#include <google/protobuf/message_lite.h>
namespace google::protobuf
Defines MessageLite, the abstract interface implemented by all (lite and non-lite) protocol message objects.
Classes in this file | |
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Interface to light weight protocol messages. |
class MessageLite
#include <google/protobuf/message_lite.h>
namespace google::protobuf
Interface to light weight protocol messages.
This interface is implemented by all protocol message objects. Non-lite messages additionally implement the Message interface, which is a subclass of MessageLite. Use MessageLite instead when you only need the subset of features which it supports – namely, nothing that uses descriptors or reflection. You can instruct the protocol compiler to generate classes which implement only MessageLite, not the full Message interface, by adding the following line to the .proto file:
option optimize_for = LITE_RUNTIME;
This is particularly useful on resource-constrained systems where the full protocol buffers runtime library is too big. Note that on non-constrained systems (e.g. servers) when you need to link in lots of protocol definitions, a better way to reduce total code footprint is to use optimize_for = CODE_SIZE. This will make the generated code smaller while still supporting all the same features (at the expense of speed). optimize_for = LITE_RUNTIME is best when you only have a small number of message types linked into your binary, in which case the size of the protocol buffers runtime itself is the biggest problem.
Known subclasses:
Members | |
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| MessageLite() |
virtual | ~MessageLite() |
Basic Operations | |
virtual string | GetTypeName() const = 0 Get the name of this message type, e.g. "foo.bar.BazProto". |
virtual MessageLite * | New() const = 0 Construct a new instance of the same type. more... |
virtual MessageLite * | New(Arena * arena) const Construct a new instance on the arena. more... |
virtual Arena * | GetArena() const Get the arena, if any, associated with this message. more... |
virtual void * | GetMaybeArenaPointer() const Get a pointer that may be equal to this message's arena, or may not be. more... |
virtual void | Clear() = 0 Clear all fields of the message and set them to their default values. more... |
virtual bool | IsInitialized() const = 0 Quickly check if all required fields have values set. |
virtual string | InitializationErrorString() const This is not implemented for Lite messages – it just returns "(cannot
determine missing fields for lite message)". more... |
virtual void | CheckTypeAndMergeFrom(const MessageLite & other) = 0 If |other| is the exact same class as this, calls MergeFrom(). more... |
ParsingMethods for parsing in protocol buffer format. Most of these are just simple wrappers around MergeFromCodedStream(). Clear() will be called before merging the input. | |
bool | ParseFromCodedStream(io::CodedInputStream * input) Fill the message with a protocol buffer parsed from the given input stream. more... |
bool | ParsePartialFromCodedStream(io::CodedInputStream * input) Like ParseFromCodedStream(), but accepts messages that are missing required fields. |
bool | ParseFromZeroCopyStream(io::ZeroCopyInputStream * input) Read a protocol buffer from the given zero-copy input stream. more... |
bool | ParsePartialFromZeroCopyStream(io::ZeroCopyInputStream * input) Like ParseFromZeroCopyStream(), but accepts messages that are missing required fields. |
bool | ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input, int size) Read a protocol buffer from the given zero-copy input stream, expecting the message to be exactly "size" bytes long. more... |
bool | ParsePartialFromBoundedZeroCopyStream(io::ZeroCopyInputStream * input, int size) Like ParseFromBoundedZeroCopyStream(), but accepts messages that are missing required fields. |
bool | ParseFromString(const string & data) Parses a protocol buffer contained in a string. more... |
bool | ParsePartialFromString(const string & data) Like ParseFromString(), but accepts messages that are missing required fields. |
bool | ParseFromArray(const void * data, int size) Parse a protocol buffer contained in an array of bytes. |
bool | ParsePartialFromArray(const void * data, int size) Like ParseFromArray(), but accepts messages that are missing required fields. |
bool | MergeFromCodedStream(io::CodedInputStream * input) |
virtual bool | MergePartialFromCodedStream(io::CodedInputStream * input) = 0 Like MergeFromCodedStream(), but succeeds even if required fields are missing in the input. more... |
SerializationMethods for serializing in protocol buffer format. Most of these are just simple wrappers around ByteSize() and SerializeWithCachedSizes(). | |
bool | SerializeToCodedStream(io::CodedOutputStream * output) const Write a protocol buffer of this message to the given output. more... |
bool | SerializePartialToCodedStream(io::CodedOutputStream * output) const Like SerializeToCodedStream(), but allows missing required fields. |
bool | SerializeToZeroCopyStream(io::ZeroCopyOutputStream * output) const Write the message to the given zero-copy output stream. more... |
bool | SerializePartialToZeroCopyStream(io::ZeroCopyOutputStream * output) const Like SerializeToZeroCopyStream(), but allows missing required fields. |
bool | SerializeToString(string * output) const Serialize the message and store it in the given string. more... |
bool | SerializePartialToString(string * output) const Like SerializeToString(), but allows missing required fields. |
bool | SerializeToArray(void * data, int size) const Serialize the message and store it in the given byte array. more... |
bool | SerializePartialToArray(void * data, int size) const Like SerializeToArray(), but allows missing required fields. |
string | SerializeAsString() const Make a string encoding the message. more... |
string | SerializePartialAsString() const Like SerializeAsString(), but allows missing required fields. |
bool | AppendToString(string * output) const Like SerializeToString(), but appends to the data to the string's existing contents. more... |
bool | AppendPartialToString(string * output) const Like AppendToString(), but allows missing required fields. |
virtual size_t | ByteSizeLong() const = 0 Computes the serialized size of the message. more... |
int | ByteSize() const Legacy ByteSize() API. |
virtual void | SerializeWithCachedSizes(io::CodedOutputStream * output) const = 0 Serializes the message without recomputing the size. more... |
virtual uint8 * | SerializeWithCachedSizesToArray(uint8 * target) const A version of SerializeWithCachedSizesToArray, below, that does not guarantee deterministic serialization. |
virtual int | GetCachedSize() const = 0 Returns the result of the last call to ByteSize(). more... |
virtual uint8 * | InternalSerializeWithCachedSizesToArray(bool deterministic, uint8 * target) const Like SerializeWithCachedSizes, but writes directly to *target, returning a pointer to the byte immediately after the last byte written. more... |
virtual MessageLite * MessageLite::New() const = 0
Construct a new instance of the same type.
Ownership is passed to the caller.
virtual MessageLite * MessageLite::New(
Arena * arena) const
Arena * arena) const
Construct a new instance on the arena.
Ownership is passed to the caller if arena is a NULL. Default implementation for backwards compatibility.
virtual Arena * MessageLite::GetArena() const
Get the arena, if any, associated with this message.
Virtual method required for generic operations but most arena-related operations should use the GetArenaNoVirtual() generated-code method. Default implementation to reduce code size by avoiding the need for per-type implementations when types do not implement arena support.
virtual void * MessageLite::GetMaybeArenaPointer() const
Get a pointer that may be equal to this message's arena, or may not be.
If the value returned by this method is equal to some arena pointer, then this message is on that arena; however, if this message is on some arena, this method may or may not return that arena's pointer. As a tradeoff, this method may be more efficient than GetArena(). The intent is to allow underlying representations that use e.g. tagged pointers to sometimes store the arena pointer directly, and sometimes in a more indirect way, and allow a fastpath comparison against the arena pointer when it's easy to obtain.
virtual void MessageLite::Clear() = 0
Clear all fields of the message and set them to their default values.
Clear() avoids freeing memory, assuming that any memory allocated to hold parts of the message will be needed again to hold the next message. If you actually want to free the memory used by a Message, you must delete it.
virtual string MessageLite::InitializationErrorString() const
This is not implemented for Lite messages – it just returns "(cannot determine missing fields for lite message)".
However, it is implemented for full messages. See message.h.
virtual void MessageLite::CheckTypeAndMergeFrom(
const MessageLite & other) = 0
const MessageLite & other) = 0
If |other| is the exact same class as this, calls MergeFrom().
Otherwise, results are undefined (probably crash).
bool MessageLite::ParseFromCodedStream(
io::CodedInputStream * input)
io::CodedInputStream * input)
Fill the message with a protocol buffer parsed from the given input stream.
Returns false on a read error or if the input is in the wrong format. A successful return does not indicate the entire input is consumed, ensure you call ConsumedEntireMessage() to check that if applicable.
bool MessageLite::ParseFromZeroCopyStream(
io::ZeroCopyInputStream * input)
io::ZeroCopyInputStream * input)
Read a protocol buffer from the given zero-copy input stream.
If successful, the entire input will be consumed.
bool MessageLite::ParseFromBoundedZeroCopyStream(
io::ZeroCopyInputStream * input,
int size)
io::ZeroCopyInputStream * input,
int size)
Read a protocol buffer from the given zero-copy input stream, expecting the message to be exactly "size" bytes long.
If successful, exactly this many bytes will have been consumed from the input.
bool MessageLite::ParseFromString(
const string & data)
const string & data)
Parses a protocol buffer contained in a string.
Returns true on success. This function takes a string in the (non-human-readable) binary wire format, matching the encoding output by MessageLite::SerializeToString(). If you'd like to convert a human-readable string into a protocol buffer object, see google::protobuf::TextFormat::ParseFromString().
bool MessageLite::MergeFromCodedStream(
io::CodedInputStream * input)
io::CodedInputStream * input)
Reads a protocol buffer from the stream and merges it into this Message.
Singular fields read from the input overwrite what is already in the Message and repeated fields are appended to those already present.
It is the responsibility of the caller to call input->LastTagWas() (for groups) or input->ConsumedEntireMessage() (for non-groups) after this returns to verify that the message's end was delimited correctly.
ParsefromCodedStream() is implemented as Clear() followed by MergeFromCodedStream().
virtual bool MessageLite::MergePartialFromCodedStream(
io::CodedInputStream * input) = 0
io::CodedInputStream * input) = 0
Like MergeFromCodedStream(), but succeeds even if required fields are missing in the input.
MergeFromCodedStream() is just implemented as MergePartialFromCodedStream() followed by IsInitialized().
bool MessageLite::SerializeToCodedStream(
io::CodedOutputStream * output) const
io::CodedOutputStream * output) const
Write a protocol buffer of this message to the given output.
Returns false on a write error. If the message is missing required fields, this may GOOGLE_CHECK-fail.
bool MessageLite::SerializeToZeroCopyStream(
io::ZeroCopyOutputStream * output) const
io::ZeroCopyOutputStream * output) const
Write the message to the given zero-copy output stream.
All required fields must be set.
bool MessageLite::SerializeToString(
string * output) const
string * output) const
Serialize the message and store it in the given string.
All required fields must be set.
bool MessageLite::SerializeToArray(
void * data,
int size) const
void * data,
int size) const
Serialize the message and store it in the given byte array.
All required fields must be set.
string MessageLite::SerializeAsString() const
Make a string encoding the message.
Is equivalent to calling SerializeToString() on a string and using that. Returns the empty string if SerializeToString() would have returned an error. Note: If you intend to generate many such strings, you may reduce heap fragmentation by instead re-using the same string object with calls to SerializeToString().
bool MessageLite::AppendToString(
string * output) const
string * output) const
Like SerializeToString(), but appends to the data to the string's existing contents.
All required fields must be set.
virtual size_t MessageLite::ByteSizeLong() const = 0
Computes the serialized size of the message.
This recursively calls ByteSizeLong() on all embedded messages.
ByteSizeLong() is generally linear in the number of fields defined for the proto.
virtual void MessageLite::SerializeWithCachedSizes(
io::CodedOutputStream * output) const = 0
io::CodedOutputStream * output) const = 0
Serializes the message without recomputing the size.
The message must not have changed since the last call to ByteSize(), and the value returned by ByteSize must be non-negative. Otherwise the results are undefined.
virtual int MessageLite::GetCachedSize() const = 0
Returns the result of the last call to ByteSize().
An embedded message's size is needed both to serialize it (because embedded messages are length-delimited) and to compute the outer message's size. Caching the size avoids computing it multiple times.
ByteSize() does not automatically use the cached size when available because this would require invalidating it every time the message was modified, which would be too hard and expensive. (E.g. if a deeply-nested sub-message is changed, all of its parents' cached sizes would need to be invalidated, which is too much work for an otherwise inlined setter method.)
virtual uint8 * MessageLite::InternalSerializeWithCachedSizesToArray(
bool deterministic,
uint8 * target) const
bool deterministic,
uint8 * target) const
Like SerializeWithCachedSizes, but writes directly to *target, returning a pointer to the byte immediately after the last byte written.
"target" must point at a byte array of at least ByteSize() bytes. If deterministic is true then we use deterministic serialization, e.g., map keys are sorted. FOR INTERNAL USE ONLY!