xref: /openbmc/qemu/qapi/string-output-visitor.c (revision b917da4c)
1 /*
2  * String printing Visitor
3  *
4  * Copyright Red Hat, Inc. 2012-2016
5  *
6  * Author: Paolo Bonzini <pbonzini@redhat.com>
7  *
8  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
9  * See the COPYING.LIB file in the top-level directory.
10  *
11  */
12 
13 #include "qemu/osdep.h"
14 #include "qemu-common.h"
15 #include "qapi/string-output-visitor.h"
16 #include "qapi/visitor-impl.h"
17 #include "qemu/host-utils.h"
18 #include <math.h>
19 #include "qemu/range.h"
20 
21 enum ListMode {
22     LM_NONE,             /* not traversing a list of repeated options */
23     LM_STARTED,          /* start_list() succeeded */
24 
25     LM_IN_PROGRESS,      /* next_list() has been called.
26                           *
27                           * Generating the next list link will consume the most
28                           * recently parsed QemuOpt instance of the repeated
29                           * option.
30                           *
31                           * Parsing a value into the list link will examine the
32                           * next QemuOpt instance of the repeated option, and
33                           * possibly enter LM_SIGNED_INTERVAL or
34                           * LM_UNSIGNED_INTERVAL.
35                           */
36 
37     LM_SIGNED_INTERVAL,  /* next_list() has been called.
38                           *
39                           * Generating the next list link will consume the most
40                           * recently stored element from the signed interval,
41                           * parsed from the most recent QemuOpt instance of the
42                           * repeated option. This may consume QemuOpt itself
43                           * and return to LM_IN_PROGRESS.
44                           *
45                           * Parsing a value into the list link will store the
46                           * next element of the signed interval.
47                           */
48 
49     LM_UNSIGNED_INTERVAL,/* Same as above, only for an unsigned interval. */
50 
51     LM_END
52 };
53 
54 typedef enum ListMode ListMode;
55 
56 struct StringOutputVisitor
57 {
58     Visitor visitor;
59     bool human;
60     GString *string;
61     bool head;
62     ListMode list_mode;
63     union {
64         int64_t s;
65         uint64_t u;
66     } range_start, range_end;
67     GList *ranges;
68 };
69 
70 static StringOutputVisitor *to_sov(Visitor *v)
71 {
72     return container_of(v, StringOutputVisitor, visitor);
73 }
74 
75 static void string_output_set(StringOutputVisitor *sov, char *string)
76 {
77     if (sov->string) {
78         g_string_free(sov->string, true);
79     }
80     sov->string = g_string_new(string);
81     g_free(string);
82 }
83 
84 static void string_output_append(StringOutputVisitor *sov, int64_t a)
85 {
86     Range *r = g_malloc0(sizeof(*r));
87     r->begin = a;
88     r->end = a + 1;
89     sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
90 }
91 
92 static void string_output_append_range(StringOutputVisitor *sov,
93                                        int64_t s, int64_t e)
94 {
95     Range *r = g_malloc0(sizeof(*r));
96     r->begin = s;
97     r->end = e + 1;
98     sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
99 }
100 
101 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
102                           bool human)
103 {
104     if (r->end - r->begin > 1) {
105         if (human) {
106             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
107                                    r->begin, r->end - 1);
108 
109         } else {
110             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
111                                    r->begin, r->end - 1);
112         }
113     } else {
114         if (human) {
115             g_string_append_printf(sov->string, "0x%" PRIx64, r->begin);
116         } else {
117             g_string_append_printf(sov->string, "%" PRId64, r->begin);
118         }
119     }
120     if (next) {
121         g_string_append(sov->string, ",");
122     }
123 }
124 
125 static void print_type_int64(Visitor *v, const char *name, int64_t *obj,
126                              Error **errp)
127 {
128     StringOutputVisitor *sov = to_sov(v);
129     GList *l;
130 
131     switch (sov->list_mode) {
132     case LM_NONE:
133         string_output_append(sov, *obj);
134         break;
135 
136     case LM_STARTED:
137         sov->range_start.s = *obj;
138         sov->range_end.s = *obj;
139         sov->list_mode = LM_IN_PROGRESS;
140         return;
141 
142     case LM_IN_PROGRESS:
143         if (sov->range_end.s + 1 == *obj) {
144             sov->range_end.s++;
145         } else {
146             if (sov->range_start.s == sov->range_end.s) {
147                 string_output_append(sov, sov->range_end.s);
148             } else {
149                 assert(sov->range_start.s < sov->range_end.s);
150                 string_output_append_range(sov, sov->range_start.s,
151                                            sov->range_end.s);
152             }
153 
154             sov->range_start.s = *obj;
155             sov->range_end.s = *obj;
156         }
157         return;
158 
159     case LM_END:
160         if (sov->range_end.s + 1 == *obj) {
161             sov->range_end.s++;
162             assert(sov->range_start.s < sov->range_end.s);
163             string_output_append_range(sov, sov->range_start.s,
164                                        sov->range_end.s);
165         } else {
166             if (sov->range_start.s == sov->range_end.s) {
167                 string_output_append(sov, sov->range_end.s);
168             } else {
169                 assert(sov->range_start.s < sov->range_end.s);
170 
171                 string_output_append_range(sov, sov->range_start.s,
172                                            sov->range_end.s);
173             }
174             string_output_append(sov, *obj);
175         }
176         break;
177 
178     default:
179         abort();
180     }
181 
182     l = sov->ranges;
183     while (l) {
184         Range *r = l->data;
185         format_string(sov, r, l->next != NULL, false);
186         l = l->next;
187     }
188 
189     if (sov->human) {
190         l = sov->ranges;
191         g_string_append(sov->string, " (");
192         while (l) {
193             Range *r = l->data;
194             format_string(sov, r, l->next != NULL, true);
195             l = l->next;
196         }
197         g_string_append(sov->string, ")");
198     }
199 }
200 
201 static void print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
202                              Error **errp)
203 {
204     /* FIXME: print_type_int64 mishandles values over INT64_MAX */
205     int64_t i = *obj;
206     print_type_int64(v, name, &i, errp);
207 }
208 
209 static void print_type_size(Visitor *v, const char *name, uint64_t *obj,
210                             Error **errp)
211 {
212     StringOutputVisitor *sov = to_sov(v);
213     static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
214     uint64_t div, val;
215     char *out;
216     int i;
217 
218     if (!sov->human) {
219         out = g_strdup_printf("%"PRIu64, *obj);
220         string_output_set(sov, out);
221         return;
222     }
223 
224     val = *obj;
225 
226     /* The exponent (returned in i) minus one gives us
227      * floor(log2(val * 1024 / 1000).  The correction makes us
228      * switch to the higher power when the integer part is >= 1000.
229      */
230     frexp(val / (1000.0 / 1024.0), &i);
231     i = (i - 1) / 10;
232     assert(i < ARRAY_SIZE(suffixes));
233     div = 1ULL << (i * 10);
234 
235     out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
236                           (double)val/div, suffixes[i], i ? "iB" : "");
237     string_output_set(sov, out);
238 }
239 
240 static void print_type_bool(Visitor *v, const char *name, bool *obj,
241                             Error **errp)
242 {
243     StringOutputVisitor *sov = to_sov(v);
244     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
245 }
246 
247 static void print_type_str(Visitor *v, const char *name, char **obj,
248                            Error **errp)
249 {
250     StringOutputVisitor *sov = to_sov(v);
251     char *out;
252 
253     if (sov->human) {
254         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
255     } else {
256         out = g_strdup(*obj ? *obj : "");
257     }
258     string_output_set(sov, out);
259 }
260 
261 static void print_type_number(Visitor *v, const char *name, double *obj,
262                               Error **errp)
263 {
264     StringOutputVisitor *sov = to_sov(v);
265     string_output_set(sov, g_strdup_printf("%f", *obj));
266 }
267 
268 static void
269 start_list(Visitor *v, const char *name, Error **errp)
270 {
271     StringOutputVisitor *sov = to_sov(v);
272 
273     /* we can't traverse a list in a list */
274     assert(sov->list_mode == LM_NONE);
275     sov->list_mode = LM_STARTED;
276     sov->head = true;
277 }
278 
279 static GenericList *next_list(Visitor *v, GenericList **list, size_t size)
280 {
281     StringOutputVisitor *sov = to_sov(v);
282     GenericList *ret = NULL;
283     if (*list) {
284         if (sov->head) {
285             ret = *list;
286         } else {
287             ret = (*list)->next;
288         }
289 
290         if (sov->head) {
291             if (ret && ret->next == NULL) {
292                 sov->list_mode = LM_NONE;
293             }
294             sov->head = false;
295         } else {
296             if (ret && ret->next == NULL) {
297                 sov->list_mode = LM_END;
298             }
299         }
300     }
301 
302     return ret;
303 }
304 
305 static void end_list(Visitor *v)
306 {
307     StringOutputVisitor *sov = to_sov(v);
308 
309     assert(sov->list_mode == LM_STARTED ||
310            sov->list_mode == LM_END ||
311            sov->list_mode == LM_NONE ||
312            sov->list_mode == LM_IN_PROGRESS);
313     sov->list_mode = LM_NONE;
314     sov->head = true;
315 
316 }
317 
318 char *string_output_get_string(StringOutputVisitor *sov)
319 {
320     char *string = g_string_free(sov->string, false);
321     sov->string = NULL;
322     return string;
323 }
324 
325 Visitor *string_output_get_visitor(StringOutputVisitor *sov)
326 {
327     return &sov->visitor;
328 }
329 
330 static void free_range(void *range, void *dummy)
331 {
332     g_free(range);
333 }
334 
335 void string_output_visitor_cleanup(StringOutputVisitor *sov)
336 {
337     if (sov->string) {
338         g_string_free(sov->string, true);
339     }
340 
341     g_list_foreach(sov->ranges, free_range, NULL);
342     g_list_free(sov->ranges);
343     g_free(sov);
344 }
345 
346 StringOutputVisitor *string_output_visitor_new(bool human)
347 {
348     StringOutputVisitor *v;
349 
350     v = g_malloc0(sizeof(*v));
351 
352     v->string = g_string_new(NULL);
353     v->human = human;
354     v->visitor.type_enum = output_type_enum;
355     v->visitor.type_int64 = print_type_int64;
356     v->visitor.type_uint64 = print_type_uint64;
357     v->visitor.type_size = print_type_size;
358     v->visitor.type_bool = print_type_bool;
359     v->visitor.type_str = print_type_str;
360     v->visitor.type_number = print_type_number;
361     v->visitor.start_list = start_list;
362     v->visitor.next_list = next_list;
363     v->visitor.end_list = end_list;
364 
365     return v;
366 }
367