| // Copyright 2020 The Pigweed Authors |
| // |
| // 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 |
| // |
| // https://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. |
| #pragma once |
| |
| #include <cstdint> |
| |
| #include "pw_protobuf/wire_format.h" |
| #include "pw_varint/varint.h" |
| |
| namespace pw::protobuf { |
| |
| // Field types that directly map to fixed wire types: |
| inline constexpr size_t kMaxSizeBytesFixed32 = 4; |
| inline constexpr size_t kMaxSizeBytesFixed64 = 8; |
| inline constexpr size_t kMaxSizeBytesSfixed32 = 4; |
| inline constexpr size_t kMaxSizeBytesSfixed64 = 8; |
| inline constexpr size_t kMaxSizeBytesFloat = kMaxSizeBytesFixed32; |
| inline constexpr size_t kMaxSizeBytesDouble = kMaxSizeBytesFixed64; |
| |
| // Field types that map to varint: |
| inline constexpr size_t kMaxSizeBytesUint32 = varint::kMaxVarint32SizeBytes; |
| inline constexpr size_t kMaxSizeBytesUint64 = varint::kMaxVarint64SizeBytes; |
| inline constexpr size_t kMaxSizeBytesSint32 = varint::kMaxVarint32SizeBytes; |
| inline constexpr size_t kMaxSizeBytesSint64 = varint::kMaxVarint64SizeBytes; |
| // The int32 field type does not use zigzag encoding, ergo negative values |
| // can result in the worst case varint size. |
| inline constexpr size_t kMaxSizeBytesInt32 = varint::kMaxVarint64SizeBytes; |
| inline constexpr size_t kMaxSizeBytesInt64 = varint::kMaxVarint64SizeBytes; |
| // The bool field type is backed by a varint, but has a limited value range. |
| inline constexpr size_t kMaxSizeBytesBool = 1; |
| |
| inline constexpr size_t kMaxSizeBytesEnum = kMaxSizeBytesInt32; |
| |
| inline constexpr size_t kMaxSizeOfFieldNumber = varint::kMaxVarint32SizeBytes; |
| |
| inline constexpr size_t kMaxSizeOfLength = varint::kMaxVarint32SizeBytes; |
| |
| // Calculate the size of a proto field key in wire format, including the key |
| // field number + wire type. |
| // type). |
| // |
| // Args: |
| // field_number: The field number for the field. |
| // |
| // Returns: |
| // The size of the field key. |
| // |
| // Precondition: The field_number must be a ValidFieldNumber. |
| template <typename T> |
| constexpr size_t FieldNumberSizeBytes(T field_number) { |
| static_assert((std::is_enum<T>() || std::is_integral<T>()) && |
| sizeof(T) <= sizeof(uint32_t), |
| "Field numbers must be 32-bit enums or integers"); |
| // The wiretype does not impact the serialized size, so use kVarint (0), which |
| // will be optimized out by the compiler. |
| return varint::EncodedSize( |
| FieldKey(static_cast<uint32_t>(field_number), WireType::kVarint)); |
| } |
| |
| // Calculates the size of a varint field (uint32/64, int32/64, sint32/64, enum). |
| template <typename T, typename U> |
| constexpr size_t SizeOfVarintField(T field_number, U value) { |
| return FieldNumberSizeBytes(field_number) + varint::EncodedSize(value); |
| } |
| |
| // Calculates the size of a delimited field (string, bytes, nested message, |
| // packed repeated), excluding the data itself. This accounts for the field |
| // tag and length varint only. The default value for length_bytes assumes |
| // the length is kMaxSizeOfLength bytes long. |
| template <typename T> |
| constexpr size_t SizeOfDelimitedFieldWithoutValue( |
| T field_number, |
| uint32_t length_bytes = std::numeric_limits<uint32_t>::max()) { |
| return FieldNumberSizeBytes(field_number) + varint::EncodedSize(length_bytes); |
| } |
| |
| // Calculates the total size of a delimited field (string, bytes, nested |
| // message, packed repeated), including the data itself. |
| template <typename T> |
| constexpr size_t SizeOfDelimitedField(T field_number, uint32_t length_bytes) { |
| return SizeOfDelimitedFieldWithoutValue(field_number, length_bytes) + |
| length_bytes; |
| } |
| |
| // Calculates the size of a proto field in the wire format. This is the size of |
| // a final serialized protobuf entry, including the key (field number + wire |
| // type), encoded payload size (for length-delimited types), and data. |
| // |
| // Args: |
| // field_number: The field number for the field. |
| // type: The wire type of the field |
| // data_size: The size of the payload. |
| // |
| // Returns: |
| // The size of the field. |
| // |
| // Precondition: The field_number must be a ValidFieldNumber. |
| // Precondition: `data_size_bytes` must be smaller than |
| // std::numeric_limits<uint32_t>::max() |
| template <typename T> |
| constexpr size_t SizeOfField(T field_number, |
| WireType type, |
| size_t data_size_bytes) { |
| if (type == WireType::kDelimited) { |
| return SizeOfDelimitedField(field_number, data_size_bytes); |
| } |
| return FieldNumberSizeBytes(field_number) + data_size_bytes; |
| } |
| |
| // Functions for calculating the size of each type of protobuf field. Varint |
| // fields (int32, uint64, etc.) accept a value argument that defaults to the |
| // largest-to-encode value for the type. |
| template <typename T> |
| constexpr size_t SizeOfFieldFloat(T field_number) { |
| return FieldNumberSizeBytes(field_number) + sizeof(float); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldDouble(T field_number) { |
| return FieldNumberSizeBytes(field_number) + sizeof(double); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldInt32(T field_number, int32_t value = -1) { |
| return SizeOfVarintField(field_number, value); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldInt64(T field_number, int64_t value = -1) { |
| return SizeOfVarintField(field_number, value); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldSint32( |
| T field_number, int32_t value = std::numeric_limits<int32_t>::min()) { |
| return SizeOfVarintField(field_number, varint::ZigZagEncode(value)); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldSint64( |
| T field_number, int64_t value = std::numeric_limits<int64_t>::min()) { |
| return SizeOfVarintField(field_number, varint::ZigZagEncode(value)); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldUint32( |
| T field_number, uint32_t value = std::numeric_limits<uint32_t>::max()) { |
| return SizeOfVarintField(field_number, value); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldUint64( |
| T field_number, uint64_t value = std::numeric_limits<uint64_t>::max()) { |
| return SizeOfVarintField(field_number, value); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldFixed32(T field_number) { |
| return FieldNumberSizeBytes(field_number) + sizeof(uint32_t); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldFixed64(T field_number) { |
| return FieldNumberSizeBytes(field_number) + sizeof(uint64_t); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldSfixed32(T field_number) { |
| return FieldNumberSizeBytes(field_number) + sizeof(uint32_t); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldSfixed64(T field_number) { |
| return FieldNumberSizeBytes(field_number) + sizeof(uint64_t); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldBool(T field_number) { |
| return FieldNumberSizeBytes(field_number) + 1; |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldString(T field_number, uint32_t length_bytes) { |
| return SizeOfDelimitedField(field_number, length_bytes); |
| } |
| template <typename T> |
| constexpr size_t SizeOfFieldBytes(T field_number, uint32_t length_bytes) { |
| return SizeOfDelimitedField(field_number, length_bytes); |
| } |
| template <typename T, typename U = int32_t> |
| constexpr size_t SizeOfFieldEnum(T field_number, U value = static_cast<U>(-1)) { |
| static_assert((std::is_enum<U>() || std::is_integral<U>()) && |
| sizeof(U) <= sizeof(uint32_t), |
| "Enum values must be 32-bit enums or integers"); |
| return SizeOfFieldInt32(field_number, static_cast<int32_t>(value)); |
| } |
| |
| } // namespace pw::protobuf |