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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
  47     /* This is the block multiplier. To keep it larger and surive division errors we must round it up */
  48     size_t adjust= (need - (size_t)(string->current_size - (size_t)(string->end - string->string))) / MEMCACHED_BLOCK_SIZE;
  49     adjust++;
  50
  51     size_t new_size= sizeof(char) * (size_t)((adjust * MEMCACHED_BLOCK_SIZE) + string->current_size);
  52     /* Test for overflow */
  53     if (new_size < need)
  54     {
  55       char error_message[1024];
  56       int error_message_length= snprintf(error_message, sizeof(error_message),"Needed %ld, got %ld", (long)need, (long)new_size);
  57       return memcached_set_error(*string->root, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, error_message, error_message_length);
  58     }
  59
  60     char *new_value= libmemcached_xrealloc(string->root, string->string, new_size, char);
  61
  62     if (new_value == NULL)
  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     memcached_set_allocated(self, false);
  92   }
  93   else
  94   {
  95     self= libmemcached_xmalloc(memc, memcached_string_st);
  96
  97     if (self == NULL)
  98     {
  99       return NULL;
 100     }
 101
 102     memcached_set_allocated(self, true);
 103   }
 104   self->root= memc;
 105
 106   _init_string(self);
 107
 108   if (memcached_failed(_string_check(self, initial_size)))
 109   {
 110     if (memcached_is_allocated(self))
 111     {
 112       libmemcached_free(memc, self);
 113     }
 114
 115     return NULL;
 116   }
 117
 118   self->options.is_initialized= true;
 119
 120   WATCHPOINT_ASSERT(self->string == self->end);
 121
 122   return self;
 123 }
 124
 125 static memcached_return_t memcached_string_append_null(memcached_string_st *string)
 126 {
 127   if (memcached_failed(_string_check(string, 1)))
 128   {
 129     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 130   }
 131
 132   *string->end= 0;
 133
 134   return MEMCACHED_SUCCESS;
 135 }
 136
 137 memcached_return_t memcached_string_append_character(memcached_string_st *string,
 138                                                      char character)
 139 {
 140   if (memcached_failed(_string_check(string, 1)))
 141   {
 142     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 143   }
 144
 145   *string->end= character;
 146   string->end++;
 147
 148   return MEMCACHED_SUCCESS;
 149 }
 150
 151 memcached_return_t memcached_string_append(memcached_string_st *string,
 152                                            const char *value, size_t length)
 153 {
 154   if (memcached_failed(_string_check(string, length)))
 155   {
 156     return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
 157   }
 158
 159   WATCHPOINT_ASSERT(length <= string->current_size);
 160   WATCHPOINT_ASSERT(string->string);
 161   WATCHPOINT_ASSERT(string->end >= string->string);
 162
 163   memcpy(string->end, value, length);
 164   string->end+= length;
 165
 166   return MEMCACHED_SUCCESS;
 167 }
 168
 169 char *memcached_string_c_copy(memcached_string_st *string)
 170 {
 171   if (memcached_string_length(string) == 0)
 172   {
 173     return NULL;
 174   }
 175
 176   char *c_ptr= static_cast<char *>(libmemcached_malloc(string->root, (memcached_string_length(string)+1) * sizeof(char)));
 177
 178   if (c_ptr == NULL)
 179   {
 180     return NULL;
 181   }
 182
 183   memcpy(c_ptr, memcached_string_value(string), memcached_string_length(string));
 184   c_ptr[memcached_string_length(string)]= 0;
 185
 186   return c_ptr;
 187 }
 188
 189 void memcached_string_reset(memcached_string_st *string)
 190 {
 191   string->end= string->string;
 192 }
 193
 194 void memcached_string_free(memcached_string_st& ptr)
 195 {
 196   memcached_string_free(&ptr);
 197 }
 198
 199 void memcached_string_free(memcached_string_st *ptr)
 200 {
 201   if (ptr == NULL)
 202   {
 203     return;
 204   }
 205
 206   if (ptr->string)
 207   {
 208     libmemcached_free(ptr->root, ptr->string);
 209   }
 210
 211   if (memcached_is_allocated(ptr))
 212   {
 213     libmemcached_free(ptr->root, ptr);
 214   }
 215   else
 216   {
 217     ptr->options.is_initialized= false;
 218   }
 219 }
 220
 221 memcached_return_t memcached_string_check(memcached_string_st *string, size_t need)
 222 {
 223   return _string_check(string, need);
 224 }
 225
 226 bool memcached_string_resize(memcached_string_st& string, const size_t need)
 227 {
 228   return memcached_success(_string_check(&string, need));
 229 }
 230
 231 size_t memcached_string_length(const memcached_string_st *self)
 232 {
 233   return size_t(self->end -self->string);
 234 }
 235
 236 size_t memcached_string_length(const memcached_string_st& self)
 237 {
 238   return size_t(self.end -self.string);
 239 }
 240
 241 size_t memcached_string_size(const memcached_string_st *self)
 242 {
 243   return self->current_size;
 244 }
 245
 246 const char *memcached_string_value(const memcached_string_st *self)
 247 {
 248   return self->string;
 249 }
 250
 251 const char *memcached_string_value(const memcached_string_st& self)
 252 {
 253   return self.string;
 254 }
 255
 256 char *memcached_string_take_value(memcached_string_st *self)
 257 {
 258   assert_msg(self, "Invalid memcached_string_st");
 259   // If we fail at adding the null, we copy and move on
 260   if (memcached_success(memcached_string_append_null(self)))
 261   {
 262     return memcached_string_c_copy(self);
 263   }
 264
 265   char *value= self->string;
 266
 267   _init_string(self);
 268
 269   return value;
 270 }
 271
 272 char *memcached_string_value_mutable(const memcached_string_st *self)
 273 {
 274   return self->string;
 275 }
 276
 277 char *memcached_string_c_str(memcached_string_st& self)
 278 {
 279   return self.string;
 280 }
 281
 282 void memcached_string_set_length(memcached_string_st *self, size_t length)
 283 {
 284   self->end= self->string +length;
 285 }
 286
 287 void memcached_string_set_length(memcached_string_st& self, const size_t length)
 288 {
 289   assert(self.current_size >= length);
 290   size_t set_length= length;
 291   if (self.current_size > length)
 292   {
 293     if (memcached_failed(_string_check(&self, length)))
 294     {
 295       set_length= self.current_size;
 296     }
 297   }
 298   self.end= self.string +set_length;
 299 }