More buildout of the Bitswap protocol

This commit is contained in:
John Jones 2017-07-24 16:03:56 -05:00
parent 9924d5dcf7
commit 3a8a85e628
6 changed files with 129 additions and 1 deletions

View file

@ -251,6 +251,10 @@ int ipfs_cid_cast(const unsigned char* incoming, size_t incoming_size, struct Ci
/**
* Compare two cids
*
* TODO: find a common denominator between versions and codecs so that
* we can compare apples to apples.
*
* @param a side A
* @param b side B
* @returns < 0 if side A is greater, > 0 if side B is greater, or 0 if equal

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@ -7,7 +7,7 @@ endif
LFLAGS =
DEPS =
OBJS = bitswap.o message.o network.o peer_request_queue.o
OBJS = bitswap.o message.o network.o peer_request_queue.o want_manager.o
%.o: %.c $(DEPS)
$(CC) -c -o $@ $< $(CFLAGS)

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@ -2,10 +2,12 @@
* Methods for the Bitswap exchange
*/
#include <stdlib.h>
#include <unistd.h> // for sleep()
#include "ipfs/core/ipfs_node.h"
#include "ipfs/exchange/exchange.h"
#include "ipfs/exchange/bitswap/bitswap.h"
#include "ipfs/exchange/bitswap/message.h"
#include "ipfs/exchange/bitswap/want_manager.h"
/**
* Create a new bitswap exchange
@ -89,6 +91,10 @@ int ipfs_bitswap_has_block(void* exchangeContext, struct Block* block) {
* Implements the Exchange->GetBlock method
* We're asking for this method to get the block from peers. Perhaps this should be
* taking in a pointer to a callback, as this could take a while (or fail).
* @param exchangeContext a BitswapContext
* @param cid the Cid to look for
* @param block a pointer to where to put the result
* @returns true(1) if found, false(0) if not
*/
int ipfs_bitswap_get_block(void* exchangeContext, struct Cid* cid, struct Block** block) {
struct BitswapContext* bitswapContext = (struct BitswapContext*)exchangeContext;
@ -97,6 +103,30 @@ int ipfs_bitswap_get_block(void* exchangeContext, struct Cid* cid, struct Block*
if (bitswapContext->ipfsNode->blockstore->Get(bitswapContext->ipfsNode->blockstore->blockstoreContext, cid, block))
return 1;
// now ask the network
//NOTE: this timeout should be configurable
int timeout = 10;
int waitSecs = 1;
int timeTaken = 0;
if (ipfs_bitswap_want_manager_add(bitswapContext, cid)) {
// loop waiting for it to fill
while(1) {
if (ipfs_bitswap_want_manager_received(bitswapContext, cid)) {
if (ipfs_bitswap_want_manager_get_block(bitswapContext, cid, block)) {
// NOTE: this should use reference counting
ipfs_bitswap_want_manager_remove(bitswapContext, cid);
return 1;
}
}
//TODO: This is a busy-loop. Find another way.
timeTaken += waitSecs;
if (timeTaken >= timeout) {
// It took too long. Stop looking.
ipfs_bitswap_want_manager_remove(bitswapContext, cid);
break;
}
sleep(waitSecs);
}
}
}
return 0;
}

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@ -0,0 +1,52 @@
#include "ipfs/exchange/bitswap/want_manager.h"
#include "ipfs/exchange/bitswap/wantlist.h"
/***
* Add a Cid to the local wantlist
* @param context the context
* @param cid the Cid
* @returns true(1) on success, false(0) otherwise
*/
int ipfs_bitswap_want_manager_add(const struct BitswapContext* context, const struct Cid* cid) {
// first see if it is already here
// increment the reference count
return 0;
}
/***
* Checks to see if the requested block has been received
* @param context the context
* @param cid the Cid
* @returns true(1) if it has been received, false(0) otherwise
*/
int ipfs_bitswap_want_manager_received(const struct BitswapContext* context, const struct Cid* cid) {
// find the entry
// check the status
return 0;
}
/***
* retrieve a block from the WantManager. NOTE: a call to want_manager_received should be done first
* @param context the context
* @param cid the Cid to get
* @param block a pointer to the block that will be allocated
* @returns true(1) on success, false(0) otherwise
*/
int ipfs_bitswap_want_manager_get_block(const struct BitswapContext* context, const struct Cid* cid, struct Block** block) {
// find the entry
// return a copy of the block
return 0;
}
/***
* We no longer are requesting this block, so remove it from the queue
* NOTE: This is reference counted, as another process may have asked for it.
* @param context the context
* @param cid the Cid
* @returns true(1) on success, false(0) otherwise.
*/
int ipfs_bitswap_want_manager_remove(const struct BitswapContext* context, const struct Cid* cid) {
// decrement the reference count
// if it is zero, remove the entry (lock first)
return 0;
}

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@ -1,3 +1,5 @@
#pragma once
/***
* Bitswap implements the exchange "interface"
* @see ../exchange.h
@ -9,6 +11,7 @@
struct BitswapContext {
struct SessionContext* sessionContext;
struct IpfsNode* ipfsNode;
struct Wantlist* localWantlist;
};
/**

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@ -0,0 +1,39 @@
#pragma once
#include "ipfs/blocks/block.h"
#include "ipfs/cid/cid.h"
#include "ipfs/exchange/bitswap/bitswap.h"
/***
* Add a Cid to the local wantlist
* @param context the context
* @param cid the Cid
* @returns true(1) on success, false(0) otherwise
*/
int ipfs_bitswap_want_manager_add(const struct BitswapContext* context, const struct Cid* cid);
/***
* Checks to see if the requested block has been received
* @param context the context
* @param cid the Cid
* @returns true(1) if it has been received, false(0) otherwise
*/
int ipfs_bitswap_want_manager_received(const struct BitswapContext* context, const struct Cid* cid);
/***
* retrieve a block from the WantManager. NOTE: a call to want_manager_received should be done first
* @param context the context
* @param cid the Cid to get
* @param block a pointer to the block that will be allocated
* @returns true(1) on success, false(0) otherwise
*/
int ipfs_bitswap_want_manager_get_block(const struct BitswapContext* context, const struct Cid* cid, struct Block** block);
/***
* We no longer are requesting this block, so remove it from the queue
* NOTE: This is reference counted, as another process may have asked for it.
* @param context the context
* @param cid the Cid
* @returns true(1) on success, false(0) otherwise.
*/
int ipfs_bitswap_want_manager_remove(const struct BitswapContext* context, const struct Cid* cid);