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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:
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  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
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  24  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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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_MEMORY_ALLOCATION_FAILURE;
  58
  59     new_value= static_cast<char *>(libmemcached_realloc(string->root, string->string, new_size));
  60
  61     if (new_value == NULL)
  62     {
  63       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
  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(const memcached_st *memc, memcached_string_st *self, size_t initial_size)
  82 {
  83   memcached_return_t rc;
  84
  85   WATCHPOINT_ASSERT(memc);
  86
  87   /* Saving malloc calls :) */
  88   if (self)
  89   {
  90     WATCHPOINT_ASSERT(self->options.is_initialized == false);
  91
  92     self->options.is_allocated= false;
  93   }
  94   else
  95   {
  96     self= static_cast<memcached_string_st *>(libmemcached_malloc(memc, sizeof(memcached_string_st)));
  97
  98     if (self == NULL)
  99     {
 100       return NULL;
 101     }
 102
 103     self->options.is_allocated= true;
 104   }
 105   self->root= const_cast<memcached_st *>(memc);
 106
 107   _init_string(self);
 108
 109   rc=  _string_check(self, initial_size);
 110   if (memcached_failed(rc))
 111   {
 112     if (rc == MEMCACHED_MEMORY_ALLOCATION_FAILURE)
 113     {
 114       memcached_set_errno(self->root, errno, NULL);
 115     }
 116     libmemcached_free(memc, self);
 117
 118     return NULL;
 119   }
 120
 121   self->options.is_initialized= true;
 122
 123   WATCHPOINT_ASSERT(self->string == self->end);
 124
 125   return self;
 126 }
 127
 128 memcached_return_t memcached_string_append_character(memcached_string_st *string,
 129                                                      char character)
 130 {
 131   memcached_return_t rc;
 132
 133   rc=  _string_check(string, 1);
 134
 135   if (memcached_failed(rc))
 136   {
 137     return rc;
 138   }
 139
 140   *string->end= character;
 141   string->end++;
 142
 143   return MEMCACHED_SUCCESS;
 144 }
 145
 146 memcached_return_t memcached_string_append(memcached_string_st *string,
 147                                            const char *value, size_t length)
 148 {
 149   memcached_return_t rc;
 150
 151   rc= _string_check(string, length);
 152
 153   if (rc != MEMCACHED_SUCCESS)
 154   {
 155     return rc;
 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   char *c_ptr;
 171
 172   if (memcached_string_length(string) == 0)
 173     return NULL;
 174
 175   c_ptr= static_cast<char *>(libmemcached_malloc(string->root, (memcached_string_length(string)+1) * sizeof(char)));
 176
 177   if (c_ptr == NULL)
 178     return NULL;
 179
 180   memcpy(c_ptr, memcached_string_value(string), memcached_string_length(string));
 181   c_ptr[memcached_string_length(string)]= 0;
 182
 183   return c_ptr;
 184 }
 185
 186 memcached_return_t memcached_string_reset(memcached_string_st *string)
 187 {
 188   string->end= string->string;
 189
 190   return MEMCACHED_SUCCESS;
 191 }
 192
 193 void memcached_string_free(memcached_string_st *ptr)
 194 {
 195   if (ptr == NULL)
 196     return;
 197
 198   if (ptr->string)
 199   {
 200     libmemcached_free(ptr->root, ptr->string);
 201   }
 202
 203   if (memcached_is_allocated(ptr))
 204   {
 205     libmemcached_free(ptr->root, ptr);
 206   }
 207   else
 208   {
 209     ptr->options.is_initialized= false;
 210   }
 211 }
 212
 213 memcached_return_t memcached_string_check(memcached_string_st *string, size_t need)
 214 {
 215   return _string_check(string, need);
 216 }
 217
 218 size_t memcached_string_length(const memcached_string_st *self)
 219 {
 220   return (size_t)(self->end - self->string);
 221 }
 222
 223 size_t memcached_string_size(const memcached_string_st *self)
 224 {
 225   return self->current_size;
 226 }
 227
 228 const char *memcached_string_value(const memcached_string_st *self)
 229 {
 230   return self->string;
 231 }
 232
 233 char *memcached_string_value_mutable(const memcached_string_st *self)
 234 {
 235   return self->string;
 236 }
 237
 238 void memcached_string_set_length(memcached_string_st *self, size_t length)
 239 {
 240   self->end= self->string + length;
 241 }