploadSession(std::string)

Create a UseResumableUploadSession option that restores previous sessions.

Parameter
Name Description
session_id
Returns
Type Description
UseResumableUploadSession

NewResumableUploadSession()

Create a UseResumableUploadSession option that requests new sessions.

Returns
Type Description
UseResumableUploadSession

version_major()

Returns the Google Cloud Storage C++ Client major version.

Returns
Type Description
int constexpr

version_minor()

Returns the Google Cloud Storage C++ Client minor version.

Returns
Type Description
int constexpr

version_patch()

Returns the Google Cloud Storage C++ Client patch version.

Returns
Type Description
int constexpr

version_pre_release()

Returns the Google Cloud Storage C++ Client pre-release version.

Returns
Type Description
char const *

version()

Returns a single integer representing the Major/Minor/Patch version.

Returns
Type Description
int constexpr

version_string()

Returns the version as a string, in MAJOR.MINOR.PATCH[-PRE][+gitrev] format.

Returns
Type Description
std::string

x_goog_api_client()

Returns the value for x-goog-api-client header.

Returns
Type Description
std::string

EncryptionDataFromBinaryKey(std::string const &)

Formats a (potentially binary) encryption key in the format required by the Google Cloud Storage API.

Parameter
Name Description
key

a binary key, must have exactly 32 bytes.

Returns
Type Description
EncryptionKeyData

EncryptionDataFromBase64Key(std::string const &)

Formats an encryption key in base64 format to the data structure required by the Google Cloud Storage API.

Parameter
Name Description
key

a base64-encoded key, must have exactly 32 bytes when decoded.

Returns
Type Description
EncryptionKeyData

CreateKeyFromGenerator(Generator &)

Creates an encryption key parameter from a pseudo-random number generator.

Example
  // Create a pseudo-random number generator (PRNG), this is included for
  // demonstration purposes only. You should consult your security team about
  // best practices to initialize PRNG. In particular, you should verify that
  // the C++ library and operating system provide enough entropy to meet the
  // security policies in your organization.

  // Use the Mersenne-Twister Engine in this example:
  //   https://en.cppreference.com/w/cpp/numeric/random/mersenne_twister_engine
  // Any C++ PRNG can be used below, the choice is arbitrary.
  using GeneratorType = std::mt19937_64;

  // Create the default random device to fetch entropy.
  std::random_device rd;

  // Compute how much entropy we need to initialize the GeneratorType:
  constexpr auto kRequiredEntropyWords =
      GeneratorType::state_size *
      (GeneratorType::word_size / std::numeric_limits<unsigned int>::digits);

  // Capture the entropy bits into a vector.
  std::vector<std::uint64_t> entropy(kRequiredEntropyWords);
  std::generate(entropy.begin(), entropy.end(), [&rd] { return rd(); });

  // Create the PRNG with the fetched entropy.
  std::seed_seq seed(entropy.begin(), entropy.end());

  // initialized with enough entropy such that the encryption keys are not
  // predictable. Note that the default constructor for all the generators in
  // the C++ standard library produce predictable keys.
  std::mt19937_64 gen(seed);

  namespace gcs = ::google::cloud::storage;
  gcs::EncryptionKeyData data = gcs::CreateKeyFromGenerator(gen);

  std::cout << "Base64 encoded key = " << data.key << "\n"
            << "Base64 encoded SHA256 of key = " << data.sha256 << "\n";
See Also

https://en.cppreference.com/w/cpp/numeric/random for a general overview of C++ pseudo-random number support.

See Also

https://en.cppreference.com/w/cpp/numeric/random/UniformRandomBitGenerator for a more detailed overview of the requirements for generators.

Parameters
Name Description
gen

the pseudo-random number generator.

typename Generator

the pseudo-random number generator type, it must meet the UniformRandomBitGenerator requirements.

Returns
Type Description
EncryptionKeyData

AcceptEncodingGzip()

Returns
Type Description
AcceptEncoding

AcceptEncodingIdentity()

Returns
Type Description
AcceptEncoding

Type Aliases

BucketPolicyOnly

Alias Of: UniformBucketLevelAccess

HeadersMap

Alias Of: std::multimap< std::string, std::string >

Represents the headers returned in a streaming upload or download operation.

ListBucketsReader

Alias Of: google::cloud::internal::PaginationRange< BucketMetadata >

ListBucketsIterator

Alias Of: ListBucketsReader::iterator

ListHmacKeysReader

Alias Of: google::cloud::internal::PaginationRange< HmacKeyMetadata >

A range to paginate over the HmacKeys for a project.

ListHmacKeysIterator

Alias Of: ListHmacKeysReader::iterator

ObjectOrPrefix

Alias Of: absl::variant< ObjectMetadata, std::string >

ListObjectsAndPrefixesReader

Alias Of: google::cloud::internal::PaginationRange< ObjectOrPrefix >

ListObjectsAndPrefixesIterator

Alias Of: ListObjectsAndPrefixesReader::iterator

ListObjectsReader

Alias Of: google::cloud::internal::PaginationRange< ObjectMetadata >

ListObjectsIterator

Alias Of: ListObjectsReader::iterator

ClientOptionList

Alias Of: ::google::cloud::OptionList< RestEndpointOption, IamEndpointOption, Oauth2CredentialsOption, ProjectIdOption, ProjectIdOption, ConnectionPoolSizeOption, DownloadBufferSizeOption, UploadBufferSizeOption, EnableCurlSslLockingOption, EnableCurlSigpipeHandlerOption, MaximumCurlSocketRecvSizeOption, MaximumCurlSocketSendSizeOption, TransferStallTimeoutOption, RetryPolicyOption, BackoffPolicyOption, IdempotencyPolicyOption, CARootsFilePathOption, storage_experimental::HttpVersionOption >

The complete list of options accepted by storage::Client.

BackoffPolicy

Alias Of: ::google::cloud::internal::BackoffPolicy

The backoff policy base class.

ExponentialBackoffPolicy

Alias Of: ::google::cloud::internal::ExponentialBackoffPolicy

Implement truncated exponential backoff with randomization.