/*!
** @brief request that a content chunk be loaded into the local machine's
** content cache.
**
** XrequestChunk() is called by a client application to load a content chunk
** into the XIA content cache. It does not return the requested data, it only
** causes the chunk to be loaded into the local content cache. XgetChunkStatus()
** may be called to get the status of the chunk to determine when it becomes
** available. Once the chunk is ready to be read, XreadChunk() should be called
** get the actual content chunk data.
**
** XrequestChunk() is a simple wrapper around the XrequestChunks() API call.
**
** @param sockfd the control socket (must be of type XSOCK_CHUNK)
** @param dag Content ID of this chunk
** @param dagLen length of dag (currently not used)
**
** @returns 0 on success
** @returns -1 if the requested chunk could not be located or a socket error
** occurred. If the error is a socket error, errno set will be set with an
** appropriate code.
*/
int XrequestChunk(int sockfd, char* dag, size_t /* dagLen */)
{
ChunkStatus cs;
cs.cid = dag;
cs.cidLen = strlen(dag);
return XrequestChunks(sockfd, &cs, 1);
}
int getListedChunks(int csock, FILE *fd, char *chunks, char *p_ad, char *p_hid)
{
ChunkStatus cs[NUM_CHUNKS];
char data[XIA_MAXCHUNK];
int len;
int status;
int n = -1;
n = buildChunkDAGs(cs, chunks, p_ad, p_hid);
// NOTE: the chunk transport is not currently reliable and chunks may need to be re-requested
// ask for the current chunk list again every REREQUEST seconds
// chunks already in the local cache will not be refetched from the network
unsigned ctr = 0;
while (1) {
if (ctr % REREQUEST == 0) {
// bring the list of chunks local
say("%srequesting list of %d chunks\n", (ctr == 0 ? "" : "re-"), n);
if (XrequestChunks(csock, cs, n) < 0) {
say("unable to request chunks\n");
return -1;
}
say("checking chunk status\n");
ctr++;
}
status = XgetChunkStatuses(csock, cs, n);
if (status == READY_TO_READ)
break;
else if (status < 0) {
say("error getting chunk status\n");
return -1;
} else if (status & WAITING_FOR_CHUNK) {
// one or more chunks aren't ready.
say("waiting... one or more chunks aren't ready yet\n");
} else if (status & INVALID_HASH) {
die(-1, "one or more chunks has an invalid hash");
} else if (status & REQUEST_FAILED) {
die(-1, "no chunks found\n");
} else {
say("unexpected result\n");
}
sleep(1);
}
say("all chunks ready\n");
for (int i = 0; i < n; i++) {
char *cid = strrchr(cs[i].cid, ':');
cid++;
say("reading chunk %s\n", cid);
if ((len = XreadChunk(csock, data, sizeof(data), 0, cs[i].cid, cs[i].cidLen)) < 0) {
say("error getting chunk\n");
return -1;
}
// write the chunk to disk
// say("writing %d bytes of chunk %s to disk\n", len, cid);
fwrite(data, 1, len, fd);
free(cs[i].cid);
cs[i].cid = NULL;
cs[i].cidLen = 0;
}
return n;
}
/*!
** @brief request that a list of content chunks be loaded into the local
** machine's content cache.
**
** XrequestChunks() is called by a client application to load a content chunk
** into the XIA content cache. It does not return the requested data, it only
** causes the chunk to be loaded into the local content cache. XgetChunkStatuses()
** may be called to get the status of the chunk to determine when it becomes
** available. Once the chunk is ready to be read, XreadChunk() should be called
** get the actual content chunk data.
**
** XrequestChunk() can be used when only a single chunk is requested.
**
** @param sockfd the control socket (must be of type XSOCK_CHUNK)
** @param chunks A list of content DAGs to retrieve
** @param numChunks number of CIDs in the chunk list
**
** @returns 0 on success
** @returns -1 if one or more of the requested chunks could not be located
** or a socket error occurred. If the error is a socket error, errno set
** will be set with an appropriate code.
*/
int XrequestChunks(int sockfd, const ChunkStatus *chunks, int numChunks)
{
int rc;
const char *buf="Chunk request";//Maybe send more useful information here.
if (validateSocket(sockfd, XSOCK_CHUNK, EAFNOSUPPORT) < 0) {
LOGF("Socket %d must be a chunk socket", sockfd);
return -1;
}
if (numChunks == 0)
return 0;
if (!chunks) {
LOG("null pointer error!");
errno = EFAULT;
return -1;
}
// If the DAG list is too long for a UDP packet to click, replace with multiple calls
if (numChunks > 300) //TODO: Make this more precise
{
rc = 0;
int i;
for (i = 0; i < numChunks; i += 300)
{
int num = (numChunks-i > 300) ? 300 : numChunks-i;
int rv = XrequestChunks(sockfd, &chunks[i], num);
if (rv == -1) {
perror("XrequestChunk(): requestChunk failed");
return(-1);
} else {
rc += rv;
}
}
return rc;
}
xia::XSocketMsg xsm;
xsm.set_type(xia::XREQUESTCHUNK);
xia::X_Requestchunk_Msg *x_requestchunk_msg = xsm.mutable_x_requestchunk();
for (int i = 0; i < numChunks; i++) {
if (chunks[i].cid != NULL)
x_requestchunk_msg->add_dag(chunks[i].cid);
else {
LOGF("NULL pointer at chunks[%d]\n", i);
}
}
if (x_requestchunk_msg->dag_size() == 0) {
// FIXME: what error should this relate to?
errno = EFAULT;
LOG("No dags specified\n");
return -1;
}
x_requestchunk_msg->set_payload((const char*)buf, strlen(buf)+1);
std::string p_buf;
xsm.SerializeToString(&p_buf);
if ((rc = click_data(sockfd, &xsm)) < 0) {
LOGF("Error talking to Click: %s", strerror(errno));
return -1;
}
#if 0
// process the reply from click
if ((rc = click_reply2(sockfd, &type)) < 0) {
LOGF("Error getting status from Click: %s", strerror(errno));
return -1;
}
#endif
return 0;
}
int getListedChunks(int csock, FILE *fd, char *chunks, char *p_ad, char *p_hid)
{
ChunkStatus cs[NUM_CHUNKS];
char data[XIA_MAXCHUNK];
int len;
int status;
int n = -1;
n = buildChunkDAGs(cs, chunks, p_ad, p_hid);
// bring the list of chunks local
say("requesting list of %d chunks\n", n);
if (XrequestChunks(csock, cs, n) < 0) {
say("unable to request chunks\n");
return -1;
}
say("checking chunk status\n");
while (1) {
status = XgetChunkStatuses(csock, cs, n);
if (status == READY_TO_READ)
break;
else if (status < 0) {
say("error getting chunk status\n");
return -1;
} else if (status & WAITING_FOR_CHUNK) {
// one or more chunks aren't ready.
say("waiting... one or more chunks aren't ready yet\n");
} else if (status & INVALID_HASH) {
die(-1, "one or more chunks has an invalid hash");
} else if (status & REQUEST_FAILED) {
die(-1, "no chunks found\n");
} else {
say("unexpected result\n");
}
sleep(1);
}
say("all chunks ready\n");
for (int i = 0; i < n; i++) {
char *cid = strrchr(cs[i].cid, ':');
cid++;
say("reading chunk %s\n", cid);
if ((len = XreadChunk(csock, data, sizeof(data), 0, cs[i].cid, cs[i].cidLen)) < 0) {
say("error getting chunk\n");
return -1;
}
// write the chunk to disk
// say("writing %d bytes of chunk %s to disk\n", len, cid);
fwrite(data, 1, len, fd);
free(cs[i].cid);
cs[i].cid = NULL;
cs[i].cidLen = 0;
}
return n;
}