62 lines
1.8 KiB
C++
62 lines
1.8 KiB
C++
// Copyright 2016 The Draco Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// 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, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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#ifndef DRACO_CORE_VARINT_ENCODING_H_
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#define DRACO_CORE_VARINT_ENCODING_H_
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#include <type_traits>
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#include "draco/core/bit_utils.h"
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#include "draco/core/encoder_buffer.h"
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namespace draco {
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// Encodes a specified integer as varint. Note that different coding is used
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// when IntTypeT is an unsigned data type.
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template <typename IntTypeT>
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bool EncodeVarint(IntTypeT val, EncoderBuffer *out_buffer) {
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if (std::is_unsigned<IntTypeT>::value) {
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// Coding of unsigned values.
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// 0-6 bit - data
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// 7 bit - next byte?
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uint8_t out = 0;
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out |= val & ((1 << 7) - 1);
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if (val >= (1 << 7)) {
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out |= (1 << 7);
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if (!out_buffer->Encode(out)) {
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return false;
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}
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if (!EncodeVarint<IntTypeT>(val >> 7, out_buffer)) {
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return false;
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}
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return true;
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}
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if (!out_buffer->Encode(out)) {
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return false;
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}
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} else {
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// IntTypeT is a signed value. Convert to unsigned symbol and encode.
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const typename std::make_unsigned<IntTypeT>::type symbol =
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ConvertSignedIntToSymbol(val);
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if (!EncodeVarint(symbol, out_buffer)) {
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return false;
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}
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}
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return true;
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}
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} // namespace draco
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#endif // DRACO_CORE_VARINT_ENCODING_H_
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