// 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.
// Authors: wink@google.com (Wink Saville),
// kenton@google.com (Kenton Varda)
// Based on original Protocol Buffers design by
// Sanjay Ghemawat, Jeff Dean, and others.
#include <climits>
#include <string>
#include <google/protobuf/stubs/logging.h>
#include <google/protobuf/stubs/common.h>
#include <google/protobuf/stubs/stringprintf.h>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/io/zero_copy_stream_impl_lite.h>
#include <google/protobuf/arena.h>
#include <google/protobuf/generated_message_util.h>
#include <google/protobuf/message_lite.h>
#include <google/protobuf/repeated_field.h>
#include <google/protobuf/stubs/stl_util.h>
#include <google/protobuf/port_def.inc>
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
#include <google/protobuf/parse_context.h>
#include "util/utf8/public/unilib.h"
#include "util/utf8/public/unilib_utf8_utils.h"
#endif
namespace google {
namespace protobuf {
string MessageLite::InitializationErrorString() const {
return "(cannot determine missing fields for lite message)";
}
namespace {
// When serializing, we first compute the byte size, then serialize the message.
// If serialization produces a different number of bytes than expected, we
// call this function, which crashes. The problem could be due to a bug in the
// protobuf implementation but is more likely caused by concurrent modification
// of the message. This function attempts to distinguish between the two and
// provide a useful error message.
void ByteSizeConsistencyError(size_t byte_size_before_serialization,
size_t byte_size_after_serialization,
size_t bytes_produced_by_serialization,
const MessageLite& message) {
GOOGLE_CHECK_EQ(byte_size_before_serialization, byte_size_after_serialization)
<< message.GetTypeName()
<< " was modified concurrently during serialization.";
GOOGLE_CHECK_EQ(bytes_produced_by_serialization, byte_size_before_serialization)
<< "Byte size calculation and serialization were inconsistent. This "
"may indicate a bug in protocol buffers or it may be caused by "
"concurrent modification of "
<< message.GetTypeName() << ".";
GOOGLE_LOG(FATAL) << "This shouldn't be called if all the sizes are equal.";
}
string InitializationErrorMessage(const char* action,
const MessageLite& message) {
// Note: We want to avoid depending on strutil in the lite library, otherwise
// we'd use:
//
// return strings::Substitute(
// "Can't $0 message of type \"$1\" because it is missing required "
// "fields: $2",
// action, message.GetTypeName(),
// message.InitializationErrorString());
string result;
result += "Can't ";
result += action;
result += " message of type \"";
result += message.GetTypeName();
result += "\" because it is missing required fields: ";
result += message.InitializationErrorString();
return result;
}
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
// This is wrapper to turn a ZeroCopyInputStream (ZCIS) into a
// InputStreamWithOverlap. This is done by copying data around the seams,
// hence the name EpsCopyInputStream, pictorially if ZCIS presents a stream
// in chunks like so
// [---------------------------------------------------------------]
// [---------------------] chunk 1
// [----------------------------] chunk 2
// chunk 3 [--------------]
// where '-' depicts bytes of the stream or chunks vertically alligned with the
// corresponding bytes between stream and chunk.
//
// This class will convert this into chunks
// [-----------------....] chunk 1
// [----....] patch
// [------------------------....] chunk 2
// [----....] patch
// chunk 3 [----------....]
// patch [----****]
// by using a fixed size buffer to patch over the seams. This requires
// copying of an "epsilon" neighboorhood around the seams. In the picture above
// dots mean bytes beyond the end of the new chunks. Each chunk is kSlopBytes
// smalller as its original chunk (above depicted as 4 dots) and the number of
// of chunks is doubled because each seam in the original stream introduces a
// new patch.
//
// The algorithm is simple but not entirely trivial. Two complications arise
// 1) The original chunk could be less than kSlopBytes. Hence we can't simply
// chop the last kSlopBytes of a chunk.
// 2) We need to leave the underlying CodedInputStream (CIS) precisely at the
// last byte read in the parse. In most cases a parse ends on a limit or end of
// the ZeroCopyInputStream, which is not problematic because CIS will never give
// us data beyond that. But the parse can end on a 0 end tag or an end group.
// If that happens in the first kSlopBytes of the patch (which are copied
// from the previous buffer) the CIS has already moved to the next chunk to
// copy the remaining bytes of the patch buffer. There exist no API to rollback
// to a previous buffer.
//
// We model this as a state machine. A call to get the next chunk either returns
// an original chunk except the last kSlopBytes or it has to copy the last
// kSlopBytes of the current chunk to the patch buffer and copy the first
// kSlopBytes of the next chunk to the end of the patch buffer.
//
// In order to deal with problem 1, we need to deal with the case that a new
// chunk can be less or equal than kSlopBytes big. We can just copy the chunk
// to the end and return (buffer, chunk->size). Pictorially
// [--------] chunk 1
// [--] chunk 2
// [---] chunk 3
// will become
// [----....] chunk 1
// [--....] patch (not full range of the buffer, only two hyphens)
// [--] chunk 2 (too small so never returned as buffer)
// [---....] patch (not full range of the buffer, only three hyphens)
// [---] chunk 3 (too small so never returned as buffer)
// [----****] patch (full range, last bytes are garbage)
// Because of this the source (the dots in above) can overlap with the
// destination buffer and so we have to use memmove.
//
// To solve problem 2, we verify after copying the last kSlopBytes the parse
// won't end before we continue to get the next chunk.
template <int kSlopBytes>
class EpsCopyInputStream {
public:
EpsCopyInputStream(io::CodedInputStream* input) : input_(input) {}
~EpsCopyInputStream() {
ABSL_ASSERT(skip_ >= 0);
input_->Skip(skip_);
}
template <typename EnsureNotEnd>
StringPiece SafeNextWithOverlap(const EnsureNotEnd& ensure_not_end) {
switch (next_state_) {
case kEOS:
// End of stream
return nullptr;
case kChunk:
// chunk_ contains a buffer of sufficient size (> kSlopBytes).
// To parse the last kSlopBytes we need to copy the bytes into the
// buffer. Hence we set,
next_state_ = kBuffer;
skip_ = chunk_.size() - kSlopBytes;
return {chunk_.begin(), chunk_.size() - kSlopBytes};
case kBuffer: {
// We have to parse the last kSlopBytes of chunk_, which could alias
// buffer_ so we have to memmove.
std::memmove(buffer_, chunk_.end() - kSlopBytes, kSlopBytes);
skip_ += kSlopBytes;
// We need to fill in the other half of buffer_ with the start of the
// next chunk. So we need to continue to the next buffer in the ZCIS,
// which makes it impossible to rollback to the current buffer :(
// We need to verify this won't happen.
if (!ensure_not_end(buffer_, kSlopBytes)) {
// We are guaranteed to exit in this interval.
next_state_ = kEOS;
return {buffer_, kSlopBytes};
}
chunk_ = GetChunk();
auto size = chunk_.size();
if (size > kSlopBytes) {
next_state_ = kChunk;
std::memcpy(buffer_ + kSlopBytes, chunk_.begin(), kSlopBytes);
return {buffer_, kSlopBytes};
} else if (size == 0) {
next_state_ = kEOS;
return {buffer_, kSlopBytes};
} else {
// next_state_ = kBuffer, but this is unnecessary
// The next chunk is not big enough. So we copy it in the current
// after the current buffer. Resulting in a buffer with
// size + kSlopBytes bytes.
std::memcpy(buffer_ + kSlopBytes, chunk_.begin(), size);
// skip_ becomes negative here.
skip_ += size - kSlopBytes;
chunk_ = {buffer_, size + kSlopBytes};
return {buffer_, size};
}
}
case kStart: {
chunk_ = GetChunk();
auto size = chunk_.size();
if (PROTOBUF_PREDICT_TRUE(size > kSlopBytes)) {
next_state_ = kBuffer;
skip_ = size - kSlopBytes;
return {chunk_.begin(), size - kSlopBytes};
}
size_t i = 0;
do {
if (size == 0) {
next_state_ = kEOS;
return {buffer_, i};
}
std::memcpy(buffer_ + i, chunk_.begin(), size);
ABSL_ASSERT(skip_ == 0);
skip_ = size;
i += size;
if (i > kSlopBytes) {
skip_ -= kSlopBytes;
chunk_ = {buffer_, i};
next_state_ = kBuffer;
return {buffer_, i - kSlopBytes};
}
if (!ensure_not_end(buffer_, i)) {
next_state_ = kEOS;
return {buffer_, i};
}
chunk_ = GetChunk();
size = chunk_.size();
} while (size <= kSlopBytes);
std::memcpy(buffer_ + i, chunk_.begin(), kSlopBytes);
next_state_ = kChunk;
return {buffer_, i};
}
}
}
StringPiece NextWithOverlap() {
return SafeNextWithOverlap([](const char*, size_t) { return true; });
}
void AdjustPos(int delta) {
ABSL_ASSERT(delta <= kSlopBytes);
skip_ += delta;
}
void SetError() { skip_ = 0; }
private:
io::CodedInputStream* input_;
StringPiece chunk_;
char buffer_[2 * kSlopBytes] = {};
enum State {
kStart,
kEOS, // -> end of stream.
kChunk, // -> chunk_ contains the data for Next.
kBuffer, // -> We need to copy the left over from previous chunk_ and
// load and patch the start of the next chunk in the
// local buffer.
};
State next_state_ = kStart;
int skip_ = 0; // how much bytes to skip to current position in the stream.
StringPiece GetChunk() {
const void* ptr;
ABSL_ASSERT(skip_ >= 0);
input_->Skip(skip_);
skip_ = 0;
int size;
if (!input_->GetDirectBufferPointer(&ptr, &size)) {
return nullptr;
}
return StringPiece(static_cast<const char*>(ptr), size);
}
};
#endif
// Several of the Parse methods below just do one thing and then call another
// method. In a naive implementation, we might have ParseFromString() call
// ParseFromArray() which would call ParseFromZeroCopyStream() which would call
// ParseFromCodedStream() which would call MergeFromCodedStream() which would
// call MergePartialFromCodedStream(). However, when parsing very small
// messages, every function call introduces significant overhead. To avoid
// this without reproducing code, we use these forced-inline helpers.
inline bool InlineMergeFromCodedStream(io::CodedInputStream* input,
MessageLite* message) {
if (!message->MergePartialFromCodedStream(input)) return false;
if (!message->IsInitialized()) {
GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *message);
return false;
}
return true;
}
inline bool InlineParsePartialFromCodedStream(io::CodedInputStream* input,
MessageLite* message) {
message->Clear();
return message->MergePartialFromCodedStream(input);
}
inline bool InlineParseFromCodedStream(io::CodedInputStream* input,
MessageLite* message) {
message->Clear();
return InlineMergeFromCodedStream(input, message);
}
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
template <template <int> class Input>
inline bool InlineMergePartialEntireInput(
Input<internal::ParseContext::kSlopBytes>* input, MessageLite* message) {
internal::ParseContext ctx;
auto chunk = input->NextWithOverlap();
if (chunk.empty()) {
return true;
}
auto res = ctx.StartParse({message->_ParseFunc(), message}, chunk);
while (res.first == internal::ParseContext::kContinue) {
int overrun = res.second;
chunk = input->NextWithOverlap();
if (chunk.empty()) {
if (!ctx.ValidEnd(overrun)) return false;
return true;
}
res = ctx.ResumeParse(chunk, overrun);
}
// Either failure or ended on a zero or end-group tag
return false;
}
#endif
inline bool InlineMergePartialEntireStream(io::CodedInputStream* cis,
MessageLite* message) {
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
EpsCopyInputStream<internal::ParseContext::kSlopBytes> input(cis);
if (InlineMergePartialEntireInput(&input, message)) {
cis->SetConsumed();
return true;
}
return false;
#else
return message->MergePartialFromCodedStream(cis) &&
cis->ConsumedEntireMessage();
#endif
}
inline bool InlineMergeEntireStream(io::CodedInputStream* input,
MessageLite* message) {
if (!InlineMergePartialEntireStream(input, message)) return false;
if (!message->IsInitialized()) {
GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *message);
return false;
}
return true;
}
inline bool InlineParsePartialEntireStream(io::CodedInputStream* input,
MessageLite* message) {
message->Clear();
return InlineMergePartialEntireStream(input, message);
}
inline bool InlineParseEntireStream(io::CodedInputStream* input,
MessageLite* message) {
message->Clear();
return InlineMergeEntireStream(input, message);
}
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
template <int kSlopBytes>
class ArrayInput {
public:
ArrayInput(StringPiece chunk) : chunk_(chunk) {}
StringPiece NextWithOverlap() {
auto s = chunk_.size();
if (s > 16) {
auto res = chunk_.substr(0, s - 16);
chunk_ = chunk_.substr(s - 16);
return res;
} else if (s == 0) {
return nullptr;
} else {
std::memcpy(buffer_, chunk_.begin(), s);
chunk_ = nullptr;
return {buffer_, s};
}
}
void SetError() {}
private:
StringPiece chunk_;
char buffer_[32] = {};
int state_ = 0;
};
#endif
inline bool InlineMergePartialFromArray(const void* data, int size,
MessageLite* msg,
bool aliasing = false) {
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
auto begin = static_cast<const char*>(data);
if (aliasing) {
// TODO(gerbens) make this safe against corruption buffer overflow.
// Short cut to allow aliasing string_piece
internal::ParseContext ctx;
ctx.extra_parse_data().aliasing = true;
return ctx.ParseExactRange({msg->_ParseFunc(), msg}, begin, begin + size);
}
ArrayInput<internal::ParseContext::kSlopBytes> input(
StringPiece(begin, size));
return InlineMergePartialEntireInput(&input, msg);
#else
io::CodedInputStream input(static_cast<const uint8*>(data), size);
return msg->MergePartialFromCodedStream(&input) &&
input.ConsumedEntireMessage();
#endif
}
inline bool InlineMergeFromArray(const void* data, int size,
MessageLite* message, bool aliasing = false) {
if (!InlineMergePartialFromArray(data, size, message, aliasing)) return false;
if (!message->IsInitialized()) {
GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *message);
return false;
}
return true;
}
inline bool InlineParsePartialFromArray(const void* data, int size,
MessageLite* message,
bool aliasing = false) {
message->Clear();
return InlineMergePartialFromArray(data, size, message, aliasing);
}
inline bool InlineParseFromArray(const void* data, int size,
MessageLite* message, bool aliasing = false) {
if (!InlineParsePartialFromArray(data, size, message, aliasing)) return false;
if (!message->IsInitialized()) {
GOOGLE_LOG(ERROR) << InitializationErrorMessage("parse", *message);
return false;
}
return true;
}
} // namespace
MessageLite* MessageLite::New(Arena* arena) const {
MessageLite* message = New();
if (arena != NULL) {
arena->Own(message);
}
return message;
}
#if GOOGLE_PROTOBUF_ENABLE_EXPERIMENTAL_PARSER
bool MessageLite::MergePartialFromCodedStream(io::CodedInputStream* cis) {
EpsCopyInputStream<internal::ParseContext::kSlopBytes> input(cis);
internal::ParseContext ctx(cis->RecursionBudget());
ctx.extra_parse_data().pool = cis->GetExtensionPool();
ctx.extra_parse_data().factory = cis->GetExtensionFactory();
auto chunk = input.SafeNextWithOverlap(
[&ctx](const char* ptr, int n) { return ctx.EnsureNoEnd(ptr, n, 0); });
if (chunk.empty()) {
cis->SetConsumed();
return true;
}
auto res = ctx.StartParse({_ParseFunc(), this}, chunk);
while (res.first == internal::ParseContext::kContinue) {
int overrun = res.second;
chunk = input.SafeNextWithOverlap([&ctx, overrun](const char* ptr, int n) {
return ctx.EnsureNoEnd(ptr, n, overrun);
});
if (chunk.empty()) {
if (!ctx.ValidEnd(overrun)) goto error;
cis->SetConsumed();
return true;
}
res = ctx.ResumeParse(chunk, overrun);
}
// Either failure or ended on a zero or end-group tag
if (res.first != internal::ParseContext::kFailure) {
cis->SetLastTag(res.first);
input.AdjustPos(res.second);
return true;
}
error:
// Error can happen at a spot from which we can't back up. But in this case
// the user can't resume the stream as the error could be in an arbitrary
// location in the stream, so just leave the stream alone. This prevents
// triggering assertion fail.
input.SetError();
return false;
}
#endif
bool MessageLite::MergeFromCodedStream(io::CodedInputStream* input) {
return InlineMergeFromCodedStream(input, this);
}
bool MessageLite::ParseFromCodedStream(io::CodedInputStream* input) {
return InlineParseFromCodedStream(input, this);
}
bool MessageLite::ParsePartialFromCodedStream(io::CodedInputStream* input) {
return InlineParsePartialFromCodedStream(input, this);
}
bool MessageLite::ParseFromZeroCopyStream(io::ZeroCopyInputStream* input) {
io::CodedInputStream decoder(input);
return InlineParseEntireStream(&decoder, this);
}
bool MessageLite::ParsePartialFromZeroCopyStream(
io::ZeroCopyInputStream* input) {
io::CodedInputStream decoder(input);
return InlineParsePartialEntireStream(&decoder, this);
}
bool MessageLite::ParseFromBoundedZeroCopyStream(io::ZeroCopyInputStream* input,
int size) {
io::CodedInputStream decoder(input);
decoder.PushLimit(size);
return InlineParseEntireStream(&decoder, this) &&
decoder.BytesUntilLimit() == 0;
}
bool MessageLite::ParsePartialFromBoundedZeroCopyStream(
io::ZeroCopyInputStream* input, int size) {
io::CodedInputStream decoder(input);
decoder.PushLimit(size);
return InlineParsePartialEntireStream(&decoder, this) &&
decoder.BytesUntilLimit() == 0;
}
bool MessageLite::ParseFromString(const string& data) {
return InlineParseFromArray(data.data(), data.size(), this);
}
bool MessageLite::ParsePartialFromString(const string& data) {
return InlineParsePartialFromArray(data.data(), data.size(), this);
}
bool MessageLite::ParseFromArray(const void* data, int size) {
return InlineParseFromArray(data, size, this);
}
bool MessageLite::ParsePartialFromArray(const void* data, int size) {
return InlineParsePartialFromArray(data, size, this);
}
// ===================================================================
uint8* MessageLite::SerializeWithCachedSizesToArray(uint8* target) const {
return InternalSerializeWithCachedSizesToArray(
io::CodedOutputStream::IsDefaultSerializationDeterministic(), target);
}
bool MessageLite::SerializeToCodedStream(io::CodedOutputStream* output) const {
GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
return SerializePartialToCodedStream(output);
}
bool MessageLite::SerializePartialToCodedStream(
io::CodedOutputStream* output) const {
const size_t size = ByteSizeLong(); // Force size to be cached.
if (size > INT_MAX) {
GOOGLE_LOG(ERROR) << GetTypeName()
<< " exceeded maximum protobuf size of 2GB: " << size;
return false;
}
uint8* buffer = output->GetDirectBufferForNBytesAndAdvance(size);
if (buffer != NULL) {
uint8* end = InternalSerializeWithCachedSizesToArray(
output->IsSerializationDeterministic(), buffer);
if (end - buffer != size) {
ByteSizeConsistencyError(size, ByteSizeLong(), end - buffer, *this);
}
return true;
} else {
int original_byte_count = output->ByteCount();
SerializeWithCachedSizes(output);
if (output->HadError()) {
return false;
}
int final_byte_count = output->ByteCount();
if (final_byte_count - original_byte_count != size) {
ByteSizeConsistencyError(size, ByteSizeLong(),
final_byte_count - original_byte_count, *this);
}
return true;
}
}
bool MessageLite::SerializeToZeroCopyStream(
io::ZeroCopyOutputStream* output) const {
io::CodedOutputStream encoder(output);
return SerializeToCodedStream(&encoder);
}
bool MessageLite::SerializePartialToZeroCopyStream(
io::ZeroCopyOutputStream* output) const {
io::CodedOutputStream encoder(output);
return SerializePartialToCodedStream(&encoder);
}
bool MessageLite::AppendToString(string* output) const {
GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
return AppendPartialToString(output);
}
bool MessageLite::AppendPartialToString(string* output) const {
size_t old_size = output->size();
size_t byte_size = ByteSizeLong();
if (byte_size > INT_MAX) {
GOOGLE_LOG(ERROR) << GetTypeName()
<< " exceeded maximum protobuf size of 2GB: " << byte_size;
return false;
}
STLStringResizeUninitialized(output, old_size + byte_size);
uint8* start =
reinterpret_cast<uint8*>(io::mutable_string_data(output) + old_size);
uint8* end = SerializeWithCachedSizesToArray(start);
if (end - start != byte_size) {
ByteSizeConsistencyError(byte_size, ByteSizeLong(), end - start, *this);
}
return true;
}
bool MessageLite::SerializeToString(string* output) const {
output->clear();
return AppendToString(output);
}
bool MessageLite::SerializePartialToString(string* output) const {
output->clear();
return AppendPartialToString(output);
}
bool MessageLite::SerializeToArray(void* data, int size) const {
GOOGLE_DCHECK(IsInitialized()) << InitializationErrorMessage("serialize", *this);
return SerializePartialToArray(data, size);
}
bool MessageLite::SerializePartialToArray(void* data, int size) const {
const size_t byte_size = ByteSizeLong();
if (byte_size > INT_MAX) {
GOOGLE_LOG(ERROR) << GetTypeName()
<< " exceeded maximum protobuf size of 2GB: " << byte_size;
return false;
}
if (size < byte_size) return false;
uint8* start = reinterpret_cast<uint8*>(data);
uint8* end = SerializeWithCachedSizesToArray(start);
if (end - start != byte_size) {
ByteSizeConsistencyError(byte_size, ByteSizeLong(), end - start, *this);
}
return true;
}
string MessageLite::SerializeAsString() const {
// If the compiler implements the (Named) Return Value Optimization,
// the local variable 'output' will not actually reside on the stack
// of this function, but will be overlaid with the object that the
// caller supplied for the return value to be constructed in.
string output;
if (!AppendToString(&output)) output.clear();
return output;
}
string MessageLite::SerializePartialAsString() const {
string output;
if (!AppendPartialToString(&output)) output.clear();
return output;
}
void MessageLite::SerializeWithCachedSizes(
io::CodedOutputStream* output) const {
GOOGLE_DCHECK(InternalGetTable());
internal::TableSerialize(
*this,
static_cast<const internal::SerializationTable*>(InternalGetTable()),
output);
}
// The table driven code optimizes the case that the CodedOutputStream buffer
// is large enough to serialize into it directly.
// If the proto is optimized for speed, this method will be overridden by
// generated code for maximum speed. If the proto is optimized for size or
// is lite, then we need to specialize this to avoid infinite recursion.
uint8* MessageLite::InternalSerializeWithCachedSizesToArray(
bool deterministic, uint8* target) const {
const internal::SerializationTable* table =
static_cast<const internal::SerializationTable*>(InternalGetTable());
if (table == NULL) {
// We only optimize this when using optimize_for = SPEED. In other cases
// we just use the CodedOutputStream path.
int size = GetCachedSize();
io::ArrayOutputStream out(target, size);
io::CodedOutputStream coded_out(&out);
coded_out.SetSerializationDeterministic(deterministic);
SerializeWithCachedSizes(&coded_out);
GOOGLE_CHECK(!coded_out.HadError());
return target + size;
} else {
return internal::TableSerializeToArray(*this, table, deterministic, target);
}
}
namespace internal {
template <>
MessageLite* GenericTypeHandler<MessageLite>::NewFromPrototype(
const MessageLite* prototype, Arena* arena) {
return prototype->New(arena);
}
template <>
void GenericTypeHandler<MessageLite>::Merge(const MessageLite& from,
MessageLite* to) {
to->CheckTypeAndMergeFrom(from);
}
template <>
void GenericTypeHandler<string>::Merge(const string& from, string* to) {
*to = from;
}
} // namespace internal
} // namespace protobuf
} // namespace google