cutils.c

   1 /*
   2  * Simple C functions to supplement the C library
   3  *
   4  * Copyright (c) 2006 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu-common.h"
  25 #include "host-utils.h"
  26
  27 void pstrcpy(char *buf, int buf_size, const char *str)
  28 {
  29     int c;
  30     char *q = buf;
  31
  32     if (buf_size <= 0)
  33         return;
  34
  35     for(;;) {
  36         c = *str++;
  37         if (c == 0 || q >= buf + buf_size - 1)
  38             break;
  39         *q++ = c;
  40     }
  41     *q = '\0';
  42 }
  43
  44 /* strcat and truncate. */
  45 char *pstrcat(char *buf, int buf_size, const char *s)
  46 {
  47     int len;
  48     len = strlen(buf);
  49     if (len < buf_size)
  50         pstrcpy(buf + len, buf_size - len, s);
  51     return buf;
  52 }
  53
  54 int strstart(const char *str, const char *val, const char **ptr)
  55 {
  56     const char *p, *q;
  57     p = str;
  58     q = val;
  59     while (*q != '\0') {
  60         if (*p != *q)
  61             return 0;
  62         p++;
  63         q++;
  64     }
  65     if (ptr)
  66         *ptr = p;
  67     return 1;
  68 }
  69
  70 int stristart(const char *str, const char *val, const char **ptr)
  71 {
  72     const char *p, *q;
  73     p = str;
  74     q = val;
  75     while (*q != '\0') {
  76         if (qemu_toupper(*p) != qemu_toupper(*q))
  77             return 0;
  78         p++;
  79         q++;
  80     }
  81     if (ptr)
  82         *ptr = p;
  83     return 1;
  84 }
  85
  86 /* XXX: use host strnlen if available ? */
  87 int qemu_strnlen(const char *s, int max_len)
  88 {
  89     int i;
  90
  91     for(i = 0; i < max_len; i++) {
  92         if (s[i] == '\0') {
  93             break;
  94         }
  95     }
  96     return i;
  97 }
  98
  99 time_t mktimegm(struct tm *tm)
 100 {
 101     time_t t;
 102     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
 103     if (m < 3) {
 104         m += 12;
 105         y--;
 106     }
 107     t = 86400 * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 +
 108                  y / 400 - 719469);
 109     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
 110     return t;
 111 }
 112
 113 int qemu_fls(int i)
 114 {
 115     return 32 - clz32(i);
 116 }
 117
 118 /*
 119  * Make sure data goes on disk, but if possible do not bother to
 120  * write out the inode just for timestamp updates.
 121  *
 122  * Unfortunately even in 2009 many operating systems do not support
 123  * fdatasync and have to fall back to fsync.
 124  */
 125 int qemu_fdatasync(int fd)
 126 {
 127 #ifdef CONFIG_FDATASYNC
 128     return fdatasync(fd);
 129 #else
 130     return fsync(fd);
 131 #endif
 132 }
 133
 134 /* io vectors */
 135
 136 void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
 137 {
 138     qiov->iov = qemu_malloc(alloc_hint * sizeof(struct iovec));
 139     qiov->niov = 0;
 140     qiov->nalloc = alloc_hint;
 141     qiov->size = 0;
 142 }
 143
 144 void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov)
 145 {
 146     int i;
 147
 148     qiov->iov = iov;
 149     qiov->niov = niov;
 150     qiov->nalloc = -1;
 151     qiov->size = 0;
 152     for (i = 0; i < niov; i++)
 153         qiov->size += iov[i].iov_len;
 154 }
 155
 156 void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
 157 {
 158     assert(qiov->nalloc != -1);
 159
 160     if (qiov->niov == qiov->nalloc) {
 161         qiov->nalloc = 2 * qiov->nalloc + 1;
 162         qiov->iov = qemu_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
 163     }
 164     qiov->iov[qiov->niov].iov_base = base;
 165     qiov->iov[qiov->niov].iov_len = len;
 166     qiov->size += len;
 167     ++qiov->niov;
 168 }
 169
 170 /*
 171  * Copies iovecs from src to the end dst until src is completely copied or the
 172  * total size of the copied iovec reaches size. The size of the last copied
 173  * iovec is changed in order to fit the specified total size if it isn't a
 174  * perfect fit already.
 175  */
 176 void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
 177 {
 178     int i;
 179     size_t done;
 180
 181     assert(dst->nalloc != -1);
 182
 183     done = 0;
 184     for (i = 0; (i < src->niov) && (done != size); i++) {
 185         if (done + src->iov[i].iov_len > size) {
 186             qemu_iovec_add(dst, src->iov[i].iov_base, size - done);
 187             break;
 188         } else {
 189             qemu_iovec_add(dst, src->iov[i].iov_base, src->iov[i].iov_len);
 190         }
 191         done += src->iov[i].iov_len;
 192     }
 193 }
 194
 195 void qemu_iovec_destroy(QEMUIOVector *qiov)
 196 {
 197     assert(qiov->nalloc != -1);
 198
 199     qemu_free(qiov->iov);
 200 }
 201
 202 void qemu_iovec_reset(QEMUIOVector *qiov)
 203 {
 204     assert(qiov->nalloc != -1);
 205
 206     qiov->niov = 0;
 207     qiov->size = 0;
 208 }
 209
 210 void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
 211 {
 212     uint8_t *p = (uint8_t *)buf;
 213     int i;
 214
 215     for (i = 0; i < qiov->niov; ++i) {
 216         memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
 217         p += qiov->iov[i].iov_len;
 218     }
 219 }
 220
 221 /*
 222  * No dma flushing needed here, as the aio code will call dma_bdrv_cb()
 223  * on completion as well, which will result in a call to
 224  * dma_bdrv_unmap() which will do the flushing ....
 225  */
 226 void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf, size_t count)
 227 {
 228     const uint8_t *p = (const uint8_t *)buf;
 229     size_t copy;
 230     int i;
 231
 232     for (i = 0; i < qiov->niov && count; ++i) {
 233         copy = count;
 234         if (copy > qiov->iov[i].iov_len)
 235             copy = qiov->iov[i].iov_len;
 236         memcpy(qiov->iov[i].iov_base, p, copy);
 237         p     += copy;
 238         count -= copy;
 239     }
 240 }