c-ipfs/importer/exporter.c
2017-09-21 07:51:18 -05:00

297 lines
8.3 KiB
C

#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include "ipfs/cid/cid.h"
#include "ipfs/merkledag/merkledag.h"
#include "ipfs/merkledag/node.h"
#include "ipfs/repo/fsrepo/fs_repo.h"
#include "ipfs/repo/init.h"
#include "ipfs/core/ipfs_node.h"
#include "libp2p/utils/logger.h"
/**
* pull objects from ipfs
*/
/***
* Helper method to retrieve a protobuf'd Node from the router
* @param local_node the context
* @param hash the hash to retrieve
* @param hash_size the length of the hash
* @param result a place to store the Node
* @returns true(1) on success, otherwise false(0)
*/
int ipfs_exporter_get_node(struct IpfsNode* local_node, const unsigned char* hash, const size_t hash_size,
struct HashtableNode** result) {
unsigned char *buffer = NULL;
size_t buffer_size = 0;
int retVal = 0;
struct KademliaMessage* msg = NULL;
if (local_node->routing->GetValue(local_node->routing, hash, hash_size, (void**)&buffer, &buffer_size)) {
libp2p_logger_debug("exporter", "get_node got a value. Converting it to a HashtableNode\n");
// unprotobuf
if (ipfs_hashtable_node_protobuf_decode(buffer, buffer_size, result)) {
libp2p_logger_debug("exporter", "Conversion to HashtableNode successful\n");
}
} else {
libp2p_logger_debug("exporter", "get_node got no value. Returning false.\n");
goto exit;
}
// copy in the hash
(*result)->hash_size = hash_size;
(*result)->hash = malloc(hash_size);
memcpy((*result)->hash, hash, hash_size);
retVal = 1;
exit:
if (buffer != NULL)
free(buffer);
if (msg != NULL)
libp2p_message_free(msg);
return retVal;
}
/***
* Get a file by its hash, and write the data to a filestream
* @param hash the base58 multihash of the cid
* @param file_descriptor where to write
* @param local_node the context
*/
int ipfs_exporter_to_filestream(const unsigned char* hash, FILE* file_descriptor, struct IpfsNode* local_node) {
// convert hash to cid
struct Cid* cid = NULL;
if ( ipfs_cid_decode_hash_from_base58(hash, strlen((char*)hash), &cid) == 0) {
return 0;
}
// find block
struct HashtableNode* read_node = NULL;
if (!ipfs_exporter_get_node(local_node, cid->hash, cid->hash_length, &read_node)) {
ipfs_cid_free(cid);
return 0;
}
// no longer need the cid
ipfs_cid_free(cid);
if (read_node->head_link == NULL) {
// convert the node's data into a UnixFS data block
struct UnixFS* unix_fs;
ipfs_unixfs_protobuf_decode(read_node->data, read_node->data_size, &unix_fs);
size_t bytes_written = fwrite(unix_fs->bytes, 1, unix_fs->bytes_size, file_descriptor);
if (bytes_written != unix_fs->bytes_size) {
ipfs_hashtable_node_free(read_node);
ipfs_unixfs_free(unix_fs);
return 0;
}
ipfs_unixfs_free(unix_fs);
} else {
struct NodeLink* link = read_node->head_link;
struct HashtableNode* link_node = NULL;
while (link != NULL) {
if ( !ipfs_exporter_get_node(local_node, link->hash, link->hash_size, &link_node)) {
ipfs_hashtable_node_free(read_node);
return 0;
}
struct UnixFS* unix_fs;
ipfs_unixfs_protobuf_decode(link_node->data, link_node->data_size, &unix_fs);
size_t bytes_written = fwrite(unix_fs->bytes, 1, unix_fs->bytes_size, file_descriptor);
if (bytes_written != unix_fs->bytes_size) {
ipfs_hashtable_node_free(link_node);
ipfs_hashtable_node_free(read_node);
ipfs_unixfs_free(unix_fs);
return 0;
}
ipfs_hashtable_node_free(link_node);
ipfs_unixfs_free(unix_fs);
link = link->next;
}
}
if (read_node != NULL)
ipfs_hashtable_node_free(read_node);
return 1;
}
/**
* get a file by its hash, and write the data to a file
* @param hash the base58 multihash of the cid
* @param file_name the file name to write to
* @returns true(1) on success
*/
int ipfs_exporter_to_file(const unsigned char* hash, const char* file_name, struct IpfsNode *local_node) {
// process blocks
FILE* file = fopen(file_name, "wb");
if (file == NULL) {
return 0;
}
int retVal = ipfs_exporter_to_filestream(hash, file, local_node);
fclose(file);
return retVal;
}
/**
* get a file by its hash, and write the data to a file
* @param hash the base58 multihash of the cid
* @param file_name the file name to write to
* @returns true(1) on success
*/
int ipfs_exporter_to_console(const unsigned char* hash, struct IpfsNode *local_node) {
// convert hash to cid
struct Cid* cid = NULL;
if ( ipfs_cid_decode_hash_from_base58(hash, strlen((char*)hash), &cid) == 0) {
return 0;
}
// find block
struct HashtableNode* read_node = NULL;
if (!ipfs_exporter_get_node(local_node, cid->hash, cid->hash_length, &read_node)) {
ipfs_cid_free(cid);
return 0;
}
// no longer need the cid
ipfs_cid_free(cid);
// process blocks
struct NodeLink* link = read_node->head_link;
printf("{Links:[");
while (link != NULL) {
unsigned char b58[100];
ipfs_cid_hash_to_base58(link->hash, link->hash_size, b58, 100);
printf("{\"Name\":\"%s\",\"Hash\":\"%s\",\"Size\":%lu}", (link->name != NULL ? link->name : ""), (char*)b58, link->t_size);
link = link->next;
}
printf("],\"Data\":\"");
for(size_t i = 0LU; i < read_node->data_size; i++) {
printf("%02x", read_node->data[i]);
}
printf("\"}\n");
if (read_node != NULL)
ipfs_hashtable_node_free(read_node);
return 1;
}
/***
* Called from the command line with ipfs object get [hash].
* Retrieves the object pointed to by hash, and displays
* its block data (links and data elements)
* @param argc number of arguments
* @param argv arguments
* @returns true(1) on success
*/
int ipfs_exporter_object_get(int argc, char** argv) {
char* repo_path = NULL;
pthread_t api_pth = 0;
if (!ipfs_repo_get_directory(argc, argv, &repo_path)) {
fprintf(stderr, "Unable to open repository: %s\n", repo_path);
return 0;
}
struct IpfsNode* local_node = NULL;
if (!ipfs_node_online_new(&api_pth, repo_path, &local_node))
return 0;
// find hash
int retVal = ipfs_exporter_to_console((unsigned char*)argv[3], local_node);
ipfs_node_free(&api_pth, local_node);
return retVal;
}
/**
* rebuild a file based on this HashtableNode, traversing links
* @param node the HashtableNode to start with
* @param local_node the context
* @param file the filestream to fill
* @returns true(1) on success, false(0) otherwise
*/
int ipfs_exporter_cat_node(struct HashtableNode* node, struct IpfsNode* local_node, FILE *file) {
// process this node, then move on to the links
// build the unixfs
struct UnixFS* unix_fs;
ipfs_unixfs_protobuf_decode(node->data, node->data_size, &unix_fs);
for(size_t i = 0LU; i < unix_fs->bytes_size; i++) {
fprintf(file, "%c", unix_fs->bytes[i]);
}
ipfs_unixfs_free(unix_fs);
// process links
struct NodeLink* current = node->head_link;
while (current != NULL) {
// find the node
struct HashtableNode* child_node = NULL;
if (!ipfs_exporter_get_node(local_node, current->hash, current->hash_size, &child_node)) {
return 0;
}
ipfs_exporter_cat_node(child_node, local_node, file);
ipfs_hashtable_node_free(child_node);
current = current->next;
}
return 1;
}
int ipfs_exporter_object_cat_to_file(struct IpfsNode *local_node, unsigned char* hash, int hash_size, FILE* file) {
struct HashtableNode* read_node = NULL;
// find block
if (!ipfs_exporter_get_node(local_node, hash, hash_size, &read_node)) {
return 0;
}
int retVal = ipfs_exporter_cat_node(read_node, local_node, file);
ipfs_hashtable_node_free(read_node);
return retVal;
}
/***
* Called from the command line with ipfs cat [hash]. Retrieves the object
* pointed to by hash, and displays its raw block data to the console
* @param argc number of arguments
* @param argv arguments
* @returns true(1) on success
*/
int ipfs_exporter_object_cat(int argc, char** argv) {
struct IpfsNode *local_node = NULL;
char* repo_dir = NULL;
if (!ipfs_repo_get_directory(argc, argv, &repo_dir)) {
fprintf(stderr, "Unable to open repo: %s\n", repo_dir);
return 0;
}
if (!ipfs_node_offline_new(repo_dir, &local_node))
return 0;
if (local_node->mode == MODE_API_AVAILABLE) {
// TODO: we should use the api for this
return 0;
} else {
// find hash
// convert hash to cid
struct Cid* cid = NULL;
if ( ipfs_cid_decode_hash_from_base58((unsigned char*)argv[2], strlen(argv[2]), &cid) == 0) {
return 0;
}
int retVal = ipfs_exporter_object_cat_to_file(local_node, cid->hash, cid->hash_length, stdout);
ipfs_cid_free(cid);
return retVal;
}
return 0;
}