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key-value-store
Commit 4fbaf0a8 authored by Shivaji's avatar Shivaji
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Merge branch 'lru-sample' into 'master' 

Lru sample

See merge request !1
parents 6dec1e51 996cb357
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Showing with 186 additions and 155 deletions
LRU.c
View file @ 4fbaf0a8
#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#define _GNU_SOURCE
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdatomic.h>
#include "LRU.h"
#define ATOMIC_TEST_AND_SET __atomic_test_and_set
#define CLEAR __atomic_clear
#define MAX_SIZE 10
struct KV *array[MAX_SIZE];
struct queue *qu;
struct queue *last;
void remove_element_from_deque(char *key)
{
queue *present = qu , *previous=NULL;
while(present->next != NULL)
{
if(present->key == key)
{
if(previous == NULL)
qu = qu->next;
if(last == present)
last = previous;
if(previous)
previous->next = present->next;
free(present);
return;
}
previous = present;
present = present->next;
}
}
void insert_into_queue(char *key)
{
queue *temp = (queue *)malloc(sizeof(queue));
temp->key = key;
temp->next = NULL;
if(qu == NULL)
{
qu = temp;
last = temp;
}
else
{
last->next = temp;
last = temp;
}
}
int find_empty_location()
{
for(int i=0;i<MAX_SIZE;i++)
{
if(array[i]->valid == FALSE)
return i;
}
}
int cache_del(char *key)
{
for(int i=0;i<MAX_SIZE;i++)
{
if(strcmp(array[i]->key , key) == 0)
{
while(ATOMIC_TEST_AND_SET(&(array[i]->lock),1) == 1);
remove_element_from_deque(key);
array[i]->valid = FALSE;
CLEAR(&(array[i]->lock),0);
return 1;
}
}
printf("Cache after DEL: \n");
print_cache();
return 0;
//TODO remove key from file also
}
void cache_put(char *key, char *value)
{
int indx=-1;
for(int i=0;i<MAX_SIZE;i++)
{
if(array[i]->key!=NULL) {
if(strcmp(array[i]->key , key) == 0)
{
indx = i;
remove_element_from_deque(key);
break;
}
}
}
printf("key is present at index: %d\n", indx);
if(indx == -1)
{
indx = find_empty_location();
// TODO should write to file if modified is true
// replacment from cache
}
while(ATOMIC_TEST_AND_SET(&(array[indx]->lock),1) == 1);
memcpy(array[indx]->key, key, KEY_SIZE);
memcpy(array[indx]->value, value, VAL_SIZE);
array[indx]->valid = TRUE;
array[indx]->modified = TRUE;
insert_into_queue(key);
CLEAR(&(array[indx]->lock),0);
printf("Cache after PUT: \n");
print_cache();
}
int cache_get(char *key, char *value)
{
for(int i=0;i<MAX_SIZE;i++)
{
if(strcmp(array[i]->key , key) == 0 && array[i]->valid)
{
while(ATOMIC_TEST_AND_SET(&(array[i]->lock),1) == 1);
remove_element_from_deque(key);
insert_into_queue(key);
CLEAR(&(array[i]->lock),0);
memcpy(value, array[i]->value, VAL_SIZE);
return 1;
}
}
return 0;
}
void init_cache() {
for(int j=0;j<MAX_SIZE;j++)
{
array[j] = (KV *)malloc(sizeof(KV));
array[j]->valid = FALSE;
array[j]->lock = 0;
}
}
void print_cache() {
for(int j=0;j<MAX_SIZE;j++)
{
printf("[%d] (%s) : (%s)\n", array[j]->valid, array[j]->key, array[j]->value);
}
}
\ No newline at end of file
#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#define _GNU_SOURCE
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdatomic.h>
#include <assert.h>
#include "LRU.h"
#define ATOMIC_TEST_AND_SET __atomic_test_and_set
#define CLEAR __atomic_clear
#define MAX_SIZE 10
struct KV *array[MAX_SIZE];
struct queue *qu=NULL;
struct queue *last;
void remove_element_from_deque(char *key)
{
queue *present = qu , *previous=NULL;
if(present == NULL)
return;
if(strcmp(present->key, key) == 0)
{
qu = qu->next;
if(last == present)
last = last->next;
free(present);
return;
}
while(present->next != NULL)
{
if(strcmp(present->key, key) == 0)
{
if(last == present)
last = previous;
previous->next = present->next;
free(present);
return;
}
previous = present;
present = present->next;
}
}
void insert_into_queue(char *key)
{
queue *temp = (queue *)malloc(sizeof(queue));
memcpy(temp->key, key, KEY_SIZE);
temp->next = NULL;
if(qu == NULL)
{
qu = temp;
last = temp;
}
else
{
last->next = temp;
last = temp;
}
}
int remove_front_element()
{
queue *temp = qu;
qu = qu->next;
assert(temp != NULL);
assert(qu != NULL);
for(int i=0;i<MAX_SIZE;i++)
{
if(strcmp(array[i]->key , temp->key) == 0)
{
// check if it is modified to write to file
array[i]->valid = FALSE;
return i;
}
}
}
int find_empty_location()
{
for(int i=0;i<MAX_SIZE;i++)
{
if(array[i]->valid == FALSE)
return i;
}
return remove_front_element();
}
int cache_del(char *key)
{
for(int i=0;i<MAX_SIZE;i++)
{
if(strcmp(array[i]->key , key) == 0)
{
while(ATOMIC_TEST_AND_SET(&(array[i]->lock),1) == 1);
remove_element_from_deque(key);
array[i]->valid = FALSE;
CLEAR(&(array[i]->lock),0);
return 1;
}
}
printf("Cache after DEL: \n");
print_cache();
return 0;
//TODO remove key from file also
}
void cache_put(char *key, char *value)
{
int indx=-1;
for(int i=0;i<MAX_SIZE;i++)
{
if(array[i]->key!=NULL) {
if(strcmp(array[i]->key , key) == 0)
{
printf("ENTERING INTO QUEUE\n");
indx = i;
remove_element_from_deque(key);
break;
}
}
}
printf("key is present at index: %d\n", indx);
if(indx == -1)
{
indx = find_empty_location();
assert(indx>=0);
// TODO should write to file if modified is true
// replacment from cache
}
while(ATOMIC_TEST_AND_SET(&(array[indx]->lock),1) == 1);
memcpy(array[indx]->key, key, KEY_SIZE);
memcpy(array[indx]->value, value, VAL_SIZE);
array[indx]->valid = TRUE;
array[indx]->modified = TRUE;
insert_into_queue(key);
CLEAR(&(array[indx]->lock),0);
print_cache();
}
int cache_get(char *key, char *value)
{
for(int i=0;i<MAX_SIZE;i++)
{
if(strcmp(array[i]->key , key) == 0 && array[i]->valid)
{
while(ATOMIC_TEST_AND_SET(&(array[i]->lock),1) == 1);
remove_element_from_deque(key);
insert_into_queue(key);
CLEAR(&(array[i]->lock),0);
memcpy(value, array[i]->value, VAL_SIZE);
return 1;
}
}
return 0;
}
void init_cache() {
for(int j=0;j<MAX_SIZE;j++)
{
array[j] = (KV *)malloc(sizeof(KV));
array[j]->valid = FALSE;
array[j]->lock = 0;
}
}
void print_cache() {
for(int j=0;j<MAX_SIZE;j++)
{
printf("[%d] (%s) : (%s)\n", array[j]->valid, array[j]->key, array[j]->value);
}
}
LRU.h
View file @ 4fbaf0a8
......@@ -22,7 +22,7 @@ typedef struct KV KV;
typedef struct queue queue;
struct queue{
char *key;
char key[KEY_SIZE];
struct queue *next;
};
......@@ -44,4 +44,6 @@ int cache_get(char *key, char *value);
void init_cache();
void print_cache();
\ No newline at end of file
void print_cache();
int remove_front_element();
\ No newline at end of file
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