construct/include/ircd/db.h

/*
 * Copyright (C) 2016 Charybdis Development Team
 * Copyright (C) 2016 Jason Volk <jason@zemos.net>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice is present in all copies.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 */

#pragma once
#define HAVE_IRCD_DB_H

/// Database: an object store from the primitives of `cell`, `column`, and `row`.
namespace ircd::db
{
	struct init;
	struct gopts;
	struct sopts;
	struct cell;
	struct row;
	struct column;
	struct database;
	enum op :uint8_t;
	enum class pos :int8_t;

	// Errors for the database subsystem. The exceptions that use _HIDENAME
	// are built from RocksDB errors which already have an info string with
	// an included name.
	//
	IRCD_EXCEPTION(ircd::error, error)
	IRCD_EXCEPTION(error, not_found)
	IRCD_EXCEPTION(error, schema_error)
	IRCD_EXCEPTION_HIDENAME(error, corruption)
	IRCD_EXCEPTION_HIDENAME(error, not_supported)
	IRCD_EXCEPTION_HIDENAME(error, invalid_argument)
	IRCD_EXCEPTION_HIDENAME(error, io_error)
	IRCD_EXCEPTION_HIDENAME(error, merge_in_progress)
	IRCD_EXCEPTION_HIDENAME(error, incomplete)
	IRCD_EXCEPTION_HIDENAME(error, shutdown_in_progress)
	IRCD_EXCEPTION_HIDENAME(error, timed_out)
	IRCD_EXCEPTION_HIDENAME(error, aborted)
	IRCD_EXCEPTION_HIDENAME(error, busy)
	IRCD_EXCEPTION_HIDENAME(error, expired)
	IRCD_EXCEPTION_HIDENAME(error, try_again)

	// db subsystem has its own logging facility
	extern struct log::log log;
}

/// Forward declarations for rocksdb because we do not include it here.
///
/// These are forward declarations to objects we may carry a pointer to.
/// Users of ircd::db should not have to deal directly with these types.
///
namespace rocksdb
{
	struct DB;
	struct Slice;
	struct Options;
	struct DBOptions;
	struct ColumnFamilyOptions;
	struct PlainTableOptions;
	struct BlockBasedTableOptions;
	struct Cache;
	struct Iterator;
	struct ColumnFamilyHandle;
	struct Snapshot;
	struct WriteBatch;
}

//
// Misc utils
//
namespace ircd::db
{
	extern const char *const version;

	rocksdb::Slice slice(const string_view &);
	string_view slice(const rocksdb::Slice &);

	bool valid(const rocksdb::Iterator &);
	string_view key(const rocksdb::Iterator &);
	string_view val(const rocksdb::Iterator &);

	std::string path(const std::string &name);
	std::vector<std::string> available();

	void log_rdb_perf_context(const bool &all = true);

	string_view reflect(const pos &);

	// Indicates an op uses both a key and value for its operation. Some only use
	// a key name so an empty value argument in a delta is okay when false.
	bool value_required(const op &);
	string_view reflect(const op &);
}

enum class ircd::db::pos
:int8_t
{
    FRONT   = -2,    // .front()    | first element
    PREV    = -1,    // std::prev() | previous element
    END     = 0,     // break;      | exit iteration (or past the end)
    NEXT    = 1,     // continue;   | next element
    BACK    = 2,     // .back()     | last element
};

enum ircd::db::op
:uint8_t
{
	GET,                     // no-op sentinel, do not use (debug asserts)
	SET,                     // (batch.Put)
	MERGE,                   // (batch.Merge)
	DELETE,                  // (batch.Delete)
	DELETE_RANGE,            // (batch.DeleteRange)
	SINGLE_DELETE,           // (batch.SingleDelete)
};

#include "db/delta.h"
#include "db/comparator.h"
#include "db/prefix.h"
#include "db/merge.h"
#include "db/database.h"
#include "db/opts.h"
#include "db/column.h"
#include "db/cell.h"
#include "db/row.h"
#include "db/index.h"
#include "db/json.h"
#include "db/iov.h"
#include "db/where.h"
#include "db/cursor.h"

namespace ircd
{
	using db::database;
}

struct ircd::db::init
{
	init();
	~init() noexcept;
};