libs/protoutil/src/ProtoOutputStream.cpp - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2017 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 #define LOG_TAG "libprotoutil"

 #include <cinttypes>
 #include <type_traits>

 #include <android-base/file.h>
 #include <android/util/protobuf.h>
 #include <android/util/ProtoOutputStream.h>
 #include <cutils/log.h>

 namespace android {
 namespace util {

 ProtoOutputStream::ProtoOutputStream()
         :mBuffer(new EncodedBuffer()),
          mCopyBegin(0),
          mCompact(false),
          mDepth(0),
          mObjectId(0),
          mExpectedObjectToken(UINT64_C(-1))
 {
 }

 ProtoOutputStream::~ProtoOutputStream()
 {
 }


 void
 ProtoOutputStream::clear()
 {
     mBuffer->clear();
     mCopyBegin = 0;
     mCompact = false;
     mDepth = 0;
     mObjectId = 0;
     mExpectedObjectToken = UINT64_C(-1);
 }

 template<typename T>
 bool
 ProtoOutputStream::internalWrite(uint64_t fieldId, T val, const char* typeName)
 {
     if (mCompact) return false;
     const uint32_t id = (uint32_t)fieldId;
     switch (fieldId & FIELD_TYPE_MASK) {
         case FIELD_TYPE_DOUBLE:   writeDoubleImpl(id, (double)val);           break;
         case FIELD_TYPE_FLOAT:    writeFloatImpl(id, (float)val);             break;
         case FIELD_TYPE_INT64:    writeInt64Impl(id, (int64_t)val);           break;
         case FIELD_TYPE_UINT64:   writeUint64Impl(id, (uint64_t)val);         break;
         case FIELD_TYPE_INT32:    writeInt32Impl(id, (int32_t)val);           break;
         case FIELD_TYPE_FIXED64:  writeFixed64Impl(id, (uint64_t)val);        break;
         case FIELD_TYPE_FIXED32:  writeFixed32Impl(id, (uint32_t)val);        break;
         case FIELD_TYPE_UINT32:   writeUint32Impl(id, (uint32_t)val);         break;
         case FIELD_TYPE_SFIXED32: writeSFixed32Impl(id, (int32_t)val);        break;
         case FIELD_TYPE_SFIXED64: writeSFixed64Impl(id, (int64_t)val);        break;
         case FIELD_TYPE_SINT32:   writeZigzagInt32Impl(id, (int32_t)val);     break;
         case FIELD_TYPE_SINT64:   writeZigzagInt64Impl(id, (int64_t)val);     break;
         case FIELD_TYPE_ENUM:
             if (std::is_integral<T>::value) {
                 writeEnumImpl(id, (int)val);
             } else {
                 goto unsupported;
             }
             break;
         case FIELD_TYPE_BOOL:
             if (std::is_integral<T>::value) {
                 writeBoolImpl(id, val != 0);
             } else {
                 goto unsupported;
             }
             break;
         default:
             goto unsupported;
     }
     return true;

 unsupported:
     ALOGW("Field type %" PRIu64 " is not supported when writing %s val.",
             (fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT, typeName);
     return false;
 }

 bool
 ProtoOutputStream::write(uint64_t fieldId, double val)
 {
     return internalWrite(fieldId, val, "double");
 }


 bool
 ProtoOutputStream::write(uint64_t fieldId, float val)
 {
     return internalWrite(fieldId, val, "float");
 }

 bool
 ProtoOutputStream::write(uint64_t fieldId, int val)
 {
     return internalWrite(fieldId, val, "int");
 }

 bool
 ProtoOutputStream::write(uint64_t fieldId, long long val)
 {
     return internalWrite(fieldId, val, "long long");
 }

 bool
 ProtoOutputStream::write(uint64_t fieldId, bool val)
 {
     if (mCompact) return false;
     const uint32_t id = (uint32_t)fieldId;
     switch (fieldId & FIELD_TYPE_MASK) {
         case FIELD_TYPE_BOOL:
             writeBoolImpl(id, val);
             return true;
         default:
             ALOGW("Field type %" PRIu64 " is not supported when writing bool val.",
                     (fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT);
             return false;
     }
 }

 bool
 ProtoOutputStream::write(uint64_t fieldId, std::string val)
 {
     if (mCompact) return false;
     const uint32_t id = (uint32_t)fieldId;
     switch (fieldId & FIELD_TYPE_MASK) {
         case FIELD_TYPE_STRING:
             writeUtf8StringImpl(id, val.c_str(), val.size());
             return true;
         default:
             ALOGW("Field type %" PRIu64 " is not supported when writing string val.",
                     (fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT);
             return false;
     }
 }

 bool
 ProtoOutputStream::write(uint64_t fieldId, const char* val, size_t size)
 {
     if (mCompact) return false;
     const uint32_t id = (uint32_t)fieldId;
     switch (fieldId & FIELD_TYPE_MASK) {
         case FIELD_TYPE_STRING:
         case FIELD_TYPE_BYTES:
             writeUtf8StringImpl(id, val, size);
             return true;
         case FIELD_TYPE_MESSAGE:
             // can directly write valid format of message bytes into ProtoOutputStream without calling start/end
             writeMessageBytesImpl(id, val, size);
             return true;
         default:
             ALOGW("Field type %" PRIu64 " is not supported when writing char[] val.",
                     (fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT);
             return false;
     }
 }

 /**
  * Make a token.
  *  Bits 61-63 - tag size (So we can go backwards later if the object had not data)
  *                - 3 bits, max value 7, max value needed 5
  *  Bit  60    - true if the object is repeated
  *  Bits 59-51 - depth (For error checking)
  *                - 9 bits, max value 511, when checking, value is masked (if we really
  *                  are more than 511 levels deep)
  *  Bits 32-50 - objectId (For error checking)
  *                - 19 bits, max value 524,287. that's a lot of objects. IDs will wrap
  *                  because of the overflow, and only the tokens are compared.
  *  Bits  0-31 - offset of the first size field in the buffer.
  */
 static uint64_t
 makeToken(uint32_t tagSize, bool repeated, uint32_t depth, uint32_t objectId, size_t sizePos) {
     return ((UINT64_C(0x07) & (uint64_t)tagSize) << 61)
             | (repeated ? (UINT64_C(1) << 60) : 0)
             | (UINT64_C(0x01ff) & (uint64_t)depth) << 51
             | (UINT64_C(0x07ffff) & (uint64_t)objectId) << 32
             | (UINT64_C(0x0ffffffff) & (uint64_t)sizePos);
 }

 /**
  * Get the encoded tag size from the token.
  */
 static uint32_t getTagSizeFromToken(uint64_t token) {
     return 0x7 & (token >> 61);
 }

 /**
  * Get the nesting depth of startObject calls from the token.
  */
 static uint32_t getDepthFromToken(uint64_t token) {
     return 0x01ff & (token >> 51);
 }

 /**
  * Get the location of the childRawSize (the first 32 bit size field) in this object.
  */
 static uint32_t getSizePosFromToken(uint64_t token) {
     return (uint32_t)token;
 }

 uint64_t
 ProtoOutputStream::start(uint64_t fieldId)
 {
     if ((fieldId & FIELD_TYPE_MASK) != FIELD_TYPE_MESSAGE) {
         ALOGE("Can't call start for non-message type field: 0x%" PRIx64, fieldId);
         return 0;
     }

     uint32_t id = (uint32_t)fieldId;
     size_t prevPos = mBuffer->wp()->pos();
     mBuffer->writeHeader(id, WIRE_TYPE_LENGTH_DELIMITED);
     size_t sizePos = mBuffer->wp()->pos();

     mDepth++;
     mObjectId++;
     mBuffer->writeRawFixed64(mExpectedObjectToken); // push previous token into stack.

     mExpectedObjectToken = makeToken(sizePos - prevPos,
         (bool)(fieldId & FIELD_COUNT_REPEATED), mDepth, mObjectId, sizePos);
     return mExpectedObjectToken;
 }

 void
 ProtoOutputStream::end(uint64_t token)
 {
     if (token != mExpectedObjectToken) {
         ALOGE("Unexpected token: 0x%" PRIx64 ", should be 0x%" PRIx64, token, mExpectedObjectToken);
         mDepth = UINT32_C(-1); // make depth invalid
         return;
     }

     uint32_t depth = getDepthFromToken(token);
     if (depth != (mDepth & 0x01ff)) {
         ALOGE("Unexpected depth: %" PRIu32 ", should be %" PRIu32, depth, mDepth);
         mDepth = UINT32_C(-1); // make depth invalid
         return;
     }
     mDepth--;

     uint32_t sizePos = getSizePosFromToken(token);
     // number of bytes written in this start-end session.
     int childRawSize = mBuffer->wp()->pos() - sizePos - 8;

     // retrieve the old token from stack.
     mBuffer->ep()->rewind()->move(sizePos);
     mExpectedObjectToken = mBuffer->readRawFixed64();

     // If raw size is larger than 0, write the negative value here to indicate a compact is needed.
     if (childRawSize > 0) {
         mBuffer->editRawFixed32(sizePos, -childRawSize);
         mBuffer->editRawFixed32(sizePos+4, -1);
     } else {
         // reset wp which erase the header tag of the message when its size is 0.
         mBuffer->wp()->rewind()->move(sizePos - getTagSizeFromToken(token));
     }
 }

 size_t
 ProtoOutputStream::bytesWritten()
 {
     return mBuffer->size();
 }

 bool
 ProtoOutputStream::compact() {
     if (mCompact) return true;
     if (mDepth != 0) {
         ALOGE("Can't compact when depth(%" PRIu32 ") is not zero. Missing or extra calls to end.", mDepth);
         return false;
     }
     // record the size of the original buffer.
     size_t rawBufferSize = mBuffer->size();
     if (rawBufferSize == 0) return true; // nothing to do if the buffer is empty;

     // reset edit pointer and recursively compute encoded size of messages.
     mBuffer->ep()->rewind();
     if (editEncodedSize(rawBufferSize) == 0) {
         ALOGE("Failed to editEncodedSize.");
         return false;
     }

     // reset both edit pointer and write pointer, and compact recursively.
     mBuffer->ep()->rewind();
     mBuffer->wp()->rewind();
     if (!compactSize(rawBufferSize)) {
         ALOGE("Failed to compactSize.");
         return false;
     }
     // copy the reset to the buffer.
     if (mCopyBegin < rawBufferSize) {
         mBuffer->copy(mCopyBegin, rawBufferSize - mCopyBegin);
     }

     // mark true means it is not legal to write to this ProtoOutputStream anymore
     mCompact = true;
     return true;
 }

 /**
  * First compaction pass.  Iterate through the data, and fill in the
  * nested object sizes so the next pass can compact them.
  */
 size_t
 ProtoOutputStream::editEncodedSize(size_t rawSize)
 {
     size_t objectStart = mBuffer->ep()->pos();
     size_t objectEnd = objectStart + rawSize;
     size_t encodedSize = 0;
     int childRawSize, childEncodedSize;
     size_t childEncodedSizePos;

     while (mBuffer->ep()->pos() < objectEnd) {
         uint32_t tag = (uint32_t)mBuffer->readRawVarint();
         encodedSize += get_varint_size(tag);
         switch (read_wire_type(tag)) {
             case WIRE_TYPE_VARINT:
                 do {
                     encodedSize++;
                 } while ((mBuffer->readRawByte() & 0x80) != 0);
                 break;
             case WIRE_TYPE_FIXED64:
                 encodedSize += 8;
                 mBuffer->ep()->move(8);
                 break;
             case WIRE_TYPE_LENGTH_DELIMITED:
                 childRawSize = (int)mBuffer->readRawFixed32();
                 childEncodedSizePos = mBuffer->ep()->pos();
                 childEncodedSize = (int)mBuffer->readRawFixed32();
                 if (childRawSize >= 0 && childRawSize == childEncodedSize) {
                     mBuffer->ep()->move(childRawSize);
                 } else if (childRawSize < 0 && childEncodedSize == -1){
                     childEncodedSize = editEncodedSize(-childRawSize);
                     mBuffer->editRawFixed32(childEncodedSizePos, childEncodedSize);
                 } else {
                     ALOGE("Bad raw or encoded values: raw=%d, encoded=%d at %zu",
                             childRawSize, childEncodedSize, childEncodedSizePos);
                     return 0;
                 }
                 encodedSize += get_varint_size(childEncodedSize) + childEncodedSize;
                 break;
             case WIRE_TYPE_FIXED32:
                 encodedSize += 4;
                 mBuffer->ep()->move(4);
                 break;
             default:
                 ALOGE("Unexpected wire type %d in editEncodedSize at [%zu, %zu]",
                         read_wire_type(tag), objectStart, objectEnd);
                 return 0;
         }
     }
     return encodedSize;
 }

 /**
  * Second compaction pass.  Iterate through the data, and copy the data
  * forward in the buffer, converting the pairs of uint32s into a single
  * unsigned varint of the size.
  */
 bool
 ProtoOutputStream::compactSize(size_t rawSize)
 {
     size_t objectStart = mBuffer->ep()->pos();
     size_t objectEnd = objectStart + rawSize;
     int childRawSize, childEncodedSize;

     while (mBuffer->ep()->pos() < objectEnd) {
         uint32_t tag = (uint32_t)mBuffer->readRawVarint();
         switch (read_wire_type(tag)) {
             case WIRE_TYPE_VARINT:
                 while ((mBuffer->readRawByte() & 0x80) != 0) {}
                 break;
             case WIRE_TYPE_FIXED64:
                 mBuffer->ep()->move(8);
                 break;
             case WIRE_TYPE_LENGTH_DELIMITED:
                 mBuffer->copy(mCopyBegin, mBuffer->ep()->pos() - mCopyBegin);

                 childRawSize = (int)mBuffer->readRawFixed32();
                 childEncodedSize = (int)mBuffer->readRawFixed32();
                 mCopyBegin = mBuffer->ep()->pos();

                 // write encoded size to buffer.
                 mBuffer->writeRawVarint32(childEncodedSize);
                 if (childRawSize >= 0 && childRawSize == childEncodedSize) {
                     mBuffer->ep()->move(childEncodedSize);
                 } else if (childRawSize < 0){
                     if (!compactSize(-childRawSize)) return false;
                 } else {
                     ALOGE("Bad raw or encoded values: raw=%d, encoded=%d",
                             childRawSize, childEncodedSize);
                     return false;
                 }
                 break;
             case WIRE_TYPE_FIXED32:
                 mBuffer->ep()->move(4);
                 break;
             default:
                 ALOGE("Unexpected wire type %d in compactSize at [%zu, %zu]",
                         read_wire_type(tag), objectStart, objectEnd);
                 return false;
         }
     }
     return true;
 }

 size_t
 ProtoOutputStream::size()
 {
     if (!compact()) {
         ALOGE("compact failed, the ProtoOutputStream data is corrupted!");
         return 0;
     }
     return mBuffer->size();
 }

 bool
 ProtoOutputStream::flush(int fd)
 {
     if (fd < 0) return false;
     if (!compact()) return false;

     sp<ProtoReader> reader = mBuffer->read();
     while (reader->readBuffer() != NULL) {
         if (!android::base::WriteFully(fd, reader->readBuffer(), reader->currentToRead())) {
             return false;
         }
         reader->move(reader->currentToRead());
     }
     return true;
 }

 bool
 ProtoOutputStream::serializeToString(std::string* out)
 {
     if (out == nullptr) return false;
     if (!compact()) return false;

     sp<ProtoReader> reader = mBuffer->read();
     out->reserve(reader->size());
     while (reader->hasNext()) {
         out->append(static_cast<const char*>(static_cast<const void*>(reader->readBuffer())),
                     reader->currentToRead());
         reader->move(reader->currentToRead());
     }
     return true;
 }

 bool
 ProtoOutputStream::serializeToVector(std::vector<uint8_t>* out)
 {
     if (out == nullptr) return false;
     if (!compact()) return false;

     sp<ProtoReader> reader = mBuffer->read();
     out->reserve(reader->size());
     while (reader->hasNext()) {
         const uint8_t* buf = reader->readBuffer();
         size_t size = reader->currentToRead();
         out->insert(out->end(), buf, buf + size);
         reader->move(size);
     }
     return true;
 }

 sp<ProtoReader>
 ProtoOutputStream::data()
 {
     if (!compact()) {
         ALOGE("compact failed, the ProtoOutputStream data is corrupted!");
         mBuffer->clear();
     }
     return mBuffer->read();
 }

 void
 ProtoOutputStream::writeRawVarint(uint64_t varint)
 {
     mBuffer->writeRawVarint64(varint);
 }

 void
 ProtoOutputStream::writeLengthDelimitedHeader(uint32_t id, size_t size)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_LENGTH_DELIMITED);
     // reserves 64 bits for length delimited fields, if first field is negative, compact it.
     mBuffer->writeRawFixed32(size);
     mBuffer->writeRawFixed32(size);
 }

 void
 ProtoOutputStream::writeRawByte(uint8_t byte)
 {
     mBuffer->writeRawByte(byte);
 }


 // =========================================================================
 // Private functions

 /**
  * bit_cast
  */
 template <class From, class To>
 inline To bit_cast(From const &from) {
     To to;
     memcpy(&to, &from, sizeof(to));
     return to;
 }

 inline void
 ProtoOutputStream::writeDoubleImpl(uint32_t id, double val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_FIXED64);
     mBuffer->writeRawFixed64(bit_cast<double, uint64_t>(val));
 }

 inline void
 ProtoOutputStream::writeFloatImpl(uint32_t id, float val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_FIXED32);
     mBuffer->writeRawFixed32(bit_cast<float, uint32_t>(val));
 }

 inline void
 ProtoOutputStream::writeInt64Impl(uint32_t id, int64_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint64(val);
 }

 inline void
 ProtoOutputStream::writeInt32Impl(uint32_t id, int32_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint32(val);
 }

 inline void
 ProtoOutputStream::writeUint64Impl(uint32_t id, uint64_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint64(val);
 }

 inline void
 ProtoOutputStream::writeUint32Impl(uint32_t id, uint32_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint32(val);
 }

 inline void
 ProtoOutputStream::writeFixed64Impl(uint32_t id, uint64_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_FIXED64);
     mBuffer->writeRawFixed64(val);
 }

 inline void
 ProtoOutputStream::writeFixed32Impl(uint32_t id, uint32_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_FIXED32);
     mBuffer->writeRawFixed32(val);
 }

 inline void
 ProtoOutputStream::writeSFixed64Impl(uint32_t id, int64_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_FIXED64);
     mBuffer->writeRawFixed64(val);
 }

 inline void
 ProtoOutputStream::writeSFixed32Impl(uint32_t id, int32_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_FIXED32);
     mBuffer->writeRawFixed32(val);
 }

 inline void
 ProtoOutputStream::writeZigzagInt64Impl(uint32_t id, int64_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint64((val << 1) ^ (val >> 63));
 }

 inline void
 ProtoOutputStream::writeZigzagInt32Impl(uint32_t id, int32_t val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint32((val << 1) ^ (val >> 31));
 }

 inline void
 ProtoOutputStream::writeEnumImpl(uint32_t id, int val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint32((uint32_t) val);
 }

 inline void
 ProtoOutputStream::writeBoolImpl(uint32_t id, bool val)
 {
     mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
     mBuffer->writeRawVarint32(val ? 1 : 0);
 }

 inline void
 ProtoOutputStream::writeUtf8StringImpl(uint32_t id, const char* val, size_t size)
 {
     if (val == NULL) return;
     writeLengthDelimitedHeader(id, size);
     for (size_t i=0; i<size; i++) {
         mBuffer->writeRawByte((uint8_t)val[i]);
     }
 }

 inline void
 ProtoOutputStream::writeMessageBytesImpl(uint32_t id, const char* val, size_t size)
 {
     if (val == NULL) return;
     writeLengthDelimitedHeader(id, size);
     for (size_t i=0; i<size; i++) {
         mBuffer->writeRawByte(val[i]);
     }
 }

 } // util
 } // android
	/*
	* Copyright (C) 2017 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	#define LOG_TAG "libprotoutil"

	#include <cinttypes>
	#include <type_traits>

	#include <android-base/file.h>
	#include <android/util/protobuf.h>
	#include <android/util/ProtoOutputStream.h>
	#include <cutils/log.h>

	namespace android {
	namespace util {

	ProtoOutputStream::ProtoOutputStream()
	:mBuffer(new EncodedBuffer()),
	mCopyBegin(0),
	mCompact(false),
	mDepth(0),
	mObjectId(0),
	mExpectedObjectToken(UINT64_C(-1))
	{
	}

	ProtoOutputStream::~ProtoOutputStream()
	{
	}


	void
	ProtoOutputStream::clear()
	{
	mBuffer->clear();
	mCopyBegin = 0;
	mCompact = false;
	mDepth = 0;
	mObjectId = 0;
	mExpectedObjectToken = UINT64_C(-1);
	}

	template<typename T>
	bool
	ProtoOutputStream::internalWrite(uint64_t fieldId, T val, const char* typeName)
	{
	if (mCompact) return false;
	const uint32_t id = (uint32_t)fieldId;
	switch (fieldId & FIELD_TYPE_MASK) {
	case FIELD_TYPE_DOUBLE: writeDoubleImpl(id, (double)val); break;
	case FIELD_TYPE_FLOAT: writeFloatImpl(id, (float)val); break;
	case FIELD_TYPE_INT64: writeInt64Impl(id, (int64_t)val); break;
	case FIELD_TYPE_UINT64: writeUint64Impl(id, (uint64_t)val); break;
	case FIELD_TYPE_INT32: writeInt32Impl(id, (int32_t)val); break;
	case FIELD_TYPE_FIXED64: writeFixed64Impl(id, (uint64_t)val); break;
	case FIELD_TYPE_FIXED32: writeFixed32Impl(id, (uint32_t)val); break;
	case FIELD_TYPE_UINT32: writeUint32Impl(id, (uint32_t)val); break;
	case FIELD_TYPE_SFIXED32: writeSFixed32Impl(id, (int32_t)val); break;
	case FIELD_TYPE_SFIXED64: writeSFixed64Impl(id, (int64_t)val); break;
	case FIELD_TYPE_SINT32: writeZigzagInt32Impl(id, (int32_t)val); break;
	case FIELD_TYPE_SINT64: writeZigzagInt64Impl(id, (int64_t)val); break;
	case FIELD_TYPE_ENUM:
	if (std::is_integral<T>::value) {
	writeEnumImpl(id, (int)val);
	} else {
	goto unsupported;
	}
	break;
	case FIELD_TYPE_BOOL:
	if (std::is_integral<T>::value) {
	writeBoolImpl(id, val != 0);
	} else {
	goto unsupported;
	}
	break;
	default:
	goto unsupported;
	}
	return true;

	unsupported:
	ALOGW("Field type %" PRIu64 " is not supported when writing %s val.",
	(fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT, typeName);
	return false;
	}

	bool
	ProtoOutputStream::write(uint64_t fieldId, double val)
	{
	return internalWrite(fieldId, val, "double");
	}


	bool
	ProtoOutputStream::write(uint64_t fieldId, float val)
	{
	return internalWrite(fieldId, val, "float");
	}

	bool
	ProtoOutputStream::write(uint64_t fieldId, int val)
	{
	return internalWrite(fieldId, val, "int");
	}

	bool
	ProtoOutputStream::write(uint64_t fieldId, long long val)
	{
	return internalWrite(fieldId, val, "long long");
	}

	bool
	ProtoOutputStream::write(uint64_t fieldId, bool val)
	{
	if (mCompact) return false;
	const uint32_t id = (uint32_t)fieldId;
	switch (fieldId & FIELD_TYPE_MASK) {
	case FIELD_TYPE_BOOL:
	writeBoolImpl(id, val);
	return true;
	default:
	ALOGW("Field type %" PRIu64 " is not supported when writing bool val.",
	(fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT);
	return false;
	}
	}

	bool
	ProtoOutputStream::write(uint64_t fieldId, std::string val)
	{
	if (mCompact) return false;
	const uint32_t id = (uint32_t)fieldId;
	switch (fieldId & FIELD_TYPE_MASK) {
	case FIELD_TYPE_STRING:
	writeUtf8StringImpl(id, val.c_str(), val.size());
	return true;
	default:
	ALOGW("Field type %" PRIu64 " is not supported when writing string val.",
	(fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT);
	return false;
	}
	}

	bool
	ProtoOutputStream::write(uint64_t fieldId, const char* val, size_t size)
	{
	if (mCompact) return false;
	const uint32_t id = (uint32_t)fieldId;
	switch (fieldId & FIELD_TYPE_MASK) {
	case FIELD_TYPE_STRING:
	case FIELD_TYPE_BYTES:
	writeUtf8StringImpl(id, val, size);
	return true;
	case FIELD_TYPE_MESSAGE:
	// can directly write valid format of message bytes into ProtoOutputStream without calling start/end
	writeMessageBytesImpl(id, val, size);
	return true;
	default:
	ALOGW("Field type %" PRIu64 " is not supported when writing char[] val.",
	(fieldId & FIELD_TYPE_MASK) >> FIELD_TYPE_SHIFT);
	return false;
	}
	}

	/**
	* Make a token.
	* Bits 61-63 - tag size (So we can go backwards later if the object had not data)
	* - 3 bits, max value 7, max value needed 5
	* Bit 60 - true if the object is repeated
	* Bits 59-51 - depth (For error checking)
	* - 9 bits, max value 511, when checking, value is masked (if we really
	* are more than 511 levels deep)
	* Bits 32-50 - objectId (For error checking)
	* - 19 bits, max value 524,287. that's a lot of objects. IDs will wrap
	* because of the overflow, and only the tokens are compared.
	* Bits 0-31 - offset of the first size field in the buffer.
	*/
	static uint64_t
	makeToken(uint32_t tagSize, bool repeated, uint32_t depth, uint32_t objectId, size_t sizePos) {
	return ((UINT64_C(0x07) & (uint64_t)tagSize) << 61)
	\| (repeated ? (UINT64_C(1) << 60) : 0)
	\| (UINT64_C(0x01ff) & (uint64_t)depth) << 51
	\| (UINT64_C(0x07ffff) & (uint64_t)objectId) << 32
	\| (UINT64_C(0x0ffffffff) & (uint64_t)sizePos);
	}

	/**
	* Get the encoded tag size from the token.
	*/
	static uint32_t getTagSizeFromToken(uint64_t token) {
	return 0x7 & (token >> 61);
	}

	/**
	* Get the nesting depth of startObject calls from the token.
	*/
	static uint32_t getDepthFromToken(uint64_t token) {
	return 0x01ff & (token >> 51);
	}

	/**
	* Get the location of the childRawSize (the first 32 bit size field) in this object.
	*/
	static uint32_t getSizePosFromToken(uint64_t token) {
	return (uint32_t)token;
	}

	uint64_t
	ProtoOutputStream::start(uint64_t fieldId)
	{
	if ((fieldId & FIELD_TYPE_MASK) != FIELD_TYPE_MESSAGE) {
	ALOGE("Can't call start for non-message type field: 0x%" PRIx64, fieldId);
	return 0;
	}

	uint32_t id = (uint32_t)fieldId;
	size_t prevPos = mBuffer->wp()->pos();
	mBuffer->writeHeader(id, WIRE_TYPE_LENGTH_DELIMITED);
	size_t sizePos = mBuffer->wp()->pos();

	mDepth++;
	mObjectId++;
	mBuffer->writeRawFixed64(mExpectedObjectToken); // push previous token into stack.

	mExpectedObjectToken = makeToken(sizePos - prevPos,
	(bool)(fieldId & FIELD_COUNT_REPEATED), mDepth, mObjectId, sizePos);
	return mExpectedObjectToken;
	}

	void
	ProtoOutputStream::end(uint64_t token)
	{
	if (token != mExpectedObjectToken) {
	ALOGE("Unexpected token: 0x%" PRIx64 ", should be 0x%" PRIx64, token, mExpectedObjectToken);
	mDepth = UINT32_C(-1); // make depth invalid
	return;
	}

	uint32_t depth = getDepthFromToken(token);
	if (depth != (mDepth & 0x01ff)) {
	ALOGE("Unexpected depth: %" PRIu32 ", should be %" PRIu32, depth, mDepth);
	mDepth = UINT32_C(-1); // make depth invalid
	return;
	}
	mDepth--;

	uint32_t sizePos = getSizePosFromToken(token);
	// number of bytes written in this start-end session.
	int childRawSize = mBuffer->wp()->pos() - sizePos - 8;

	// retrieve the old token from stack.
	mBuffer->ep()->rewind()->move(sizePos);
	mExpectedObjectToken = mBuffer->readRawFixed64();

	// If raw size is larger than 0, write the negative value here to indicate a compact is needed.
	if (childRawSize > 0) {
	mBuffer->editRawFixed32(sizePos, -childRawSize);
	mBuffer->editRawFixed32(sizePos+4, -1);
	} else {
	// reset wp which erase the header tag of the message when its size is 0.
	mBuffer->wp()->rewind()->move(sizePos - getTagSizeFromToken(token));
	}
	}

	size_t
	ProtoOutputStream::bytesWritten()
	{
	return mBuffer->size();
	}

	bool
	ProtoOutputStream::compact() {
	if (mCompact) return true;
	if (mDepth != 0) {
	ALOGE("Can't compact when depth(%" PRIu32 ") is not zero. Missing or extra calls to end.", mDepth);
	return false;
	}
	// record the size of the original buffer.
	size_t rawBufferSize = mBuffer->size();
	if (rawBufferSize == 0) return true; // nothing to do if the buffer is empty;

	// reset edit pointer and recursively compute encoded size of messages.
	mBuffer->ep()->rewind();
	if (editEncodedSize(rawBufferSize) == 0) {
	ALOGE("Failed to editEncodedSize.");
	return false;
	}

	// reset both edit pointer and write pointer, and compact recursively.
	mBuffer->ep()->rewind();
	mBuffer->wp()->rewind();
	if (!compactSize(rawBufferSize)) {
	ALOGE("Failed to compactSize.");
	return false;
	}
	// copy the reset to the buffer.
	if (mCopyBegin < rawBufferSize) {
	mBuffer->copy(mCopyBegin, rawBufferSize - mCopyBegin);
	}

	// mark true means it is not legal to write to this ProtoOutputStream anymore
	mCompact = true;
	return true;
	}

	/**
	* First compaction pass. Iterate through the data, and fill in the
	* nested object sizes so the next pass can compact them.
	*/
	size_t
	ProtoOutputStream::editEncodedSize(size_t rawSize)
	{
	size_t objectStart = mBuffer->ep()->pos();
	size_t objectEnd = objectStart + rawSize;
	size_t encodedSize = 0;
	int childRawSize, childEncodedSize;
	size_t childEncodedSizePos;

	while (mBuffer->ep()->pos() < objectEnd) {
	uint32_t tag = (uint32_t)mBuffer->readRawVarint();
	encodedSize += get_varint_size(tag);
	switch (read_wire_type(tag)) {
	case WIRE_TYPE_VARINT:
	do {
	encodedSize++;
	} while ((mBuffer->readRawByte() & 0x80) != 0);
	break;
	case WIRE_TYPE_FIXED64:
	encodedSize += 8;
	mBuffer->ep()->move(8);
	break;
	case WIRE_TYPE_LENGTH_DELIMITED:
	childRawSize = (int)mBuffer->readRawFixed32();
	childEncodedSizePos = mBuffer->ep()->pos();
	childEncodedSize = (int)mBuffer->readRawFixed32();
	if (childRawSize >= 0 && childRawSize == childEncodedSize) {
	mBuffer->ep()->move(childRawSize);
	} else if (childRawSize < 0 && childEncodedSize == -1){
	childEncodedSize = editEncodedSize(-childRawSize);
	mBuffer->editRawFixed32(childEncodedSizePos, childEncodedSize);
	} else {
	ALOGE("Bad raw or encoded values: raw=%d, encoded=%d at %zu",
	childRawSize, childEncodedSize, childEncodedSizePos);
	return 0;
	}
	encodedSize += get_varint_size(childEncodedSize) + childEncodedSize;
	break;
	case WIRE_TYPE_FIXED32:
	encodedSize += 4;
	mBuffer->ep()->move(4);
	break;
	default:
	ALOGE("Unexpected wire type %d in editEncodedSize at [%zu, %zu]",
	read_wire_type(tag), objectStart, objectEnd);
	return 0;
	}
	}
	return encodedSize;
	}

	/**
	* Second compaction pass. Iterate through the data, and copy the data
	* forward in the buffer, converting the pairs of uint32s into a single
	* unsigned varint of the size.
	*/
	bool
	ProtoOutputStream::compactSize(size_t rawSize)
	{
	size_t objectStart = mBuffer->ep()->pos();
	size_t objectEnd = objectStart + rawSize;
	int childRawSize, childEncodedSize;

	while (mBuffer->ep()->pos() < objectEnd) {
	uint32_t tag = (uint32_t)mBuffer->readRawVarint();
	switch (read_wire_type(tag)) {
	case WIRE_TYPE_VARINT:
	while ((mBuffer->readRawByte() & 0x80) != 0) {}
	break;
	case WIRE_TYPE_FIXED64:
	mBuffer->ep()->move(8);
	break;
	case WIRE_TYPE_LENGTH_DELIMITED:
	mBuffer->copy(mCopyBegin, mBuffer->ep()->pos() - mCopyBegin);

	childRawSize = (int)mBuffer->readRawFixed32();
	childEncodedSize = (int)mBuffer->readRawFixed32();
	mCopyBegin = mBuffer->ep()->pos();

	// write encoded size to buffer.
	mBuffer->writeRawVarint32(childEncodedSize);
	if (childRawSize >= 0 && childRawSize == childEncodedSize) {
	mBuffer->ep()->move(childEncodedSize);
	} else if (childRawSize < 0){
	if (!compactSize(-childRawSize)) return false;
	} else {
	ALOGE("Bad raw or encoded values: raw=%d, encoded=%d",
	childRawSize, childEncodedSize);
	return false;
	}
	break;
	case WIRE_TYPE_FIXED32:
	mBuffer->ep()->move(4);
	break;
	default:
	ALOGE("Unexpected wire type %d in compactSize at [%zu, %zu]",
	read_wire_type(tag), objectStart, objectEnd);
	return false;
	}
	}
	return true;
	}

	size_t
	ProtoOutputStream::size()
	{
	if (!compact()) {
	ALOGE("compact failed, the ProtoOutputStream data is corrupted!");
	return 0;
	}
	return mBuffer->size();
	}

	bool
	ProtoOutputStream::flush(int fd)
	{
	if (fd < 0) return false;
	if (!compact()) return false;

	sp<ProtoReader> reader = mBuffer->read();
	while (reader->readBuffer() != NULL) {
	if (!android::base::WriteFully(fd, reader->readBuffer(), reader->currentToRead())) {
	return false;
	}
	reader->move(reader->currentToRead());
	}
	return true;
	}

	bool
	ProtoOutputStream::serializeToString(std::string* out)
	{
	if (out == nullptr) return false;
	if (!compact()) return false;

	sp<ProtoReader> reader = mBuffer->read();
	out->reserve(reader->size());
	while (reader->hasNext()) {
	out->append(static_cast<const char>(static_cast<const void>(reader->readBuffer())),
	reader->currentToRead());
	reader->move(reader->currentToRead());
	}
	return true;
	}

	bool
	ProtoOutputStream::serializeToVector(std::vector<uint8_t>* out)
	{
	if (out == nullptr) return false;
	if (!compact()) return false;

	sp<ProtoReader> reader = mBuffer->read();
	out->reserve(reader->size());
	while (reader->hasNext()) {
	const uint8_t* buf = reader->readBuffer();
	size_t size = reader->currentToRead();
	out->insert(out->end(), buf, buf + size);
	reader->move(size);
	}
	return true;
	}

	sp<ProtoReader>
	ProtoOutputStream::data()
	{
	if (!compact()) {
	ALOGE("compact failed, the ProtoOutputStream data is corrupted!");
	mBuffer->clear();
	}
	return mBuffer->read();
	}

	void
	ProtoOutputStream::writeRawVarint(uint64_t varint)
	{
	mBuffer->writeRawVarint64(varint);
	}

	void
	ProtoOutputStream::writeLengthDelimitedHeader(uint32_t id, size_t size)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_LENGTH_DELIMITED);
	// reserves 64 bits for length delimited fields, if first field is negative, compact it.
	mBuffer->writeRawFixed32(size);
	mBuffer->writeRawFixed32(size);
	}

	void
	ProtoOutputStream::writeRawByte(uint8_t byte)
	{
	mBuffer->writeRawByte(byte);
	}


	// =========================================================================
	// Private functions

	/**
	* bit_cast
	*/
	template <class From, class To>
	inline To bit_cast(From const &from) {
	To to;
	memcpy(&to, &from, sizeof(to));
	return to;
	}

	inline void
	ProtoOutputStream::writeDoubleImpl(uint32_t id, double val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_FIXED64);
	mBuffer->writeRawFixed64(bit_cast<double, uint64_t>(val));
	}

	inline void
	ProtoOutputStream::writeFloatImpl(uint32_t id, float val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_FIXED32);
	mBuffer->writeRawFixed32(bit_cast<float, uint32_t>(val));
	}

	inline void
	ProtoOutputStream::writeInt64Impl(uint32_t id, int64_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint64(val);
	}

	inline void
	ProtoOutputStream::writeInt32Impl(uint32_t id, int32_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint32(val);
	}

	inline void
	ProtoOutputStream::writeUint64Impl(uint32_t id, uint64_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint64(val);
	}

	inline void
	ProtoOutputStream::writeUint32Impl(uint32_t id, uint32_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint32(val);
	}

	inline void
	ProtoOutputStream::writeFixed64Impl(uint32_t id, uint64_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_FIXED64);
	mBuffer->writeRawFixed64(val);
	}

	inline void
	ProtoOutputStream::writeFixed32Impl(uint32_t id, uint32_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_FIXED32);
	mBuffer->writeRawFixed32(val);
	}

	inline void
	ProtoOutputStream::writeSFixed64Impl(uint32_t id, int64_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_FIXED64);
	mBuffer->writeRawFixed64(val);
	}

	inline void
	ProtoOutputStream::writeSFixed32Impl(uint32_t id, int32_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_FIXED32);
	mBuffer->writeRawFixed32(val);
	}

	inline void
	ProtoOutputStream::writeZigzagInt64Impl(uint32_t id, int64_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint64((val << 1) ^ (val >> 63));
	}

	inline void
	ProtoOutputStream::writeZigzagInt32Impl(uint32_t id, int32_t val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint32((val << 1) ^ (val >> 31));
	}

	inline void
	ProtoOutputStream::writeEnumImpl(uint32_t id, int val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint32((uint32_t) val);
	}

	inline void
	ProtoOutputStream::writeBoolImpl(uint32_t id, bool val)
	{
	mBuffer->writeHeader(id, WIRE_TYPE_VARINT);
	mBuffer->writeRawVarint32(val ? 1 : 0);
	}

	inline void
	ProtoOutputStream::writeUtf8StringImpl(uint32_t id, const char* val, size_t size)
	{
	if (val == NULL) return;
	writeLengthDelimitedHeader(id, size);
	for (size_t i=0; i<size; i++) {
	mBuffer->writeRawByte((uint8_t)val[i]);
	}
	}

	inline void
	ProtoOutputStream::writeMessageBytesImpl(uint32_t id, const char* val, size_t size)
	{
	if (val == NULL) return;
	writeLengthDelimitedHeader(id, size);
	for (size_t i=0; i<size; i++) {
	mBuffer->writeRawByte(val[i]);
	}
	}

	} // util
	} // android