/*
This file is part of GNUnet.
Copyright (C) 2020--2021 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @author Tobias Frisch
* @file src/messenger/gnunet-service-messenger_message_store.h
* @brief GNUnet MESSENGER service
*/
#ifndef GNUNET_SERVICE_MESSENGER_MESSAGE_STORE_H
#define GNUNET_SERVICE_MESSENGER_MESSAGE_STORE_H
#include "platform.h"
#include "gnunet_container_lib.h"
#include "gnunet_disk_lib.h"
struct GNUNET_MESSENGER_MessageEntry
{
off_t offset;
uint16_t length;
};
struct GNUNET_MESSENGER_Message;
struct GNUNET_MESSENGER_MessageLink
{
uint8_t multiple;
struct GNUNET_HashCode first;
struct GNUNET_HashCode second;
};
struct GNUNET_MESSENGER_MessageStore
{
struct GNUNET_DISK_FileHandle *storage_messages;
struct GNUNET_CONTAINER_MultiHashMap *entries;
struct GNUNET_CONTAINER_MultiHashMap *messages;
struct GNUNET_CONTAINER_MultiHashMap *links;
int rewrite_entries;
int write_links;
};
/**
* Initializes a message store as fully empty.
*
* @param[out] store Message store
*/
void
init_message_store (struct GNUNET_MESSENGER_MessageStore *store);
/**
* Clears a message store, wipes its content and deallocates its memory.
*
* @param[in/out] store Message store
*/
void
clear_message_store (struct GNUNET_MESSENGER_MessageStore *store);
/**
* Loads messages from a directory into a message store.
*
* @param[out] store Message store
* @param[in] directory Path to a directory
*/
void
load_message_store (struct GNUNET_MESSENGER_MessageStore *store,
const char *directory);
/**
* Saves messages from a message store into a directory.
*
* @param[in] store Message store
* @param[in] directory Path to a directory
*/
void
save_message_store (struct GNUNET_MESSENGER_MessageStore *store,
const char *directory);
/**
* Checks if a message matching a given hash is stored in a message store.
* The function returns #GNUNET_YES if a match is found, #GNUNET_NO otherwise.
*
* The message has not to be loaded from disk into memory for this check!
*
* @param[in] store Message store
* @param[in] hash Hash of message
* @return #GNUNET_YES on match, otherwise #GNUNET_NO
*/
int
contains_store_message (const struct GNUNET_MESSENGER_MessageStore *store,
const struct GNUNET_HashCode *hash);
/**
* Returns the message from a message store matching a given hash. If no matching
* message is found, NULL gets returned.
*
* This function requires the message to be loaded into memory!
* @see contains_store_message()
*
* @param[in/out] store Message store
* @param[in] hash Hash of message
* @return Message or NULL
*/
const struct GNUNET_MESSENGER_Message*
get_store_message (struct GNUNET_MESSENGER_MessageStore *store,
const struct GNUNET_HashCode *hash);
/**
* Returns the message link from a message store matching a given hash. If the
* flag is set to #GNUNET_YES, only links from deleted messages will be returned or NULL.
*
* Otherwise message links will also returned for messages found in the store under the given
* hash. The link which will be returned copies link information from the message for
* temporary usage.
*
* @param[in/out] store Message store
* @param[in] hash Hash of message
* @param[in] deleted_only Flag
* @return Message link or NULL
*/
const struct GNUNET_MESSENGER_MessageLink*
get_store_message_link (struct GNUNET_MESSENGER_MessageStore *store,
const struct GNUNET_HashCode *hash,
int deleted_only);
/**
* Stores a message into the message store. The result indicates if the operation was successful.
*
* @param[in/out] store Message store
* @param[in] hash Hash of message
* @param[in/out] message Message
* @return #GNUNET_OK on success, otherwise #GNUNET_NO
*/
int
put_store_message (struct GNUNET_MESSENGER_MessageStore *store,
const struct GNUNET_HashCode *hash,
struct GNUNET_MESSENGER_Message *message);
/**
* Deletes a message in the message store. It will be removed from disk space and memory. The result
* indicates if the operation was successful.
*
* @param[in/out] store Message store
* @param[in] hash Hash of message
* @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
*/
int
delete_store_message (struct GNUNET_MESSENGER_MessageStore *store,
const struct GNUNET_HashCode *hash);
#endif //GNUNET_SERVICE_MESSENGER_MESSAGE_STORE_H