lib/dynamic-string.c

   1 /*
   2  * Copyright (c) 2008, 2009, 2010 Nicira Networks.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18 #include "dynamic-string.h"
  19 #include <assert.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <time.h>
  23 #include "timeval.h"
  24 #include "util.h"
  25
  26 void
  27 ds_init(struct ds *ds)
  28 {
  29     ds->string = NULL;
  30     ds->length = 0;
  31     ds->allocated = 0;
  32 }
  33
  34 void
  35 ds_clear(struct ds *ds)
  36 {
  37     ds->length = 0;
  38 }
  39
  40 void
  41 ds_truncate(struct ds *ds, size_t new_length)
  42 {
  43     if (ds->length > new_length) {
  44         ds->length = new_length;
  45         ds->string[new_length] = '\0';
  46     }
  47 }
  48
  49 void
  50 ds_reserve(struct ds *ds, size_t min_length)
  51 {
  52     if (min_length > ds->allocated || !ds->string) {
  53         ds->allocated += MAX(min_length, ds->allocated);
  54         ds->allocated = MAX(8, ds->allocated);
  55         ds->string = xrealloc(ds->string, ds->allocated + 1);
  56     }
  57 }
  58
  59 char *
  60 ds_put_uninit(struct ds *ds, size_t n)
  61 {
  62     ds_reserve(ds, ds->length + n);
  63     ds->length += n;
  64     ds->string[ds->length] = '\0';
  65     return &ds->string[ds->length - n];
  66 }
  67
  68 void
  69 ds_put_char__(struct ds *ds, char c)
  70 {
  71     *ds_put_uninit(ds, 1) = c;
  72 }
  73
  74 /* Appends unicode code point 'uc' to 'ds' in UTF-8 encoding. */
  75 void
  76 ds_put_utf8(struct ds *ds, int uc)
  77 {
  78     if (uc <= 0x7f) {
  79         ds_put_char(ds, uc);
  80     } else if (uc <= 0x7ff) {
  81         ds_put_char(ds, 0xc0 | (uc >> 6));
  82         ds_put_char(ds, 0x80 | (uc & 0x3f));
  83     } else if (uc <= 0xffff) {
  84         ds_put_char(ds, 0xe0 | (uc >> 12));
  85         ds_put_char(ds, 0x80 | ((uc >> 6) & 0x3f));
  86         ds_put_char(ds, 0x80 | (uc & 0x3f));
  87     } else if (uc <= 0x10ffff) {
  88         ds_put_char(ds, 0xf0 | (uc >> 18));
  89         ds_put_char(ds, 0x80 | ((uc >> 12) & 0x3f));
  90         ds_put_char(ds, 0x80 | ((uc >> 6) & 0x3f));
  91         ds_put_char(ds, 0x80 | (uc & 0x3f));
  92     } else {
  93         /* Invalid code point.  Insert the Unicode general substitute
  94          * REPLACEMENT CHARACTER. */
  95         ds_put_utf8(ds, 0xfffd);
  96     }
  97 }
  98
  99 void
 100 ds_put_char_multiple(struct ds *ds, char c, size_t n)
 101 {
 102     memset(ds_put_uninit(ds, n), c, n);
 103 }
 104
 105 void
 106 ds_put_buffer(struct ds *ds, const char *s, size_t n)
 107 {
 108     memcpy(ds_put_uninit(ds, n), s, n);
 109 }
 110
 111 void
 112 ds_put_cstr(struct ds *ds, const char *s)
 113 {
 114     size_t s_len = strlen(s);
 115     memcpy(ds_put_uninit(ds, s_len), s, s_len);
 116 }
 117
 118 void
 119 ds_put_and_free_cstr(struct ds *ds, char *s)
 120 {
 121     ds_put_cstr(ds, s);
 122     free(s);
 123 }
 124
 125 void
 126 ds_put_format(struct ds *ds, const char *format, ...)
 127 {
 128     va_list args;
 129
 130     va_start(args, format);
 131     ds_put_format_valist(ds, format, args);
 132     va_end(args);
 133 }
 134
 135 void
 136 ds_put_format_valist(struct ds *ds, const char *format, va_list args_)
 137 {
 138     va_list args;
 139     size_t available;
 140     int needed;
 141
 142     va_copy(args, args_);
 143     available = ds->string ? ds->allocated - ds->length + 1 : 0;
 144     needed = vsnprintf(&ds->string[ds->length], available, format, args);
 145     va_end(args);
 146
 147     if (needed < available) {
 148         ds->length += needed;
 149     } else {
 150         size_t available;
 151
 152         ds_reserve(ds, ds->length + needed);
 153
 154         va_copy(args, args_);
 155         available = ds->allocated - ds->length + 1;
 156         needed = vsnprintf(&ds->string[ds->length], available, format, args);
 157         va_end(args);
 158
 159         assert(needed < available);
 160         ds->length += needed;
 161     }
 162 }
 163
 164 void
 165 ds_put_printable(struct ds *ds, const char *s, size_t n)
 166 {
 167     ds_reserve(ds, ds->length + n);
 168     while (n-- > 0) {
 169         unsigned char c = *s++;
 170         if (c < 0x20 || c > 0x7e || c == '\\' || c == '"') {
 171             ds_put_format(ds, "\\%03o", (int) c);
 172         } else {
 173             ds_put_char(ds, c);
 174         }
 175     }
 176 }
 177
 178 void
 179 ds_put_strftime(struct ds *ds, const char *template, const struct tm *tm)
 180 {
 181     if (!tm) {
 182         time_t now = time_wall();
 183         tm = localtime(&now);
 184     }
 185     for (;;) {
 186         size_t avail = ds->string ? ds->allocated - ds->length + 1 : 0;
 187         size_t used = strftime(&ds->string[ds->length], avail, template, tm);
 188         if (used) {
 189             ds->length += used;
 190             return;
 191         }
 192         ds_reserve(ds, ds->length + (avail < 32 ? 64 : 2 * avail));
 193     }
 194 }
 195
 196 int
 197 ds_get_line(struct ds *ds, FILE *file)
 198 {
 199     ds_clear(ds);
 200     for (;;) {
 201         int c = getc(file);
 202         if (c == EOF) {
 203             return ds->length ? 0 : EOF;
 204         } else if (c == '\n') {
 205             return 0;
 206         } else {
 207             ds_put_char(ds, c);
 208         }
 209     }
 210 }
 211
 212 char *
 213 ds_cstr(struct ds *ds)
 214 {
 215     if (!ds->string) {
 216         ds_reserve(ds, 0);
 217     }
 218     ds->string[ds->length] = '\0';
 219     return ds->string;
 220 }
 221
 222 const char *
 223 ds_cstr_ro(const struct ds *ds)
 224 {
 225     return ds_cstr((struct ds *) ds);
 226 }
 227
 228 /* Returns a null-terminated string representing the current contents of 'ds',
 229  * which the caller is expected to free with free(), then clears the contents
 230  * of 'ds'. */
 231 char *
 232 ds_steal_cstr(struct ds *ds)
 233 {
 234     char *s = ds_cstr(ds);
 235     ds_init(ds);
 236     return s;
 237 }
 238
 239 void
 240 ds_destroy(struct ds *ds)
 241 {
 242     free(ds->string);
 243 }
 244
 245 /* Swaps the content of 'a' and 'b'. */
 246 void
 247 ds_swap(struct ds *a, struct ds *b)
 248 {
 249     struct ds temp = *a;
 250     *a = *b;
 251     *b = temp;
 252 }
 253
 254 /* Writes the 'size' bytes in 'buf' to 'string' as hex bytes arranged 16 per
 255  * line.  Numeric offsets are also included, starting at 'ofs' for the first
 256  * byte in 'buf'.  If 'ascii' is true then the corresponding ASCII characters
 257  * are also rendered alongside. */
 258 void
 259 ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,
 260                 uintptr_t ofs, bool ascii)
 261 {
 262   const uint8_t *buf = buf_;
 263   const size_t per_line = 16; /* Maximum bytes per line. */
 264
 265   while (size > 0)
 266     {
 267       size_t start, end, n;
 268       size_t i;
 269
 270       /* Number of bytes on this line. */
 271       start = ofs % per_line;
 272       end = per_line;
 273       if (end - start > size)
 274         end = start + size;
 275       n = end - start;
 276
 277       /* Print line. */
 278       ds_put_format(ds, "%08jx  ", (uintmax_t) ROUND_DOWN(ofs, per_line));
 279       for (i = 0; i < start; i++)
 280         ds_put_format(ds, "   ");
 281       for (; i < end; i++)
 282         ds_put_format(ds, "%02hhx%c",
 283                 buf[i - start], i == per_line / 2 - 1? '-' : ' ');
 284       if (ascii)
 285         {
 286           for (; i < per_line; i++)
 287             ds_put_format(ds, "   ");
 288           ds_put_format(ds, "|");
 289           for (i = 0; i < start; i++)
 290             ds_put_format(ds, " ");
 291           for (; i < end; i++) {
 292               int c = buf[i - start];
 293               ds_put_char(ds, c >= 32 && c < 127 ? c : '.');
 294           }
 295           for (; i < per_line; i++)
 296             ds_put_format(ds, " ");
 297           ds_put_format(ds, "|");
 298         }
 299       ds_put_format(ds, "\n");
 300
 301       ofs += n;
 302       buf += n;
 303       size -= n;
 304     }
 305 }
 306
 307 int
 308 ds_last(const struct ds *ds)
 309 {
 310     return ds->length > 0 ? (unsigned char) ds->string[ds->length - 1] : EOF;
 311 }
 312
 313 void
 314 ds_chomp(struct ds *ds, int c)
 315 {
 316     if (ds->length > 0 && ds->string[ds->length - 1] == (char) c) {
 317         ds->string[--ds->length] = '\0';
 318     }
 319 }