lib/util/talloc_report.c

   1 /*
   2  * talloc_report into a string
   3  *
   4  * Copyright Volker Lendecke <vl@samba.org> 2015
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "replace.h"
  21 #include "talloc_report.h"
  22
  23 /*
  24  * talloc_vasprintf into a buffer that doubles its size. The real string
  25  * length is maintained in "pstr_len".
  26  */
  27
  28 static char *talloc_vasprintf_append_largebuf(char *buf, ssize_t *pstr_len,
  29                                               const char *fmt, va_list ap)
  30 {
  31         ssize_t str_len = *pstr_len;
  32         size_t buflen, needed, space;
  33         char *start, *tmpbuf;
  34         va_list ap2;
  35         int printlen;
  36
  37         if (str_len == -1) {
  38                 return NULL;
  39         }
  40         if (buf == NULL) {
  41                 return NULL;
  42         }
  43         if (fmt == NULL) {
  44                 return NULL;
  45         }
  46         buflen = talloc_get_size(buf);
  47
  48         if (buflen > str_len) {
  49                 start = buf + str_len;
  50                 space = buflen - str_len;
  51         } else {
  52                 start = NULL;
  53                 space = 0;
  54         }
  55
  56         va_copy(ap2, ap);
  57         printlen = vsnprintf(start, space, fmt, ap2);
  58         va_end(ap2);
  59
  60         if (printlen < 0) {
  61                 goto fail;
  62         }
  63
  64         needed = str_len + printlen + 1;
  65
  66         if (needed > buflen) {
  67                 buflen = MAX(128, buflen);
  68
  69                 while (buflen < needed) {
  70                         buflen *= 2;
  71                 }
  72
  73                 tmpbuf = talloc_realloc(NULL, buf, char, buflen);
  74                 if (tmpbuf == NULL) {
  75                         goto fail;
  76                 }
  77                 buf = tmpbuf;
  78
  79                 va_copy(ap2, ap);
  80                 vsnprintf(buf + str_len, buflen - str_len, fmt, ap2);
  81                 va_end(ap2);
  82         }
  83         *pstr_len = (needed - 1);
  84         return buf;
  85 fail:
  86         *pstr_len = -1;
  87         return buf;
  88 }
  89
  90 static char *talloc_asprintf_append_largebuf(char *buf, ssize_t *pstr_len,
  91                                              const char *fmt, ...)
  92 {
  93         va_list ap;
  94
  95         va_start(ap, fmt);
  96         buf = talloc_vasprintf_append_largebuf(buf, pstr_len, fmt, ap);
  97         va_end(ap);
  98         return buf;
  99 }
 100
 101 struct talloc_report_str_state {
 102         ssize_t str_len;
 103         char *s;
 104 };
 105
 106 static void talloc_report_str_helper(const void *ptr, int depth, int max_depth,
 107                                      int is_ref, void *private_data)
 108 {
 109         struct talloc_report_str_state *state = private_data;
 110         const char *name = talloc_get_name(ptr);
 111
 112         if (ptr == state->s) {
 113                 return;
 114         }
 115
 116         if (is_ref) {
 117                 state->s = talloc_asprintf_append_largebuf(
 118                         state->s, &state->str_len,
 119                         "%*sreference to: %s\n", depth*4, "", name);
 120                 return;
 121         }
 122
 123         if (depth == 0) {
 124                 state->s = talloc_asprintf_append_largebuf(
 125                         state->s, &state->str_len,
 126                         "%stalloc report on '%s' "
 127                         "(total %6lu bytes in %3lu blocks)\n",
 128                         (max_depth < 0 ? "full " :""), name,
 129                         (unsigned long)talloc_total_size(ptr),
 130                         (unsigned long)talloc_total_blocks(ptr));
 131                 return;
 132         }
 133
 134         if (strcmp(name, "char") == 0) {
 135                 /*
 136                  * Print out the first 50 bytes of the string
 137                  */
 138                 state->s = talloc_asprintf_append_largebuf(
 139                         state->s, &state->str_len,
 140                         "%*s%-30s contains %6lu bytes in %3lu blocks "
 141                         "(ref %d): %*s\n", depth*4, "", name,
 142                         (unsigned long)talloc_total_size(ptr),
 143                         (unsigned long)talloc_total_blocks(ptr),
 144                         talloc_reference_count(ptr),
 145                         MIN(50, talloc_get_size(ptr)),
 146                         (const char *)ptr);
 147                 return;
 148         }
 149
 150         state->s = talloc_asprintf_append_largebuf(
 151                 state->s, &state->str_len,
 152                 "%*s%-30s contains %6lu bytes in %3lu blocks (ref %d) %p\n",
 153                 depth*4, "", name,
 154                 (unsigned long)talloc_total_size(ptr),
 155                 (unsigned long)talloc_total_blocks(ptr),
 156                 talloc_reference_count(ptr), ptr);
 157 }
 158
 159 char *talloc_report_str(TALLOC_CTX *mem_ctx, TALLOC_CTX *root)
 160 {
 161         struct talloc_report_str_state state;
 162
 163         state.s = talloc_strdup(mem_ctx, "");
 164         if (state.s == NULL) {
 165                 return NULL;
 166         }
 167         state.str_len = 0;
 168
 169         talloc_report_depth_cb(root, 0, -1, talloc_report_str_helper, &state);
 170
 171         if (state.str_len == -1) {
 172                 talloc_free(state.s);
 173                 return NULL;
 174         }
 175
 176         return talloc_realloc(mem_ctx, state.s, char, state.str_len+1);
 177 }