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Diffstat (limited to 'src/lmdb/database.cpp')
| -rw-r--r-- | src/lmdb/database.cpp | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/lmdb/database.cpp b/src/lmdb/database.cpp new file mode 100644 index 000000000..c6b244671 --- /dev/null +++ b/src/lmdb/database.cpp @@ -0,0 +1,187 @@ +// Copyright (c) 2014-2018, The Monero Project +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without modification, are +// permitted provided that the following conditions are met: +// +// 1. Redistributions of source code must retain the above copyright notice, this list of +// conditions and the following disclaimer. +// +// 2. Redistributions in binary form must reproduce the above copyright notice, this list +// of conditions and the following disclaimer in the documentation and/or other +// materials provided with the distribution. +// +// 3. Neither the name of the copyright holder nor the names of its contributors may be +// used to endorse or promote products derived from this software without specific +// prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY +// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL +// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +#include "database.h" +#include "lmdb/error.h" +#include "lmdb/util.h" + +#ifdef _WIN32 +namespace +{ + constexpr const mdb_mode_t open_flags = 0; +} +#else +#include <sys/stat.h> + +namespace +{ + constexpr const mdb_mode_t open_flags = (S_IRUSR | S_IWUSR); +} +#endif + +namespace lmdb +{ + namespace + { + constexpr const std::size_t max_resize = 1 * 1024 * 1024 * 1024; // 1 GB + void acquire_context(context& ctx) noexcept + { + while (ctx.lock.test_and_set()); + ++(ctx.active); + ctx.lock.clear(); + } + + void release_context(context& ctx) noexcept + { + --(ctx.active); + } + } + + void release_read_txn::operator()(MDB_txn* ptr) const noexcept + { + if (ptr) + { + MDB_env* const env = mdb_txn_env(ptr); + abort_txn{}(ptr); + if (env) + { + context* ctx = reinterpret_cast<context*>(mdb_env_get_userctx(env)); + if (ctx) + release_context(*ctx); + } + } + } + + expect<environment> open_environment(const char* path, MDB_dbi max_dbs) noexcept + { + MONERO_PRECOND(path != nullptr); + + MDB_env* obj = nullptr; + MONERO_LMDB_CHECK(mdb_env_create(std::addressof(obj))); + environment out{obj}; + + MONERO_LMDB_CHECK(mdb_env_set_maxdbs(out.get(), max_dbs)); + MONERO_LMDB_CHECK(mdb_env_open(out.get(), path, 0, open_flags)); + return {std::move(out)}; + } + + expect<write_txn> database::do_create_txn(unsigned int flags) noexcept + { + MONERO_PRECOND(handle() != nullptr); + + for (unsigned attempts = 0; attempts < 3; ++attempts) + { + acquire_context(ctx); + + MDB_txn* txn = nullptr; + const int err = + mdb_txn_begin(handle(), nullptr, flags, &txn); + if (!err && txn != nullptr) + return write_txn{txn}; + + release_context(ctx); + if (err != MDB_MAP_RESIZED) + return {lmdb::error(err)}; + MONERO_CHECK(this->resize()); + } + return {lmdb::error(MDB_MAP_RESIZED)}; + } + + database::database(environment env) + : env(std::move(env)), ctx{{}, ATOMIC_FLAG_INIT} + { + if (handle()) + { + const int err = mdb_env_set_userctx(handle(), std::addressof(ctx)); + if (err) + MONERO_THROW(lmdb::error(err), "Failed to set user context"); + } + } + + database::~database() noexcept + { + while (ctx.active); + } + + expect<void> database::resize() noexcept + { + MONERO_PRECOND(handle() != nullptr); + + while (ctx.lock.test_and_set()); + while (ctx.active); + + MDB_envinfo info{}; + MONERO_LMDB_CHECK(mdb_env_info(handle(), &info)); + + const std::size_t resize = std::min(info.me_mapsize, max_resize); + const int err = mdb_env_set_mapsize(handle(), info.me_mapsize + resize); + ctx.lock.clear(); + if (err) + return {lmdb::error(err)}; + return success(); + } + + expect<read_txn> database::create_read_txn(suspended_txn txn) noexcept + { + if (txn) + { + acquire_context(ctx); + const int err = mdb_txn_renew(txn.get()); + if (err) + { + release_context(ctx); + return {lmdb::error(err)}; + } + return read_txn{txn.release()}; + } + auto new_txn = do_create_txn(MDB_RDONLY); + if (new_txn) + return read_txn{new_txn->release()}; + return new_txn.error(); + } + + expect<suspended_txn> database::reset_txn(read_txn txn) noexcept + { + MONERO_PRECOND(txn != nullptr); + mdb_txn_reset(txn.get()); + release_context(ctx); + return suspended_txn{txn.release()}; + } + + expect<write_txn> database::create_write_txn() noexcept + { + return do_create_txn(0); + } + + expect<void> database::commit(write_txn txn) noexcept + { + MONERO_PRECOND(txn != nullptr); + MONERO_LMDB_CHECK(mdb_txn_commit(txn.get())); + txn.release(); + release_context(ctx); + return success(); + } +} // lmdb |