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-rw-r--r--example/multi_index.cpp433
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diff --git a/example/multi_index.cpp b/example/multi_index.cpp
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--- a/example/multi_index.cpp
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-//
-// Copyright (c) 2022 Klemens Morgenstern (klemens.morgenstern@gmx.net)
-//
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//
-
-#include <boost/sqlite.hpp>
-#include <boost/multi_index_container.hpp>
-#include <boost/multi_index/ordered_index.hpp>
-#include <boost/multi_index/key.hpp>
-#include <boost/optional.hpp>
-#include <algorithm>
-#include <iostream>
-
-using namespace boost;
-
-namespace mi = boost::multi_index;
-
-struct boost_library
-{
- std::string name, version;
-};
-
-using my_container = mi::multi_index_container<
- boost_library,
- mi::indexed_by<
- mi::ordered_unique<mi::key<&boost_library::name>>,
- mi::ordered_non_unique<mi::key<&boost_library::version>>
- >
->;
-
-
-struct multi_index_cursor final
- : sqlite::vtab::cursor<sqlite::string_view>
-{
- my_container &data;
-
- multi_index_cursor(my_container &data) : data(data) {}
- bool inverse = false;
- int index = 0;
- using const_iterator = typename my_container::const_iterator;
- using const_iterator1 = typename my_container::nth_index_const_iterator<0>::type;
- using const_iterator2 = typename my_container::nth_index_const_iterator<1>::type;
-
- const_iterator begin{data.begin()}, end{data.end()};
- const_iterator1 begin1 = data.get<0>().cbegin(), end1 = data.get<0>().cend();
- const_iterator2 begin2 = data.get<1>().cbegin(), end2 = data.get<1>().cend();
-
- sqlite::result<void> next()
- {
- switch (index)
- {
- case 0: inverse ? end-- : begin++; break;
- case 1: inverse ? end1-- : begin1++; break;
- case 2: inverse ? end2-- : begin2++; break;
- }
- return {};
- }
-
- sqlite::result<sqlite3_int64> row_id()
- {
- static_assert(sizeof(const_iterator) <= sizeof(sqlite3_int64), "");
-
- switch (index)
- {
- case 0: return reinterpret_cast<sqlite3_int64>(inverse ? &*std::prev(end ) : &*begin);
- case 1: return reinterpret_cast<sqlite3_int64>(inverse ? &*std::prev(end1) : &*begin1);
- case 2: return reinterpret_cast<sqlite3_int64>(inverse ? &*std::prev(end2) : &*begin2);
- }
-
- return sqlite3_int64();
- }
- sqlite::result<sqlite::string_view> column(int i, bool /*nochange*/)
- {
- const boost_library * lib;
- switch (index)
- {
- case 0: lib = &(inverse ? *std::prev(end) : *begin); break;
- case 1: lib = &(inverse ? *std::prev(end1) : *begin1); break;
- case 2: lib = &(inverse ? *std::prev(end2) : *begin2); break;
- }
-
- const auto & elem = *lib;
- if (i == 0)
- return elem.name;
- else
- return elem.version;
- }
-
-
- sqlite::result<void> filter(int idx, const char * idxStr, span<sqlite::value> values)
- {
- inverse = (idx == 0b1000) & idx;
- index = idx & 0b11;
-
- boost::optional<sqlite::cstring_ref> lower, upper, equal;
- int lower_op = 0, upper_op = 0;
-
- bool surely_empty = false;
-
- for (auto i = 0u; i < values.size(); i++)
- {
- auto txt = values[i].get_text();
- switch (idxStr[i])
- {
- case SQLITE_INDEX_CONSTRAINT_EQ:
- if (equal && (*equal != txt))
- // two different equal constraints do that to you.
- surely_empty = true;
- else
- equal.emplace(txt);
- break;
- case SQLITE_INDEX_CONSTRAINT_GT:
- case SQLITE_INDEX_CONSTRAINT_GE:
- if (lower == txt)
- {
- // pick the more restrictive one
- if (lower_op == SQLITE_INDEX_CONSTRAINT_GE)
- lower_op = idxStr[i];
- }
- else
- {
- lower = (std::max)(lower.value_or(txt), txt);
- lower_op = idxStr[i];
- }
-
- break;
- case SQLITE_INDEX_CONSTRAINT_LE:
- case SQLITE_INDEX_CONSTRAINT_LT:
- if (upper == txt)
- {
- if (upper_op == SQLITE_INDEX_CONSTRAINT_LT)
- upper_op = idxStr[i];
- }
- else
- {
- upper = (std::min)(upper.value_or(txt), txt);
- upper_op = idxStr[i];
- }
- break;
- }
- }
-
- if (lower && equal && lower > equal)
- surely_empty = true;
-
- if (upper && equal && upper < equal)
- surely_empty = true;
- if (surely_empty)
- {
- end = begin;
- end1 = begin1;
- end2 = begin2;
- return {};
- }
-
- switch (index)
- {
- default: break;
- case 1:
- if (equal)
- std::tie(begin1, end1) = data.get<0>().equal_range(*equal);
- else
- {
- if (lower)
- {
- if (lower_op == SQLITE_INDEX_CONSTRAINT_GE)
- begin1 = data.get<0>().lower_bound(*lower);
- else // SQLITE_INDEX_CONSTRAINT_GT
- begin1 = data.get<0>().upper_bound(*lower);
- }
- if (upper)
- {
- if (upper_op == SQLITE_INDEX_CONSTRAINT_LE)
- end1 = data.get<0>().upper_bound(*upper);
- else // SQLITE_INDEX_CONSTRAINT_LT
- end1 = data.get<0>().lower_bound(*upper);
- }
- break;
- case 2:
- if (equal)
- std::tie(begin2, end2) = data.get<1>().equal_range(*equal);
- else
- {
- if (lower)
- {
- if (lower_op == SQLITE_INDEX_CONSTRAINT_GE)
- begin2 = data.get<1>().lower_bound(*lower);
- else // SQLITE_INDEX_CONSTRAINT_GT
- begin2 = data.get<1>().upper_bound(*lower);
- }
-
- if (upper)
- {
- if (upper_op == SQLITE_INDEX_CONSTRAINT_LE)
- end2 = data.get<1>().upper_bound(*upper);
- else // SQLITE_INDEX_CONSTRAINT_LT
- end2 = data.get<1>().lower_bound(*upper);
- }
- }
- break;
- }
- }
- return {};
- }
-
- bool eof() noexcept
- {
- switch (index)
- {
- case 0: return begin == end;
- case 1: return begin1 == end1;
- case 2: return begin2 == end2;
- default: return true;
- }
- }
-};
-
-struct map_impl final
- : sqlite::vtab::table<multi_index_cursor>,
- sqlite::vtab::modifiable
-{
- my_container data;
- const char * declaration() override
- {
- return R"(
- create table url(
- name text primary key unique not null,
- version text);)";
- }
- enum indices // 32
- {
- no_index = 0b00000000,
- equal = 0b00000001,
- gt = 0b00000100,
- ge = 0b00001100,
- lt = 0000010000,
- le = 0b00110000,
- order_asc = 0b01000000,
- order_desc = 0b10000000,
- };
-
- sqlite::result<cursor_type> open() override
- {
- return cursor_type(data);
- }
-
- sqlite::result<void> delete_(sqlite::value key) override
- {
- data.erase(key.get_text());
- return {};
- }
- sqlite::result<sqlite_int64> insert(sqlite::value /*key*/, span<sqlite::value> values,
- int /*on_conflict*/) override
- {
- data.insert({values[0].get_text(), values[1].get_text()});
- return 0;
- }
-
- sqlite::result<sqlite_int64> update(sqlite::value old_key, sqlite::value new_key,
- span<sqlite::value> values, int /*on_conflict*/) override
- {
- if (new_key.get_int() != old_key.get_int())
- {
-
- auto node = reinterpret_cast<my_container::value_type *>(old_key.get_int());
- data.erase(data.iterator_to(*node));
- }
-
- auto res = data.insert({values[0].get_text(), values[1].get_text()});
- if (!res.second)
- data.replace(res.first, {values[0].get_text(), values[1].get_text()});
- return 0;
- }
-
- sqlite::result<void> best_index(sqlite::vtab::index_info & info) override
- {
- // we're using the index to encode the mode, because it's simple enough.
- // more complex application should use it as an index like intended
-
- int idx = 0;
- int idx_res = 0;
- sqlite::unique_ptr<char[]> str;
- // idx = 1 => name
- // idx = 2 => version
- if (!info.constraints().empty())
- {
- auto sz = info.constraints().size() + 1u;
- str.reset(new (sqlite::memory_tag{}) char[sz]);
- std::memset(str.get(), '\0', sz);
- }
-
- for (auto & ct : info.constraints())
- {
- if (idx_res == 0) // if we're first, set the thing
- idx_res = (ct.iColumn + 1);
- // check if we're already building an index
- if (idx_res != (ct.iColumn + 1)) // wrong column, ignore.
- continue;
- if ( ct.usable != 0 ) // aye, that's us
- {
- switch (ct.op)
- {
- // we'll stick to these
- case SQLITE_INDEX_CONSTRAINT_EQ: BOOST_FALLTHROUGH;
- case SQLITE_INDEX_CONSTRAINT_GT: BOOST_FALLTHROUGH;
- case SQLITE_INDEX_CONSTRAINT_GE: BOOST_FALLTHROUGH;
- case SQLITE_INDEX_CONSTRAINT_LE: BOOST_FALLTHROUGH;
- case SQLITE_INDEX_CONSTRAINT_LT:
- str[idx] = ct.op;
- info.usage_of(ct).argvIndex = ++idx; // use it -> value in this position in `filter`.
- info.usage_of(ct).omit = 1; // tell sqlite that we're sure enough, so sqlite doesn't check
- break;
- default:
- break;
- }
- }
- }
-
- if (info.order_by().size() == 1u)
- {
- if ((info.order_by()[0].iColumn == 0)
- || (idx == 0) || (idx == 1))
- {
- info.set_already_ordered();
- if (info.order_by()[0].desc != 0)
- idx |= 0b1001; // encode inversion, because why not ?
- }
- else if ((info.order_by()[0].iColumn == 0) || (idx == 0) || (idx == 2))
- {
- info.set_already_ordered();
- if (info.order_by()[0].desc)
- idx |= 0b1010; // encode inversion, because why not ?
- }
- }
- info.set_index(idx_res);
- if (str)
- info.set_index_string(str.release(), true);
- return {};
- }
-};
-
-struct multi_index_map final : sqlite::vtab::eponymous_module<map_impl>
-{
- sqlite::result<map_impl> connect(sqlite::connection, int, const char * const *)
- {
- return map_impl{};
- }
-};
-
-
-std::initializer_list<std::tuple<std::string, std::string>> data = {
- {"atomic", "1.53.0"},
- {"chrono", "1.47.0"},
- {"container", "1.48.0"},
- {"context", "1.51.0"},
- {"contract", "1.67.0"},
- {"coroutine", "1.53.0"},
- {"date_time", "1.29.0"},
- {"exception", "1.36.0"},
- {"fiber", "1.62.0"},
- {"filesystem", "1.30.0"},
- {"graph", "1.18.0"},
- {"graph_parallel", "1.40.0"},
- {"headers", "1.00.0"},
- {"iostreams", "1.33.0"},
- {"json", "1.75.0"},
- {"locale", "1.48.0"},
- {"log", "1.54.0"},
- {"math", "1.23.0"},
- {"mpi", "1.35.0"},
- {"nowide", "1.73.0"},
- {"program_options", "1.32.0"},
- {"python", "1.19.0"},
- {"random", "1.15.0"},
- {"regex", "1.18.0"},
- {"serialization", "1.32.0"},
- {"stacktrace", "1.65.0"},
- {"system", "1.35.0"},
- {"test", "1.21.0"},
- {"thread", "1.25.0"},
- {"timer", "1.9.0"},
- {"type_erasure", "1.54.0"},
- {"url", "1.81.0"},
- {"wave", "1.33.0"}
-};
-
-void print(std::ostream & os, sqlite::resultset rw, boost::source_location loc = BOOST_CURRENT_LOCATION)
-{
- os << loc.file_name() << "(" << loc.line() << "): ";
- os << "[";
- for (auto & r : rw)
- os << r.at(0).get_text() << ", ";
- os << "]" << std::endl;
-}
-
-int main (int /*argc*/, char * /*argv*/[])
-{
- sqlite::connection conn{":memory:"};
- auto & m = sqlite::create_module(conn, "my_map", multi_index_map());
- boost::ignore_unused(m);
-
- {
- auto p = conn.prepare("insert into my_map (name, version) values (?, ?);");
- for (const auto & d : ::data)
- p.execute(d);
- }
-
- print(std::cout, conn.query("select * from my_map order by name desc;"));
- print(std::cout, conn.query("select * from my_map where name = 'url';"));
- print(std::cout, conn.query("select * from my_map where name < 'url';"));
- print(std::cout, conn.query("select * from my_map where name >= 'system' ;"));
- print(std::cout, conn.query("select * from my_map where name >= 'system' and name < 'url' ;"));
- print(std::cout, conn.query("select * from my_map where name > 'system' and name <= 'url' ;"));
- print(std::cout, conn.query("select * from my_map where name > 'json';"));
- print(std::cout, conn.query("select * from my_map where name >= 'json';"));
- print(std::cout, conn.query("select * from my_map where name < 'json';"));
-
- print(std::cout, conn.query("select * from my_map where name == 'json' order by name asc;"));
- print(std::cout, conn.query("select * from my_map where name == 'json' and name == 'url';"));
- print(std::cout, conn.query("select * from my_map where name == 'json' order by name desc;"));
-
- print(std::cout, conn.query("select * from my_map where name < 'url' and name >= 'system' order by name desc;"));
- print(std::cout, conn.query("select * from my_map where version == '1.81.0';"));
-
- print(std::cout, conn.query("select * from my_map where version > '1.32.0' order by version desc;"));
- conn.query("delete from my_map where version == '1.81.0';");
- print(std::cout, conn.query("select * from my_map where name < 'system' and name <= 'system' ;"));
-
-
- return 0;
-} \ No newline at end of file
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