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 };
  68
  69 static StringOutputVisitor *to_sov(Visitor *v)
  70 {
  71     return container_of(v, StringOutputVisitor, visitor);
  72 }
  73
  74 static void string_output_set(StringOutputVisitor *sov, char *string)
  75 {
  76     if (sov->string) {
  77         g_string_free(sov->string, true);
  78     }
  79     sov->string = g_string_new(string);
  80     g_free(string);
  81 }
  82
  83 static void string_output_append(StringOutputVisitor *sov, int64_t a)
  84 {
  85     Range *r = g_malloc0(sizeof(*r));
  86     r->begin = a;
  87     r->end = a + 1;
  88     sov->ranges = range_list_insert(sov->ranges, r);
  89 }
  90
  91 static void string_output_append_range(StringOutputVisitor *sov,
  92                                        int64_t s, int64_t e)
  93 {
  94     Range *r = g_malloc0(sizeof(*r));
  95     r->begin = s;
  96     r->end = e + 1;
  97     sov->ranges = range_list_insert(sov->ranges, r);
  98 }
  99
 100 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
 101                           bool human)
 102 {
 103     if (r->end - r->begin > 1) {
 104         if (human) {
 105             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
 106                                    r->begin, r->end - 1);
 107
 108         } else {
 109             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
 110                                    r->begin, r->end - 1);
 111         }
 112     } else {
 113         if (human) {
 114             g_string_append_printf(sov->string, "0x%" PRIx64, r->begin);
 115         } else {
 116             g_string_append_printf(sov->string, "%" PRId64, r->begin);
 117         }
 118     }
 119     if (next) {
 120         g_string_append(sov->string, ",");
 121     }
 122 }
 123
 124 static void print_type_int64(Visitor *v, const char *name, int64_t *obj,
 125                              Error **errp)
 126 {
 127     StringOutputVisitor *sov = to_sov(v);
 128     GList *l;
 129
 130     switch (sov->list_mode) {
 131     case LM_NONE:
 132         string_output_append(sov, *obj);
 133         break;
 134
 135     case LM_STARTED:
 136         sov->range_start.s = *obj;
 137         sov->range_end.s = *obj;
 138         sov->list_mode = LM_IN_PROGRESS;
 139         return;
 140
 141     case LM_IN_PROGRESS:
 142         if (sov->range_end.s + 1 == *obj) {
 143             sov->range_end.s++;
 144         } else {
 145             if (sov->range_start.s == sov->range_end.s) {
 146                 string_output_append(sov, sov->range_end.s);
 147             } else {
 148                 assert(sov->range_start.s < sov->range_end.s);
 149                 string_output_append_range(sov, sov->range_start.s,
 150                                            sov->range_end.s);
 151             }
 152
 153             sov->range_start.s = *obj;
 154             sov->range_end.s = *obj;
 155         }
 156         return;
 157
 158     case LM_END:
 159         if (sov->range_end.s + 1 == *obj) {
 160             sov->range_end.s++;
 161             assert(sov->range_start.s < sov->range_end.s);
 162             string_output_append_range(sov, sov->range_start.s,
 163                                        sov->range_end.s);
 164         } else {
 165             if (sov->range_start.s == sov->range_end.s) {
 166                 string_output_append(sov, sov->range_end.s);
 167             } else {
 168                 assert(sov->range_start.s < sov->range_end.s);
 169
 170                 string_output_append_range(sov, sov->range_start.s,
 171                                            sov->range_end.s);
 172             }
 173             string_output_append(sov, *obj);
 174         }
 175         break;
 176
 177     default:
 178         abort();
 179     }
 180
 181     l = sov->ranges;
 182     while (l) {
 183         Range *r = l->data;
 184         format_string(sov, r, l->next != NULL, false);
 185         l = l->next;
 186     }
 187
 188     if (sov->human) {
 189         l = sov->ranges;
 190         g_string_append(sov->string, " (");
 191         while (l) {
 192             Range *r = l->data;
 193             format_string(sov, r, l->next != NULL, true);
 194             l = l->next;
 195         }
 196         g_string_append(sov->string, ")");
 197     }
 198 }
 199
 200 static void print_type_uint64(Visitor *v, const char *name, uint64_t *obj,
 201                              Error **errp)
 202 {
 203     /* FIXME: print_type_int64 mishandles values over INT64_MAX */
 204     int64_t i = *obj;
 205     print_type_int64(v, name, &i, errp);
 206 }
 207
 208 static void print_type_size(Visitor *v, const char *name, uint64_t *obj,
 209                             Error **errp)
 210 {
 211     StringOutputVisitor *sov = to_sov(v);
 212     static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
 213     uint64_t div, val;
 214     char *out;
 215     int i;
 216
 217     if (!sov->human) {
 218         out = g_strdup_printf("%"PRIu64, *obj);
 219         string_output_set(sov, out);
 220         return;
 221     }
 222
 223     val = *obj;
 224
 225     /* The exponent (returned in i) minus one gives us
 226      * floor(log2(val * 1024 / 1000).  The correction makes us
 227      * switch to the higher power when the integer part is >= 1000.
 228      */
 229     frexp(val / (1000.0 / 1024.0), &i);
 230     i = (i - 1) / 10;
 231     assert(i < ARRAY_SIZE(suffixes));
 232     div = 1ULL << (i * 10);
 233
 234     out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
 235                           (double)val/div, suffixes[i], i ? "iB" : "");
 236     string_output_set(sov, out);
 237 }
 238
 239 static void print_type_bool(Visitor *v, const char *name, bool *obj,
 240                             Error **errp)
 241 {
 242     StringOutputVisitor *sov = to_sov(v);
 243     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
 244 }
 245
 246 static void print_type_str(Visitor *v, const char *name, char **obj,
 247                            Error **errp)
 248 {
 249     StringOutputVisitor *sov = to_sov(v);
 250     char *out;
 251
 252     if (sov->human) {
 253         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
 254     } else {
 255         out = g_strdup(*obj ? *obj : "");
 256     }
 257     string_output_set(sov, out);
 258 }
 259
 260 static void print_type_number(Visitor *v, const char *name, double *obj,
 261                               Error **errp)
 262 {
 263     StringOutputVisitor *sov = to_sov(v);
 264     string_output_set(sov, g_strdup_printf("%f", *obj));
 265 }
 266
 267 static void
 268 start_list(Visitor *v, const char *name, GenericList **list, size_t size,
 269            Error **errp)
 270 {
 271     StringOutputVisitor *sov = to_sov(v);
 272
 273     /* we can't traverse a list in a list */
 274     assert(sov->list_mode == LM_NONE);
 275     /* We don't support visits without a list */
 276     assert(list);
 277     /* List handling is only needed if there are at least two elements */
 278     if (*list && (*list)->next) {
 279         sov->list_mode = LM_STARTED;
 280     }
 281 }
 282
 283 static GenericList *next_list(Visitor *v, GenericList *tail, size_t size)
 284 {
 285     StringOutputVisitor *sov = to_sov(v);
 286     GenericList *ret = tail->next;
 287
 288     if (ret && !ret->next) {
 289         sov->list_mode = LM_END;
 290     }
 291     return ret;
 292 }
 293
 294 static void end_list(Visitor *v)
 295 {
 296     StringOutputVisitor *sov = to_sov(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 }
 304
 305 char *string_output_get_string(StringOutputVisitor *sov)
 306 {
 307     char *string = g_string_free(sov->string, false);
 308     sov->string = NULL;
 309     return string;
 310 }
 311
 312 Visitor *string_output_get_visitor(StringOutputVisitor *sov)
 313 {
 314     return &sov->visitor;
 315 }
 316
 317 static void free_range(void *range, void *dummy)
 318 {
 319     g_free(range);
 320 }
 321
 322 void string_output_visitor_cleanup(StringOutputVisitor *sov)
 323 {
 324     if (sov->string) {
 325         g_string_free(sov->string, true);
 326     }
 327
 328     g_list_foreach(sov->ranges, free_range, NULL);
 329     g_list_free(sov->ranges);
 330     g_free(sov);
 331 }
 332
 333 StringOutputVisitor *string_output_visitor_new(bool human)
 334 {
 335     StringOutputVisitor *v;
 336
 337     v = g_malloc0(sizeof(*v));
 338
 339     v->string = g_string_new(NULL);
 340     v->human = human;
 341     v->visitor.type = VISITOR_OUTPUT;
 342     v->visitor.type_int64 = print_type_int64;
 343     v->visitor.type_uint64 = print_type_uint64;
 344     v->visitor.type_size = print_type_size;
 345     v->visitor.type_bool = print_type_bool;
 346     v->visitor.type_str = print_type_str;
 347     v->visitor.type_number = print_type_number;
 348     v->visitor.start_list = start_list;
 349     v->visitor.next_list = next_list;
 350     v->visitor.end_list = end_list;
 351
 352     return v;
 353 }