lib/dynamic-string.c

   1 /*
   2  * Copyright (c) 2008, 2009 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_format(struct ds *ds, const char *format, ...)
 120 {
 121     va_list args;
 122
 123     va_start(args, format);
 124     ds_put_format_valist(ds, format, args);
 125     va_end(args);
 126 }
 127
 128 void
 129 ds_put_format_valist(struct ds *ds, const char *format, va_list args_)
 130 {
 131     va_list args;
 132     size_t available;
 133     int needed;
 134
 135     va_copy(args, args_);
 136     available = ds->string ? ds->allocated - ds->length + 1 : 0;
 137     needed = vsnprintf(&ds->string[ds->length], available, format, args);
 138     va_end(args);
 139
 140     if (needed < available) {
 141         ds->length += needed;
 142     } else {
 143         size_t available;
 144
 145         ds_reserve(ds, ds->length + needed);
 146
 147         va_copy(args, args_);
 148         available = ds->allocated - ds->length + 1;
 149         needed = vsnprintf(&ds->string[ds->length], available, format, args);
 150         va_end(args);
 151
 152         assert(needed < available);
 153         ds->length += needed;
 154     }
 155 }
 156
 157 void
 158 ds_put_printable(struct ds *ds, const char *s, size_t n)
 159 {
 160     ds_reserve(ds, ds->length + n);
 161     while (n-- > 0) {
 162         unsigned char c = *s++;
 163         if (c < 0x20 || c > 0x7e || c == '\\' || c == '"') {
 164             ds_put_format(ds, "\\%03o", (int) c);
 165         } else {
 166             ds_put_char(ds, c);
 167         }
 168     }
 169 }
 170
 171 void
 172 ds_put_strftime(struct ds *ds, const char *template, const struct tm *tm)
 173 {
 174     if (!tm) {
 175         time_t now = time_now();
 176         tm = localtime(&now);
 177     }
 178     for (;;) {
 179         size_t avail = ds->string ? ds->allocated - ds->length + 1 : 0;
 180         size_t used = strftime(&ds->string[ds->length], avail, template, tm);
 181         if (used) {
 182             ds->length += used;
 183             return;
 184         }
 185         ds_reserve(ds, ds->length + (avail < 32 ? 64 : 2 * avail));
 186     }
 187 }
 188
 189 int
 190 ds_get_line(struct ds *ds, FILE *file)
 191 {
 192     ds_clear(ds);
 193     for (;;) {
 194         int c = getc(file);
 195         if (c == EOF) {
 196             return ds->length ? 0 : EOF;
 197         } else if (c == '\n') {
 198             return 0;
 199         } else {
 200             ds_put_char(ds, c);
 201         }
 202     }
 203 }
 204
 205 char *
 206 ds_cstr(struct ds *ds)
 207 {
 208     if (!ds->string) {
 209         ds_reserve(ds, 0);
 210     }
 211     ds->string[ds->length] = '\0';
 212     return ds->string;
 213 }
 214
 215 /* Returns a null-terminated string representing the current contents of 'ds',
 216  * which the caller is expected to free with free(), then clears the contents
 217  * of 'ds'. */
 218 char *
 219 ds_steal_cstr(struct ds *ds)
 220 {
 221     char *s = ds_cstr(ds);
 222     ds_init(ds);
 223     return s;
 224 }
 225
 226 void
 227 ds_destroy(struct ds *ds)
 228 {
 229     free(ds->string);
 230 }
 231
 232 /* Writes the 'size' bytes in 'buf' to 'string' as hex bytes arranged 16 per
 233  * line.  Numeric offsets are also included, starting at 'ofs' for the first
 234  * byte in 'buf'.  If 'ascii' is true then the corresponding ASCII characters
 235  * are also rendered alongside. */
 236 void
 237 ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,
 238                 uintptr_t ofs, bool ascii)
 239 {
 240   const uint8_t *buf = buf_;
 241   const size_t per_line = 16; /* Maximum bytes per line. */
 242
 243   while (size > 0)
 244     {
 245       size_t start, end, n;
 246       size_t i;
 247
 248       /* Number of bytes on this line. */
 249       start = ofs % per_line;
 250       end = per_line;
 251       if (end - start > size)
 252         end = start + size;
 253       n = end - start;
 254
 255       /* Print line. */
 256       ds_put_format(ds, "%08jx  ", (uintmax_t) ROUND_DOWN(ofs, per_line));
 257       for (i = 0; i < start; i++)
 258         ds_put_format(ds, "   ");
 259       for (; i < end; i++)
 260         ds_put_format(ds, "%02hhx%c",
 261                 buf[i - start], i == per_line / 2 - 1? '-' : ' ');
 262       if (ascii)
 263         {
 264           for (; i < per_line; i++)
 265             ds_put_format(ds, "   ");
 266           ds_put_format(ds, "|");
 267           for (i = 0; i < start; i++)
 268             ds_put_format(ds, " ");
 269           for (; i < end; i++) {
 270               int c = buf[i - start];
 271               ds_put_char(ds, c >= 32 && c < 127 ? c : '.');
 272           }
 273           for (; i < per_line; i++)
 274             ds_put_format(ds, " ");
 275           ds_put_format(ds, "|");
 276         }
 277       ds_put_format(ds, "\n");
 278
 279       ofs += n;
 280       buf += n;
 281       size -= n;
 282     }
 283 }
 284
 285 int
 286 ds_last(const struct ds *ds)
 287 {
 288     return ds->length > 0 ? (unsigned char) ds->string[ds->length - 1] : EOF;
 289 }
 290
 291 void
 292 ds_chomp(struct ds *ds, int c)
 293 {
 294     if (ds->length > 0 && ds->string[ds->length - 1] == (char) c) {
 295         ds->string[--ds->length] = '\0';
 296     }
 297 }