lib/dynamic-string.c

   1 /*
   2  * Copyright (c) 2008 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 void
  75 ds_put_char_multiple(struct ds *ds, char c, size_t n)
  76 {
  77     memset(ds_put_uninit(ds, n), c, n);
  78 }
  79
  80 void
  81 ds_put_buffer(struct ds *ds, const char *s, size_t n)
  82 {
  83     memcpy(ds_put_uninit(ds, n), s, n);
  84 }
  85
  86 void
  87 ds_put_cstr(struct ds *ds, const char *s)
  88 {
  89     size_t s_len = strlen(s);
  90     memcpy(ds_put_uninit(ds, s_len), s, s_len);
  91 }
  92
  93 void
  94 ds_put_format(struct ds *ds, const char *format, ...)
  95 {
  96     va_list args;
  97
  98     va_start(args, format);
  99     ds_put_format_valist(ds, format, args);
 100     va_end(args);
 101 }
 102
 103 void
 104 ds_put_format_valist(struct ds *ds, const char *format, va_list args_)
 105 {
 106     va_list args;
 107     size_t available;
 108     int needed;
 109
 110     va_copy(args, args_);
 111     available = ds->string ? ds->allocated - ds->length + 1 : 0;
 112     needed = vsnprintf(&ds->string[ds->length], available, format, args);
 113     va_end(args);
 114
 115     if (needed < available) {
 116         ds->length += needed;
 117     } else {
 118         size_t available;
 119
 120         ds_reserve(ds, ds->length + needed);
 121
 122         va_copy(args, args_);
 123         available = ds->allocated - ds->length + 1;
 124         needed = vsnprintf(&ds->string[ds->length], available, format, args);
 125         va_end(args);
 126
 127         assert(needed < available);
 128         ds->length += needed;
 129     }
 130 }
 131
 132 void
 133 ds_put_printable(struct ds *ds, const char *s, size_t n)
 134 {
 135     ds_reserve(ds, ds->length + n);
 136     while (n-- > 0) {
 137         unsigned char c = *s++;
 138         if (c < 0x20 || c > 0x7e || c == '\\' || c == '"') {
 139             ds_put_format(ds, "\\%03o", (int) c);
 140         } else {
 141             ds_put_char(ds, c);
 142         }
 143     }
 144 }
 145
 146 void
 147 ds_put_strftime(struct ds *ds, const char *template, const struct tm *tm)
 148 {
 149     if (!tm) {
 150         time_t now = time_now();
 151         tm = localtime(&now);
 152     }
 153     for (;;) {
 154         size_t avail = ds->string ? ds->allocated - ds->length + 1 : 0;
 155         size_t used = strftime(&ds->string[ds->length], avail, template, tm);
 156         if (used) {
 157             ds->length += used;
 158             return;
 159         }
 160         ds_reserve(ds, ds->length + (avail < 32 ? 64 : 2 * avail));
 161     }
 162 }
 163
 164 int
 165 ds_get_line(struct ds *ds, FILE *file)
 166 {
 167     ds_clear(ds);
 168     for (;;) {
 169         int c = getc(file);
 170         if (c == EOF) {
 171             return ds->length ? 0 : EOF;
 172         } else if (c == '\n') {
 173             return 0;
 174         } else {
 175             ds_put_char(ds, c);
 176         }
 177     }
 178 }
 179
 180 char *
 181 ds_cstr(struct ds *ds)
 182 {
 183     if (!ds->string) {
 184         ds_reserve(ds, 0);
 185     }
 186     ds->string[ds->length] = '\0';
 187     return ds->string;
 188 }
 189
 190 void
 191 ds_destroy(struct ds *ds)
 192 {
 193     free(ds->string);
 194 }
 195
 196 /* Writes the 'size' bytes in 'buf' to 'string' as hex bytes arranged 16 per
 197  * line.  Numeric offsets are also included, starting at 'ofs' for the first
 198  * byte in 'buf'.  If 'ascii' is true then the corresponding ASCII characters
 199  * are also rendered alongside. */
 200 void
 201 ds_put_hex_dump(struct ds *ds, const void *buf_, size_t size,
 202                 uintptr_t ofs, bool ascii)
 203 {
 204   const uint8_t *buf = buf_;
 205   const size_t per_line = 16; /* Maximum bytes per line. */
 206
 207   while (size > 0)
 208     {
 209       size_t start, end, n;
 210       size_t i;
 211
 212       /* Number of bytes on this line. */
 213       start = ofs % per_line;
 214       end = per_line;
 215       if (end - start > size)
 216         end = start + size;
 217       n = end - start;
 218
 219       /* Print line. */
 220       ds_put_format(ds, "%08jx  ", (uintmax_t) ROUND_DOWN(ofs, per_line));
 221       for (i = 0; i < start; i++)
 222         ds_put_format(ds, "   ");
 223       for (; i < end; i++)
 224         ds_put_format(ds, "%02hhx%c",
 225                 buf[i - start], i == per_line / 2 - 1? '-' : ' ');
 226       if (ascii)
 227         {
 228           for (; i < per_line; i++)
 229             ds_put_format(ds, "   ");
 230           ds_put_format(ds, "|");
 231           for (i = 0; i < start; i++)
 232             ds_put_format(ds, " ");
 233           for (; i < end; i++) {
 234               int c = buf[i - start];
 235               ds_put_char(ds, c >= 32 && c < 127 ? c : '.');
 236           }
 237           for (; i < per_line; i++)
 238             ds_put_format(ds, " ");
 239           ds_put_format(ds, "|");
 240         }
 241       ds_put_format(ds, "\n");
 242
 243       ofs += n;
 244       buf += n;
 245       size -= n;
 246     }
 247 }
 248
 249 int
 250 ds_last(const struct ds *ds)
 251 {
 252     return ds->length > 0 ? (unsigned char) ds->string[ds->length - 1] : EOF;
 253 }
 254
 255 void
 256 ds_chomp(struct ds *ds, int c)
 257 {
 258     if (ds->length > 0 && ds->string[ds->length - 1] == (char) c) {
 259         ds->string[--ds->length] = '\0';
 260     }
 261 }