ssize_t handler_get(gfcontext_t *ctx, char *path, void* arg){
int fildes;
ssize_t file_len, bytes_transferred;
ssize_t read_len, write_len;
char buffer[BUFFER_SIZE];
if( 0 > (fildes = content_get(path)))
return gfs_sendheader(ctx, GF_FILE_NOT_FOUND, 0);
/* Calculating the file size */
file_len = lseek(fildes, 0, SEEK_END);
gfs_sendheader(ctx, GF_OK, file_len);
/* Sending the file contents chunk by chunk. */
bytes_transferred = 0;
while(bytes_transferred < file_len){
read_len = pread(fildes, buffer, BUFFER_SIZE, bytes_transferred);
if (read_len <= 0){
fprintf(stderr, "handle_with_file read error, %zd, %zu, %zu", read_len, bytes_transferred, file_len );
gfs_abort(ctx);
return -1;
}
write_len = gfs_send(ctx, buffer, read_len);
if (write_len != read_len){
fprintf(stderr, "handle_with_file write error");
gfs_abort(ctx);
return -1;
}
bytes_transferred += write_len;
}
return bytes_transferred;
}
ssize_t handle_with_file(gfcontext_t *ctx, char *path, void* arg){
int fildes;
size_t file_len, bytes_transferred;
ssize_t read_len, write_len;
char buffer[4096];
char *data_dir = arg;
strcpy(buffer,data_dir);
strcat(buffer,path);
if( 0 > (fildes = open(buffer, O_RDONLY))){
if (errno == ENOENT)
/* If the file just wasn't found, then send FILE_NOT_FOUND code*/
return gfs_sendheader(ctx, GF_FILE_NOT_FOUND, 0);
else
/* Otherwise, it must have been a server error. gfserver library will handle*/
return EXIT_FAILURE;
}
/* Calculating the file size */
file_len = lseek(fildes, 0, SEEK_END);
lseek(fildes, 0, SEEK_SET);
gfs_sendheader(ctx, GF_OK, file_len);
/* Sending the file contents chunk by chunk. */
bytes_transferred = 0;
while(bytes_transferred < file_len){
read_len = read(fildes, buffer, 4096);
if (read_len <= 0){
fprintf(stderr, "handle_with_file read error, %zd, %zu, %zu", read_len, bytes_transferred, file_len );
return EXIT_FAILURE;
}
write_len = gfs_send(ctx, buffer, read_len);
if (write_len != read_len){
fprintf(stderr, "handle_with_file write error");
return EXIT_FAILURE;
}
bytes_transferred += write_len;
}
return bytes_transferred;
}
ssize_t handle_with_cache(gfcontext_t *ctx, char *path, void* arg)
{
mqd_t msg_q;
void *mem;
struct request_info *req;
struct shm_info *shm_blk;
sem_t *sem1;
sem_t *sem2;
int file_in_cache;
size_t file_size = 0;
size_t bytes_transferred = 0;
ssize_t write_len;
size_t cache_file_size;
pthread_mutex_lock(seg_q_mutex);
while (steque_isempty(seg_q)) {
pthread_cond_wait(seg_q_cond, seg_q_mutex);
}
shm_blk = (struct shm_info *)steque_pop(seg_q);
pthread_mutex_unlock(seg_q_mutex);
if ((sem1 = sem_open(shm_blk->sem1_name, O_CREAT, 0644, 0)) ==
SEM_FAILED) {
perror("sem_open");
return -1;
}
if ((sem2 = sem_open(shm_blk->sem2_name, O_CREAT, 0644, 0)) ==
SEM_FAILED) {
perror("sem_open");
return -1;
}
retry:
errno = 0;
msg_q = mq_open(QUEUE_NAME, O_WRONLY);
if (msg_q == -1) {
if (errno == ENOENT || errno == EACCES) {
/* simplecached isn't ready yet, sleep and then retry */
fprintf(stdout, "waiting for simplecached\n");
sleep(2);
goto retry;
}
perror("mq_open");
return -1;
}
mem = mmap(NULL, seg_size, PROT_READ | PROT_WRITE, MAP_SHARED,
shm_blk->memfd, 0);
if (!mem) {
perror("mmap");
return -1;
}
req = malloc(sizeof(*req) + strlen(path) + 1);
memcpy(&req->mem_i, (char *)shm_blk + sizeof(int), sizeof(req->mem_i));
req->mem_size = seg_size;
req->file_len = strlen(path) + 1;
strncpy(req->file_path, path, strlen(path));
req->file_path[strlen(path)] = '\0';
mq_send(msg_q, (char *)req, sizeof(*req) + strlen(path) + 1, 0);
free(req);
sem_wait(sem1);
file_in_cache = *(int *)mem;
sem_post(sem1);
if (file_in_cache == -1) {
gfs_sendheader(ctx, GF_FILE_NOT_FOUND, 0);
goto finish;
}
sem_wait(sem1);
file_size = *(size_t *)mem;
cache_file_size = file_size;
gfs_sendheader(ctx, GF_OK, file_size);
sem_post(sem1);
if (!file_size) {
goto finish;
}
while (file_size) {
sem_wait(sem1);
bytes_transferred = seg_size < file_size ?
seg_size : file_size;
write_len = gfs_send(ctx, (char *)mem, bytes_transferred);
if (write_len != bytes_transferred) {
fprintf(stderr, "write error");
}
file_size -= bytes_transferred;
sem_post(sem1);
}
sem_wait(sem1);
file_size = *(size_t *)mem;
if (file_size) {
fprintf(stderr, "transfer error");
}
sem_post(sem1);
finish:
mq_close(msg_q);
sem_close(sem1);
sem_close(sem2);
sem_unlink(shm_blk->sem1_name);
sem_unlink(shm_blk->sem2_name);
munmap(mem, seg_size);
pthread_mutex_lock(seg_q_mutex);
steque_push(seg_q, shm_blk);
pthread_mutex_unlock(seg_q_mutex);
pthread_cond_signal(seg_q_cond);
return cache_file_size;
}
ssize_t handle_with_cache(gfcontext_t *ctx, char *path, void *arg) {
/* Get thread id */
Workload *wld = (Workload *)arg;
pthread_t tid = pthread_self();
printf("entered %ld\n", tid);
/* Sequence of steps to pop a segment number from the queue */
/* Read phase */
/* Lock the mutex */
pthread_mutex_lock(wld->sq_mtx_p);
/* Wait until the queue is empty and writers are waiting */
while(steque_isempty(wld->segqueue)) {
fprintf(stderr, "[handle_with_cache, thread_id = %ld] Waiting for shm segment\n", tid);
pthread_cond_wait(wld->sq_notempty_p, wld->sq_mtx_p);
}
/* Pop a segment number */
long shm_segnum = (long) steque_pop(wld->segqueue);
fprintf(stderr, "[handle_with_cache, thread_id = %ld] Popped shm segment %ld\n", tid, shm_segnum);
/* unlock the mutex */
fprintf(stderr, "[handle_with_cache, thread_id = %ld] Unlocking the mutex\n", tid);
pthread_mutex_unlock(wld->sq_mtx_p);
/* convert the shm_segnum to shm_segid string */
fprintf(stderr, "[handle_with_cache, thread_id = %ld] converting segnum to segid\n", tid);
char shm_segid[SEGID_LEN];
memset(shm_segid, 0, SEGID_LEN);
if (sprintf(shm_segid, "%ld", shm_segnum) < 0) {
err_exit("handle_with_cache", "sprintf", 1);
}
/* Open descriptor for shared memory region */
int shm_fd = shm_open(shm_segid, O_RDWR, 0);
if (shm_fd == -1) {
strerr_exit("handle_with_cache, shm_open", errno);
}
/* obtain the pointer to shared memory */
Shm_Block *shmb_p;
shmb_p = mmap(NULL, wld->shm_blocksize, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
if (shmb_p == MAP_FAILED) {
err_exit("handle_with_cache", "mmap failed", errno);
}
/* close shm file descriptor; its no longer needed */
close(shm_fd);
/* SHM data buffer starts after the shm metadata */
char *shm_buf = (char *) shmb_p + sizeof(Shm_Block);
/* Initialize writer (simplecached) semaphore to 1; initially available */
if (sem_init(&shmb_p->sem_writer, 1, 1) == -1) {
err_exit("handle_with_cache", "Unable to initialize writer semaphore.", errno);
}
/* Initialize reader (handle_with_cache) semaphore to 0; initially unavailable */
if (sem_init(&shmb_p->sem_reader, 1, 0) == -1) {
err_exit("handle_with_cache", "Unable to initialize reader semaphore.", errno);
}
/* Compose message to be sent to simplecached with URL, shm segment id and shm_blocksize */
char msg[MQ_MSGSIZE];
if(sprintf(msg, "%s %ld %zu", path, shm_segnum, wld->shm_blocksize) < 0 ) {
err_exit("handle_with_cache", "sprintf", 1);
}
/* Send message */
fprintf(stderr, "[handle_with_cache, thread_id = %ld] Sending message on mqueue\n", tid);
if (mq_send(wld->mqd, msg, strlen(msg), 0) == -1)
strerr_exit("handle_with_cache, mq_send", errno);
/* Lock the reader */
if (sem_wait(&shmb_p->sem_reader) == -1) {
strerr_exit("handle_with_cache, sem_wait (hdr)", errno);
}
/* Read file size from simplecached */
fprintf(stderr, "[handle_with_cache, thread_id = %ld] Reading file-size from simplecached\n", tid);
int file_size = shmb_p->file_size;
fprintf(stderr, "[handle_with_cache] Req path = %s, file_size = %d\n", path, file_size);
/* send GFS header */
if (file_size == -1) {
fprintf(stderr, "[handle_with_cache, thread_id = %ld] FNF, about to lock mutex\n", tid);
pthread_mutex_lock(wld->sq_mtx_p);
fprintf(stderr, "[handle_with_cache, thread_id = %ld] Enqueuing the segnum %ld\n", tid, shm_segnum);
steque_enqueue(wld->segqueue, (steque_item) shm_segnum);
pthread_mutex_unlock(wld->sq_mtx_p);
pthread_cond_broadcast(wld->sq_notempty_p);
return gfs_sendheader(ctx, GF_FILE_NOT_FOUND, 0);
}
/* unlock the writer */
if (sem_post(&shmb_p->sem_writer) == -1) {
strerr_exit("handle_with_cache, sem_post (hdr)", errno);
}
gfs_sendheader(ctx, GF_OK, file_size);
/* STEPS FOR FILE TRANSFER */
/* We use a pair of semaphores to alternate control between reader (i.e. handle_with_cache)
and the writer (i.e. simplecached). We also keep track of number of trnasfers and bytes
transferred */
int nxfrs = 0;
ssize_t bytes_xfrd = 0;
for (nxfrs = 0, bytes_xfrd = 0 ;; nxfrs++, bytes_xfrd += shmb_p->cnt) {
/* Lock the reader semaphore. If it is already locked, this call will block. Thus, the
control will never go past this point unless the writer has unlocked the semaphore. */
if (sem_wait(&shmb_p->sem_reader) == -1) {
strerr_exit("handle_with_cache, sem_wait (data)", errno);
}
/* File is done on the writer side */
if (shmb_p->cnt == 0) {
break;
}
/* Read Bytes from the shared memory */
// printf("\n[handle_with_cache] writing data below \n\n");
// write(STDOUT_FILENO, shm_buf, shmb_p->cnt);
if (gfs_send(ctx, shm_buf, shmb_p->cnt) != shmb_p->cnt) {
err_exit("handle_with_cache", "gfs_send", EXIT_FAILURE);
}
/* Unlock the writer */
if (sem_post(&shmb_p->sem_writer) == -1) {
strerr_exit("handle_with_cache, sem_post (data)", errno);
}
}
/* Work is done; steps to put the shared memory segment back into queue */
fprintf(stderr, "[handle_with_cache, thread_id = %ld] FF, about to lock mutex\n", tid);
pthread_mutex_lock(wld->sq_mtx_p);
fprintf(stderr, "[handle_with_cache, thread_id = %ld] Enqueuing the segnum %ld\n", tid, shm_segnum);
steque_enqueue(wld->segqueue, (steque_item) shm_segnum);
pthread_mutex_unlock(wld->sq_mtx_p);
pthread_cond_broadcast(wld->sq_notempty_p);
return bytes_xfrd;
}
ssize_t handle_with_cache(gfcontext_t* ctx, char *path, void* arg) {
char* fldes;
pthread_mutex_lock(&fldes_mutex);
while (fldes_queue_size == 0) {
pthread_cond_wait(&read_cond, &fldes_mutex);
}
fldes = (char*)steque_pop(&fldes_queue);
fldes_queue_size--;
// fprintf(stdout, "fldes is:%s.", fldes);
pthread_mutex_unlock(&fldes_mutex);
pthread_cond_broadcast(&write_cond);
//pthread_cond_signal(&write_cond);
shm_data* mem = create_shm_channel(fldes);
mqd_t mq;
do {
mq = mq_open (MSGQID, O_RDWR);
} while(mq == (mqd_t) -1 || mq == 0);
msgq_data data;
strcpy(data.path, path);
strcpy(data.fldes, fldes);
data.segment_size = segment_size;
// pthread_mutex_lock(&msgq_mutex);
int msg_rsp = mq_send(mq, (const char *) &data, 1024, 1);
if (msg_rsp < 0) {
fprintf(stderr, "Error %d (%s) on server proxy mq_send.\n", errno, strerror(errno));
fflush(stdout);
// exit(1);
}
mq_close(mq);
// pthread_mutex_unlock(&msgq_mutex);
pthread_mutex_lock(&mem->file_len_mutex);
while(mem->file_length == 0) {
pthread_cond_wait(&mem->proxy_cond, &mem->file_len_mutex);
}
int file_len = mem->file_length;
pthread_mutex_unlock(&mem->file_len_mutex);
pthread_cond_broadcast(&mem->cache_cond);
// fprintf(stdout, "Received file length is: %d\n", file_len);
// fflush(stdout);
if(file_len < 0) {
// fprintf(stdout, "File not found in cache\n");
// fflush(stdout);
destroy_shm_seg(fldes, mem);
return gfs_sendheader(ctx, GF_FILE_NOT_FOUND, 0);
}else {
gfs_sendheader(ctx, GF_OK, file_len);
int bytes_transferred = 0;
int write_len = 0;
char *data_start = (void *)(mem + 1);
while (bytes_transferred < file_len) {
pthread_mutex_lock(&mem->data_mutex);
while(mem->bytes_written == 0) {
pthread_cond_wait(&mem->proxy_cond, &mem->data_mutex);
}
int read_len = mem->bytes_written;
write_len = gfs_send(ctx, data_start, read_len);
if (write_len != read_len) {
fprintf(stderr, "handle_with_cache write error");
return EXIT_FAILURE;
}
mem->bytes_written = 0;
pthread_mutex_unlock(&mem->data_mutex);
pthread_cond_broadcast(&mem->cache_cond);
bytes_transferred += write_len;
}
destroy_shm_seg(fldes, mem);
fflush(stdout);
return bytes_transferred;
}
}
