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// Copyright 2009-present MongoDB, Inc.
//
// 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
//
// http://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.
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <iostream>
#include <bsoncxx/builder/basic/document.hpp>
#include <bsoncxx/builder/basic/kvp.hpp>
#include <bsoncxx/builder/basic/sub_binary.hpp>
#include <bsoncxx/json.hpp>
#include <bsoncxx/types.hpp>
#include <bsoncxx/vector/accessor.hpp>
#include <bsoncxx/vector/formats.hpp>
#include <examples/macros.hh>
int EXAMPLES_CDECL main() {
using bsoncxx::binary_sub_type;
using bsoncxx::builder::basic::kvp;
using bsoncxx::builder::basic::make_document;
using bsoncxx::builder::basic::sub_binary;
using bsoncxx::vector::accessor;
using bsoncxx::vector::formats::f_float32;
using bsoncxx::vector::formats::f_int8;
using bsoncxx::vector::formats::f_packed_bit;
bsoncxx::document::value doc = make_document(
//
// Added along with BSON Binary Vector support, the new sub_binary builder
// allows allocating any type of BSON Binary item in-place. A callback taking
// a sub_binary argument can calculate the required space before calling allocate()
// on the sub_binary to get a pointer to the new in-place allocation.
//
// Every byte of the allocated binary region must be written or the resulting BSON
// will have undefined contents. If allocate() isn't called exactly once,
// an exception will be thrown.
//
kvp("binary",
[&](sub_binary sbin) {
uint32_t len = 10;
uint8_t* data = sbin.allocate(binary_sub_type::k_binary, len);
memset(data, 0x55, len);
}),
//
// The sub_binary also provides an allocate() method for BSON Binary Vector.
// Instead of a sub_type and byte length, this takes a vector format
// and an element count.
//
// This example uses the f_int8 vector format, which has int8_t elements.
// The allocate() call here returns a bsoncxx::vector::accessor instance
// that works like a random access container but does not own memory directly.
//
kvp("vector_int8",
[&](sub_binary sbin) {
auto vec = sbin.allocate(f_int8{}, 10);
int8_t i = -5;
std::generate(vec.begin(), vec.end(), [&] { return ++i; });
}),
//
// BSON Binary Vector supports formats that do not map directly to C++
// built-in types. The f_float32 format is an unaligned little endian
// serialization of IEEE 754 32-bit binary floating point. On some platforms,
// this sort of data could be accessed using a raw float*, but for consistent
// portability we have a bsoncxx::v_noabi::vector::elements::float32 type which
// has the unaligned little-endian representation in memory but supports automatic
// conversion to and from 'float'.
//
// The vector accessor works like a container of floats. Elements can be assigned
// from float expressions or used as float expressions. Assignment operators
// operate by automatically convering to float and then back to elements::float32.
//
kvp("vector_float32",
[&](sub_binary sbin) {
auto vec = sbin.allocate(f_float32{}, 10);
// Calculate a fibonacci sequence starting near the smallest representable value
vec[0] = 0.f;
vec[1] = 1e-38f;
for (size_t i = 2; i < vec.size(); i++) {
vec[i] = vec[i - 1] + vec[i - 2];
}
// Demonstrate assignment operators
vec[0] += 1.f;
vec[1] *= 1e38f;
vec[1] /= 2.f;
vec[1] -= 1.f + vec[0];
}),
//
// packed_bit vectors support any number of single-bit elements,
// using an accessor that works like a random-access container of
// bool values. This works using a reference-proxy type
// bsoncxx::v_noabi::vector::elements::packed_bit_element and an iterator
// bsoncxx::v_noabi::vector::iterators::packed_bit_element.
//
// Every bsoncxx::vector::accessor can be accessed either in per-element
// or per-byte mode. Byte mode is particularly useful for applications that
// may want to use packed_bit vectors in the serialized format without
// accessing individual elements.
//
kvp("vector_packed_bit", [&](sub_binary sbin) {
auto vec = sbin.allocate(f_packed_bit{}, 61);
// Start by setting all bits to 1
std::fill(vec.begin(), vec.end(), true);
// Flip a bit using a boolean expression
vec[5] = !vec[5];
// Assignment of a packed_bit_element reference copies the referenced bit value
vec[6] = vec[1];
vec[7] = vec[5];
// Bits can be assigned from boolean expressions, and from zero.
vec[8] = 0;
vec[60] = false;
// Demonstrate addressing bits backward from the end of the vector
std::fill(vec.end() - 20, vec.end() - 4, false);
std::fill(vec.end() - 8, vec.end() - 5, true);
// Flip all bits, operating an entire byte at a time.
// The last byte will have bits that do not correspond to any elements, and writes to these are ignored.
for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) {
*i ^= 0xFF;
}
// Demonstrate copying bit ranges and byte ranges using std::copy
std::copy(vec.byte_begin(), vec.byte_begin() + 2, vec.byte_begin() + 2);
std::copy(vec.begin() + 5, vec.begin() + 9, vec.begin() + 56);
}));
// Demonstrate extended JSON serialization of the entire document
std::cout << bsoncxx::to_json(doc) << std::endl;
// Iterate over elements in the int8 vector
{
accessor<f_int8 const> vec{doc["vector_int8"].get_binary()};
std::cout << "int8: " << vec.size() << std::endl;
for (auto&& i : vec) {
std::cout << int{i} << " ";
}
std::cout << std::endl;
}
// Iterate over bytes in the int8 vector
{
accessor<f_int8 const> vec{doc["vector_int8"].get_binary()};
std::cout << "int8 bytes: " << vec.byte_size() << std::hex << std::endl;
for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) {
std::cout << int{*i} << " ";
}
std::cout << std::dec << std::endl;
}
// Iterate over elements in the float32 vector
{
accessor<f_float32 const> vec{doc["vector_float32"].get_binary()};
std::cout << "float32: " << vec.size() << std::endl;
for (auto&& i : vec) {
std::cout << i << " ";
}
std::cout << std::endl;
}
// Iterate over bytes in the float32 vector
{
accessor<f_float32 const> vec{doc["vector_float32"].get_binary()};
std::cout << "float32 bytes: " << vec.byte_size() << std::hex << std::endl;
for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) {
std::cout << int{*i} << " ";
}
std::cout << std::dec << std::endl;
}
// Iterate over elements in the packed_bit vector
{
accessor<f_packed_bit const> vec{doc["vector_packed_bit"].get_binary()};
std::cout << "packed_bit: " << vec.size() << std::endl;
for (auto&& i : vec) {
std::cout << i << " ";
}
std::cout << std::endl;
}
// Iterate over bytes in the packed_bit vector
{
accessor<f_packed_bit const> vec{doc["vector_packed_bit"].get_binary()};
std::cout << "packed_bit bytes: " << vec.byte_size() << std::hex << std::endl;
for (auto i = vec.byte_begin(); i != vec.byte_end(); i++) {
std::cout << int{*i} << " ";
}
std::cout << std::dec << std::endl;
}
return 0;
}
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