73 lines
1.7 KiB
C
73 lines
1.7 KiB
C
#include <stdio.h>
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#include <string.h>
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#include "ipfs/cid/cid.h"
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#include "ipfs/merkledag/merkledag.h"
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#include "ipfs/merkledag/node.h"
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#include "ipfs/repo/fsrepo/fs_repo.h"
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/**
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* pull objects from ipfs
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*/
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/**
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* get a file by its hash, and write the data to a file
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* @param hash the base58 multihash of the cid
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* @param file_name the file name to write to
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* @returns true(1) on success
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*/
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int ipfs_exporter_to_file(const unsigned char* hash, const char* file_name, const struct FSRepo* fs_repo) {
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// convert hash to cid
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struct Cid* cid = NULL;
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if ( ipfs_cid_decode_hash_from_base58(hash, strlen((char*)hash), &cid) == 0) {
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return 0;
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}
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// find block
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struct Node* read_node = NULL;
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if (ipfs_merkledag_get(cid, &read_node, fs_repo) == 0) {
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ipfs_cid_free(cid);
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return 0;
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}
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// no longer need the cid
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ipfs_cid_free(cid);
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// process blocks
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FILE* file = fopen(file_name, "wb");
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if (file == NULL) {
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ipfs_node_free(read_node);
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return 0;
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}
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size_t bytes_written = fwrite(read_node->data, 1, read_node->data_size, file);
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if (bytes_written != read_node->data_size) {
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fclose(file);
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ipfs_node_free(read_node);
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return 0;
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}
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struct NodeLink* link = read_node->head_link;
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struct Node* link_node = NULL;
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while (link != NULL) {
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if ( ipfs_merkledag_get(link->cid, &link_node, fs_repo) == 0) {
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fclose(file);
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ipfs_node_free(read_node);
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return 0;
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}
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bytes_written = fwrite(link_node->data, 1, link_node->data_size, file);
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if (bytes_written != link_node->data_size) {
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ipfs_node_free(link_node);
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fclose(file);
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ipfs_node_free(read_node);
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return 0;
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}
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ipfs_node_free(link_node);
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link = link->next;
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}
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fclose(file);
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if (read_node != NULL)
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ipfs_node_free(read_node);
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return 1;
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}
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