diff options
Diffstat (limited to 'src/fs/fs_namespace.c')
| -rw-r--r-- | src/fs/fs_namespace.c | 954 |
1 files changed, 954 insertions, 0 deletions
diff --git a/src/fs/fs_namespace.c b/src/fs/fs_namespace.c new file mode 100644 index 0000000..bfd7594 --- /dev/null +++ b/src/fs/fs_namespace.c @@ -0,0 +1,954 @@ +/* + This file is part of GNUnet + (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file fs/fs_namespace.c + * @brief create and destroy namespaces + * @author Christian Grothoff + */ +#include "platform.h" +#include "gnunet_constants.h" +#include "gnunet_signatures.h" +#include "gnunet_util_lib.h" +#include "gnunet_fs_service.h" +#include "fs_api.h" + + +/** + * Maximum legal size for an sblock. + */ +#define MAX_SBLOCK_SIZE (60 * 1024) + + +/** + * Return the name of the directory in which we store + * our local namespaces (or rather, their public keys). + * + * @param h global fs handle + * @return NULL on error, otherwise the name of the directory + */ +static char * +get_namespace_directory (struct GNUNET_FS_Handle *h) +{ + char *dn; + + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_filename (h->cfg, "FS", "IDENTITY_DIR", + &dn)) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Configuration fails to specify `%s' in section `%s'\n"), + "IDENTITY_DIR", "fs"); + return NULL; + } + return dn; +} + + +/** + * Return the name of the directory in which we store + * the update information graph for the given local namespace. + * + * @param ns namespace handle + * @return NULL on error, otherwise the name of the directory + */ +static char * +get_update_information_directory (struct GNUNET_FS_Namespace *ns) +{ + char *dn; + char *ret; + + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_filename (ns->h->cfg, "FS", "UPDATE_DIR", + &dn)) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Configuration fails to specify `%s' in section `%s'\n"), + "UPDATE_DIR", "fs"); + return NULL; + } + GNUNET_asprintf (&ret, "%s%s%s", dn, DIR_SEPARATOR_STR, ns->name); + GNUNET_free (dn); + return ret; +} + + +/** + * Write the namespace update node graph to a file. + * + * @param ns namespace to dump + */ +static void +write_update_information_graph (struct GNUNET_FS_Namespace *ns) +{ + char *fn; + struct GNUNET_BIO_WriteHandle *wh; + unsigned int i; + struct NamespaceUpdateNode *n; + char *uris; + + fn = get_update_information_directory (ns); + wh = GNUNET_BIO_write_open (fn); + if (wh == NULL) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to open `%s' for writing: %s\n"), STRERROR (errno)); + GNUNET_free (fn); + return; + } + if (GNUNET_OK != GNUNET_BIO_write_int32 (wh, ns->update_node_count)) + goto END; + for (i = 0; i < ns->update_node_count; i++) + { + n = ns->update_nodes[i]; + uris = GNUNET_FS_uri_to_string (n->uri); + if ((GNUNET_OK != GNUNET_BIO_write_string (wh, n->id)) || + (GNUNET_OK != GNUNET_BIO_write_meta_data (wh, n->md)) || + (GNUNET_OK != GNUNET_BIO_write_string (wh, n->update)) || + (GNUNET_OK != GNUNET_BIO_write_string (wh, uris))) + { + GNUNET_free (uris); + break; + } + GNUNET_free (uris); + } +END: + if (GNUNET_OK != GNUNET_BIO_write_close (wh)) + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Failed to write `%s': %s\n"), + STRERROR (errno)); + GNUNET_free (fn); +} + + +/** + * Read the namespace update node graph from a file. + * + * @param ns namespace to read + */ +static void +read_update_information_graph (struct GNUNET_FS_Namespace *ns) +{ + char *fn; + struct GNUNET_BIO_ReadHandle *rh; + unsigned int i; + struct NamespaceUpdateNode *n; + char *uris; + uint32_t count; + char *emsg; + + fn = get_update_information_directory (ns); + if (GNUNET_YES != GNUNET_DISK_file_test (fn)) + { + GNUNET_free (fn); + return; + } + rh = GNUNET_BIO_read_open (fn); + if (rh == NULL) + { + GNUNET_free (fn); + return; + } + if (GNUNET_OK != GNUNET_BIO_read_int32 (rh, &count)) + { + GNUNET_break (0); + goto END; + } + if (count > 1024 * 1024) + { + GNUNET_break (0); + goto END; + } + if (count == 0) + { + GNUNET_break (GNUNET_OK == GNUNET_BIO_read_close (rh, NULL)); + GNUNET_free (fn); + return; + } + ns->update_nodes = + GNUNET_malloc (count * sizeof (struct NamespaceUpdateNode *)); + + for (i = 0; i < count; i++) + { + n = GNUNET_malloc (sizeof (struct NamespaceUpdateNode)); + if ((GNUNET_OK != GNUNET_BIO_read_string (rh, "identifier", &n->id, 1024)) + || (GNUNET_OK != GNUNET_BIO_read_meta_data (rh, "meta", &n->md)) || + (GNUNET_OK != + GNUNET_BIO_read_string (rh, "update-id", &n->update, 1024)) || + (GNUNET_OK != GNUNET_BIO_read_string (rh, "uri", &uris, 1024 * 2))) + { + GNUNET_break (0); + GNUNET_free_non_null (n->id); + GNUNET_free_non_null (n->update); + if (n->md != NULL) + GNUNET_CONTAINER_meta_data_destroy (n->md); + GNUNET_free (n); + break; + } + n->uri = GNUNET_FS_uri_parse (uris, &emsg); + GNUNET_free (uris); + if (n->uri == NULL) + { + GNUNET_break (0); + GNUNET_free (emsg); + GNUNET_free (n->id); + GNUNET_free_non_null (n->update); + GNUNET_CONTAINER_meta_data_destroy (n->md); + GNUNET_free (n); + break; + } + ns->update_nodes[i] = n; + } + ns->update_node_count = i; +END: + if (GNUNET_OK != GNUNET_BIO_read_close (rh, &emsg)) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Failed to write `%s': %s\n"), emsg); + GNUNET_free (emsg); + } + GNUNET_free (fn); +} + + + + +/** + * Create a namespace with the given name; if one already + * exists, return a handle to the existing namespace. + * + * @param h handle to the file sharing subsystem + * @param name name to use for the namespace + * @return handle to the namespace, NULL on error + */ +struct GNUNET_FS_Namespace * +GNUNET_FS_namespace_create (struct GNUNET_FS_Handle *h, const char *name) +{ + char *dn; + char *fn; + struct GNUNET_FS_Namespace *ret; + + dn = get_namespace_directory (h); + GNUNET_asprintf (&fn, "%s%s%s", dn, DIR_SEPARATOR_STR, name); + GNUNET_free (dn); + ret = GNUNET_malloc (sizeof (struct GNUNET_FS_Namespace)); + ret->h = h; + ret->rc = 1; + ret->key = GNUNET_CRYPTO_rsa_key_create_from_file (fn); + if (ret->key == NULL) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to create or read private key for namespace `%s'\n"), + name); + GNUNET_free (ret); + GNUNET_free (fn); + return NULL; + } + ret->name = GNUNET_strdup (name); + ret->filename = fn; + return ret; +} + + +/** + * Duplicate a namespace handle. + * + * @param ns namespace handle + * @return duplicated handle to the namespace + */ +struct GNUNET_FS_Namespace * +GNUNET_FS_namespace_dup (struct GNUNET_FS_Namespace *ns) +{ + ns->rc++; + return ns; +} + + +/** + * Delete a namespace handle. Can be used for a clean shutdown (free + * memory) or also to freeze the namespace to prevent further + * insertions by anyone. + * + * @param namespace handle to the namespace that should be deleted / freed + * @param freeze prevents future insertions; creating a namespace + * with the same name again will create a fresh namespace instead + * + * @return GNUNET_OK on success, GNUNET_SYSERR on error + */ +int +GNUNET_FS_namespace_delete (struct GNUNET_FS_Namespace *namespace, int freeze) +{ + unsigned int i; + struct NamespaceUpdateNode *nsn; + + namespace->rc--; + if (freeze) + { + if (0 != UNLINK (namespace->filename)) + GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "unlink", + namespace->filename); + } + if (0 != namespace->rc) + return GNUNET_OK; + GNUNET_CRYPTO_rsa_key_free (namespace->key); + GNUNET_free (namespace->filename); + GNUNET_free (namespace->name); + for (i = 0; i < namespace->update_node_count; i++) + { + nsn = namespace->update_nodes[i]; + GNUNET_CONTAINER_meta_data_destroy (nsn->md); + GNUNET_FS_uri_destroy (nsn->uri); + GNUNET_free (nsn->id); + GNUNET_free (nsn->update); + GNUNET_free (nsn); + } + GNUNET_array_grow (namespace->update_nodes, namespace->update_node_count, + 0); + if (namespace->update_map != NULL) + GNUNET_CONTAINER_multihashmap_destroy (namespace->update_map); + GNUNET_free (namespace); + return GNUNET_OK; +} + + +/** + * Context for the 'process_namespace' callback. + * Specifies a function to call on each namespace. + */ +struct ProcessNamespaceContext +{ + /** + * Function to call. + */ + GNUNET_FS_NamespaceInfoProcessor cb; + + /** + * Closure for 'cb'. + */ + void *cb_cls; +}; + + +/** + * Function called with a filename of a namespace. Reads the key and + * calls the callback. + * + * @param cls closure (struct ProcessNamespaceContext) + * @param filename complete filename (absolute path) + * @return GNUNET_OK to continue to iterate, + * GNUNET_SYSERR to abort iteration with error! + */ +static int +process_namespace (void *cls, const char *filename) +{ + struct ProcessNamespaceContext *pnc = cls; + struct GNUNET_CRYPTO_RsaPrivateKey *key; + struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk; + GNUNET_HashCode id; + const char *name; + const char *t; + + key = GNUNET_CRYPTO_rsa_key_create_from_file (filename); + if (key == NULL) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _ + ("Failed to read namespace private key file `%s', deleting it!\n"), + filename); + if (0 != UNLINK (filename)) + GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink", filename); + return GNUNET_OK; + } + GNUNET_CRYPTO_rsa_key_get_public (key, &pk); + GNUNET_CRYPTO_rsa_key_free (key); + GNUNET_CRYPTO_hash (&pk, sizeof (pk), &id); + name = filename; + while (NULL != (t = strstr (name, DIR_SEPARATOR_STR))) + name = t + 1; + pnc->cb (pnc->cb_cls, name, &id); + return GNUNET_OK; +} + + +/** + * Build a list of all available local (!) namespaces The returned + * names are only the nicknames since we only iterate over the local + * namespaces. + * + * @param h handle to the file sharing subsystem + * @param cb function to call on each known namespace + * @param cb_cls closure for cb + */ +void +GNUNET_FS_namespace_list (struct GNUNET_FS_Handle *h, + GNUNET_FS_NamespaceInfoProcessor cb, void *cb_cls) +{ + char *dn; + struct ProcessNamespaceContext ctx; + + dn = get_namespace_directory (h); + if (dn == NULL) + return; + ctx.cb = cb; + ctx.cb_cls = cb_cls; + GNUNET_DISK_directory_scan (dn, &process_namespace, &ctx); + GNUNET_free (dn); +} + + +/** + * Context for the SKS publication. + */ +struct GNUNET_FS_PublishSksContext +{ + + /** + * URI of the new entry in the namespace. + */ + struct GNUNET_FS_Uri *uri; + + /** + * Namespace update node to add to namespace on success (or to be + * deleted if publishing failed). + */ + struct NamespaceUpdateNode *nsn; + + /** + * Namespace we're publishing to. + */ + struct GNUNET_FS_Namespace *namespace; + + /** + * Handle to the datastore. + */ + struct GNUNET_DATASTORE_Handle *dsh; + + /** + * Function to call once we're done. + */ + GNUNET_FS_PublishContinuation cont; + + /** + * Closure for cont. + */ + void *cont_cls; + + /** + * Handle for our datastore request. + */ + struct GNUNET_DATASTORE_QueueEntry *dqe; +}; + + +/** + * Function called by the datastore API with + * the result from the PUT (SBlock) request. + * + * @param cls closure of type "struct GNUNET_FS_PublishSksContext*" + * @param success GNUNET_OK on success + * @param min_expiration minimum expiration time required for content to be stored + * @param msg error message (or NULL) + */ +static void +sb_put_cont (void *cls, int success, + struct GNUNET_TIME_Absolute min_expiration, + const char *msg) +{ + struct GNUNET_FS_PublishSksContext *psc = cls; + GNUNET_HashCode hc; + + psc->dqe = NULL; + if (GNUNET_OK != success) + { + if (NULL != psc->cont) + psc->cont (psc->cont_cls, NULL, msg); + GNUNET_FS_publish_sks_cancel (psc); + return; + } + if (NULL != psc->nsn) + { + /* FIXME: this can be done much more + * efficiently by simply appending to the + * file and overwriting the 4-byte header */ + if (psc->namespace->update_nodes == NULL) + read_update_information_graph (psc->namespace); + GNUNET_array_append (psc->namespace->update_nodes, + psc->namespace->update_node_count, psc->nsn); + if (psc->namespace->update_map != NULL) + { + GNUNET_CRYPTO_hash (psc->nsn->id, strlen (psc->nsn->id), &hc); + GNUNET_CONTAINER_multihashmap_put (psc->namespace->update_map, &hc, + psc->nsn, + GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE); + } + psc->nsn = NULL; + write_update_information_graph (psc->namespace); + } + if (NULL != psc->cont) + psc->cont (psc->cont_cls, psc->uri, NULL); + GNUNET_FS_publish_sks_cancel (psc); +} + + +/** + * Publish an SBlock on GNUnet. + * + * @param h handle to the file sharing subsystem + * @param namespace namespace to publish in + * @param identifier identifier to use + * @param update update identifier to use + * @param meta metadata to use + * @param uri URI to refer to in the SBlock + * @param bo block options + * @param options publication options + * @param cont continuation + * @param cont_cls closure for cont + * @return NULL on error ('cont' will still be called) + */ +struct GNUNET_FS_PublishSksContext * +GNUNET_FS_publish_sks (struct GNUNET_FS_Handle *h, + struct GNUNET_FS_Namespace *namespace, + const char *identifier, const char *update, + const struct GNUNET_CONTAINER_MetaData *meta, + const struct GNUNET_FS_Uri *uri, + const struct GNUNET_FS_BlockOptions *bo, + enum GNUNET_FS_PublishOptions options, + GNUNET_FS_PublishContinuation cont, void *cont_cls) +{ + struct GNUNET_FS_PublishSksContext *psc; + struct GNUNET_CRYPTO_AesSessionKey sk; + struct GNUNET_CRYPTO_AesInitializationVector iv; + struct GNUNET_FS_Uri *sks_uri; + char *uris; + size_t size; + size_t slen; + size_t nidlen; + size_t idlen; + ssize_t mdsize; + struct SBlock *sb; + struct SBlock *sb_enc; + char *dest; + struct GNUNET_CONTAINER_MetaData *mmeta; + GNUNET_HashCode key; /* hash of thisId = key */ + GNUNET_HashCode id; /* hash of hc = identifier */ + GNUNET_HashCode query; /* id ^ nsid = DB query */ + + if (NULL == meta) + mmeta = GNUNET_CONTAINER_meta_data_create (); + else + mmeta = GNUNET_CONTAINER_meta_data_duplicate (meta); + uris = GNUNET_FS_uri_to_string (uri); + slen = strlen (uris) + 1; + idlen = strlen (identifier); + if (update != NULL) + nidlen = strlen (update) + 1; + else + nidlen = 1; + mdsize = GNUNET_CONTAINER_meta_data_get_serialized_size (mmeta); + size = sizeof (struct SBlock) + slen + nidlen + mdsize; + if (size > MAX_SBLOCK_SIZE) + { + size = MAX_SBLOCK_SIZE; + mdsize = size - (sizeof (struct SBlock) + slen + nidlen); + } + sb = GNUNET_malloc (sizeof (struct SBlock) + size); + dest = (char *) &sb[1]; + if (update != NULL) + memcpy (dest, update, nidlen); + else + memset (dest, 0, 1); + dest += nidlen; + memcpy (dest, uris, slen); + GNUNET_free (uris); + dest += slen; + mdsize = + GNUNET_CONTAINER_meta_data_serialize (mmeta, &dest, mdsize, + GNUNET_CONTAINER_META_DATA_SERIALIZE_PART); + GNUNET_CONTAINER_meta_data_destroy (mmeta); + if (mdsize == -1) + { + GNUNET_break (0); + GNUNET_free (sb); + if (NULL != cont) + cont (cont_cls, NULL, _("Internal error.")); + return NULL; + } + size = sizeof (struct SBlock) + mdsize + slen + nidlen; + sb_enc = GNUNET_malloc (size); + GNUNET_CRYPTO_hash (identifier, idlen, &key); + GNUNET_CRYPTO_hash (&key, sizeof (GNUNET_HashCode), &id); + sks_uri = GNUNET_malloc (sizeof (struct GNUNET_FS_Uri)); + sks_uri->type = sks; + GNUNET_CRYPTO_rsa_key_get_public (namespace->key, &sb_enc->subspace); + GNUNET_CRYPTO_hash (&sb_enc->subspace, + sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded), + &sks_uri->data.sks.namespace); + sks_uri->data.sks.identifier = GNUNET_strdup (identifier); + GNUNET_CRYPTO_hash_xor (&id, &sks_uri->data.sks.namespace, + &sb_enc->identifier); + GNUNET_CRYPTO_hash_to_aes_key (&key, &sk, &iv); + GNUNET_CRYPTO_aes_encrypt (&sb[1], size - sizeof (struct SBlock), &sk, &iv, + &sb_enc[1]); + sb_enc->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_FS_SBLOCK); + sb_enc->purpose.size = + htonl (slen + mdsize + nidlen + sizeof (struct SBlock) - + sizeof (struct GNUNET_CRYPTO_RsaSignature)); + GNUNET_assert (GNUNET_OK == + GNUNET_CRYPTO_rsa_sign (namespace->key, &sb_enc->purpose, + &sb_enc->signature)); + psc = GNUNET_malloc (sizeof (struct GNUNET_FS_PublishSksContext)); + psc->uri = sks_uri; + psc->cont = cont; + psc->namespace = GNUNET_FS_namespace_dup (namespace); + psc->cont_cls = cont_cls; + if (0 != (options & GNUNET_FS_PUBLISH_OPTION_SIMULATE_ONLY)) + { + GNUNET_free (sb_enc); + GNUNET_free (sb); + sb_put_cont (psc, GNUNET_OK, GNUNET_TIME_UNIT_ZERO_ABS, NULL); + return NULL; + } + psc->dsh = GNUNET_DATASTORE_connect (h->cfg); + if (NULL == psc->dsh) + { + GNUNET_free (sb_enc); + GNUNET_free (sb); + sb_put_cont (psc, GNUNET_NO, GNUNET_TIME_UNIT_ZERO_ABS, _("Failed to connect to datastore.")); + return NULL; + } + GNUNET_CRYPTO_hash_xor (&sks_uri->data.sks.namespace, &id, &query); + if (NULL != update) + { + psc->nsn = GNUNET_malloc (sizeof (struct NamespaceUpdateNode)); + psc->nsn->id = GNUNET_strdup (identifier); + psc->nsn->update = GNUNET_strdup (update); + psc->nsn->md = GNUNET_CONTAINER_meta_data_duplicate (meta); + psc->nsn->uri = GNUNET_FS_uri_dup (uri); + } + psc->dqe = GNUNET_DATASTORE_put (psc->dsh, 0, &sb_enc->identifier, size, sb_enc, + GNUNET_BLOCK_TYPE_FS_SBLOCK, bo->content_priority, + bo->anonymity_level, bo->replication_level, + bo->expiration_time, -2, 1, + GNUNET_CONSTANTS_SERVICE_TIMEOUT, &sb_put_cont, psc); + GNUNET_free (sb); + GNUNET_free (sb_enc); + return psc; +} + + +/** + * Abort the SKS publishing operation. + * + * @param psc context of the operation to abort. + */ +void +GNUNET_FS_publish_sks_cancel (struct GNUNET_FS_PublishSksContext *psc) +{ + if (NULL != psc->dqe) + { + GNUNET_DATASTORE_cancel (psc->dqe); + psc->dqe = NULL; + } + if (NULL != psc->dsh) + { + GNUNET_DATASTORE_disconnect (psc->dsh, GNUNET_NO); + psc->dsh = NULL; + } + GNUNET_FS_namespace_delete (psc->namespace, GNUNET_NO); + GNUNET_FS_uri_destroy (psc->uri); + if (NULL != psc->nsn) + { + GNUNET_CONTAINER_meta_data_destroy (psc->nsn->md); + GNUNET_FS_uri_destroy (psc->nsn->uri); + GNUNET_free (psc->nsn->id); + GNUNET_free (psc->nsn->update); + GNUNET_free (psc->nsn); + } + GNUNET_free (psc); +} + + +/** + * Closure for 'process_update_node'. + */ +struct ProcessUpdateClosure +{ + /** + * Function to call for each node. + */ + GNUNET_FS_IdentifierProcessor ip; + + /** + * Closure for 'ip'. + */ + void *ip_cls; +}; + + +/** + * Call the iterator in the closure for each node. + * + * @param cls closure (of type 'struct ProcessUpdateClosure *') + * @param key current key code + * @param value value in the hash map (of type 'struct NamespaceUpdateNode *') + * @return GNUNET_YES if we should continue to + * iterate, + * GNUNET_NO if not. + */ +static int +process_update_node (void *cls, const GNUNET_HashCode * key, void *value) +{ + struct ProcessUpdateClosure *pc = cls; + struct NamespaceUpdateNode *nsn = value; + + pc->ip (pc->ip_cls, nsn->id, nsn->uri, nsn->md, nsn->update); + return GNUNET_YES; +} + + +/** + * Closure for 'find_trees'. + */ +struct FindTreeClosure +{ + /** + * Namespace we are operating on. + */ + struct GNUNET_FS_Namespace *namespace; + + /** + * Array with 'head's of TREEs. + */ + struct NamespaceUpdateNode **tree_array; + + /** + * Size of 'tree_array' + */ + unsigned int tree_array_size; + + /** + * Current generational ID used. + */ + unsigned int nug; + + /** + * Identifier for the current TREE, or UINT_MAX for none yet. + */ + unsigned int id; +}; + + +/** + * Find all nodes reachable from the current node (including the + * current node itself). If they are in no tree, add them to the + * current one. If they are the head of another tree, merge the + * trees. If they are in the middle of another tree, let them be. + * We can tell that a node is already in an tree by checking if + * its 'nug' field is set to the current 'nug' value. It is the + * head of an tree if it is in the 'tree_array' under its respective + * 'tree_id'. + * + * In short, we're trying to find the smallest number of tree to + * cover a directed graph. + * + * @param cls closure (of type 'struct FindTreeClosure') + * @param key current key code + * @param value value in the hash map + * @return GNUNET_YES if we should continue to + * iterate, + * GNUNET_NO if not. + */ +static int +find_trees (void *cls, const GNUNET_HashCode * key, void *value) +{ + struct FindTreeClosure *fc = cls; + struct NamespaceUpdateNode *nsn = value; + GNUNET_HashCode hc; + + if (nsn->nug == fc->nug) + { + if (nsn->tree_id == UINT_MAX) + return GNUNET_YES; /* circular */ + GNUNET_assert (nsn->tree_id < fc->tree_array_size); + if (fc->tree_array[nsn->tree_id] != nsn) + return GNUNET_YES; /* part of "another" (directed) TREE, + * and not root of it, end trace */ + if (nsn->tree_id == fc->id) + return GNUNET_YES; /* that's our own root (can this be?) */ + /* merge existing TREE, we have a root for both */ + fc->tree_array[nsn->tree_id] = NULL; + if (fc->id == UINT_MAX) + fc->id = nsn->tree_id; /* take over ID */ + } + else + { + nsn->nug = fc->nug; + nsn->tree_id = UINT_MAX; /* mark as undef */ + /* trace */ + GNUNET_CRYPTO_hash (nsn->update, strlen (nsn->update), &hc); + GNUNET_CONTAINER_multihashmap_get_multiple (fc->namespace->update_map, &hc, + &find_trees, fc); + } + return GNUNET_YES; +} + + +/** + * List all of the identifiers in the namespace for which we could + * produce an update. Namespace updates form a graph where each node + * has a name. Each node can have any number of URI/meta-data entries + * which can each be linked to other nodes. Cycles are possible. + * + * Calling this function with "next_id" NULL will cause the library to + * call "ip" with a root for each strongly connected component of the + * graph (a root being a node from which all other nodes in the Tree + * are reachable). + * + * Calling this function with "next_id" being the name of a node will + * cause the library to call "ip" with all children of the node. Note + * that cycles within the final tree are possible (including self-loops). + * I know, odd definition of a tree, but the GUI will display an actual + * tree (GtkTreeView), so that's what counts for the term here. + * + * @param namespace namespace to inspect for updateable content + * @param next_id ID to look for; use NULL to look for tree roots + * @param ip function to call on each updateable identifier + * @param ip_cls closure for ip + */ +void +GNUNET_FS_namespace_list_updateable (struct GNUNET_FS_Namespace *namespace, + const char *next_id, + GNUNET_FS_IdentifierProcessor ip, + void *ip_cls) +{ + unsigned int i; + unsigned int nug; + GNUNET_HashCode hc; + struct NamespaceUpdateNode *nsn; + struct ProcessUpdateClosure pc; + struct FindTreeClosure fc; + + if (namespace->update_nodes == NULL) + read_update_information_graph (namespace); + if (namespace->update_nodes == NULL) + { + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "No updateable nodes found for ID `%s'\n", next_id); + return; /* no nodes */ + } + if (namespace->update_map == NULL) + { + /* need to construct */ + namespace->update_map = + GNUNET_CONTAINER_multihashmap_create (2 + + 3 * namespace->update_node_count / + 4); + for (i = 0; i < namespace->update_node_count; i++) + { + nsn = namespace->update_nodes[i]; + GNUNET_CRYPTO_hash (nsn->id, strlen (nsn->id), &hc); + GNUNET_CONTAINER_multihashmap_put (namespace->update_map, &hc, nsn, + GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE); + } + } + if (next_id != NULL) + { + GNUNET_CRYPTO_hash (next_id, strlen (next_id), &hc); + pc.ip = ip; + pc.ip_cls = ip_cls; + GNUNET_CONTAINER_multihashmap_get_multiple (namespace->update_map, &hc, + &process_update_node, &pc); + return; + } + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Calculating TREEs to find roots of update trees\n"); + /* Find heads of TREEs in update graph */ + nug = ++namespace->nug_gen; + fc.tree_array = NULL; + fc.tree_array_size = 0; + + for (i = 0; i < namespace->update_node_count; i++) + { + nsn = namespace->update_nodes[i]; + if (nsn->nug == nug) + { + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "TREE of node `%s' is %u\n", nsn->id, + nsn->nug); + continue; /* already placed in TREE */ + } + GNUNET_CRYPTO_hash (nsn->update, strlen (nsn->update), &hc); + nsn->nug = nug; + nsn->tree_id = UINT_MAX; + fc.id = UINT_MAX; + fc.nug = nug; + fc.namespace = namespace; + GNUNET_CONTAINER_multihashmap_get_multiple (namespace->update_map, &hc, + &find_trees, &fc); + if (fc.id == UINT_MAX) + { + /* start new TREE */ + for (fc.id = 0; fc.id < fc.tree_array_size; fc.id++) + { + if (fc.tree_array[fc.id] == NULL) + { + fc.tree_array[fc.id] = nsn; + nsn->tree_id = fc.id; + break; + } + } + if (fc.id == fc.tree_array_size) + { + GNUNET_array_append (fc.tree_array, fc.tree_array_size, nsn); + nsn->tree_id = fc.id; + } + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Starting new TREE %u with node `%s'\n", nsn->tree_id, + nsn->id); + /* put all nodes with same identifier into this TREE */ + GNUNET_CRYPTO_hash (nsn->id, strlen (nsn->id), &hc); + fc.id = nsn->tree_id; + fc.nug = nug; + fc.namespace = namespace; + GNUNET_CONTAINER_multihashmap_get_multiple (namespace->update_map, &hc, + &find_trees, &fc); + } + else + { + /* make head of TREE "id" */ + fc.tree_array[fc.id] = nsn; + nsn->tree_id = fc.id; + } + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "TREE of node `%s' is %u\n", nsn->id, + fc.id); + } + for (i = 0; i < fc.tree_array_size; i++) + { + nsn = fc.tree_array[i]; + if (NULL != nsn) + { + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Root of TREE %u is node `%s'\n", i, + nsn->id); + ip (ip_cls, nsn->id, nsn->uri, nsn->md, nsn->update); + } + } + GNUNET_array_grow (fc.tree_array, fc.tree_array_size, 0); + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Done processing TREEs\n"); +} + + +/* end of fs_namespace.c */ |