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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
   9  *  modification, are permitted provided that the following conditions are
  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.
  19  *
  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
  26  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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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
  41 inline static memcached_return_t _string_check(memcached_string_st *string, size_t need)
  42 {
  43   if (need && need > (size_t)(string->current_size - (size_t)(string->end - string->string)))
  44   {
  45     size_t current_offset= (size_t) (string->end - string->string);
  46     char *new_value;
  47     size_t adjust;
  48     size_t new_size;
  49
  50     /* This is the block multiplier. To keep it larger and surive division errors we must round it up */
  51     adjust= (need - (size_t)(string->current_size - (size_t)(string->end - string->string))) / MEMCACHED_BLOCK_SIZE;
  52     adjust++;
  53
  54     new_size= sizeof(char) * (size_t)((adjust * MEMCACHED_BLOCK_SIZE) + string->current_size);
  55     /* Test for overflow */
  56     if (new_size < need)
  57       return memcached_set_error(*string->root, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
  58
  59     new_value= static_cast<char *>(libmemcached_realloc(string->root, string->string, new_size));
  60
  61     if (not new_value)
  62     {
  63       return memcached_set_error(*string->root, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
  64     }
  65
  66     string->string= new_value;
  67     string->end= string->string + current_offset;
  68
  69     string->current_size+= (MEMCACHED_BLOCK_SIZE * adjust);
  70   }
  71
  72   return MEMCACHED_SUCCESS;
  73 }
  74
  75 static inline void _init_string(memcached_string_st *self)
  76 {
  77   self->current_size= 0;
  78   self->end= self->string= NULL;
  79 }
  80
  81 memcached_string_st *memcached_string_create(memcached_st *memc, memcached_string_st *self, size_t initial_size)
  82 {
  83   WATCHPOINT_ASSERT(memc);
  84
  85   /* Saving malloc calls :) */
  86   if (self)
  87   {
  88     WATCHPOINT_ASSERT(self->options.is_initialized == false);
  89
  90     memcached_set_allocated(self, false);
  91   }
  92   else
  93   {
  94     self= static_cast<memcached_string_st *>(libmemcached_malloc(memc, sizeof(memcached_string_st)));
  95
  96     if (self == NULL)
  97     {
  98       return NULL;
  99     }
 100
 101     memcached_set_allocated(self, true);
 102   }
 103   self->root= memc;
 104
 105   _init_string(self);
 106
 107   if (memcached_failed(_string_check(self, initial_size)))
 108   {
 109     if (memcached_is_allocated(self))
 110     {
 111       libmemcached_free(memc, self);
 112     }
 113
 114     return NULL;
 115   }
 116
 117   self->options.is_initialized= true;
 118
 119   WATCHPOINT_ASSERT(self->string == self->end);
 120
 121   return self;
 122 }
 123
 124 static memcached_return_t memcached_string_append_null(memcached_string_st *string)
 125 {
 126   if (memcached_failed(_string_check(string, 1)))
 127   {
 128     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 129   }
 130
 131   *string->end= 0;
 132
 133   return MEMCACHED_SUCCESS;
 134 }
 135
 136 memcached_return_t memcached_string_append_character(memcached_string_st *string,
 137                                                      char character)
 138 {
 139   if (memcached_failed(_string_check(string, 1)))
 140   {
 141     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 142   }
 143
 144   *string->end= character;
 145   string->end++;
 146
 147   return MEMCACHED_SUCCESS;
 148 }
 149
 150 memcached_return_t memcached_string_append(memcached_string_st *string,
 151                                            const char *value, size_t length)
 152 {
 153   if (memcached_failed(_string_check(string, length)))
 154   {
 155     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 156   }
 157
 158   WATCHPOINT_ASSERT(length <= string->current_size);
 159   WATCHPOINT_ASSERT(string->string);
 160   WATCHPOINT_ASSERT(string->end >= string->string);
 161
 162   memcpy(string->end, value, length);
 163   string->end+= length;
 164
 165   return MEMCACHED_SUCCESS;
 166 }
 167
 168 char *memcached_string_c_copy(memcached_string_st *string)
 169 {
 170   if (not memcached_string_length(string))
 171     return NULL;
 172
 173   char *c_ptr= static_cast<char *>(libmemcached_malloc(string->root, (memcached_string_length(string)+1) * sizeof(char)));
 174
 175   if (not c_ptr)
 176     return NULL;
 177
 178   memcpy(c_ptr, memcached_string_value(string), memcached_string_length(string));
 179   c_ptr[memcached_string_length(string)]= 0;
 180
 181   return c_ptr;
 182 }
 183
 184 memcached_return_t memcached_string_reset(memcached_string_st *string)
 185 {
 186   string->end= string->string;
 187
 188   return MEMCACHED_SUCCESS;
 189 }
 190
 191 void memcached_string_free(memcached_string_st *ptr)
 192 {
 193   if (not ptr)
 194     return;
 195
 196   if (ptr->string)
 197   {
 198     libmemcached_free(ptr->root, ptr->string);
 199   }
 200
 201   if (memcached_is_allocated(ptr))
 202   {
 203     libmemcached_free(ptr->root, ptr);
 204   }
 205   else
 206   {
 207     ptr->options.is_initialized= false;
 208   }
 209 }
 210
 211 memcached_return_t memcached_string_check(memcached_string_st *string, size_t need)
 212 {
 213   return _string_check(string, need);
 214 }
 215
 216 size_t memcached_string_length(const memcached_string_st *self)
 217 {
 218   return (size_t)(self->end - self->string);
 219 }
 220
 221 size_t memcached_string_size(const memcached_string_st *self)
 222 {
 223   return self->current_size;
 224 }
 225
 226 const char *memcached_string_value(const memcached_string_st *self)
 227 {
 228   return self->string;
 229 }
 230
 231 char *memcached_string_take_value(memcached_string_st *self)
 232 {
 233   assert_msg(self, "Invalid memcached_string_st");
 234   // If we fail at adding the null, we copy and move on
 235   if (memcached_success(memcached_string_append_null(self)))
 236   {
 237     return memcached_string_c_copy(self);
 238   }
 239
 240   char *value= self->string;
 241
 242   _init_string(self);
 243
 244   return value;
 245 }
 246
 247 char *memcached_string_value_mutable(const memcached_string_st *self)
 248 {
 249   return self->string;
 250 }
 251
 252 void memcached_string_set_length(memcached_string_st *self, size_t length)
 253 {
 254   self->end= self->string + length;
 255 }