e2sim/e2apv1sim/src/ASN1/asn/per/visitor.hpp

   1 #pragma once
   2 /******************************************************************************
   3 *
   4 *   Copyright (c) 2019 AT&T Intellectual Property.
   5 *   Copyright (c) 2018-2019 Nokia.
   6 *
   7 *   Licensed under the Apache License, Version 2.0 (the "License");
   8 *   you may not use this file except in compliance with the License.
   9 *   You may obtain a copy of the License at
  10 *
  11 *       http://www.apache.org/licenses/LICENSE-2.0
  12 *
  13 *   Unless required by applicable law or agreed to in writing, software
  14 *   distributed under the License is distributed on an "AS IS" BASIS,
  15 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16 *   See the License for the specific language governing permissions and
  17 *   limitations under the License.
  18 *
  19 ******************************************************************************/
  20
  21 // Standard Includes: ANSI C/C++, MSA, and Third-Party Libraries
  22
  23 // Local Includes: Application specific classes, functions, and libraries
  24 #include "asn/per/common.hpp"
  25
  26 namespace asn {
  27 namespace per {
  28
  29 /********************************************************************************
  30 VisitorEncoder
  31 *********************************************************************************/
  32 struct VisitorEncoder
  33 {
  34         explicit VisitorEncoder(EncoderCtx& ctx) : m_ctx(ctx) {}
  35
  36         template <typename IE>
  37         bool operator() (IE const& ie) const
  38         {
  39                 Element<IE, IE::ie_type>::run(ie, m_ctx);
  40                 return static_cast<bool>(m_ctx);
  41         }
  42         EncoderCtx&             m_ctx;
  43 };
  44
  45 /********************************************************************************
  46 VisitorDecoder
  47 *********************************************************************************/
  48 struct VisitorDecoder
  49 {
  50         VisitorDecoder(DecoderCtx& ctx) : m_ctx(ctx) {}
  51
  52         template <typename IE>
  53         bool operator() (IE& ie) const
  54         {
  55                 Element<IE, IE::ie_type>::run(ie, m_ctx);
  56                 return static_cast<bool>(m_ctx);
  57         }
  58         DecoderCtx& m_ctx;
  59 };
  60
  61 /***************************************************************************************
  62 * Open Type Visitor // Encode Open Type (10.2)
  63 ***************************************************************************************/
  64 struct OpenTypeVisitorEncoder
  65 {
  66         explicit OpenTypeVisitorEncoder(EncoderCtx& ctx) : m_ctx(ctx) {}
  67
  68         template <typename IE>
  69         bool operator() (IE const& ie) const
  70         {
  71                 size_t reserved_size = 1; //1 byte length is most likely
  72                 Tools::bit_accessor::padByte(m_ctx.refBuffer());
  73
  74                 if (m_ctx.refBuffer().getBytesLeft())
  75                 {
  76                         EncoderCtx::buf_type::pointer p = m_ctx.refBuffer().advance(reserved_size);
  77                         EncoderCtx::buf_type::pointer start = p + reserved_size;
  78
  79                         Element<IE, IE::ie_type>::run(ie, m_ctx);
  80
  81                         if (m_ctx)
  82                         {
  83                                 Tools::bit_accessor::padByte(m_ctx.refBuffer());
  84                                 EncoderCtx::buf_type::pointer p_new = m_ctx.refBuffer().begin();
  85                                 size_t size = p_new - start;
  86                                 size_t needed = LengthDeterminantDefault::bytes_needed(size) - reserved_size;
  87                                 if (needed) //1 byte is not enough for the length determinant. it is hardly possible
  88                                 {
  89                                         if (m_ctx.refBuffer().getBytesLeft() < needed) {
  90                                                 m_ctx.refErrorCtx().lengthErrorBytes(m_ctx.refBuffer().getBytesLeft(), needed);
  91                                                 return false;
  92                                         }
  93                                         memmove(start + needed, start, size);
  94                                         p_new += needed;
  95                                 }
  96                                 m_ctx.refBuffer().set_begin(p, 0);
  97                                 LengthDeterminantDefault::run(m_ctx, size);
  98                                 if (m_ctx) {
  99                                         m_ctx.refBuffer().set_begin(p_new, 0);
 100                                         Tools::bit_accessor::padByte(m_ctx.refBuffer());
 101                                 }
 102                         }
 103                 }
 104                 else
 105                 {
 106                         m_ctx.refErrorCtx().lengthErrorBytes(m_ctx.refBuffer().getBytesLeft(), reserved_size);
 107                 }
 108                 return static_cast<bool>(m_ctx);
 109         }
 110         EncoderCtx& m_ctx;
 111 };
 112
 113 /***************************************************************************************
 114 * Open Type Visitor // Decode Open Type (10.2)
 115 ***************************************************************************************/
 116 struct OpenTypeVisitorDecoder
 117 {
 118         explicit OpenTypeVisitorDecoder(DecoderCtx& ctx) : m_ctx(ctx) {}
 119
 120         template <typename IE>
 121         bool operator() (IE& ie) const
 122         {
 123                 size_t size = LengthDeterminantDefault::run(m_ctx);
 124                 DecoderCtx::buf_type& buffer = m_ctx.refBuffer();
 125                 if (buffer.getBytesLeft() < size)
 126                 {
 127                         m_ctx.refErrorCtx().lengthErrorBytes(buffer.getBytesLeft(), size);
 128                         return false;
 129                 }
 130                 DecoderCtx::buf_type::pointer end = buffer.end();
 131                 buffer.set_end(buffer.begin() + size);
 132                 Element<IE, IE::ie_type>::run(ie, m_ctx);
 133                 buffer.set_end(end);
 134
 135                 return static_cast<bool>(m_ctx);
 136         }
 137         DecoderCtx& m_ctx;
 138 };
 139
 140 } //namespace per
 141 } //namespace asn