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[FFI] Serialization To/From JSONGraph
This PR implements serialization function for generic ffi::Any based on the reflection that is preserves the overall object graph reference relation. These extra APIs are implemented through the reflection system. They can be used to further modernize and unify the serialization mechanisms in the project under the new reflection mechanism.
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‎ffi/CMakeLists.txt‎

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@@ -68,6 +68,7 @@ if (TVM_FFI_USE_EXTRA_CXX_API)
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"${CMAKE_CURRENT_SOURCE_DIR}/src/ffi/extra/structural_hash.cc"
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"${CMAKE_CURRENT_SOURCE_DIR}/src/ffi/extra/json_parser.cc"
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"${CMAKE_CURRENT_SOURCE_DIR}/src/ffi/extra/json_writer.cc"
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"${CMAKE_CURRENT_SOURCE_DIR}/src/ffi/extra/serialization.cc"
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)
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endif()
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‎ffi/include/tvm/ffi/extra/base64.h‎

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/*
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* Licensed to the Apache Software Foundation (ASF) under one
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* or more contributor license agreements. See the NOTICE file
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* distributed with this work for additional information
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* regarding copyright ownership. The ASF licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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/*!
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*
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* \file tvm/ffi/extra/base64.h
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* \brief Base64 encoding and decoding utilities
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*/
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#ifndef TVM_FFI_EXTRA_BASE64_H_
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#define TVM_FFI_EXTRA_BASE64_H_
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#include <tvm/ffi/string.h>
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#include <string>
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namespace tvm {
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namespace ffi {
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/*!
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* \brief Encode a byte array into a base64 string
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* \param bytes The byte array to encode
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* \return The base64 encoded string
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*/
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inline String Base64Encode(TVMFFIByteArray bytes) {
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// encoding every 3 bytes into 4 characters
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constexpr const char kEncodeTable[] =
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"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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std::string encoded;
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encoded.reserve(4 * (bytes.size + 2) / 3);
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for (size_t i = 0; i < (bytes.size / 3) * 3; i += 3) {
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int32_t buf[3];
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buf[0] = static_cast<int32_t>(bytes.data[i]);
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buf[1] = static_cast<int32_t>(bytes.data[i + 1]);
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buf[2] = static_cast<int32_t>(bytes.data[i + 2]);
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encoded.push_back(kEncodeTable[buf[0] >> 2]);
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encoded.push_back(kEncodeTable[((buf[0] << 4) | (buf[1] >> 4)) & 0x3F]);
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encoded.push_back(kEncodeTable[((buf[1] << 2) | (buf[2] >> 6)) & 0x3F]);
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encoded.push_back(kEncodeTable[buf[2] & 0x3F]);
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}
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if (bytes.size % 3 == 1) {
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int32_t buf[1] = {static_cast<int32_t>(bytes.data[bytes.size - 1])};
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encoded.push_back(kEncodeTable[buf[0] >> 2]);
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encoded.push_back(kEncodeTable[(buf[0] << 4) & 0x3F]);
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encoded.push_back('=');
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encoded.push_back('=');
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} else if (bytes.size % 3 == 2) {
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int32_t buf[2] = {static_cast<int32_t>(bytes.data[bytes.size - 2]),
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static_cast<int32_t>(bytes.data[bytes.size - 1])};
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encoded.push_back(kEncodeTable[buf[0] >> 2]);
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encoded.push_back(kEncodeTable[((buf[0] << 4) | (buf[1] >> 4)) & 0x3F]);
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encoded.push_back(kEncodeTable[(buf[1] << 2) & 0x3F]);
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encoded.push_back('=');
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}
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return String(encoded);
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}
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/*!
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* \brief Encode a bytes object into a base64 string
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* \param data The bytes object to encode
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* \return The base64 encoded string
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*/
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inline String Base64Encode(const Bytes& data) {
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return Base64Encode(TVMFFIByteArray{data.data(), data.size()});
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}
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/*!
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* \brief Decode a base64 string into a byte array
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* \param data The base64 encoded string to decode
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* \return The decoded byte array
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*/
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inline Bytes Base64Decode(TVMFFIByteArray bytes) {
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constexpr const char kDecodeTable[] = {
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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62, // '+'
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0, 0, 0,
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63, // '/'
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52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
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0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
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15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'
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0, 0, 0, 0, 0, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
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42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'
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};
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std::string decoded;
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decoded.reserve(bytes.size * 3 / 4);
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if (bytes.size == 0) return Bytes();
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TVM_FFI_ICHECK(bytes.size % 4 == 0) << "invalid base64 encoding";
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// leverage this property to simplify decoding
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static_assert('=' < sizeof(kDecodeTable) && kDecodeTable[static_cast<size_t>('=')] == 0);
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// base64 is always multiple of 4 bytes
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for (size_t i = 0; i < bytes.size; i += 4) {
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// decode every 4 characters into 24bits, each character contains 6 bits
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// note that = is also decoded as 0, which is safe to skip
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int32_t buf[4] = {
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static_cast<int32_t>(bytes.data[i]),
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static_cast<int32_t>(bytes.data[i + 1]),
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static_cast<int32_t>(bytes.data[i + 2]),
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static_cast<int32_t>(bytes.data[i + 3]),
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};
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int32_t value_i24 = (static_cast<int32_t>(kDecodeTable[buf[0]]) << 18) |
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(static_cast<int32_t>(kDecodeTable[buf[1]]) << 12) |
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(static_cast<int32_t>(kDecodeTable[buf[2]]) << 6) |
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static_cast<int32_t>(kDecodeTable[buf[3]]);
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// unpack 24bits into 3 bytes, each contains 8 bits
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decoded.push_back(static_cast<char>((value_i24 >> 16) & 0xFF));
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if (buf[2] != '=') {
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decoded.push_back(static_cast<char>((value_i24 >> 8) & 0xFF));
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}
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if (buf[3] != '=') {
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decoded.push_back(static_cast<char>(value_i24 & 0xFF));
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}
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}
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return Bytes(decoded);
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}
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/*!
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* \brief Decode a base64 string into a byte array
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* \param data The base64 encoded string to decode
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* \return The decoded byte array
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*/
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inline Bytes Base64Decode(const String& data) {
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return Base64Decode(TVMFFIByteArray{data.data(), data.size()});
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}
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} // namespace ffi
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} // namespace tvm
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#endif // TVM_FFI_EXTRA_BASE64_H_

‎ffi/include/tvm/ffi/extra/json.h‎

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* under the License.
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*/
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/*!
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* \file tvm/ffi/json/json.h
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* \file tvm/ffi/extra/json.h
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* \brief Minimal lightweight JSON parsing and serialization utilities
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*/
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#ifndef TVM_FFI_EXTRA_JSON_H_

‎ffi/include/tvm/ffi/extra/serialization.h‎

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/*
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* Licensed to the Apache Software Foundation (ASF) under one
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* or more contributor license agreements. See the NOTICE file
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* distributed with this work for additional information
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* regarding copyright ownership. The ASF licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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/*!
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* \file tvm/ffi/extra/serialization.h
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* \brief Reflection-based serialization utilities
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*/
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#ifndef TVM_FFI_EXTRA_SERIALIZATION_H_
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#define TVM_FFI_EXTRA_SERIALIZATION_H_
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#include <tvm/ffi/extra/base.h>
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#include <tvm/ffi/extra/json.h>
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namespace tvm {
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namespace ffi {
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/**
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* \brief Serialize ffi::Any to a JSON that stores the object graph.
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*
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* The JSON graph structure is stored as follows:
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*
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* ```json
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* {
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* "root_index": <int>, // Index of root node in nodes array
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* "nodes": [<node>, ...], // Array of serialized nodes
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* "metadata": <object> // Optional metadata
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* }
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* ```
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*
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* Each node has the format: `{"type": "<type_key>", "data": <type_data>}`
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* For object types and strings, the data may contain indices to other nodes.
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* For object fields whose static type is known as a primitive type, it is stored directly,
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* otherwise, it is stored as a reference to the nodes array by an index.
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*
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* This function preserves the type and multiple references to the same object,
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* which is useful for debugging and serialization.
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*
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* \param value The ffi::Any value to serialize.
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* \param metadata Extra metadata attached to "metadata" field of the JSON object.
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* \return The serialized JSON value.
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*/
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TVM_FFI_EXTRA_CXX_API json::Value ToJSONGraph(const Any& value, const Any& metadata = Any(nullptr));
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/**
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* \brief Deserialize a JSON that stores the object graph to an ffi::Any value.
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*
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* This function can be used to implement deserialization
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* and debugging.
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*
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* \param value The JSON value to deserialize.
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* \return The deserialized object graph.
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*/
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TVM_FFI_EXTRA_CXX_API Any FromJSONGraph(const json::Value& value);
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} // namespace ffi
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} // namespace tvm
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#endif // TVM_FFI_EXTRA_SERIALIZATION_H_

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