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tdlib-fork/tddb/td/db/SqliteKeyValue.cpp

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//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
//
// 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 "td/db/SqliteKeyValue.h"
#include "td/utils/ScopeGuard.h"
namespace td {
Result<bool> SqliteKeyValue::init(string path) {
path_ = std::move(path);
bool is_created = false;
SqliteDb db;
TRY_STATUS(db.init(path, &is_created));
TRY_STATUS(db.exec("PRAGMA encoding=\"UTF-8\""));
TRY_STATUS(db.exec("PRAGMA synchronous=NORMAL"));
TRY_STATUS(db.exec("PRAGMA journal_mode=WAL"));
TRY_STATUS(db.exec("PRAGMA temp_store=MEMORY"));
TRY_STATUS(init_with_connection(std::move(db), "KV"));
return is_created;
}
Status SqliteKeyValue::init_with_connection(SqliteDb connection, string table_name) {
auto init_guard = ScopeExit() + [&]() {
close();
};
db_ = std::move(connection);
table_name_ = std::move(table_name);
TRY_STATUS(init(db_, table_name_));
TRY_RESULT_ASSIGN(set_stmt_,
db_.get_statement(PSLICE() << "REPLACE INTO " << table_name_ << " (k, v) VALUES (?1, ?2)"));
TRY_RESULT_ASSIGN(get_stmt_, db_.get_statement(PSLICE() << "SELECT v FROM " << table_name_ << " WHERE k = ?1"));
TRY_RESULT_ASSIGN(erase_stmt_, db_.get_statement(PSLICE() << "DELETE FROM " << table_name_ << " WHERE k = ?1"));
TRY_RESULT_ASSIGN(get_all_stmt_, db_.get_statement(PSLICE() << "SELECT k, v FROM " << table_name_));
TRY_RESULT_ASSIGN(erase_by_prefix_stmt_,
db_.get_statement(PSLICE() << "DELETE FROM " << table_name_ << " WHERE ?1 <= k AND k < ?2"));
TRY_RESULT_ASSIGN(erase_by_prefix_rare_stmt_,
db_.get_statement(PSLICE() << "DELETE FROM " << table_name_ << " WHERE ?1 <= k"));
TRY_RESULT_ASSIGN(get_by_prefix_stmt_,
db_.get_statement(PSLICE() << "SELECT k, v FROM " << table_name_ << " WHERE ?1 <= k AND k < ?2"));
TRY_RESULT_ASSIGN(get_by_prefix_rare_stmt_,
db_.get_statement(PSLICE() << "SELECT k, v FROM " << table_name_ << " WHERE ?1 <= k"));
init_guard.dismiss();
return Status::OK();
}
Status SqliteKeyValue::drop() {
if (empty()) {
return Status::OK();
}
auto result = drop(db_, table_name_);
close();
return result;
}
SqliteKeyValue::SeqNo SqliteKeyValue::set(Slice key, Slice value) {
set_stmt_.bind_blob(1, key).ensure();
set_stmt_.bind_blob(2, value).ensure();
set_stmt_.step().ensure();
set_stmt_.reset();
return 0;
}
string SqliteKeyValue::get(Slice key) {
SCOPE_EXIT {
get_stmt_.reset();
};
get_stmt_.bind_blob(1, key).ensure();
get_stmt_.step().ensure();
if (!get_stmt_.has_row()) {
return "";
}
auto data = get_stmt_.view_blob(0).str();
get_stmt_.step().ignore();
return data;
}
SqliteKeyValue::SeqNo SqliteKeyValue::erase(Slice key) {
erase_stmt_.bind_blob(1, key).ensure();
erase_stmt_.step().ensure();
erase_stmt_.reset();
return 0;
}
void SqliteKeyValue::erase_by_prefix(Slice prefix) {
auto next = next_prefix(prefix);
if (next.empty()) {
SCOPE_EXIT {
erase_by_prefix_rare_stmt_.reset();
};
erase_by_prefix_rare_stmt_.bind_blob(1, prefix).ensure();
erase_by_prefix_rare_stmt_.step().ensure();
} else {
SCOPE_EXIT {
erase_by_prefix_stmt_.reset();
};
erase_by_prefix_stmt_.bind_blob(1, prefix).ensure();
erase_by_prefix_stmt_.bind_blob(2, next).ensure();
erase_by_prefix_stmt_.step().ensure();
}
}
string SqliteKeyValue::next_prefix(Slice prefix) {
string next = prefix.str();
size_t pos = next.size();
while (pos) {
pos--;
auto value = static_cast<uint8>(next[pos]);
value++;
next[pos] = static_cast<char>(value);
if (value != 0) {
return next;
}
}
return string{};
}
} // namespace td