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| 1 | +// Copyright 2009-present MongoDB, Inc. |
| 2 | +// |
| 3 | +// Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | +// you may not use this file except in compliance with the License. |
| 5 | +// You may obtain a copy of the License at |
| 6 | +// |
| 7 | +// http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +// |
| 9 | +// Unless required by applicable law or agreed to in writing, software |
| 10 | +// distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | +// See the License for the specific language governing permissions and |
| 13 | +// limitations under the License. |
| 14 | + |
| 15 | +#include <algorithm> |
| 16 | +#include <cmath> |
| 17 | +#include <cstdlib> |
| 18 | +#include <iostream> |
| 19 | + |
| 20 | +#include <bsoncxx/builder/basic/document.hpp> |
| 21 | +#include <bsoncxx/builder/basic/kvp.hpp> |
| 22 | +#include <bsoncxx/builder/basic/sub_binary.hpp> |
| 23 | +#include <bsoncxx/json.hpp> |
| 24 | +#include <bsoncxx/types.hpp> |
| 25 | +#include <bsoncxx/vector/accessor.hpp> |
| 26 | +#include <bsoncxx/vector/formats.hpp> |
| 27 | + |
| 28 | +#include <examples/macros.hh> |
| 29 | + |
| 30 | +int EXAMPLES_CDECL main() { |
| 31 | + using bsoncxx::binary_sub_type; |
| 32 | + using bsoncxx::builder::basic::kvp; |
| 33 | + using bsoncxx::builder::basic::make_document; |
| 34 | + using bsoncxx::builder::basic::sub_binary; |
| 35 | + using bsoncxx::vector::accessor; |
| 36 | + using bsoncxx::vector::formats::f_float32; |
| 37 | + using bsoncxx::vector::formats::f_int8; |
| 38 | + using bsoncxx::vector::formats::f_packed_bit; |
| 39 | + |
| 40 | + bsoncxx::document::value doc = make_document( |
| 41 | + |
| 42 | + // |
| 43 | + // Added along with BSON Binary Vector support, the new sub_binary builder |
| 44 | + // allows allocating any type of BSON Binary item in-place. A callback taking |
| 45 | + // a sub_binary argument can calculate the required space before calling allocate() |
| 46 | + // on the sub_binary to get a pointer to the new in-place allocation. |
| 47 | + // |
| 48 | + // Every byte of the allocated binary region must be written or the resulting BSON |
| 49 | + // will have undefined contents. If allocate() isn't called exactly once, |
| 50 | + // an exception will be thrown. |
| 51 | + // |
| 52 | + kvp("binary", |
| 53 | + [&](sub_binary sbin) { |
| 54 | + uint32_t len = 10; |
| 55 | + uint8_t* data = sbin.allocate(binary_sub_type::k_binary, len); |
| 56 | + memset(data, 0x55, len); |
| 57 | + }), |
| 58 | + |
| 59 | + // |
| 60 | + // The sub_binary also provides an allocate() method for BSON Binary Vector. |
| 61 | + // Instead of a sub_type and byte length, this takes a vector format |
| 62 | + // and an element count. |
| 63 | + // |
| 64 | + // This example uses the f_int8 vector format, which has int8_t elements. |
| 65 | + // The allocate() call here returns a bsoncxx::vector::accessor instance |
| 66 | + // that works like a random access container but does not own memory directly. |
| 67 | + // |
| 68 | + kvp("vector_int8", |
| 69 | + [&](sub_binary sbin) { |
| 70 | + auto vec = sbin.allocate(f_int8{}, 10); |
| 71 | + int8_t i = -5; |
| 72 | + std::generate(vec.begin(), vec.end(), [&] { return ++i; }); |
| 73 | + }), |
| 74 | + |
| 75 | + // |
| 76 | + // BSON Binary Vector supports formats that do not map directly to C++ |
| 77 | + // built-in types. The f_float32 format is an unaligned little endian |
| 78 | + // serialization of IEEE 754 32-bit binary floating point. On some platforms, |
| 79 | + // this sort of data could be accessed using a raw float*, but for consistent |
| 80 | + // portability we have a bsoncxx::v_noabi::vector::elements::float32 type which |
| 81 | + // has the unaligned little-endian representation in memory but supports automatic |
| 82 | + // conversion to and from 'float'. |
| 83 | + // |
| 84 | + // The vector accessor works like a container of floats. Elements can be assigned |
| 85 | + // from float expressions or used as float expressions. Assignment operators |
| 86 | + // operate by automatically convering to float and then back to elements::float32. |
| 87 | + // |
| 88 | + kvp("vector_float32", |
| 89 | + [&](sub_binary sbin) { |
| 90 | + auto vec = sbin.allocate(f_float32{}, 10); |
| 91 | + // Calculate a fibonacci sequence starting near the smallest representable value |
| 92 | + vec[0] = 0.f; |
| 93 | + vec[1] = 1e-38f; |
| 94 | + for (size_t i = 2; i < vec.size(); i++) { |
| 95 | + vec[i] = vec[i - 1] + vec[i - 2]; |
| 96 | + } |
| 97 | + // Demonstrate assignment operators |
| 98 | + vec[0] += 1.f; |
| 99 | + vec[1] *= 1e38f; |
| 100 | + vec[1] /= 2.f; |
| 101 | + vec[1] -= 1.f + vec[0]; |
| 102 | + }), |
| 103 | + |
| 104 | + // |
| 105 | + // packed_bit vectors support any number of single-bit elements, |
| 106 | + // using an accessor that works like a random-access container of |
| 107 | + // bool values. This works using a reference-proxy type |
| 108 | + // bsoncxx::v_noabi::vector::elements::packed_bit_element and an iterator |
| 109 | + // bsoncxx::v_noabi::vector::iterators::packed_bit_element. |
| 110 | + // |
| 111 | + // Every bsoncxx::vector::accessor can be accessed either in per-element |
| 112 | + // or per-byte mode. Byte mode is particularly useful for applications that |
| 113 | + // may want to use packed_bit vectors in the serialized format without |
| 114 | + // accessing individual elements. |
| 115 | + // |
| 116 | + kvp("vector_packed_bit", [&](sub_binary sbin) { |
| 117 | + auto vec = sbin.allocate(f_packed_bit{}, 61); |
| 118 | + // Start by setting all bits to 1 |
| 119 | + std::fill(vec.begin(), vec.end(), true); |
| 120 | + // Flip a bit using a boolean expression |
| 121 | + vec[5] = !vec[5]; |
| 122 | + // Assignment of a packed_bit_element reference copies the referenced bit value |
| 123 | + vec[6] = vec[1]; |
| 124 | + vec[7] = vec[5]; |
| 125 | + // Bits can be assigned from boolean expressions, and from zero. |
| 126 | + vec[8] = 0; |
| 127 | + vec[60] = false; |
| 128 | + // Demonstrate addressing bits backward from the end of the vector |
| 129 | + std::fill(vec.end() - 20, vec.end() - 4, false); |
| 130 | + std::fill(vec.end() - 8, vec.end() - 5, true); |
| 131 | + // Flip all bits, operating an entire byte at a time. |
| 132 | + // The last byte will have bits that do not correspond to any elements, and writes to these are ignored. |
| 133 | + for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) { |
| 134 | + *i ^= 0xFF; |
| 135 | + } |
| 136 | + // Demonstrate copying bit ranges and byte ranges using std::copy |
| 137 | + std::copy(vec.byte_begin(), vec.byte_begin() + 2, vec.byte_begin() + 2); |
| 138 | + std::copy(vec.begin() + 5, vec.begin() + 9, vec.begin() + 56); |
| 139 | + })); |
| 140 | + |
| 141 | + // Demonstrate extended JSON serialization of the entire document |
| 142 | + std::cout << bsoncxx::to_json(doc) << std::endl; |
| 143 | + |
| 144 | + // Iterate over elements in the int8 vector |
| 145 | + { |
| 146 | + accessor<f_int8 const> vec{doc["vector_int8"].get_binary()}; |
| 147 | + std::cout << "int8: " << vec.size() << std::endl; |
| 148 | + for (auto&& i : vec) { |
| 149 | + std::cout << int{i} << " "; |
| 150 | + } |
| 151 | + std::cout << std::endl; |
| 152 | + } |
| 153 | + |
| 154 | + // Iterate over bytes in the int8 vector |
| 155 | + { |
| 156 | + accessor<f_int8 const> vec{doc["vector_int8"].get_binary()}; |
| 157 | + std::cout << "int8 bytes: " << vec.byte_size() << std::hex << std::endl; |
| 158 | + for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) { |
| 159 | + std::cout << int{*i} << " "; |
| 160 | + } |
| 161 | + std::cout << std::dec << std::endl; |
| 162 | + } |
| 163 | + |
| 164 | + // Iterate over elements in the float32 vector |
| 165 | + { |
| 166 | + accessor<f_float32 const> vec{doc["vector_float32"].get_binary()}; |
| 167 | + std::cout << "float32: " << vec.size() << std::endl; |
| 168 | + for (auto&& i : vec) { |
| 169 | + std::cout << i << " "; |
| 170 | + } |
| 171 | + std::cout << std::endl; |
| 172 | + } |
| 173 | + |
| 174 | + // Iterate over bytes in the float32 vector |
| 175 | + { |
| 176 | + accessor<f_float32 const> vec{doc["vector_float32"].get_binary()}; |
| 177 | + std::cout << "float32 bytes: " << vec.byte_size() << std::hex << std::endl; |
| 178 | + for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) { |
| 179 | + std::cout << int{*i} << " "; |
| 180 | + } |
| 181 | + std::cout << std::dec << std::endl; |
| 182 | + } |
| 183 | + |
| 184 | + // Iterate over elements in the packed_bit vector |
| 185 | + { |
| 186 | + accessor<f_packed_bit const> vec{doc["vector_packed_bit"].get_binary()}; |
| 187 | + std::cout << "packed_bit: " << vec.size() << std::endl; |
| 188 | + for (auto&& i : vec) { |
| 189 | + std::cout << i << " "; |
| 190 | + } |
| 191 | + std::cout << std::endl; |
| 192 | + } |
| 193 | + |
| 194 | + // Iterate over bytes in the packed_bit vector |
| 195 | + { |
| 196 | + accessor<f_packed_bit const> vec{doc["vector_packed_bit"].get_binary()}; |
| 197 | + std::cout << "packed_bit bytes: " << vec.byte_size() << std::hex << std::endl; |
| 198 | + for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) { |
| 199 | + std::cout << int{*i} << " "; |
| 200 | + } |
| 201 | + std::cout << std::dec << std::endl; |
| 202 | + } |
| 203 | + |
| 204 | + return 0; |
| 205 | +} |
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