2 This file is part of GNUnet
3 (C) 2012 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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21 * @file src/regex/regex_graph.c
22 * @brief functions for creating .dot graphs from regexes
23 * @author Maximilian Szengel
26 #include "gnunet_regex_lib.h"
27 #include "regex_internal.h"
30 * Context for graph creation. Passed as the cls to
31 * GNUNET_REGEX_automaton_save_graph_step.
33 struct GNUNET_REGEX_Graph_Context
36 * File pointer to the dot file used for output.
41 * Verbose flag, if it's set to GNUNET_YES additional info will be printed in
49 * Recursive function doing DFS with 'v' as a start, detecting all SCCs inside
50 * the subgraph reachable from 'v'. Used with scc_tarjan function to detect all
51 * SCCs inside an automaton.
53 * @param scc_counter counter for numbering the sccs
54 * @param v start vertex
55 * @param index current index
56 * @param stack stack for saving all SCCs
57 * @param stack_size current size of the stack
60 scc_tarjan_strongconnect (unsigned int *scc_counter,
61 struct GNUNET_REGEX_State *v, unsigned int *index,
62 struct GNUNET_REGEX_State **stack,
63 unsigned int *stack_size)
65 struct GNUNET_REGEX_State *w;
66 struct GNUNET_REGEX_Transition *t;
71 stack[(*stack_size)++] = v;
74 for (t = v->transitions_head; NULL != t; t = t->next)
83 scc_tarjan_strongconnect (scc_counter, w, index, stack, stack_size);
84 v->lowlink = (v->lowlink > w->lowlink) ? w->lowlink : v->lowlink;
86 else if (0 != w->contained)
87 v->lowlink = (v->lowlink > w->index) ? w->index : v->lowlink;
90 if (v->lowlink == v->index)
92 w = stack[--(*stack_size)];
100 w->scc_id = *scc_counter;
101 w = stack[--(*stack_size)];
104 w->scc_id = *scc_counter;
111 * Detect all SCCs (Strongly Connected Components) inside the given automaton.
112 * SCCs will be marked using the scc_id on each state.
114 * @param a the automaton for which SCCs should be computed and assigned.
117 scc_tarjan (struct GNUNET_REGEX_Automaton *a)
120 unsigned int scc_counter;
121 struct GNUNET_REGEX_State *v;
122 struct GNUNET_REGEX_State *stack[a->state_count];
123 unsigned int stack_size;
125 for (v = a->states_head; NULL != v; v = v->next)
136 for (v = a->states_head; NULL != v; v = v->next)
139 scc_tarjan_strongconnect (&scc_counter, v, &index, stack, &stack_size);
145 * Save a state to an open file pointer. cls is expected to be a file pointer to
146 * an open file. Used only in conjunction with
147 * GNUNET_REGEX_automaton_save_graph.
149 * @param cls file pointer.
150 * @param count current count of the state, not used.
154 GNUNET_REGEX_automaton_save_graph_step (void *cls, unsigned int count,
155 struct GNUNET_REGEX_State *s)
157 struct GNUNET_REGEX_Graph_Context *ctx = cls;
158 struct GNUNET_REGEX_Transition *ctran;
164 if (GNUNET_YES == ctx->verbose)
165 GNUNET_asprintf (&name, "%i (%s)", s->proof_id, s->name);
167 GNUNET_asprintf (&name, "%i", s->proof_id);
171 GNUNET_asprintf (&s_acc,
172 "\"%s\" [shape=doublecircle, color=\"0.%i 0.8 0.95\"];\n",
177 GNUNET_asprintf (&s_acc, "\"%s\" [color=\"0.%i 0.8 0.95\"];\n", name, s->scc_id);
182 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not print state %s\n", s->name);
185 fwrite (s_acc, strlen (s_acc), 1, ctx->filep);
189 for (ctran = s->transitions_head; NULL != ctran; ctran = ctran->next)
191 if (NULL == ctran->to_state)
193 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
194 "Transition from State %i has no state for transitioning\n",
199 if (GNUNET_YES == ctx->verbose)
200 GNUNET_asprintf (&to_name, "%i (%s)", ctran->to_state->proof_id, ctran->to_state->name);
202 GNUNET_asprintf (&to_name, "%i", ctran->to_state->proof_id);
204 if (ctran->label == 0)
206 GNUNET_asprintf (&s_tran,
207 "\"%s\" -> \"%s\" [label = \"epsilon\", color=\"0.%i 0.8 0.95\"];\n",
208 name, to_name, s->scc_id);
212 GNUNET_asprintf (&s_tran,
213 "\"%s\" -> \"%s\" [label = \"%c\", color=\"0.%i 0.8 0.95\"];\n",
214 name, to_name, ctran->label, s->scc_id);
217 GNUNET_free (to_name);
221 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not print state %s\n",
226 fwrite (s_tran, strlen (s_tran), 1, ctx->filep);
227 GNUNET_free (s_tran);
236 * Save the given automaton as a GraphViz dot file
238 * @param a the automaton to be saved
239 * @param filename where to save the file
240 * @param verbose if set to GNUNET_YES the generated graph will include extra
241 * information such as the NFA states that were used to generate
245 GNUNET_REGEX_automaton_save_graph (struct GNUNET_REGEX_Automaton *a,
246 const char *filename,
251 struct GNUNET_REGEX_Graph_Context ctx;
255 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not print NFA, was NULL!");
259 if (NULL == filename || strlen (filename) < 1)
261 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "No Filename given!");
265 ctx.filep = fopen (filename, "w");
267 if (NULL == ctx.filep)
269 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not open file for writing: %s",
274 /* First add the SCCs to the automaton, so we can color them nicely */
277 start = "digraph G {\nrankdir=LR\n";
278 fwrite (start, strlen (start), 1, ctx.filep);
280 GNUNET_REGEX_automaton_traverse (a, &GNUNET_REGEX_automaton_save_graph_step,
284 fwrite (end, strlen (end), 1, ctx.filep);