/**
* \brief This function unsubscribe client from the layer
*/
int vs_layer_unsubscribe(struct VSLayer *layer, struct VSession *vsession)
{
struct VSEntitySubscriber *layer_subscriber;
/* Try to find layer subscriber */
layer_subscriber = layer->layer_subs.first;
while(layer_subscriber != NULL) {
if(layer_subscriber->node_sub->session->session_id == vsession->session_id) {
break;
}
layer_subscriber = layer_subscriber->next;
}
/* Client has to be subscribed to the layer */
if(layer_subscriber == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() client not subscribed to the layer (id: %d)\n",
__FUNCTION__, layer->id);
return 0;
}
/* Remove client from the list of subscribers */
v_list_free_item(&layer->layer_subs, layer_subscriber);
return 1;
}
/**
* \brief This function is called, when server receive ack command of packet
* that contained node_destroy command that was sent to the client
*
* When this function is called, then we can be sure, that client knows, that
* this node was destroyed. When the last one of follower acknowledge receiving
* of this command, then this node could be deleted
*/
int vs_handle_node_destroy_ack(struct VS_CTX *vs_ctx,
struct VSession *vsession,
struct Generic_Cmd *cmd)
{
struct VSNode *node;
struct VSEntityFollower *node_follower, *next_node_follower;
struct Node_Destroy_Ack_Cmd *node_destroy_ack = (struct Node_Destroy_Ack_Cmd*)cmd;
/* Try to find node */
if((node = vs_node_find(vs_ctx, node_destroy_ack->node_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() node (id: %d) not found\n",
__FUNCTION__, node_destroy_ack->node_id);
return 0;
}
/* Remove corresponding follower from the list of followers */
node_follower = node->node_folls.first;
while(node_follower != NULL) {
next_node_follower = node_follower->next;
if(node_follower->node_sub->session->session_id == vsession->session_id) {
node_follower->state = ENTITY_DELETED;
v_list_free_item(&node->node_folls, node_follower);
break;
}
node_follower = next_node_follower;
}
/* When node doesn't have any follower, then it is possible to destroy this node*/
if(node->node_folls.first == NULL) {
node->state = ENTITY_DELETED;
vs_node_destroy(vs_ctx, node);
}
return 1;
}
/**
* \brief This function will try to remove node from the server. The node can't
* have any child node or subscriber.
*/
static int vs_node_destroy(struct VS_CTX *vs_ctx, struct VSNode *node)
{
/* Node can't have any followers. The VSNode can be destroyed, when server
* receive ack of node_destroy command from all clients */
if(node->node_folls.first == NULL) {
/* Node can't have any child node */
if(node->children_links.first == NULL) {
/* Remove node permissions */
if(node->permissions.first != NULL) {
v_list_free(&node->permissions);
}
/* Remove link on this node from parent node */
if(node->parent_link != NULL) {
struct VSNode *parent_node = node->parent_link->parent;
v_list_free_item(&parent_node->children_links, node->parent_link);
}
/* Remove all tag groups and tags */
if(node->tag_groups.lb.first != NULL) {
vs_node_taggroups_destroy(node);
}
v_hash_array_destroy(&node->tag_groups);
/* Remove all layers */
if(node->layers.lb.first != NULL) {
vs_node_layers_destroy(node);
}
v_hash_array_destroy(&node->layers);
v_print_log(VRS_PRINT_DEBUG_MSG, "Node: %d destroyed\n", node->id);
/* Remove node from the hashed linked list of nodes */
v_hash_array_remove_item(&vs_ctx->data.nodes, node);
free(node);
return 1;
} else {
/* This should never happen */
v_print_log(VRS_PRINT_DEBUG_MSG,
"%s(): node (id: %d) with child nodes can't be destroyed\n",
__FUNCTION__, node->id);
return 0;
}
} else {
/* This should never happen */
v_print_log(VRS_PRINT_WARNING,
"%(): node (id: %d) with followers can't be destroyed\n",
__FUNCTION__, node->id);
return 0;
}
}
/**
* \brief This function unsubscribes client from the tag group
*/
int vs_taggroup_unsubscribe(struct VSTagGroup *tg,
struct VSession *vsession)
{
struct VSEntitySubscriber *tg_subscriber;
/* If client is subscribed to this tag group, then remove this client
* from list of subscribers */
tg_subscriber = tg->tg_subs.first;
while(tg_subscriber != NULL) {
if(tg_subscriber->node_sub->session == vsession) {
VSTag *tag;
VBucket *bucket;
struct VSEntityFollower *tag_follower;
/* Go through all tags in this tag group */
bucket = tg->tags.lb.first;
while(bucket != NULL) {
tag = (struct VSTag*)bucket->data;
tag_follower = tag->tag_folls.first;
/* Remove client from list of tag followers */
while(tag_follower != NULL) {
if(tag_follower->node_sub->session == vsession) {
v_list_free_item(&tag->tag_folls, tag_follower);
break;
}
tag_follower = tag_follower->next;
}
bucket = bucket->next;
}
/* Remove client from list of tag group subscribers */
v_list_free_item(&tg->tg_subs, tg_subscriber);
return 1;
}
tg_subscriber = tg_subscriber->next;
}
return 0;
}
int vs_handle_taggroup_destroy_ack(struct VS_CTX *vs_ctx,
struct VSession *vsession,
struct Generic_Cmd *cmd)
{
struct VSNode *node;
struct VSTagGroup *tg;
struct VSEntityFollower *tg_foll, *next_tg_foll;
struct TagGroup_Destroy_Ack_Cmd *cmd_tg_destroy_ack = (struct TagGroup_Destroy_Ack_Cmd*)cmd;
/* Try to find node */
if((node = vs_node_find(vs_ctx, cmd_tg_destroy_ack->node_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() node (id: %d) not found\n",
__FUNCTION__, cmd_tg_destroy_ack->node_id);
return 0;
}
if( (tg = vs_taggroup_find(node, cmd_tg_destroy_ack->taggroup_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG,
"%s() tag_group (id: %d) in node (id: %d) not found\n",
__FUNCTION__,
cmd_tg_destroy_ack->taggroup_id,
cmd_tg_destroy_ack->node_id);
return 0;
}
tg_foll = tg->tg_folls.first;
while(tg_foll != NULL) {
next_tg_foll = tg_foll->next;
if(tg_foll->node_sub->session->session_id == vsession->session_id) {
tg_foll->state = ENTITY_DELETED;
v_list_free_item(&tg->tg_folls, tg_foll);
}
tg_foll = next_tg_foll;
}
/* When taggroup doesn't have any follower, then it is possible to destroy
* this taggroup */
if(tg->tg_folls.first == NULL) {
tg->state = ENTITY_DELETED;
vs_taggroup_destroy(node, tg);
}
return 1;
}
int vs_handle_layer_destroy_ack(struct VS_CTX *vs_ctx,
struct VSession *vsession,
struct Generic_Cmd *cmd)
{
struct VSNode *node;
struct VSLayer *layer;
struct VSEntityFollower *layer_foll, *next_layer_foll;
struct Layer_Destroy_Ack_Cmd *layer_destroy_cmd = (struct Layer_Destroy_Ack_Cmd*)cmd;
/* Try to find node */
if((node = vs_node_find(vs_ctx, layer_destroy_cmd->node_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() node (id: %d) not found\n",
__FUNCTION__, layer_destroy_cmd->node_id);
return 0;
}
/* Try to find layer */
if( (layer = vs_layer_find(node, layer_destroy_cmd->layer_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() layer (id: %d) in node (id: %d) not found\n",
__FUNCTION__, layer_destroy_cmd->layer_id, layer_destroy_cmd->node_id);
return 0;
}
/* Mark the layer in this session as DELETED and remove this follower from
* the list of layer followers */
layer_foll = layer->layer_folls.first;
while(layer_foll != NULL) {
next_layer_foll = layer_foll->next;
if(layer_foll->node_sub->session->session_id == vsession->session_id) {
layer_foll->state = ENTITY_DELETED;
v_list_free_item(&layer->layer_folls, layer_foll);
}
layer_foll = next_layer_foll;
}
/* When layer doesn't have any follower, then it is possible to destroy
* this layer */
if(layer->layer_folls.first == NULL) {
layer->state = ENTITY_DELETED;
vs_layer_destroy(node, layer);
}
return 0;
}
/**
* \brief This function do recursive unsubscribing from node
*/
static int vs_node_unsubscribe(struct VSNode *node,
struct VSNodeSubscriber *node_subscriber,
int level)
{
struct VSNode *child_node;
struct VSLink *link;
struct VBucket *tg_bucket, *layer_bucket;
struct VSTagGroup *tg;
struct VSLayer *layer;
struct VSNodeSubscriber *_node_subscriber, *_next_node_subscriber;
struct VSEntityFollower *node_follower;
struct VSEntityFollower *taggroup_follower;
struct VSEntityFollower *layer_follower;
/* Unsubscribe from all child nodes */
link = node->children_links.first;
while(link != NULL) {
child_node = link->child;
_node_subscriber = child_node->node_subs.first;
while(_node_subscriber != NULL) {
_next_node_subscriber = _node_subscriber->next;
if(_node_subscriber->session->session_id == node_subscriber->session->session_id) {
/* Unsubscribe from child node */
vs_node_unsubscribe(child_node, _node_subscriber, level+1);
break;
}
_node_subscriber = _next_node_subscriber;
}
link = link->next;
}
/* Unsubscribe client from all tag groups */
tg_bucket = node->tag_groups.lb.first;
while(tg_bucket != NULL) {
tg = (struct VSTagGroup*)tg_bucket->data;
/* Remove client from the list of TagGroup subscribers */
vs_taggroup_unsubscribe(tg, node_subscriber->session);
/* Remove client from the list of TagGroup followers */
taggroup_follower = tg->tg_folls.first;
while(taggroup_follower != NULL) {
if(taggroup_follower->node_sub->session->session_id == node_subscriber->session->session_id) {
v_list_free_item(&tg->tg_folls, taggroup_follower);
break;
}
taggroup_follower = taggroup_follower->next;
}
tg_bucket = tg_bucket->next;
}
/* Unsubscribe client from all layers */
layer_bucket = node->layers.lb.first;
while(layer_bucket != NULL) {
layer = (struct VSLayer*)layer_bucket->data;
/* Remove client from the list of Layer subscribers */
vs_layer_unsubscribe(layer, node_subscriber->session);
/* Remove client from the list of Layer followers */
layer_follower = layer->layer_folls.first;
while(layer_follower != NULL) {
if(layer_follower->node_sub->session->session_id == node_subscriber->session->session_id) {
v_list_free_item(&layer->layer_folls, layer_follower);
break;
}
layer_follower = layer_follower->next;
}
layer_bucket = layer_bucket->next;
}
if(level > 0) {
/* Remove this session from list of followers too */
node_follower = node->node_folls.first;
while(node_follower != NULL) {
if(node_follower->node_sub->session->session_id == node_subscriber->session->session_id) {
/* Remove client from list of clients, that knows about this node */
v_print_log(VRS_PRINT_DEBUG_MSG,
"Removing session: %d from the list of node: %d followers\n",
node_subscriber->session->session_id, node->id);
v_list_free_item(&node->node_folls, node_follower);
break;
}
node_follower = node_follower->next;
}
}
/* Finally remove this session from list of node subscribers */
v_list_free_item(&node->node_subs, node_subscriber);
return 1;
}
/**
* \brief This function creates new VSNode at Verse server
*/
struct VSNode *vs_node_create(struct VS_CTX *vs_ctx,
struct VSNode *parent_node,
struct VSUser *owner,
uint32 node_id,
uint16 custom_type)
{
struct VSNode *node;
struct VSLink *link;
struct VBucket *bucket;
if(! (v_hash_array_count_items(&vs_ctx->data.nodes) < VRS_MAX_COMMON_NODE_COUNT) ) {
v_print_log(VRS_PRINT_DEBUG_MSG,
"max number: %d of nodes reached\n",
VRS_MAX_COMMON_NODE_COUNT);
return NULL;
}
node = (struct VSNode*)calloc(1, sizeof(struct VSNode));
if(node == NULL) {
v_print_log(VRS_PRINT_ERROR, "Out of memory\n");
return NULL;
}
vs_node_init(node);
if(node_id == VRS_RESERVED_NODE_ID) {
/* Try to find first free node_id. It is fast and easy, When
* VRS_LAST_COMMON_NODE_ID did not reach 0xFFFFFFFF-1 value yet and not used
* node_id are not reused.*/
node->id = vs_ctx->data.last_common_node_id + 1;
while( v_hash_array_find_item(&vs_ctx->data.nodes, &node) != NULL) {
node->id++;
/* Node id 0xFFFFFFFF has special purpose and node IDs in range <0, 65535>
* have special purposes too (skip them) */
if(node->id > VRS_LAST_COMMON_NODE_ID)
node->id = VRS_FIRST_COMMON_NODE_ID;
/* TODO: implement faster finding of free node id */
}
vs_ctx->data.last_common_node_id = node->id;
} else {
node->id = node_id;
}
/* Create link to the parent node */
if(parent_node != NULL) {
link = vs_link_create(parent_node, node);
if(link == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "link between nodes %d %d could not be created\n",
parent_node->id, node->id);
free(node);
return NULL;
}
} else {
/* This can happen only for root node */
assert(node_id == VRS_ROOT_NODE_ID);
node->parent_link = NULL;
node->level = 0;
}
/* Add node to the hashed array of all verse nodes */
bucket = v_hash_array_add_item(&vs_ctx->data.nodes, node, sizeof(struct VSNode));
if(bucket == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "node %d could not be added to the hashed list of nodes\n",
node->id);
if(node->parent_link != NULL) {
v_list_free_item(&parent_node->children_links, node->parent_link);
}
free(node);
return NULL;
}
node->owner = owner;
node->type = custom_type;
return node;
}
/**
* \brief This function is called, when acknowledgment packet was received.
*
* This function processes all ACK and NAK commands and it add not obsolete
* commands from the history of sent packets to the out queue again. This
* function also removes positively and negatively acknowledged packets from
* history of sent packets. ANK ID is updated.
*
* \param[in] *C The verse context.
*
* \return This function returns index of last ACK command in sequence of
* system command, when ACK and NAK commands are the beginning of system
* commands, otherwise it returns -2. When no ACK or NAK command was found,
* then -1 is returned;
*/
static int handle_ack_nak_commands(struct vContext *C)
{
struct VSession *vsession = CTX_current_session(C);
struct VDgramConn *vconn = CTX_current_dgram_conn(C);
struct VPacket *r_packet = CTX_r_packet(C);
struct VSent_Packet *sent_packet;
struct VSent_Command *sent_cmd, *sent_cmd_prev;
unsigned long int rtt = ULONG_MAX;
struct timeval tv;
uint32 ack_id, nak_id;
int i, ret=-1;
gettimeofday(&tv, NULL);
/* Compute SRTT */
if(r_packet->sys_cmd[0].cmd.id==CMD_ACK_ID) {
unsigned long int tmp;
int i=0;
/* Try to find the smallest RTT from acknowledged packets */
for(i=0; r_packet->sys_cmd[i].cmd.id!=CMD_RESERVED_ID; i++) {
if(r_packet->sys_cmd[i].cmd.id==CMD_ACK_ID) {
sent_packet = v_packet_history_find_packet(&vconn->packet_history,
r_packet->sys_cmd[i].ack_cmd.pay_id);
if(sent_packet!=NULL) {
tmp = packet_rtt(sent_packet, &tv);
if(tmp<rtt) rtt=tmp;
}
}
}
if(rtt<ULONG_MAX) {
/* Computation of SRTT as described in RFC */
if(vconn->srtt==0) {
vconn->srtt = rtt;
} else {
vconn->srtt = RTT_ALPHA*vconn->srtt + (1-RTT_ALPHA)*rtt;
}
v_print_log(VRS_PRINT_DEBUG_MSG, "RTT: %d [us]\n", rtt);
v_print_log(VRS_PRINT_DEBUG_MSG, "SRTT: %d [us]\n", vconn->srtt);
}
}
/* Process all ACK and NAK commands. ACK and NAK commands should be first
* and there should not be other system commands between ACK and NAK
* commands. */
for(i=0;
r_packet->sys_cmd[i].cmd.id == CMD_NAK_ID ||
r_packet->sys_cmd[i].cmd.id == CMD_ACK_ID;
i++) {
if(r_packet->sys_cmd[i].cmd.id == CMD_ACK_ID) {
/* Check if ACK and NAK commands are the first system commands */
if(ret!=-2 && ret==i-1) {
ret = i;
} else {
ret = -2;
}
/* If this is not the last ACK command in the sequence of
* ACK/NAK commands, then remove all packets from history of
* sent packet, that are in following sub-sequence of ACK
* commands */
if(r_packet->sys_cmd[i+1].cmd.id == CMD_NAK_ID ||
r_packet->sys_cmd[i+1].cmd.id == CMD_ACK_ID)
{
/* Remove all acknowledged payload packets from the history
* of sent payload packets */
for(ack_id = r_packet->sys_cmd[i].ack_cmd.pay_id;
ack_id < r_packet->sys_cmd[i+1].nak_cmd.pay_id;
ack_id++)
{
v_packet_history_rem_packet(C, ack_id);
}
} else {
/* Remove this acknowledged payload packets from the history
* of sent payload packets */
v_packet_history_rem_packet(C, r_packet->sys_cmd[i].ack_cmd.pay_id);
/* This is the last ACK command in the sequence of ACK/NAK
* commands. Update ANK ID. */
vconn->ank_id = r_packet->sys_cmd[i].ack_cmd.pay_id;
}
} else if(r_packet->sys_cmd[i].cmd.id == CMD_NAK_ID) {
/* Check if ACK and NAK commands are the first system commands */
if(ret!=-2 && ret==i-1) {
ret = i;
} else {
ret = -2;
}
/* Go through the sub-sequence of NAk commands and try to re-send
* not-obsolete data from these packets */
for(nak_id = r_packet->sys_cmd[i].nak_cmd.pay_id;
nak_id < r_packet->sys_cmd[i+1].ack_cmd.pay_id;
nak_id++)
{
/* Add not obsolete data of lost packet to the outgoing queue */
/* Update ANK ID */
sent_packet = v_packet_history_find_packet(&vconn->packet_history, nak_id);
if(sent_packet != NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "Try to re-send packet: %d\n", nak_id);
sent_cmd = sent_packet->cmds.last;
/* Go through all commands in command list and add not
* obsolete commands to the outgoing queue */
while(sent_cmd != NULL) {
sent_cmd_prev = sent_cmd->prev;
if(sent_cmd->vbucket != NULL && sent_cmd->vbucket->data != NULL) {
/* Try to add command back to the outgoing command queue */
if(v_out_queue_push_head(vsession->out_queue,
sent_cmd->prio,
(struct Generic_Cmd*)sent_cmd->vbucket->data) == 1)
{
/* Remove bucket from the history of sent commands too */
v_hash_array_remove_item(&vconn->packet_history.cmd_hist[sent_cmd->id]->cmds, sent_cmd->vbucket->data);
/* When command was added back to the queue,
* then delete only sent command */
v_list_free_item(&sent_packet->cmds, sent_cmd);
}
}
sent_cmd = sent_cmd_prev;
}
/* When all not obsolete commands are added to outgoing
* queue, then this packet could be removed from packet
* history*/
v_packet_history_rem_packet(C, nak_id);
}
}
}
}
return ret;
}
/**
* \brief This function tries to handle Tag_Destroy command
*/
int vs_handle_tag_destroy_ack(struct VS_CTX *vs_ctx,
struct VSession *vsession,
struct Generic_Cmd *cmd)
{
struct VSNode *node;
struct VSTagGroup *tg;
struct VSTag *tag;
struct VSEntityFollower *tag_follower;
struct Tag_Destroy_Ack_Cmd *tag_destroy_ack = (struct Tag_Destroy_Ack_Cmd*)cmd;
uint32 node_id = tag_destroy_ack->node_id;
uint16 taggroup_id = tag_destroy_ack->taggroup_id;
uint16 tag_id = tag_destroy_ack->tag_id;
int ret = 0;
/* Try to find node */
if((node = vs_node_find(vs_ctx, node_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() node (id: %d) not found\n",
__FUNCTION__, node_id);
return 0;
}
pthread_mutex_lock(&node->mutex);
/* Try to find TagGroup */
if( (tg = vs_taggroup_find(node, taggroup_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() tag_group (id: %d) in node (id: %d) not found\n",
__FUNCTION__, taggroup_id, node_id);
goto end;
}
/* Try to find Tag */
if ( (tag = vs_tag_find(tg, tag_id)) == NULL) {
v_print_log(VRS_PRINT_DEBUG_MSG, "%s() tag (id: %d) in tag_group (id: %d), node (id: %d) not found\n",
__FUNCTION__, tag_id, taggroup_id, node_id);
goto end;
}
/* Try to find tag follower that generated this fake command */
tag_follower = tag->tag_folls.first;
while(tag_follower != NULL) {
if(tag_follower->node_sub->session->session_id == vsession->session_id) {
tag_follower->state = ENTITY_DELETED;
v_list_free_item(&tag->tag_folls, tag_follower);
break;
}
tag_follower = tag_follower->next;
}
/* When tag doesn't have any follower, then it is possible to destroy
* this tag and remove it from list of tags from the tag group */
if(tag->tag_folls.first == NULL) {
tag->state = ENTITY_DELETED;
vs_tag_destroy(tg, tag);
}
ret = 1;
end:
pthread_mutex_unlock(&node->mutex);
return ret;
}