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   1 /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   2  *
   3  *  Libmemcached library
   4  *
   5  *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
   6  *  Copyright (C) 2006-2009 Brian Aker All rights reserved.
   7  *
   8  *  Redistribution and use in source and binary forms, with or without
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  10  *  met:
  11  *
  12  *      * Redistributions of source code must retain the above copyright
  13  *  notice, this list of conditions and the following disclaimer.
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  15  *      * Redistributions in binary form must reproduce the above
  16  *  copyright notice, this list of conditions and the following disclaimer
  17  *  in the documentation and/or other materials provided with the
  18  *  distribution.
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  20  *      * The names of its contributors may not be used to endorse or
  21  *  promote products derived from this software without specific prior
  22  *  written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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  36  */
  37
  38
  39 #include <libmemcached/common.h>
  40 #include <cassert>
  41
  42 inline static memcached_return_t _string_check(memcached_string_st *string, size_t need)
  43 {
  44   if (need && need > (size_t)(string->current_size - (size_t)(string->end - string->string)))
  45   {
  46     size_t current_offset= (size_t) (string->end - string->string);
  47     char *new_value;
  48     size_t adjust;
  49     size_t new_size;
  50
  51     /* This is the block multiplier. To keep it larger and surive division errors we must round it up */
  52     adjust= (need - (size_t)(string->current_size - (size_t)(string->end - string->string))) / MEMCACHED_BLOCK_SIZE;
  53     adjust++;
  54
  55     new_size= sizeof(char) * (size_t)((adjust * MEMCACHED_BLOCK_SIZE) + string->current_size);
  56     /* Test for overflow */
  57     if (new_size < need)
  58       return memcached_set_error(*string->root, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
  59
  60     new_value= static_cast<char *>(libmemcached_realloc(string->root, string->string, new_size));
  61
  62     if (not new_value)
  63     {
  64       return memcached_set_error(*string->root, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
  65     }
  66
  67     string->string= new_value;
  68     string->end= string->string + current_offset;
  69
  70     string->current_size+= (MEMCACHED_BLOCK_SIZE * adjust);
  71   }
  72
  73   return MEMCACHED_SUCCESS;
  74 }
  75
  76 static inline void _init_string(memcached_string_st *self)
  77 {
  78   self->current_size= 0;
  79   self->end= self->string= NULL;
  80 }
  81
  82 memcached_string_st *memcached_string_create(memcached_st *memc, memcached_string_st *self, size_t initial_size)
  83 {
  84   WATCHPOINT_ASSERT(memc);
  85
  86   /* Saving malloc calls :) */
  87   if (self)
  88   {
  89     WATCHPOINT_ASSERT(self->options.is_initialized == false);
  90
  91     self->options.is_allocated= false;
  92   }
  93   else
  94   {
  95     self= static_cast<memcached_string_st *>(libmemcached_malloc(memc, sizeof(memcached_string_st)));
  96
  97     if (self == NULL)
  98     {
  99       return NULL;
 100     }
 101
 102     self->options.is_allocated= true;
 103   }
 104   self->root= memc;
 105
 106   _init_string(self);
 107
 108   if (memcached_failed(_string_check(self, initial_size)))
 109   {
 110     libmemcached_free(memc, self);
 111
 112     return NULL;
 113   }
 114
 115   self->options.is_initialized= true;
 116
 117   WATCHPOINT_ASSERT(self->string == self->end);
 118
 119   return self;
 120 }
 121
 122 static memcached_return_t memcached_string_append_null(memcached_string_st *string)
 123 {
 124   if (memcached_failed(_string_check(string, 1)))
 125   {
 126     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 127   }
 128
 129   *string->end= 0;
 130
 131   return MEMCACHED_SUCCESS;
 132 }
 133
 134 memcached_return_t memcached_string_append_character(memcached_string_st *string,
 135                                                      char character)
 136 {
 137   if (memcached_failed(_string_check(string, 1)))
 138   {
 139     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 140   }
 141
 142   *string->end= character;
 143   string->end++;
 144
 145   return MEMCACHED_SUCCESS;
 146 }
 147
 148 memcached_return_t memcached_string_append(memcached_string_st *string,
 149                                            const char *value, size_t length)
 150 {
 151   if (memcached_failed(_string_check(string, length)))
 152   {
 153     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 154   }
 155
 156   WATCHPOINT_ASSERT(length <= string->current_size);
 157   WATCHPOINT_ASSERT(string->string);
 158   WATCHPOINT_ASSERT(string->end >= string->string);
 159
 160   memcpy(string->end, value, length);
 161   string->end+= length;
 162
 163   return MEMCACHED_SUCCESS;
 164 }
 165
 166 char *memcached_string_c_copy(memcached_string_st *string)
 167 {
 168   if (not memcached_string_length(string))
 169     return NULL;
 170
 171   char *c_ptr= static_cast<char *>(libmemcached_malloc(string->root, (memcached_string_length(string)+1) * sizeof(char)));
 172
 173   if (not c_ptr)
 174     return NULL;
 175
 176   memcpy(c_ptr, memcached_string_value(string), memcached_string_length(string));
 177   c_ptr[memcached_string_length(string)]= 0;
 178
 179   return c_ptr;
 180 }
 181
 182 memcached_return_t memcached_string_reset(memcached_string_st *string)
 183 {
 184   string->end= string->string;
 185
 186   return MEMCACHED_SUCCESS;
 187 }
 188
 189 void memcached_string_free(memcached_string_st *ptr)
 190 {
 191   if (not ptr)
 192     return;
 193
 194   if (ptr->string)
 195   {
 196     libmemcached_free(ptr->root, ptr->string);
 197   }
 198
 199   if (memcached_is_allocated(ptr))
 200   {
 201     libmemcached_free(ptr->root, ptr);
 202   }
 203   else
 204   {
 205     ptr->options.is_initialized= false;
 206   }
 207 }
 208
 209 memcached_return_t memcached_string_check(memcached_string_st *string, size_t need)
 210 {
 211   return _string_check(string, need);
 212 }
 213
 214 size_t memcached_string_length(const memcached_string_st *self)
 215 {
 216   return (size_t)(self->end - self->string);
 217 }
 218
 219 size_t memcached_string_size(const memcached_string_st *self)
 220 {
 221   return self->current_size;
 222 }
 223
 224 const char *memcached_string_value(const memcached_string_st *self)
 225 {
 226   return self->string;
 227 }
 228
 229 char *memcached_string_take_value(memcached_string_st *self)
 230 {
 231   assert(self);
 232   // If we fail at adding the null, we copy and move on
 233   if (memcached_success(memcached_string_append_null(self)))
 234   {
 235     return memcached_string_c_copy(self);
 236   }
 237
 238   char *value= self->string;
 239
 240   _init_string(self);
 241
 242   return value;
 243 }
 244
 245 char *memcached_string_value_mutable(const memcached_string_st *self)
 246 {
 247   return self->string;
 248 }
 249
 250 void memcached_string_set_length(memcached_string_st *self, size_t length)
 251 {
 252   self->end= self->string + length;
 253 }