qapi/string-output-visitor.c

   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/cutils.h"
  15 #include "qapi/string-output-visitor.h"
  16 #include "qapi/visitor-impl.h"
  17 #include <math.h>
  18 #include "qemu/range.h"
  19
  20 enum ListMode {
  21     LM_NONE,             /* not traversing a list of repeated options */
  22     LM_STARTED,          /* next_list() ready to be called */
  23
  24     LM_IN_PROGRESS,      /* next_list() has been called.
  25                           *
  26                           * Generating the next list link will consume the most
  27                           * recently parsed QemuOpt instance of the repeated
  28                           * option.
  29                           *
  30                           * Parsing a value into the list link will examine the
  31                           * next QemuOpt instance of the repeated option, and
  32                           * possibly enter LM_SIGNED_INTERVAL or
  33                           * LM_UNSIGNED_INTERVAL.
  34                           */
  35
  36     LM_SIGNED_INTERVAL,  /* next_list() has been called.
  37                           *
  38                           * Generating the next list link will consume the most
  39                           * recently stored element from the signed interval,
  40                           * parsed from the most recent QemuOpt instance of the
  41                           * repeated option. This may consume QemuOpt itself
  42                           * and return to LM_IN_PROGRESS.
  43                           *
  44                           * Parsing a value into the list link will store the
  45                           * next element of the signed interval.
  46                           */
  47
  48     LM_UNSIGNED_INTERVAL,/* Same as above, only for an unsigned interval. */
  49
  50     LM_END,              /* next_list() called, about to see last element. */
  51 };
  52
  53 typedef enum ListMode ListMode;
  54
  55 struct StringOutputVisitor
  56 {
  57     Visitor visitor;
  58     bool human;
  59     GString *string;
  60     char **result;
  61     ListMode list_mode;
  62     union {
  63         int64_t s;
  64         uint64_t u;
  65     } range_start, range_end;
  66     GList *ranges;
  67     void *list; /* Only needed for sanity checking the caller */
  68     unsigned int struct_nesting;
  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     switch (sov->list_mode) {
  79     case LM_STARTED:
  80         sov->list_mode = LM_IN_PROGRESS;
  81         /* fall through */
  82     case LM_NONE:
  83         if (sov->string) {
  84             g_string_free(sov->string, true);
  85         }
  86         sov->string = g_string_new(string);
  87         g_free(string);
  88         break;
  89
  90     case LM_IN_PROGRESS:
  91     case LM_END:
  92         g_string_append(sov->string, ", ");
  93         g_string_append(sov->string, string);
  94         break;
  95
  96     default:
  97         abort();
  98     }
  99 }
 100
 101 static void string_output_append(StringOutputVisitor *sov, int64_t a)
 102 {
 103     Range *r = g_malloc0(sizeof(*r));
 104
 105     range_set_bounds(r, a, a);
 106     sov->ranges = range_list_insert(sov->ranges, r);
 107 }
 108
 109 static void string_output_append_range(StringOutputVisitor *sov,
 110                                        int64_t s, int64_t e)
 111 {
 112     Range *r = g_malloc0(sizeof(*r));
 113
 114     range_set_bounds(r, s, e);
 115     sov->ranges = range_list_insert(sov->ranges, r);
 116 }
 117
 118 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
 119                           bool human)
 120 {
 121     if (range_lob(r) != range_upb(r)) {
 122         if (human) {
 123             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
 124                                    range_lob(r), range_upb(r));
 125
 126         } else {
 127             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
 128                                    range_lob(r), range_upb(r));
 129         }
 130     } else {
 131         if (human) {
 132             g_string_append_printf(sov->string, "0x%" PRIx64, range_lob(r));
 133         } else {
 134             g_string_append_printf(sov->string, "%" PRId64, range_lob(r));
 135         }
 136     }
 137     if (next) {
 138         g_string_append(sov->string, ",");
 139     }
 140 }
 141
 142 static bool print_type_int64(Visitor *v, const char *name, int64_t *obj,
 143                              Error **errp)
 144 {
 145     StringOutputVisitor *sov = to_sov(v);
 146     GList *l;
 147
 148     if (sov->struct_nesting) {
 149         return true;
 150     }
 151
 152     switch (sov->list_mode) {
 153     case LM_NONE:
 154         string_output_append(sov, *obj);
 155         break;
 156
 157     case LM_STARTED:
 158         sov->range_start.s = *obj;
 159         sov->range_end.s = *obj;
 160         sov->list_mode = LM_IN_PROGRESS;
 161         return true;
 162
 163     case LM_IN_PROGRESS:
 164         if (sov->range_end.s + 1 == *obj) {
 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                 string_output_append_range(sov, sov->range_start.s,
 172                                            sov->range_end.s);
 173             }
 174
 175             sov->range_start.s = *obj;
 176             sov->range_end.s = *obj;
 177         }
 178         return true;
 179
 180     case LM_END:
 181         if (sov->range_end.s + 1 == *obj) {
 182             sov->range_end.s++;
 183             assert(sov->range_start.s < sov->range_end.s);
 184             string_output_append_range(sov, sov->range_start.s,
 185                                        sov->range_end.s);
 186         } else {
 187             if (sov->range_start.s == sov->range_end.s) {
 188                 string_output_append(sov, sov->range_end.s);
 189             } else {
 190                 assert(sov->range_start.s < sov->range_end.s);
 191
 192                 string_output_append_range(sov, sov->range_start.s,
 193                                            sov->range_end.s);
 194             }
 195             string_output_append(sov, *obj);
 196         }
 197         break;
 198
 199     default:
 200         abort();
 201     }
 202
 203     l = sov->ranges;
 204     while (l) {
 205         Range *r = l->data;
 206         format_string(sov, r, l->next != NULL, false);
 207         l = l->next;
 208     }
 209
 210     if (sov->human) {
 211         l = sov->ranges;
 212         g_string_append(sov->string, " (");
 213         while (l) {
 214             Range *r = l->data;
 215             format_string(sov, r, l->next != NULL, true);
 216             l = l->next;
 217         }
 218         g_string_append(sov->string, ")");
 219     }
 220
 221     return true;
 222 }
 223
 224 static bool print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
 225                              Error **errp)
 226 {
 227     /* FIXME: print_type_int64 mishandles values over INT64_MAX */
 228     int64_t i = *obj;
 229     return print_type_int64(v, name, &i, errp);
 230 }
 231
 232 static bool print_type_size(Visitor *v, const char *name, uint64_t *obj,
 233                             Error **errp)
 234 {
 235     StringOutputVisitor *sov = to_sov(v);
 236     uint64_t val;
 237     char *out, *psize;
 238
 239     if (sov->struct_nesting) {
 240         return true;
 241     }
 242
 243     if (!sov->human) {
 244         out = g_strdup_printf("%"PRIu64, *obj);
 245         string_output_set(sov, out);
 246         return true;
 247     }
 248
 249     val = *obj;
 250     psize = size_to_str(val);
 251     out = g_strdup_printf("%"PRIu64" (%s)", val, psize);
 252     string_output_set(sov, out);
 253
 254     g_free(psize);
 255     return true;
 256 }
 257
 258 static bool print_type_bool(Visitor *v, const char *name, bool *obj,
 259                             Error **errp)
 260 {
 261     StringOutputVisitor *sov = to_sov(v);
 262
 263     if (sov->struct_nesting) {
 264         return true;
 265     }
 266
 267     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
 268     return true;
 269 }
 270
 271 static bool print_type_str(Visitor *v, const char *name, char **obj,
 272                            Error **errp)
 273 {
 274     StringOutputVisitor *sov = to_sov(v);
 275     char *out;
 276
 277     if (sov->struct_nesting) {
 278         return true;
 279     }
 280
 281     if (sov->human) {
 282         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
 283     } else {
 284         out = g_strdup(*obj ? *obj : "");
 285     }
 286     string_output_set(sov, out);
 287     return true;
 288 }
 289
 290 static bool print_type_number(Visitor *v, const char *name, double *obj,
 291                               Error **errp)
 292 {
 293     StringOutputVisitor *sov = to_sov(v);
 294
 295     if (sov->struct_nesting) {
 296         return true;
 297     }
 298
 299     string_output_set(sov, g_strdup_printf("%.17g", *obj));
 300     return true;
 301 }
 302
 303 static bool print_type_null(Visitor *v, const char *name, QNull **obj,
 304                             Error **errp)
 305 {
 306     StringOutputVisitor *sov = to_sov(v);
 307     char *out;
 308
 309     if (sov->struct_nesting) {
 310         return true;
 311     }
 312
 313     if (sov->human) {
 314         out = g_strdup("<null>");
 315     } else {
 316         out = g_strdup("");
 317     }
 318     string_output_set(sov, out);
 319     return true;
 320 }
 321
 322 static bool start_struct(Visitor *v, const char *name, void **obj,
 323                          size_t size, Error **errp)
 324 {
 325     StringOutputVisitor *sov = to_sov(v);
 326
 327     sov->struct_nesting++;
 328     return true;
 329 }
 330
 331 static void end_struct(Visitor *v, void **obj)
 332 {
 333     StringOutputVisitor *sov = to_sov(v);
 334
 335     if (--sov->struct_nesting) {
 336         return;
 337     }
 338
 339     /* TODO actually print struct fields */
 340     string_output_set(sov, g_strdup("<omitted>"));
 341 }
 342
 343 static bool
 344 start_list(Visitor *v, const char *name, GenericList **list, size_t size,
 345            Error **errp)
 346 {
 347     StringOutputVisitor *sov = to_sov(v);
 348
 349     if (sov->struct_nesting) {
 350         return true;
 351     }
 352
 353     /* we can't traverse a list in a list */
 354     assert(sov->list_mode == LM_NONE);
 355     /* We don't support visits without a list */
 356     assert(list);
 357     sov->list = list;
 358     /* List handling is only needed if there are at least two elements */
 359     if (*list && (*list)->next) {
 360         sov->list_mode = LM_STARTED;
 361     }
 362     return true;
 363 }
 364
 365 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
 366 {
 367     StringOutputVisitor *sov = to_sov(v);
 368     GenericList *ret = tail->next;
 369
 370     if (sov->struct_nesting) {
 371         return ret;
 372     }
 373
 374     if (ret && !ret->next) {
 375         sov->list_mode = LM_END;
 376     }
 377     return ret;
 378 }
 379
 380 static void end_list(Visitor *v, void **obj)
 381 {
 382     StringOutputVisitor *sov = to_sov(v);
 383
 384     if (sov->struct_nesting) {
 385         return;
 386     }
 387
 388     assert(sov->list == obj);
 389     assert(sov->list_mode == LM_STARTED ||
 390            sov->list_mode == LM_END ||
 391            sov->list_mode == LM_NONE ||
 392            sov->list_mode == LM_IN_PROGRESS);
 393     sov->list_mode = LM_NONE;
 394 }
 395
 396 static void string_output_complete(Visitor *v, void *opaque)
 397 {
 398     StringOutputVisitor *sov = to_sov(v);
 399
 400     assert(opaque == sov->result);
 401     *sov->result = g_string_free(sov->string, false);
 402     sov->string = NULL;
 403 }
 404
 405 static void free_range(void *range, void *dummy)
 406 {
 407     g_free(range);
 408 }
 409
 410 static void string_output_free(Visitor *v)
 411 {
 412     StringOutputVisitor *sov = to_sov(v);
 413
 414     if (sov->string) {
 415         g_string_free(sov->string, true);
 416     }
 417
 418     g_list_foreach(sov->ranges, free_range, NULL);
 419     g_list_free(sov->ranges);
 420     g_free(sov);
 421 }
 422
 423 Visitor *string_output_visitor_new(bool human, char **result)
 424 {
 425     StringOutputVisitor *v;
 426
 427     v = g_malloc0(sizeof(*v));
 428
 429     v->string = g_string_new(NULL);
 430     v->human = human;
 431     v->result = result;
 432     *result = NULL;
 433
 434     v->visitor.type = VISITOR_OUTPUT;
 435     v->visitor.type_int64 = print_type_int64;
 436     v->visitor.type_uint64 = print_type_uint64;
 437     v->visitor.type_size = print_type_size;
 438     v->visitor.type_bool = print_type_bool;
 439     v->visitor.type_str = print_type_str;
 440     v->visitor.type_number = print_type_number;
 441     v->visitor.type_null = print_type_null;
 442     v->visitor.start_struct = start_struct;
 443     v->visitor.end_struct = end_struct;
 444     v->visitor.start_list = start_list;
 445     v->visitor.next_list = next_list;
 446     v->visitor.end_list = end_list;
 447     v->visitor.complete = string_output_complete;
 448     v->visitor.free = string_output_free;
 449
 450     return &v->visitor;
 451 }