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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef GOOGLE_PROTOBUF_UTIL_CONVERTER_DEFAULT_VALUE_OBJECTWRITER_H__
#define GOOGLE_PROTOBUF_UTIL_CONVERTER_DEFAULT_VALUE_OBJECTWRITER_H__
#include <cstdint>
#include <functional>
#include <memory>
#include <stack>
#include <vector>
#include <google/protobuf/stubs/common.h>
#include <google/protobuf/util/internal/type_info.h>
#include <google/protobuf/util/internal/datapiece.h>
#include <google/protobuf/util/internal/object_writer.h>
#include <google/protobuf/util/internal/utility.h>
#include <google/protobuf/util/type_resolver.h>
#include <google/protobuf/stubs/strutil.h>
// Must be included last.
#include <google/protobuf/port_def.inc>
namespace google {
namespace protobuf {
namespace util {
namespace converter {
// An ObjectWriter that renders non-repeated primitive fields of proto messages
// with their default values. DefaultValueObjectWriter holds objects, lists and
// fields it receives in a tree structure and writes them out to another
// ObjectWriter when EndObject() is called on the root object. It also writes
// out all non-repeated primitive fields that haven't been explicitly rendered
// with their default values (0 for numbers, "" for strings, etc).
class PROTOBUF_EXPORT DefaultValueObjectWriter : public ObjectWriter {
public:
// A Callback function to check whether a field needs to be scrubbed.
//
// Returns true if the field should not be present in the output. Returns
// false otherwise.
//
// The 'path' parameter is a vector of path to the field from root. For
// example: if a nested field "a.b.c" (b is the parent message field of c and
// a is the parent message field of b), then the vector should contain { "a",
// "b", "c" }.
//
// The Field* should point to the google::protobuf::Field of "c".
typedef std::function<bool(
const std::vector<std::string>& /*path of the field*/,
const google::protobuf::Field* /*field*/)>
FieldScrubCallBack;
DefaultValueObjectWriter(TypeResolver* type_resolver,
const google::protobuf::Type& type,
ObjectWriter* ow);
virtual ~DefaultValueObjectWriter();
// ObjectWriter methods.
DefaultValueObjectWriter* StartObject(StringPiece name) override;
DefaultValueObjectWriter* EndObject() override;
DefaultValueObjectWriter* StartList(StringPiece name) override;
DefaultValueObjectWriter* EndList() override;
DefaultValueObjectWriter* RenderBool(StringPiece name,
bool value) override;
DefaultValueObjectWriter* RenderInt32(StringPiece name,
int32_t value) override;
DefaultValueObjectWriter* RenderUint32(StringPiece name,
uint32_t value) override;
DefaultValueObjectWriter* RenderInt64(StringPiece name,
int64_t value) override;
DefaultValueObjectWriter* RenderUint64(StringPiece name,
uint64_t value) override;
DefaultValueObjectWriter* RenderDouble(StringPiece name,
double value) override;
DefaultValueObjectWriter* RenderFloat(StringPiece name,
float value) override;
DefaultValueObjectWriter* RenderString(StringPiece name,
StringPiece value) override;
DefaultValueObjectWriter* RenderBytes(StringPiece name,
StringPiece value) override;
DefaultValueObjectWriter* RenderNull(StringPiece name) override;
// Register the callback for scrubbing of fields.
void RegisterFieldScrubCallBack(FieldScrubCallBack field_scrub_callback);
// If set to true, empty lists are suppressed from output when default values
// are written.
void set_suppress_empty_list(bool value) { suppress_empty_list_ = value; }
// If set to true, original proto field names are used
void set_preserve_proto_field_names(bool value) {
preserve_proto_field_names_ = value;
}
// If set to true, enums are rendered as ints from output when default values
// are written.
void set_print_enums_as_ints(bool value) { use_ints_for_enums_ = value; }
protected:
enum NodeKind {
PRIMITIVE = 0,
OBJECT = 1,
LIST = 2,
MAP = 3,
};
// "Node" represents a node in the tree that holds the input of
// DefaultValueObjectWriter.
class PROTOBUF_EXPORT Node {
public:
Node(const std::string& name, const google::protobuf::Type* type,
NodeKind kind, const DataPiece& data, bool is_placeholder,
const std::vector<std::string>& path, bool suppress_empty_list,
bool preserve_proto_field_names, bool use_ints_for_enums,
FieldScrubCallBack field_scrub_callback);
virtual ~Node() {
for (int i = 0; i < children_.size(); ++i) {
delete children_[i];
}
}
// Adds a child to this node. Takes ownership of this child.
void AddChild(Node* child) { children_.push_back(child); }
// Finds the child given its name.
Node* FindChild(StringPiece name);
// Populates children of this Node based on its type. If there are already
// children created, they will be merged to the result. Caller should pass
// in TypeInfo for looking up types of the children.
virtual void PopulateChildren(const TypeInfo* typeinfo);
// If this node is a leaf (has data), writes the current node to the
// ObjectWriter; if not, then recursively writes the children to the
// ObjectWriter.
virtual void WriteTo(ObjectWriter* ow);
// Accessors
const std::string& name() const { return name_; }
const std::vector<std::string>& path() const { return path_; }
const google::protobuf::Type* type() const { return type_; }
void set_type(const google::protobuf::Type* type) { type_ = type; }
NodeKind kind() const { return kind_; }
int number_of_children() const { return children_.size(); }
void set_data(const DataPiece& data) { data_ = data; }
bool is_any() const { return is_any_; }
void set_is_any(bool is_any) { is_any_ = is_any; }
void set_is_placeholder(bool is_placeholder) {
is_placeholder_ = is_placeholder;
}
protected:
// Returns the Value Type of a map given the Type of the map entry and a
// TypeInfo instance.
const google::protobuf::Type* GetMapValueType(
const google::protobuf::Type& found_type, const TypeInfo* typeinfo);
// Calls WriteTo() on every child in children_.
void WriteChildren(ObjectWriter* ow);
// The name of this node.
std::string name_;
// google::protobuf::Type of this node. Owned by TypeInfo.
const google::protobuf::Type* type_;
// The kind of this node.
NodeKind kind_;
// Whether this is a node for "Any".
bool is_any_;
// The data of this node when it is a leaf node.
DataPiece data_;
// Children of this node.
std::vector<Node*> children_;
// Whether this node is a placeholder for an object or list automatically
// generated when creating the parent node. Should be set to false after
// the parent node's StartObject()/StartList() method is called with this
// node's name.
bool is_placeholder_;
// Path of the field of this node
std::vector<std::string> path_;
// Whether to suppress empty list output.
bool suppress_empty_list_;
// Whether to preserve original proto field names
bool preserve_proto_field_names_;
// Whether to always print enums as ints
bool use_ints_for_enums_;
// Function for determining whether a field needs to be scrubbed or not.
FieldScrubCallBack field_scrub_callback_;
private:
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Node);
};
// Creates a new Node and returns it. Caller owns memory of returned object.
virtual Node* CreateNewNode(const std::string& name,
const google::protobuf::Type* type, NodeKind kind,
const DataPiece& data, bool is_placeholder,
const std::vector<std::string>& path,
bool suppress_empty_list,
bool preserve_proto_field_names,
bool use_ints_for_enums,
FieldScrubCallBack field_scrub_callback);
// Creates a DataPiece containing the default value of the type of the field.
static DataPiece CreateDefaultDataPieceForField(
const google::protobuf::Field& field, const TypeInfo* typeinfo) {
return CreateDefaultDataPieceForField(field, typeinfo, false);
}
// Same as the above but with a flag to use ints instead of enum names.
static DataPiece CreateDefaultDataPieceForField(
const google::protobuf::Field& field, const TypeInfo* typeinfo,
bool use_ints_for_enums);
protected:
// Returns a pointer to current Node in tree.
Node* current() { return current_; }
private:
// Populates children of "node" if it is an "any" Node and its real type has
// been given.
void MaybePopulateChildrenOfAny(Node* node);
// Writes the root_ node to ow_ and resets the root_ and current_ pointer to
// nullptr.
void WriteRoot();
// Adds or replaces the data_ of a primitive child node.
void RenderDataPiece(StringPiece name, const DataPiece& data);
// Returns the default enum value as a DataPiece, or the first enum value if
// there is no default. For proto3, where we cannot specify an explicit
// default, a zero value will always be returned.
static DataPiece FindEnumDefault(const google::protobuf::Field& field,
const TypeInfo* typeinfo,
bool use_ints_for_enums);
// Type information for all the types used in the descriptor. Used to find
// google::protobuf::Type of nested messages/enums.
const TypeInfo* typeinfo_;
// Whether the TypeInfo object is owned by this class.
bool own_typeinfo_;
// google::protobuf::Type of the root message type.
const google::protobuf::Type& type_;
// Holds copies of strings passed to RenderString.
std::vector<std::unique_ptr<std::string>> string_values_;
// The current Node. Owned by its parents.
Node* current_;
// The root Node.
std::unique_ptr<Node> root_;
// The stack to hold the path of Nodes from current_ to root_;
std::stack<Node*> stack_;
// Whether to suppress output of empty lists.
bool suppress_empty_list_;
// Whether to preserve original proto field names
bool preserve_proto_field_names_;
// Whether to always print enums as ints
bool use_ints_for_enums_;
// Function for determining whether a field needs to be scrubbed or not.
FieldScrubCallBack field_scrub_callback_;
ObjectWriter* ow_;
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DefaultValueObjectWriter);
};
} // namespace converter
} // namespace util
} // namespace protobuf
} // namespace google
#include <google/protobuf/port_undef.inc>
#endif // GOOGLE_PROTOBUF_UTIL_CONVERTER_DEFAULT_VALUE_OBJECTWRITER_H__
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