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-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     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     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
  88     range_set_bounds(r, a, a);
  89     sov->ranges = range_list_insert(sov->ranges, r);
  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
  97     range_set_bounds(r, s, e);
  98     sov->ranges = range_list_insert(sov->ranges, r);
  99 }
 100
 101 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
 102                           bool human)
 103 {
 104     if (range_lob(r) != range_upb(r)) {
 105         if (human) {
 106             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
 107                                    range_lob(r), range_upb(r));
 108
 109         } else {
 110             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
 111                                    range_lob(r), range_upb(r));
 112         }
 113     } else {
 114         if (human) {
 115             g_string_append_printf(sov->string, "0x%" PRIx64, range_lob(r));
 116         } else {
 117             g_string_append_printf(sov->string, "%" PRId64, range_lob(r));
 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, GenericList **list, size_t size,
 270            Error **errp)
 271 {
 272     StringOutputVisitor *sov = to_sov(v);
 273
 274     /* we can't traverse a list in a list */
 275     assert(sov->list_mode == LM_NONE);
 276     /* We don't support visits without a list */
 277     assert(list);
 278     sov->list = list;
 279     /* List handling is only needed if there are at least two elements */
 280     if (*list && (*list)->next) {
 281         sov->list_mode = LM_STARTED;
 282     }
 283 }
 284
 285 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
 286 {
 287     StringOutputVisitor *sov = to_sov(v);
 288     GenericList *ret = tail->next;
 289
 290     if (ret && !ret->next) {
 291         sov->list_mode = LM_END;
 292     }
 293     return ret;
 294 }
 295
 296 static void end_list(Visitor *v, void **obj)
 297 {
 298     StringOutputVisitor *sov = to_sov(v);
 299
 300     assert(sov->list == obj);
 301     assert(sov->list_mode == LM_STARTED ||
 302            sov->list_mode == LM_END ||
 303            sov->list_mode == LM_NONE ||
 304            sov->list_mode == LM_IN_PROGRESS);
 305     sov->list_mode = LM_NONE;
 306 }
 307
 308 char *string_output_get_string(StringOutputVisitor *sov)
 309 {
 310     char *string = g_string_free(sov->string, false);
 311     sov->string = NULL;
 312     return string;
 313 }
 314
 315 Visitor *string_output_get_visitor(StringOutputVisitor *sov)
 316 {
 317     return &sov->visitor;
 318 }
 319
 320 static void free_range(void *range, void *dummy)
 321 {
 322     g_free(range);
 323 }
 324
 325 static void string_output_free(Visitor *v)
 326 {
 327     StringOutputVisitor *sov = to_sov(v);
 328
 329     string_output_visitor_cleanup(sov);
 330 }
 331
 332 void string_output_visitor_cleanup(StringOutputVisitor *sov)
 333 {
 334     if (sov->string) {
 335         g_string_free(sov->string, true);
 336     }
 337
 338     g_list_foreach(sov->ranges, free_range, NULL);
 339     g_list_free(sov->ranges);
 340     g_free(sov);
 341 }
 342
 343 StringOutputVisitor *string_output_visitor_new(bool human)
 344 {
 345     StringOutputVisitor *v;
 346
 347     v = g_malloc0(sizeof(*v));
 348
 349     v->string = g_string_new(NULL);
 350     v->human = human;
 351     v->visitor.type = VISITOR_OUTPUT;
 352     v->visitor.type_int64 = print_type_int64;
 353     v->visitor.type_uint64 = print_type_uint64;
 354     v->visitor.type_size = print_type_size;
 355     v->visitor.type_bool = print_type_bool;
 356     v->visitor.type_str = print_type_str;
 357     v->visitor.type_number = print_type_number;
 358     v->visitor.start_list = start_list;
 359     v->visitor.next_list = next_list;
 360     v->visitor.end_list = end_list;
 361     v->visitor.free = string_output_free;
 362
 363     return v;
 364 }