git.m6w6.name Git - m6w6/libmemcached/blob - libmemcached/string.c

   1 /* LibMemcached
   2  * Copyright (C) 2006-2009 Brian Aker
   3  * All rights reserved.
   4  *
   5  * Use and distribution licensed under the BSD license.  See
   6  * the COPYING file in the parent directory for full text.
   7  *
   8  * Summary: String structure used for libmemcached.
   9  *
  10  */
  11
  12 #include "common.h"
  13
  14 inline static memcached_return_t _string_check(memcached_string_st *string, size_t need)
  15 {
  16   if (need && need > (size_t)(string->current_size - (size_t)(string->end - string->string)))
  17   {
  18     size_t current_offset= (size_t) (string->end - string->string);
  19     char *new_value;
  20     size_t adjust;
  21     size_t new_size;
  22
  23     /* This is the block multiplier. To keep it larger and surive division errors we must round it up */
  24     adjust= (need - (size_t)(string->current_size - (size_t)(string->end - string->string))) / string->block_size;
  25     adjust++;
  26
  27     new_size= sizeof(char) * (size_t)((adjust * string->block_size) + string->current_size);
  28     /* Test for overflow */
  29     if (new_size < need)
  30       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
  31
  32     new_value= string->root->call_realloc(string->root, string->string, new_size);
  33
  34     if (new_value == NULL)
  35       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
  36
  37     string->string= new_value;
  38     string->end= string->string + current_offset;
  39
  40     string->current_size+= (string->block_size * adjust);
  41   }
  42
  43   return MEMCACHED_SUCCESS;
  44 }
  45
  46 memcached_string_st *memcached_string_create(memcached_st *memc, memcached_string_st *string, size_t initial_size)
  47 {
  48   memcached_return_t rc;
  49
  50   /* Saving malloc calls :) */
  51   if (string)
  52   {
  53     WATCHPOINT_ASSERT(memc->options.is_safe && string->options.is_initialized == false);
  54
  55     memset(string, 0, sizeof(memcached_string_st));
  56   }
  57   else
  58   {
  59     string= memc->call_calloc(memc, 1, sizeof(memcached_string_st));
  60
  61     if (string == NULL)
  62     {
  63       return NULL;
  64     }
  65
  66     string->options.is_allocated= true;
  67   }
  68   string->block_size= MEMCACHED_BLOCK_SIZE;
  69   string->root= memc;
  70
  71   rc=  _string_check(string, initial_size);
  72   if (rc != MEMCACHED_SUCCESS)
  73   {
  74     memc->call_free(memc, string);
  75     return NULL;
  76   }
  77
  78   string->options.is_initialized= true;
  79
  80   WATCHPOINT_ASSERT(string->string == string->end);
  81
  82   return string;
  83 }
  84
  85 memcached_return_t memcached_string_append_character(memcached_string_st *string,
  86                                                    char character)
  87 {
  88   memcached_return_t rc;
  89
  90   rc=  _string_check(string, 1);
  91
  92   if (rc != MEMCACHED_SUCCESS)
  93     return rc;
  94
  95   *string->end= character;
  96   string->end++;
  97
  98   return MEMCACHED_SUCCESS;
  99 }
 100
 101 memcached_return_t memcached_string_append(memcached_string_st *string,
 102                                          const char *value, size_t length)
 103 {
 104   memcached_return_t rc;
 105
 106   rc= _string_check(string, length);
 107
 108   if (rc != MEMCACHED_SUCCESS)
 109     return rc;
 110
 111   WATCHPOINT_ASSERT(length <= string->current_size);
 112   WATCHPOINT_ASSERT(string->string);
 113   WATCHPOINT_ASSERT(string->end >= string->string);
 114
 115   memcpy(string->end, value, length);
 116   string->end+= length;
 117
 118   return MEMCACHED_SUCCESS;
 119 }
 120
 121 char *memcached_string_c_copy(memcached_string_st *string)
 122 {
 123   char *c_ptr;
 124
 125   if (memcached_string_length(string) == 0)
 126     return NULL;
 127
 128   c_ptr= string->root->call_malloc(string->root, (memcached_string_length(string)+1) * sizeof(char));
 129
 130   if (c_ptr == NULL)
 131     return NULL;
 132
 133   memcpy(c_ptr, memcached_string_value(string), memcached_string_length(string));
 134   c_ptr[memcached_string_length(string)]= 0;
 135
 136   return c_ptr;
 137 }
 138
 139 memcached_return_t memcached_string_reset(memcached_string_st *string)
 140 {
 141   string->end= string->string;
 142
 143   return MEMCACHED_SUCCESS;
 144 }
 145
 146 void memcached_string_free(memcached_string_st *ptr)
 147 {
 148   if (ptr == NULL)
 149     return;
 150
 151   if (ptr->string)
 152   {
 153     ptr->root->call_free(ptr->root, ptr->string);
 154   }
 155
 156   if (memcached_is_allocated(ptr))
 157   {
 158     ptr->root->call_free(ptr->root, ptr);
 159   }
 160   else
 161   {
 162     ptr->options.is_initialized= false;
 163     memset(ptr, 0, sizeof(memcached_string_st));
 164   }
 165 }
 166
 167 memcached_return_t memcached_string_check(memcached_string_st *string, size_t need)
 168 {
 169   return _string_check(string, need);
 170 }
 171