xref: /openbmc/qemu/qapi/string-output-visitor.c (revision fcf5ef2a)
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,          /* next_list() ready to be called */
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,              /* next_list() called, about to see last element. */
52 };
53 
54 typedef enum ListMode ListMode;
55 
56 struct StringOutputVisitor
57 {
58     Visitor visitor;
59     bool human;
60     GString *string;
61     char **result;
62     ListMode list_mode;
63     union {
64         int64_t s;
65         uint64_t u;
66     } range_start, range_end;
67     GList *ranges;
68     void *list; /* Only needed for sanity checking the caller */
69 };
70 
71 static StringOutputVisitor *to_sov(Visitor *v)
72 {
73     return container_of(v, StringOutputVisitor, visitor);
74 }
75 
76 static void string_output_set(StringOutputVisitor *sov, char *string)
77 {
78     if (sov->string) {
79         g_string_free(sov->string, true);
80     }
81     sov->string = g_string_new(string);
82     g_free(string);
83 }
84 
85 static void string_output_append(StringOutputVisitor *sov, int64_t a)
86 {
87     Range *r = g_malloc0(sizeof(*r));
88 
89     range_set_bounds(r, a, a);
90     sov->ranges = range_list_insert(sov->ranges, r);
91 }
92 
93 static void string_output_append_range(StringOutputVisitor *sov,
94                                        int64_t s, int64_t e)
95 {
96     Range *r = g_malloc0(sizeof(*r));
97 
98     range_set_bounds(r, s, e);
99     sov->ranges = range_list_insert(sov->ranges, r);
100 }
101 
102 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
103                           bool human)
104 {
105     if (range_lob(r) != range_upb(r)) {
106         if (human) {
107             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
108                                    range_lob(r), range_upb(r));
109 
110         } else {
111             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
112                                    range_lob(r), range_upb(r));
113         }
114     } else {
115         if (human) {
116             g_string_append_printf(sov->string, "0x%" PRIx64, range_lob(r));
117         } else {
118             g_string_append_printf(sov->string, "%" PRId64, range_lob(r));
119         }
120     }
121     if (next) {
122         g_string_append(sov->string, ",");
123     }
124 }
125 
126 static void print_type_int64(Visitor *v, const char *name, int64_t *obj,
127                              Error **errp)
128 {
129     StringOutputVisitor *sov = to_sov(v);
130     GList *l;
131 
132     switch (sov->list_mode) {
133     case LM_NONE:
134         string_output_append(sov, *obj);
135         break;
136 
137     case LM_STARTED:
138         sov->range_start.s = *obj;
139         sov->range_end.s = *obj;
140         sov->list_mode = LM_IN_PROGRESS;
141         return;
142 
143     case LM_IN_PROGRESS:
144         if (sov->range_end.s + 1 == *obj) {
145             sov->range_end.s++;
146         } else {
147             if (sov->range_start.s == sov->range_end.s) {
148                 string_output_append(sov, sov->range_end.s);
149             } else {
150                 assert(sov->range_start.s < sov->range_end.s);
151                 string_output_append_range(sov, sov->range_start.s,
152                                            sov->range_end.s);
153             }
154 
155             sov->range_start.s = *obj;
156             sov->range_end.s = *obj;
157         }
158         return;
159 
160     case LM_END:
161         if (sov->range_end.s + 1 == *obj) {
162             sov->range_end.s++;
163             assert(sov->range_start.s < sov->range_end.s);
164             string_output_append_range(sov, sov->range_start.s,
165                                        sov->range_end.s);
166         } else {
167             if (sov->range_start.s == sov->range_end.s) {
168                 string_output_append(sov, sov->range_end.s);
169             } else {
170                 assert(sov->range_start.s < sov->range_end.s);
171 
172                 string_output_append_range(sov, sov->range_start.s,
173                                            sov->range_end.s);
174             }
175             string_output_append(sov, *obj);
176         }
177         break;
178 
179     default:
180         abort();
181     }
182 
183     l = sov->ranges;
184     while (l) {
185         Range *r = l->data;
186         format_string(sov, r, l->next != NULL, false);
187         l = l->next;
188     }
189 
190     if (sov->human) {
191         l = sov->ranges;
192         g_string_append(sov->string, " (");
193         while (l) {
194             Range *r = l->data;
195             format_string(sov, r, l->next != NULL, true);
196             l = l->next;
197         }
198         g_string_append(sov->string, ")");
199     }
200 }
201 
202 static void print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
203                              Error **errp)
204 {
205     /* FIXME: print_type_int64 mishandles values over INT64_MAX */
206     int64_t i = *obj;
207     print_type_int64(v, name, &i, errp);
208 }
209 
210 static void print_type_size(Visitor *v, const char *name, uint64_t *obj,
211                             Error **errp)
212 {
213     StringOutputVisitor *sov = to_sov(v);
214     static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
215     uint64_t div, val;
216     char *out;
217     int i;
218 
219     if (!sov->human) {
220         out = g_strdup_printf("%"PRIu64, *obj);
221         string_output_set(sov, out);
222         return;
223     }
224 
225     val = *obj;
226 
227     /* The exponent (returned in i) minus one gives us
228      * floor(log2(val * 1024 / 1000).  The correction makes us
229      * switch to the higher power when the integer part is >= 1000.
230      */
231     frexp(val / (1000.0 / 1024.0), &i);
232     i = (i - 1) / 10;
233     assert(i < ARRAY_SIZE(suffixes));
234     div = 1ULL << (i * 10);
235 
236     out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
237                           (double)val/div, suffixes[i], i ? "iB" : "");
238     string_output_set(sov, out);
239 }
240 
241 static void print_type_bool(Visitor *v, const char *name, bool *obj,
242                             Error **errp)
243 {
244     StringOutputVisitor *sov = to_sov(v);
245     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
246 }
247 
248 static void print_type_str(Visitor *v, const char *name, char **obj,
249                            Error **errp)
250 {
251     StringOutputVisitor *sov = to_sov(v);
252     char *out;
253 
254     if (sov->human) {
255         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
256     } else {
257         out = g_strdup(*obj ? *obj : "");
258     }
259     string_output_set(sov, out);
260 }
261 
262 static void print_type_number(Visitor *v, const char *name, double *obj,
263                               Error **errp)
264 {
265     StringOutputVisitor *sov = to_sov(v);
266     string_output_set(sov, g_strdup_printf("%f", *obj));
267 }
268 
269 static void
270 start_list(Visitor *v, const char *name, GenericList **list, size_t size,
271            Error **errp)
272 {
273     StringOutputVisitor *sov = to_sov(v);
274 
275     /* we can't traverse a list in a list */
276     assert(sov->list_mode == LM_NONE);
277     /* We don't support visits without a list */
278     assert(list);
279     sov->list = list;
280     /* List handling is only needed if there are at least two elements */
281     if (*list && (*list)->next) {
282         sov->list_mode = LM_STARTED;
283     }
284 }
285 
286 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
287 {
288     StringOutputVisitor *sov = to_sov(v);
289     GenericList *ret = tail->next;
290 
291     if (ret && !ret->next) {
292         sov->list_mode = LM_END;
293     }
294     return ret;
295 }
296 
297 static void end_list(Visitor *v, void **obj)
298 {
299     StringOutputVisitor *sov = to_sov(v);
300 
301     assert(sov->list == obj);
302     assert(sov->list_mode == LM_STARTED ||
303            sov->list_mode == LM_END ||
304            sov->list_mode == LM_NONE ||
305            sov->list_mode == LM_IN_PROGRESS);
306     sov->list_mode = LM_NONE;
307 }
308 
309 static void string_output_complete(Visitor *v, void *opaque)
310 {
311     StringOutputVisitor *sov = to_sov(v);
312 
313     assert(opaque == sov->result);
314     *sov->result = g_string_free(sov->string, false);
315     sov->string = NULL;
316 }
317 
318 static void free_range(void *range, void *dummy)
319 {
320     g_free(range);
321 }
322 
323 static void string_output_free(Visitor *v)
324 {
325     StringOutputVisitor *sov = to_sov(v);
326 
327     if (sov->string) {
328         g_string_free(sov->string, true);
329     }
330 
331     g_list_foreach(sov->ranges, free_range, NULL);
332     g_list_free(sov->ranges);
333     g_free(sov);
334 }
335 
336 Visitor *string_output_visitor_new(bool human, char **result)
337 {
338     StringOutputVisitor *v;
339 
340     v = g_malloc0(sizeof(*v));
341 
342     v->string = g_string_new(NULL);
343     v->human = human;
344     v->result = result;
345     *result = NULL;
346 
347     v->visitor.type = VISITOR_OUTPUT;
348     v->visitor.type_int64 = print_type_int64;
349     v->visitor.type_uint64 = print_type_uint64;
350     v->visitor.type_size = print_type_size;
351     v->visitor.type_bool = print_type_bool;
352     v->visitor.type_str = print_type_str;
353     v->visitor.type_number = print_type_number;
354     v->visitor.start_list = start_list;
355     v->visitor.next_list = next_list;
356     v->visitor.end_list = end_list;
357     v->visitor.complete = string_output_complete;
358     v->visitor.free = string_output_free;
359 
360     return &v->visitor;
361 }
362