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 "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 bool 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 true;
 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 true;
 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     return true;
 202 }
 203
 204 static bool print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
 205                              Error **errp)
 206 {
 207     /* FIXME: print_type_int64 mishandles values over INT64_MAX */
 208     int64_t i = *obj;
 209     return print_type_int64(v, name, &i, errp);
 210 }
 211
 212 static bool print_type_size(Visitor *v, const char *name, uint64_t *obj,
 213                             Error **errp)
 214 {
 215     StringOutputVisitor *sov = to_sov(v);
 216     uint64_t val;
 217     char *out, *psize;
 218
 219     if (!sov->human) {
 220         out = g_strdup_printf("%"PRIu64, *obj);
 221         string_output_set(sov, out);
 222         return true;
 223     }
 224
 225     val = *obj;
 226     psize = size_to_str(val);
 227     out = g_strdup_printf("%"PRIu64" (%s)", val, psize);
 228     string_output_set(sov, out);
 229
 230     g_free(psize);
 231     return true;
 232 }
 233
 234 static bool print_type_bool(Visitor *v, const char *name, bool *obj,
 235                             Error **errp)
 236 {
 237     StringOutputVisitor *sov = to_sov(v);
 238     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
 239     return true;
 240 }
 241
 242 static bool print_type_str(Visitor *v, const char *name, char **obj,
 243                            Error **errp)
 244 {
 245     StringOutputVisitor *sov = to_sov(v);
 246     char *out;
 247
 248     if (sov->human) {
 249         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
 250     } else {
 251         out = g_strdup(*obj ? *obj : "");
 252     }
 253     string_output_set(sov, out);
 254     return true;
 255 }
 256
 257 static bool print_type_number(Visitor *v, const char *name, double *obj,
 258                               Error **errp)
 259 {
 260     StringOutputVisitor *sov = to_sov(v);
 261     string_output_set(sov, g_strdup_printf("%f", *obj));
 262     return true;
 263 }
 264
 265 static bool print_type_null(Visitor *v, const char *name, QNull **obj,
 266                             Error **errp)
 267 {
 268     StringOutputVisitor *sov = to_sov(v);
 269     char *out;
 270
 271     if (sov->human) {
 272         out = g_strdup("<null>");
 273     } else {
 274         out = g_strdup("");
 275     }
 276     string_output_set(sov, out);
 277     return true;
 278 }
 279
 280 static bool
 281 start_list(Visitor *v, const char *name, GenericList **list, size_t size,
 282            Error **errp)
 283 {
 284     StringOutputVisitor *sov = to_sov(v);
 285
 286     /* we can't traverse a list in a list */
 287     assert(sov->list_mode == LM_NONE);
 288     /* We don't support visits without a list */
 289     assert(list);
 290     sov->list = list;
 291     /* List handling is only needed if there are at least two elements */
 292     if (*list && (*list)->next) {
 293         sov->list_mode = LM_STARTED;
 294     }
 295     return true;
 296 }
 297
 298 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
 299 {
 300     StringOutputVisitor *sov = to_sov(v);
 301     GenericList *ret = tail->next;
 302
 303     if (ret && !ret->next) {
 304         sov->list_mode = LM_END;
 305     }
 306     return ret;
 307 }
 308
 309 static void end_list(Visitor *v, void **obj)
 310 {
 311     StringOutputVisitor *sov = to_sov(v);
 312
 313     assert(sov->list == obj);
 314     assert(sov->list_mode == LM_STARTED ||
 315            sov->list_mode == LM_END ||
 316            sov->list_mode == LM_NONE ||
 317            sov->list_mode == LM_IN_PROGRESS);
 318     sov->list_mode = LM_NONE;
 319 }
 320
 321 static void string_output_complete(Visitor *v, void *opaque)
 322 {
 323     StringOutputVisitor *sov = to_sov(v);
 324
 325     assert(opaque == sov->result);
 326     *sov->result = g_string_free(sov->string, false);
 327     sov->string = NULL;
 328 }
 329
 330 static void free_range(void *range, void *dummy)
 331 {
 332     g_free(range);
 333 }
 334
 335 static void string_output_free(Visitor *v)
 336 {
 337     StringOutputVisitor *sov = to_sov(v);
 338
 339     if (sov->string) {
 340         g_string_free(sov->string, true);
 341     }
 342
 343     g_list_foreach(sov->ranges, free_range, NULL);
 344     g_list_free(sov->ranges);
 345     g_free(sov);
 346 }
 347
 348 Visitor *string_output_visitor_new(bool human, char **result)
 349 {
 350     StringOutputVisitor *v;
 351
 352     v = g_malloc0(sizeof(*v));
 353
 354     v->string = g_string_new(NULL);
 355     v->human = human;
 356     v->result = result;
 357     *result = NULL;
 358
 359     v->visitor.type = VISITOR_OUTPUT;
 360     v->visitor.type_int64 = print_type_int64;
 361     v->visitor.type_uint64 = print_type_uint64;
 362     v->visitor.type_size = print_type_size;
 363     v->visitor.type_bool = print_type_bool;
 364     v->visitor.type_str = print_type_str;
 365     v->visitor.type_number = print_type_number;
 366     v->visitor.type_null = print_type_null;
 367     v->visitor.start_list = start_list;
 368     v->visitor.next_list = next_list;
 369     v->visitor.end_list = end_list;
 370     v->visitor.complete = string_output_complete;
 371     v->visitor.free = string_output_free;
 372
 373     return &v->visitor;
 374 }