forked from agorise/c-ipfs
c2fe60949e
Files can be refered to directly using their hash, or the hash of their directory and the file name.
91 lines
2.6 KiB
C
91 lines
2.6 KiB
C
/**
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* A basic storage building block of the IPFS system
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "libp2p/crypto/sha256.h"
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#include "mh/multihash.h"
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#include "mh/hashes.h"
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#include "ipfs/merkledag/merkledag.h"
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#include "ipfs/unixfs/unixfs.h"
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/***
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* Adds a node to the dagService and blockService
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* @param node the node to add
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* @param fs_repo the repo to add to
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* @param bytes_written the number of bytes written
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* @returns true(1) on success
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*/
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int ipfs_merkledag_add(struct Node* node, struct FSRepo* fs_repo, size_t* bytes_written) {
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// taken from merkledag.go line 59
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int retVal = 0;
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// compute the hash if necessary
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if (node->hash == NULL) {
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size_t protobuf_size = ipfs_node_protobuf_encode_size(node);
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unsigned char protobuf[protobuf_size];
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size_t bytes_encoded;
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retVal = ipfs_node_protobuf_encode(node, protobuf, protobuf_size, &bytes_encoded);
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node->hash_size = 32;
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node->hash = (unsigned char*)malloc(node->hash_size);
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if (node->hash == NULL) {
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return 0;
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}
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if (libp2p_crypto_hashing_sha256(protobuf, bytes_encoded, &node->hash[0]) == 0) {
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free(node->hash);
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return 0;
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}
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}
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// write to block store & datastore
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retVal = ipfs_repo_fsrepo_node_write(node, fs_repo, bytes_written);
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if (retVal == 0) {
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return 0;
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}
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// TODO: call HasBlock (unsure why as yet)
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return 1;
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}
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/***
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* Retrieves a node from the datastore based on the hash
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* @param hash the key to look for
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* @param hash_size the length of the key
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* @param node the node to be created
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* @param fs_repo the repository
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* @returns true(1) on success
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*/
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int ipfs_merkledag_get(const unsigned char* hash, size_t hash_size, struct Node** node, const struct FSRepo* fs_repo) {
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int retVal = 1;
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size_t key_length = 100;
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unsigned char key[key_length];
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// look for the node in the datastore. If it is not there, it is not a node.
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// If it exists, it is only a block.
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retVal = fs_repo->config->datastore->datastore_get((char*)hash, hash_size, key, key_length, &key_length, fs_repo->config->datastore);
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if (retVal == 0)
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return 0;
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// we have the record from the db. Go get the node from the blockstore
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retVal = ipfs_repo_fsrepo_node_read(hash, hash_size, node, fs_repo);
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if (retVal == 0) {
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return 0;
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}
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return 1;
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}
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int ipfs_merkledag_get_by_multihash(const unsigned char* multihash, size_t multihash_length, struct Node** node, const struct FSRepo* fs_repo) {
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// convert to hash
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size_t hash_size = 0;
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unsigned char* hash = NULL;
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if (mh_multihash_digest(multihash, multihash_length, &hash, &hash_size) < 0) {
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return 0;
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}
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return ipfs_merkledag_get(hash, hash_size, node, fs_repo);
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}
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