qapi/string-output-visitor.c

   1 /*
   2  * String printing Visitor
   3  *
   4  * Copyright Red Hat, Inc. 2012
   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-common.h"
  14 #include "qapi/string-output-visitor.h"
  15 #include "qapi/visitor-impl.h"
  16 #include "qapi/qmp/qerror.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,          /* start_list() succeeded */
  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
  52 };
  53
  54 typedef enum ListMode ListMode;
  55
  56 struct StringOutputVisitor
  57 {
  58     Visitor visitor;
  59     bool human;
  60     GString *string;
  61     bool head;
  62     ListMode list_mode;
  63     union {
  64         int64_t s;
  65         uint64_t u;
  66     } range_start, range_end;
  67     GList *ranges;
  68 };
  69
  70 static void string_output_set(StringOutputVisitor *sov, char *string)
  71 {
  72     if (sov->string) {
  73         g_string_free(sov->string, true);
  74     }
  75     sov->string = g_string_new(string);
  76     g_free(string);
  77 }
  78
  79 static void string_output_append(StringOutputVisitor *sov, int64_t a)
  80 {
  81     Range *r = g_malloc0(sizeof(*r));
  82     r->begin = a;
  83     r->end = a + 1;
  84     sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
  85 }
  86
  87 static void string_output_append_range(StringOutputVisitor *sov,
  88                                        int64_t s, int64_t e)
  89 {
  90     Range *r = g_malloc0(sizeof(*r));
  91     r->begin = s;
  92     r->end = e + 1;
  93     sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
  94 }
  95
  96 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
  97                           bool human)
  98 {
  99     if (r->end - r->begin > 1) {
 100         if (human) {
 101             g_string_append_printf(sov->string, "%" PRIx64 "-%" PRIx64,
 102                                    r->begin, r->end - 1);
 103
 104         } else {
 105             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
 106                                    r->begin, r->end - 1);
 107         }
 108     } else {
 109         if (human) {
 110             g_string_append_printf(sov->string, "%" PRIx64, r->begin);
 111         } else {
 112             g_string_append_printf(sov->string, "%" PRId64, r->begin);
 113         }
 114     }
 115     if (next) {
 116         g_string_append(sov->string, ",");
 117     }
 118 }
 119
 120 static void print_type_int(Visitor *v, int64_t *obj, const char *name,
 121                            Error **errp)
 122 {
 123     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 124     GList *l;
 125
 126     switch (sov->list_mode) {
 127     case LM_NONE:
 128         string_output_append(sov, *obj);
 129         break;
 130
 131     case LM_STARTED:
 132         sov->range_start.s = *obj;
 133         sov->range_end.s = *obj;
 134         sov->list_mode = LM_IN_PROGRESS;
 135         return;
 136
 137     case LM_IN_PROGRESS:
 138         if (sov->range_end.s + 1 == *obj) {
 139             sov->range_end.s++;
 140         } else {
 141             if (sov->range_start.s == sov->range_end.s) {
 142                 string_output_append(sov, sov->range_end.s);
 143             } else {
 144                 assert(sov->range_start.s < sov->range_end.s);
 145                 string_output_append_range(sov, sov->range_start.s,
 146                                            sov->range_end.s);
 147             }
 148
 149             sov->range_start.s = *obj;
 150             sov->range_end.s = *obj;
 151         }
 152         return;
 153
 154     case LM_END:
 155         if (sov->range_end.s + 1 == *obj) {
 156             sov->range_end.s++;
 157             assert(sov->range_start.s < sov->range_end.s);
 158             string_output_append_range(sov, sov->range_start.s,
 159                                        sov->range_end.s);
 160         } else {
 161             if (sov->range_start.s == sov->range_end.s) {
 162                 string_output_append(sov, sov->range_end.s);
 163             } else {
 164                 assert(sov->range_start.s < sov->range_end.s);
 165
 166                 string_output_append_range(sov, sov->range_start.s,
 167                                            sov->range_end.s);
 168             }
 169             string_output_append(sov, *obj);
 170         }
 171         break;
 172
 173     default:
 174         abort();
 175     }
 176
 177     l = sov->ranges;
 178     while (l) {
 179         Range *r = l->data;
 180         format_string(sov, r, l->next != NULL, false);
 181         l = l->next;
 182     }
 183
 184     if (sov->human) {
 185         l = sov->ranges;
 186         g_string_append(sov->string, " (");
 187         while (l) {
 188             Range *r = l->data;
 189             format_string(sov, r, l->next != NULL, false);
 190             l = l->next;
 191         }
 192         g_string_append(sov->string, ")");
 193     }
 194 }
 195
 196 static void print_type_size(Visitor *v, uint64_t *obj, const char *name,
 197                            Error **errp)
 198 {
 199     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 200     static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
 201     uint64_t div, val;
 202     char *out;
 203     int i;
 204
 205     if (!sov->human) {
 206         out = g_strdup_printf("%"PRIu64, *obj);
 207         string_output_set(sov, out);
 208         return;
 209     }
 210
 211     val = *obj;
 212
 213     /* The exponent (returned in i) minus one gives us
 214      * floor(log2(val * 1024 / 1000).  The correction makes us
 215      * switch to the higher power when the integer part is >= 1000.
 216      */
 217     frexp(val / (1000.0 / 1024.0), &i);
 218     i = (i - 1) / 10;
 219     assert(i < ARRAY_SIZE(suffixes));
 220     div = 1ULL << (i * 10);
 221
 222     out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
 223                           (double)val/div, suffixes[i], i ? "iB" : "");
 224     string_output_set(sov, out);
 225 }
 226
 227 static void print_type_bool(Visitor *v, bool *obj, const char *name,
 228                             Error **errp)
 229 {
 230     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 231     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
 232 }
 233
 234 static void print_type_str(Visitor *v, char **obj, const char *name,
 235                            Error **errp)
 236 {
 237     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 238     char *out;
 239
 240     if (sov->human) {
 241         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
 242     } else {
 243         out = g_strdup(*obj ? *obj : "");
 244     }
 245     string_output_set(sov, out);
 246 }
 247
 248 static void print_type_number(Visitor *v, double *obj, const char *name,
 249                               Error **errp)
 250 {
 251     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 252     string_output_set(sov, g_strdup_printf("%f", *obj));
 253 }
 254
 255 static void
 256 start_list(Visitor *v, const char *name, Error **errp)
 257 {
 258     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 259
 260     /* we can't traverse a list in a list */
 261     assert(sov->list_mode == LM_NONE);
 262     sov->list_mode = LM_STARTED;
 263     sov->head = true;
 264 }
 265
 266 static GenericList *
 267 next_list(Visitor *v, GenericList **list, Error **errp)
 268 {
 269     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 270     GenericList *ret = NULL;
 271     if (*list) {
 272         if (sov->head) {
 273             ret = *list;
 274         } else {
 275             ret = (*list)->next;
 276         }
 277
 278         if (sov->head) {
 279             if (ret && ret->next == NULL) {
 280                 sov->list_mode = LM_NONE;
 281             }
 282             sov->head = false;
 283         } else {
 284             if (ret && ret->next == NULL) {
 285                 sov->list_mode = LM_END;
 286             }
 287         }
 288     }
 289
 290     return ret;
 291 }
 292
 293 static void
 294 end_list(Visitor *v, Error **errp)
 295 {
 296     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
 297
 298     assert(sov->list_mode == LM_STARTED ||
 299            sov->list_mode == LM_END ||
 300            sov->list_mode == LM_NONE ||
 301            sov->list_mode == LM_IN_PROGRESS);
 302     sov->list_mode = LM_NONE;
 303     sov->head = true;
 304
 305 }
 306
 307 char *string_output_get_string(StringOutputVisitor *sov)
 308 {
 309     char *string = g_string_free(sov->string, false);
 310     sov->string = NULL;
 311     return string;
 312 }
 313
 314 Visitor *string_output_get_visitor(StringOutputVisitor *sov)
 315 {
 316     return &sov->visitor;
 317 }
 318
 319 static void free_range(void *range, void *dummy)
 320 {
 321     g_free(range);
 322 }
 323
 324 void string_output_visitor_cleanup(StringOutputVisitor *sov)
 325 {
 326     if (sov->string) {
 327         g_string_free(sov->string, true);
 328     }
 329
 330     g_list_foreach(sov->ranges, free_range, NULL);
 331     g_list_free(sov->ranges);
 332     g_free(sov);
 333 }
 334
 335 StringOutputVisitor *string_output_visitor_new(bool human)
 336 {
 337     StringOutputVisitor *v;
 338
 339     v = g_malloc0(sizeof(*v));
 340
 341     v->string = g_string_new(NULL);
 342     v->human = human;
 343     v->visitor.type_enum = output_type_enum;
 344     v->visitor.type_int = print_type_int;
 345     v->visitor.type_size = print_type_size;
 346     v->visitor.type_bool = print_type_bool;
 347     v->visitor.type_str = print_type_str;
 348     v->visitor.type_number = print_type_number;
 349     v->visitor.start_list = start_list;
 350     v->visitor.next_list = next_list;
 351     v->visitor.end_list = end_list;
 352
 353     return v;
 354 }