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 };
  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     switch (sov->list_mode) {
  78     case LM_STARTED:
  79         sov->list_mode = LM_IN_PROGRESS;
  80         /* fall through */
  81     case LM_NONE:
  82         if (sov->string) {
  83             g_string_free(sov->string, true);
  84         }
  85         sov->string = g_string_new(string);
  86         g_free(string);
  87         break;
  88
  89     case LM_IN_PROGRESS:
  90     case LM_END:
  91         g_string_append(sov->string, ", ");
  92         g_string_append(sov->string, string);
  93         break;
  94
  95     default:
  96         abort();
  97     }
  98 }
  99
 100 static void string_output_append(StringOutputVisitor *sov, int64_t a)
 101 {
 102     Range *r = g_malloc0(sizeof(*r));
 103
 104     range_set_bounds(r, a, a);
 105     sov->ranges = range_list_insert(sov->ranges, r);
 106 }
 107
 108 static void string_output_append_range(StringOutputVisitor *sov,
 109                                        int64_t s, int64_t e)
 110 {
 111     Range *r = g_malloc0(sizeof(*r));
 112
 113     range_set_bounds(r, s, e);
 114     sov->ranges = range_list_insert(sov->ranges, r);
 115 }
 116
 117 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
 118                           bool human)
 119 {
 120     if (range_lob(r) != range_upb(r)) {
 121         if (human) {
 122             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
 123                                    range_lob(r), range_upb(r));
 124
 125         } else {
 126             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
 127                                    range_lob(r), range_upb(r));
 128         }
 129     } else {
 130         if (human) {
 131             g_string_append_printf(sov->string, "0x%" PRIx64, range_lob(r));
 132         } else {
 133             g_string_append_printf(sov->string, "%" PRId64, range_lob(r));
 134         }
 135     }
 136     if (next) {
 137         g_string_append(sov->string, ",");
 138     }
 139 }
 140
 141 static bool print_type_int64(Visitor *v, const char *name, int64_t *obj,
 142                              Error **errp)
 143 {
 144     StringOutputVisitor *sov = to_sov(v);
 145     GList *l;
 146
 147     switch (sov->list_mode) {
 148     case LM_NONE:
 149         string_output_append(sov, *obj);
 150         break;
 151
 152     case LM_STARTED:
 153         sov->range_start.s = *obj;
 154         sov->range_end.s = *obj;
 155         sov->list_mode = LM_IN_PROGRESS;
 156         return true;
 157
 158     case LM_IN_PROGRESS:
 159         if (sov->range_end.s + 1 == *obj) {
 160             sov->range_end.s++;
 161         } else {
 162             if (sov->range_start.s == sov->range_end.s) {
 163                 string_output_append(sov, sov->range_end.s);
 164             } else {
 165                 assert(sov->range_start.s < sov->range_end.s);
 166                 string_output_append_range(sov, sov->range_start.s,
 167                                            sov->range_end.s);
 168             }
 169
 170             sov->range_start.s = *obj;
 171             sov->range_end.s = *obj;
 172         }
 173         return true;
 174
 175     case LM_END:
 176         if (sov->range_end.s + 1 == *obj) {
 177             sov->range_end.s++;
 178             assert(sov->range_start.s < sov->range_end.s);
 179             string_output_append_range(sov, sov->range_start.s,
 180                                        sov->range_end.s);
 181         } else {
 182             if (sov->range_start.s == sov->range_end.s) {
 183                 string_output_append(sov, sov->range_end.s);
 184             } else {
 185                 assert(sov->range_start.s < sov->range_end.s);
 186
 187                 string_output_append_range(sov, sov->range_start.s,
 188                                            sov->range_end.s);
 189             }
 190             string_output_append(sov, *obj);
 191         }
 192         break;
 193
 194     default:
 195         abort();
 196     }
 197
 198     l = sov->ranges;
 199     while (l) {
 200         Range *r = l->data;
 201         format_string(sov, r, l->next != NULL, false);
 202         l = l->next;
 203     }
 204
 205     if (sov->human) {
 206         l = sov->ranges;
 207         g_string_append(sov->string, " (");
 208         while (l) {
 209             Range *r = l->data;
 210             format_string(sov, r, l->next != NULL, true);
 211             l = l->next;
 212         }
 213         g_string_append(sov->string, ")");
 214     }
 215
 216     return true;
 217 }
 218
 219 static bool print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
 220                              Error **errp)
 221 {
 222     /* FIXME: print_type_int64 mishandles values over INT64_MAX */
 223     int64_t i = *obj;
 224     return print_type_int64(v, name, &i, errp);
 225 }
 226
 227 static bool print_type_size(Visitor *v, const char *name, uint64_t *obj,
 228                             Error **errp)
 229 {
 230     StringOutputVisitor *sov = to_sov(v);
 231     uint64_t val;
 232     char *out, *psize;
 233
 234     if (!sov->human) {
 235         out = g_strdup_printf("%"PRIu64, *obj);
 236         string_output_set(sov, out);
 237         return true;
 238     }
 239
 240     val = *obj;
 241     psize = size_to_str(val);
 242     out = g_strdup_printf("%"PRIu64" (%s)", val, psize);
 243     string_output_set(sov, out);
 244
 245     g_free(psize);
 246     return true;
 247 }
 248
 249 static bool print_type_bool(Visitor *v, const char *name, bool *obj,
 250                             Error **errp)
 251 {
 252     StringOutputVisitor *sov = to_sov(v);
 253     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
 254     return true;
 255 }
 256
 257 static bool print_type_str(Visitor *v, const char *name, char **obj,
 258                            Error **errp)
 259 {
 260     StringOutputVisitor *sov = to_sov(v);
 261     char *out;
 262
 263     if (sov->human) {
 264         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
 265     } else {
 266         out = g_strdup(*obj ? *obj : "");
 267     }
 268     string_output_set(sov, out);
 269     return true;
 270 }
 271
 272 static bool print_type_number(Visitor *v, const char *name, double *obj,
 273                               Error **errp)
 274 {
 275     StringOutputVisitor *sov = to_sov(v);
 276     string_output_set(sov, g_strdup_printf("%.17g", *obj));
 277     return true;
 278 }
 279
 280 static bool print_type_null(Visitor *v, const char *name, QNull **obj,
 281                             Error **errp)
 282 {
 283     StringOutputVisitor *sov = to_sov(v);
 284     char *out;
 285
 286     if (sov->human) {
 287         out = g_strdup("<null>");
 288     } else {
 289         out = g_strdup("");
 290     }
 291     string_output_set(sov, out);
 292     return true;
 293 }
 294
 295 static bool start_struct(Visitor *v, const char *name, void **obj,
 296                          size_t size, Error **errp)
 297 {
 298     return true;
 299 }
 300
 301 static void end_struct(Visitor *v, void **obj)
 302 {
 303     StringOutputVisitor *sov = to_sov(v);
 304
 305     /* TODO actually print struct fields */
 306     string_output_set(sov, g_strdup("<omitted>"));
 307 }
 308
 309 static bool
 310 start_list(Visitor *v, const char *name, GenericList **list, size_t size,
 311            Error **errp)
 312 {
 313     StringOutputVisitor *sov = to_sov(v);
 314
 315     /* we can't traverse a list in a list */
 316     assert(sov->list_mode == LM_NONE);
 317     /* We don't support visits without a list */
 318     assert(list);
 319     sov->list = list;
 320     /* List handling is only needed if there are at least two elements */
 321     if (*list && (*list)->next) {
 322         sov->list_mode = LM_STARTED;
 323     }
 324     return true;
 325 }
 326
 327 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
 328 {
 329     StringOutputVisitor *sov = to_sov(v);
 330     GenericList *ret = tail->next;
 331
 332     if (ret && !ret->next) {
 333         sov->list_mode = LM_END;
 334     }
 335     return ret;
 336 }
 337
 338 static void end_list(Visitor *v, void **obj)
 339 {
 340     StringOutputVisitor *sov = to_sov(v);
 341
 342     assert(sov->list == obj);
 343     assert(sov->list_mode == LM_STARTED ||
 344            sov->list_mode == LM_END ||
 345            sov->list_mode == LM_NONE ||
 346            sov->list_mode == LM_IN_PROGRESS);
 347     sov->list_mode = LM_NONE;
 348 }
 349
 350 static void string_output_complete(Visitor *v, void *opaque)
 351 {
 352     StringOutputVisitor *sov = to_sov(v);
 353
 354     assert(opaque == sov->result);
 355     *sov->result = g_string_free(sov->string, false);
 356     sov->string = NULL;
 357 }
 358
 359 static void free_range(void *range, void *dummy)
 360 {
 361     g_free(range);
 362 }
 363
 364 static void string_output_free(Visitor *v)
 365 {
 366     StringOutputVisitor *sov = to_sov(v);
 367
 368     if (sov->string) {
 369         g_string_free(sov->string, true);
 370     }
 371
 372     g_list_foreach(sov->ranges, free_range, NULL);
 373     g_list_free(sov->ranges);
 374     g_free(sov);
 375 }
 376
 377 Visitor *string_output_visitor_new(bool human, char **result)
 378 {
 379     StringOutputVisitor *v;
 380
 381     v = g_malloc0(sizeof(*v));
 382
 383     v->string = g_string_new(NULL);
 384     v->human = human;
 385     v->result = result;
 386     *result = NULL;
 387
 388     v->visitor.type = VISITOR_OUTPUT;
 389     v->visitor.type_int64 = print_type_int64;
 390     v->visitor.type_uint64 = print_type_uint64;
 391     v->visitor.type_size = print_type_size;
 392     v->visitor.type_bool = print_type_bool;
 393     v->visitor.type_str = print_type_str;
 394     v->visitor.type_number = print_type_number;
 395     v->visitor.type_null = print_type_null;
 396     v->visitor.start_struct = start_struct;
 397     v->visitor.end_struct = end_struct;
 398     v->visitor.start_list = start_list;
 399     v->visitor.next_list = next_list;
 400     v->visitor.end_list = end_list;
 401     v->visitor.complete = string_output_complete;
 402     v->visitor.free = string_output_free;
 403
 404     return &v->visitor;
 405 }