c-ipfs/exchange/bitswap/engine.c
2017-08-31 16:41:10 -05:00

184 lines
6.5 KiB
C

#include <unistd.h>
#include "libp2p/utils/logger.h"
#include "ipfs/core/null.h"
#include "ipfs/exchange/bitswap/engine.h"
#include "ipfs/exchange/bitswap/wantlist_queue.h"
#include "ipfs/exchange/bitswap/peer_request_queue.h"
/***
* Implementation of the bitswap engine
*/
/***
* Allocate resources for a BitswapEngine
* @returns a new struct BitswapEngine
*/
struct BitswapEngine* ipfs_bitswap_engine_new() {
struct BitswapEngine* engine = (struct BitswapEngine*) malloc(sizeof(struct BitswapEngine));
if (engine != NULL) {
engine->shutting_down = 0;
}
return engine;
}
/***
* Deallocate resources from struct BitswapEngine
* @param engine the engine to free
* @returns true(1)
*/
int ipfs_bitswap_engine_free(struct BitswapEngine* engine) {
free(engine);
return 1;
}
/***
* A separate thread that processes the queue of local requests
* @param context the context
*/
void* ipfs_bitswap_engine_wantlist_processor_start(void* ctx) {
struct BitswapContext* context = (struct BitswapContext*)ctx;
// the loop
while (!context->bitswap_engine->shutting_down) {
struct WantListQueueEntry* item = ipfs_bitswap_wantlist_queue_pop(context->localWantlist);
if (item != NULL) {
// if there is something on the queue process it.
ipfs_bitswap_wantlist_process_entry(context, item);
} else {
// if there is nothing on the queue, wait...
sleep(2);
}
}
return NULL;
}
/***
* A separate thread that processes the queue of remote requests
* @param context the context
*/
void* ipfs_bitswap_engine_peer_request_processor_start(void* ctx) {
struct BitswapContext* context = (struct BitswapContext*)ctx;
// the loop
struct Libp2pLinkedList* current = context->ipfsNode->peerstore->head_entry;
int did_some_processing = 0;
while (1) {
if (context->bitswap_engine->shutting_down) // system shutting down
break;
if (current == NULL) { // the PeerStore is empty
libp2p_logger_debug("bitswap_engine", "Peerstore is empty. Pausing.\n");
sleep(1);
continue;
}
if (current->item == NULL) {
// error
libp2p_logger_error("bitswap_engine", "Peerstore has a null entry.\n");
break;
}
// see if they want something
struct Libp2pPeer* current_peer_entry = ((struct PeerEntry*)current->item)->peer;
if (current_peer_entry == NULL) {
// error
libp2p_logger_error("bitswap_engine", "Peerstore has an item that is a null peer.\n");
break;
}
if (current_peer_entry->connection_type == CONNECTION_TYPE_CONNECTED) {
if (current_peer_entry->sessionContext == NULL || current_peer_entry->sessionContext->default_stream == NULL) {
current_peer_entry->connection_type = CONNECTION_TYPE_NOT_CONNECTED;
} else {
libp2p_logger_debug("bitswap_engine", "We're connected to %s. Lets see if there is a message waiting for us.\n", libp2p_peer_id_to_string(current_peer_entry));
int retVal = current_peer_entry->sessionContext->default_stream->peek(current_peer_entry->sessionContext);
if (retVal < 0) {
libp2p_logger_debug("bitswap_engine", "We thought we were connected, but Peek reported an error.\n");
libp2p_peer_handle_connection_error(current_peer_entry);
} else if (retVal > 0) {
libp2p_logger_debug("bitswap_engine", "%d bytes waiting on network for peer %s.\n", retVal, libp2p_peer_id_to_string(current_peer_entry));
unsigned char* buffer = NULL;
size_t buffer_len = 0;
if (current_peer_entry->sessionContext->default_stream->read(current_peer_entry->sessionContext, &buffer, &buffer_len, 1)) {
// handle it
int retVal = libp2p_protocol_marshal(buffer, buffer_len, current_peer_entry->sessionContext, context->ipfsNode->protocol_handlers);
free(buffer);
did_some_processing = 1;
if (retVal == -1) {
libp2p_logger_error("bitswap_engine", "protocol_marshal tried to handle the network traffic, but failed.\n");
// there was a problem. Clean up
libp2p_peer_handle_connection_error(current_peer_entry);
}
} else {
libp2p_logger_error("bitswap_engine", "It was said that there was %d bytes to read, but there wasn't. Cleaning up connection.\n");
libp2p_peer_handle_connection_error(current_peer_entry);
}
}
}
} else {
if (current_peer_entry->is_local) {
//libp2p_logger_debug("bitswap_engine", "Local peer %s. Skipping.\n", current_peer_entry->id);
} else {
//libp2p_logger_debug("bitswap_engine", "We are not connected to this peer %s.\n", current_peer_entry->id);
}
}
// attempt to get queue and process
struct PeerRequestEntry* entry = ipfs_bitswap_peer_request_queue_find_entry(context->peerRequestQueue, current_peer_entry);
if (entry != NULL) {
//libp2p_logger_debug("bitswap_engine", "Processing queue for peer %s.\n", current_peer_entry->id);
// we have a queue. Do some queue processing
struct PeerRequest* item = entry->current;
if (item != NULL) {
// if there is something on the queue process it.
if (ipfs_bitswap_peer_request_process_entry(context, item))
did_some_processing = 1;
}
}
// get next peer (or reset to head entry)
if (current->next == NULL) {
current = context->ipfsNode->peerstore->head_entry;
if (!did_some_processing) {
// we did nothing in this run through the peerstore. sleep for a sec
sleep(1);
}
did_some_processing = 0;
}
else {
//libp2p_logger_debug("bitswap_engine", "Moving on to the next peer.\n");
current = current->next;
}
}
return NULL;
}
/**
* Starts the bitswap engine that processes queue items. There
* should only be one of these per ipfs instance.
*
* @param context the context
* @returns true(1) on success, false(0) otherwise
*/
int ipfs_bitswap_engine_start(const struct BitswapContext* context) {
context->bitswap_engine->shutting_down = 0;
// fire off the threads
if (pthread_create(&context->bitswap_engine->wantlist_processor_thread, NULL, ipfs_bitswap_engine_wantlist_processor_start, (void*)context)) {
return 0;
}
if (pthread_create(&context->bitswap_engine->peer_request_processor_thread, NULL, ipfs_bitswap_engine_peer_request_processor_start, (void*)context)) {
ipfs_bitswap_engine_stop(context);
return 0;
}
return 1;
}
/***
* Shut down the engine
* @param context the context
* @returns true(1) on success, false(0) otherwise
*/
int ipfs_bitswap_engine_stop(const struct BitswapContext* context) {
context->bitswap_engine->shutting_down = 1;
int error1 = pthread_join(context->bitswap_engine->wantlist_processor_thread, NULL);
int error2 = pthread_join(context->bitswap_engine->peer_request_processor_thread, NULL);
ipfs_bitswap_engine_free(context->bitswap_engine);
return !error1 && !error2;
}