diff --git a/main.c b/main.c
index 71548f56ff1b056167dec4902ca56ad343eb4a3c..104200728ca59683a2cf2cb785662192dad5dfaf 100644
--- a/main.c
+++ b/main.c
@@ -7,6 +7,7 @@
#include <malloc.h>
struct ring_buffer{
+ unsigned int number_of_commands;
unsigned int head;
unsigned int tail;
unsigned int size;
@@ -33,7 +34,7 @@ unsigned int get_free_slots_left_in_the_buffer(struct ring_buffer *rb){
}
bool buffer_has_space_for_command(struct ring_buffer *rb, int command_lenght){
- return (get_free_slots_left_in_the_buffer(rb) - sizeof (struct varied_length_command_info) - command_lenght) > 0;
+ return (get_free_slots_left_in_the_buffer(rb) - sizeof (struct varied_length_command_info) - command_lenght) >= 0;
}
@@ -72,28 +73,26 @@ void print_buffer_content(struct ring_buffer *rb){
}
int insert_in_to_buffer(struct ring_buffer *rb, char *command){
- /* What happens when the entry fits exactly in to the size of the buffer? */
- /* First check if we can fit the command with it's data within the current buffer's length. */
unsigned int command_size = strlen(command);
int cmd_info_size = sizeof (struct varied_length_command_info);
int required_length = command_size+cmd_info_size;
+ printf("required lenght: %d, space left: %d\n", required_length, rb->real_size-rb->head);
/* Special case when we can not fit entry in to a contiguous range*/
- if(rb->head > rb->tail && rb->real_size - rb->head < required_length){
+ //rb->head >= rb->tail &&
+ if( rb->real_size - rb->head < required_length){
int remaining_space = rb->real_size - rb->head;
printf("Command will be split!\n ");
printf("Space left in the buffer: %d\n", get_free_slots_left_in_the_buffer(rb));
printf("Space left in the current turn of the buffer: %d\n", remaining_space);
printf("Rquired length: %d\n", required_length);
- /* Need to add the command here */
void *full_cmd = malloc(required_length);
struct varied_length_command_info cmd_info;
cmd_info.command_lenght = command_size;
memcpy(full_cmd, &cmd_info, cmd_info_size);
memcpy(full_cmd+cmd_info_size, command, command_size+1);
-
int reminder = required_length-remaining_space;
void *addr_of_buffer = &rb->buffer[rb->head];
void *addr_of_entry = full_cmd;
@@ -121,13 +120,7 @@ int insert_in_to_buffer(struct ring_buffer *rb, char *command){
memcpy(command_slot, command, strlen(command)+1);
printf("Written to slot: %s\n", command_slot);
- //command_slot = command_slot + strlen(command);
rb->head += sizeof(struct varied_length_command_info) + strlen(command);
-
- /* TODO */
- //Handle the case when the end of the buffer is reached.
- //rb->buffer[rb->head] = command;
- //rb->head = (rb->head + 1) % rb->size;
return 0;
}
}
@@ -138,6 +131,7 @@ int insert_in_to_buffer(struct ring_buffer *rb, char *command){
int insert(struct ring_buffer *rb, char *command){
if(buffer_has_space_for_command(rb, strlen(command)) > 0){
insert_in_to_buffer(rb, command);
+ rb->number_of_commands+=1;
return 0;
}
printf("No space to insert the entry, dropping!\n");
@@ -149,11 +143,11 @@ int insert(struct ring_buffer *rb, char *command){
* */
struct cmd_and_next_index *retrieve_command_at_index(struct ring_buffer *rb, int index){
- if(buffer_is_empty(rb)){
+ if(rb->number_of_commands == 0){
printf("Buffer is empty\n");
return NULL;
}
-
+ rb->number_of_commands-=1;
//First check if current index fits the size of the info block
@@ -196,8 +190,10 @@ struct cmd_and_next_index *retrieve_command_at_index(struct ring_buffer *rb, int
int space_left_for_command = rb->real_size-(index+sizeof (struct varied_length_command_info));
/* Case 2: when info is within current turn of the buffer, but the command is not */
if(cmd_info->command_lenght > space_left_for_command){
+ printf("Executing 2nd edge case\n");
+ printf("Reading directly from buffer: %s\n", &rb->buffer[index]+sizeof (struct varied_length_command_info));
void *destination = extracted_command;
- memcpy(destination, cmd_info_addr+sizeof (struct varied_length_command_info), space_left_for_command);
+ memcpy(destination, &rb->buffer[index]+sizeof (struct varied_length_command_info), space_left_for_command);
void *src = &rb->buffer[0];
destination+=space_left_for_command;
memcpy(destination, src, cmd_info->command_lenght-space_left_for_command);
@@ -219,9 +215,6 @@ struct cmd_and_next_index *retrieve_command_at_index(struct ring_buffer *rb, int
rb->tail = index;
return data;
}
-
-
-
}
}
@@ -245,6 +238,14 @@ struct ring_buffer * initialise_ring_buffer_on_persistent_memory(PMEMobjpool *po
return &rootp->rb;
}
+void print_head_and_tail(struct ring_buffer *rb){
+ printf("Head is at: %d, Tail is at: %d\n", rb->head, rb->tail);
+}
+
+void print_commands_in_the_byffer(struct ring_buffer *rb){
+ printf("Commands in the buffer: %d\n", rb->number_of_commands);
+}
+
int main() {
PMEMobjpool *pop;
struct ring_buffer *rb = initialise_ring_buffer_on_persistent_memory(pop);
@@ -252,11 +253,10 @@ int main() {
rb->real_size = rb->size-1;
rb->head = 0;
rb->tail = 0;
+ rb->number_of_commands = 0;
printf("Initialized ring_buffer\n");
print_available_buffer_slots(rb);
- // When we establish communication we send the information about ring buffer to the consumer;
- //Consumer sends request to read command at the specific index
- //Once the index has been read the value latest_read_index is updated and head can move to up to the latest read index -1;
+
int cmd_index = 0;
/* Case 1 */
insert(rb, "abcd");
@@ -275,6 +275,45 @@ int main() {
cmd_data = retrieve_command_at_index(rb, cmd_index);
cmd_index = cmd_data->next_index;
printf("Extracted command: %s, next index: %d\n", cmd_data->command, cmd_data->next_index);
+ print_available_buffer_slots(rb);
+
+ print_head_and_tail(rb);
+ /* Extracting nonexistent command */
+ cmd_data = retrieve_command_at_index(rb, cmd_index);
+
+
+ /* Case 4 */
+
+ insert(rb, "abcd");
+ print_head_and_tail(rb);
+ cmd_data = retrieve_command_at_index(rb, cmd_index);
+ cmd_index = cmd_data->next_index;
+ print_head_and_tail(rb);
+ print_available_buffer_slots(rb);
+ print_commands_in_the_byffer(rb);
+
+ /* Case 5 Fits exactly in to the buffer length */
+ insert(rb, "ab");
+ cmd_data = retrieve_command_at_index(rb, cmd_index);
+ cmd_index = cmd_data->next_index;
+ printf("Next index is: %d\n", cmd_index);
+ print_head_and_tail(rb);
+
+ /* Case 6 starts from 0 */
+ insert(rb, "cd");
+ cmd_data = retrieve_command_at_index(rb, cmd_index);
+ cmd_index = cmd_data->next_index;
+ printf("Next index is: %d \n", cmd_index);
+ print_head_and_tail(rb);
+
+ /* Case 7 */
+
+ insert(rb, "abcdefghijklmn");
+ cmd_data = retrieve_command_at_index(rb, cmd_index);
+ printf("Retrieved command :%s\n", cmd_data->command);
+ cmd_index = cmd_data->next_index;
+ printf("Next index is: %d \n", cmd_index);
+ print_head_and_tail(rb);
return 0;
}