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13 General Public License for more details.
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21 * @author Bartlomiej Polot
22 * @file regex/regex_block_lib.c
23 * @brief functions for manipulating non-accept blocks stored for
27 #include "regex_block_lib.h"
29 #define LOG(kind,...) GNUNET_log_from (kind,"regex-bck",__VA_ARGS__)
32 * Struct to keep track of the xquery while iterating all the edges in a block.
34 struct regex_block_xquery_ctx
37 * Xquery: string we are looking for.
42 * Has any edge matched the xquery so far? (GNUNET_OK / GNUNET_NO)
47 * Key of the block we are iterating (for debug purposes).
54 * Iterator over all edges in a block, checking for a presence of a given query.
56 * @param cls Closure, (xquery context).
57 * @param token Token that follows to next state.
58 * @param len Lenght of token.
59 * @param key Hash of next state.
61 * @return GNUNET_YES, to keep iterating
64 check_edge (void *cls,
67 const struct GNUNET_HashCode *key)
69 struct regex_block_xquery_ctx *ctx = cls;
71 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
72 "edge %.*s [%u]: %s->%s\n",
73 (int) len, token, len, ctx->key, GNUNET_h2s(key));
74 if (NULL == ctx->xquery)
76 if (strlen (ctx->xquery) < len)
77 return GNUNET_YES; /* too long */
78 if (0 == strncmp (ctx->xquery, token, len))
79 ctx->found = GNUNET_OK;
80 return GNUNET_YES; /* keep checking for malformed data! */
85 REGEX_BLOCK_check (const struct RegexBlock *block,
90 struct regex_block_xquery_ctx ctx;
92 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
93 "Checking block with xquery `%s'\n",
94 NULL != xquery ? xquery : "NULL");
95 if ( (GNUNET_YES == ntohl (block->accepting)) &&
96 ( (NULL == xquery) || ('\0' == xquery[0]) ) )
99 ctx.found = GNUNET_NO;
100 ctx.key = GNUNET_strdup (GNUNET_h2s (&block->key));
101 res = REGEX_BLOCK_iterate (block, size, &check_edge, &ctx);
102 GNUNET_free (ctx.key);
103 if (GNUNET_SYSERR == res)
104 return GNUNET_SYSERR;
112 REGEX_BLOCK_iterate (const struct RegexBlock *block,
114 REGEX_INTERNAL_EgdeIterator iterator,
117 struct RegexEdge *edge;
119 unsigned int n_token;
124 offset = sizeof (struct RegexBlock);
125 if (offset >= size) /* Is it safe to access the regex block? */
128 return GNUNET_SYSERR;
130 n = ntohl (block->n_proof);
132 if (offset >= size) /* Is it safe to access the regex proof? */
135 return GNUNET_SYSERR;
137 aux = (char *) &block[1]; /* Skip regex block */
138 aux = &aux[n]; /* Skip regex proof */
139 n = ntohl (block->n_edges);
140 LOG (GNUNET_ERROR_TYPE_DEBUG,
141 "Start iterating block of size %u, proof %u, off %u edges %u\n",
142 size, ntohl (block->n_proof), offset, n);
143 /* aux always points at the end of the previous block */
144 for (i = 0; i < n; i++)
146 offset += sizeof (struct RegexEdge);
147 LOG (GNUNET_ERROR_TYPE_DEBUG, "* Edge %u, off %u\n", i, offset);
148 if (offset >= size) /* Is it safe to access the next edge block? */
150 LOG (GNUNET_ERROR_TYPE_WARNING,
151 "* Size not enough for RegexEdge, END\n");
153 return GNUNET_SYSERR;
155 edge = (struct RegexEdge *) aux;
156 n_token = ntohl (edge->n_token);
158 LOG (GNUNET_ERROR_TYPE_DEBUG,
159 "* Token length %u, off %u\n", n_token, offset);
160 if (offset > size) /* Is it safe to access the edge token? */
162 LOG (GNUNET_ERROR_TYPE_WARNING,
163 "* Size not enough for edge token, END\n");
165 return GNUNET_SYSERR;
167 aux = (char *) &edge[1]; /* Skip edge block */
168 if (NULL != iterator)
169 if (GNUNET_NO == iterator (iter_cls, aux, n_token, &edge->key))
171 aux = &aux[n_token]; /* Skip edge token */
173 /* The total size should be exactly the size of (regex + all edges) blocks
174 * If size == -1, block is from cache and therefore previously checked and
175 * assumed correct. */
176 if ( (offset != size) && (SIZE_MAX != size) )
179 return GNUNET_SYSERR;
186 * Construct a regex block to be stored in the DHT.
188 * @param proof proof string for the block
189 * @param num_edges number of edges in the block
190 * @param edges the edges of the block
191 * @return the regex block
194 REGEX_BLOCK_create (const struct GNUNET_HashCode *key,
196 unsigned int num_edges,
197 const struct REGEX_BLOCK_Edge *edges,
201 struct RegexBlock *block;
202 struct RegexEdge *block_edge;
210 size = sizeof (struct RegexBlock) + len;
211 block = GNUNET_malloc (size);
213 block->n_proof = htonl (len);
214 block->n_edges = htonl (num_edges);
215 block->accepting = htonl (accepting);
217 /* Store the proof at the end of the block. */
218 aux = (char *) &block[1];
219 memcpy (aux, proof, len);
222 /* Store each edge in a variable length MeshEdge struct at the
223 * very end of the MeshRegexBlock structure.
225 for (i = 0; i < num_edges; i++)
227 /* aux points at the end of the last block */
228 len = strlen (edges[i].label);
229 size += sizeof (struct RegexEdge) + len;
230 // Calculate offset FIXME is this ok? use size instead?
231 offset = aux - (char *) block;
232 block = GNUNET_realloc (block, size);
233 aux = &((char *) block)[offset];
234 block_edge = (struct RegexEdge *) aux;
235 block_edge->key = edges[i].destination;
236 block_edge->n_token = htonl (len);
237 aux = (char *) &block_edge[1];
238 memcpy (aux, edges[i].label, len);
246 /* end of regex_block_lib.c */