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))) / MEMCACHED_BLOCK_SIZE;
  25     adjust++;
  26
  27     new_size= sizeof(char) * (size_t)((adjust * MEMCACHED_BLOCK_SIZE) + string->current_size);
  28     /* Test for overflow */
  29     if (new_size < need)
  30       return MEMCACHED_MEMORY_ALLOCATION_FAILURE;
  31
  32     new_value= libmemcached_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+= (MEMCACHED_BLOCK_SIZE * adjust);
  41   }
  42
  43   return MEMCACHED_SUCCESS;
  44 }
  45
  46 static inline void _init_string(memcached_string_st *self)
  47 {
  48   self->current_size= 0;
  49   self->end= self->string= NULL;
  50 }
  51
  52 memcached_string_st *memcached_string_create(const memcached_st *memc, memcached_string_st *self, size_t initial_size)
  53 {
  54   memcached_return_t rc;
  55
  56   WATCHPOINT_ASSERT(memc);
  57
  58   /* Saving malloc calls :) */
  59   if (self)
  60   {
  61     WATCHPOINT_ASSERT(self->options.is_initialized == false);
  62
  63     self->options.is_allocated= false;
  64   }
  65   else
  66   {
  67     self= libmemcached_malloc(memc, sizeof(memcached_string_st));
  68
  69     if (self == NULL)
  70     {
  71       return NULL;
  72     }
  73
  74     self->options.is_allocated= true;
  75   }
  76   self->root= memc;
  77
  78   _init_string(self);
  79
  80   rc=  _string_check(self, initial_size);
  81   if (rc != MEMCACHED_SUCCESS)
  82   {
  83     libmemcached_free(memc, self);
  84     return NULL;
  85   }
  86
  87   self->options.is_initialized= true;
  88
  89   WATCHPOINT_ASSERT(self->string == self->end);
  90
  91   return self;
  92 }
  93
  94 memcached_return_t memcached_string_append_character(memcached_string_st *string,
  95                                                      char character)
  96 {
  97   memcached_return_t rc;
  98
  99   rc=  _string_check(string, 1);
 100
 101   if (rc != MEMCACHED_SUCCESS)
 102     return rc;
 103
 104   *string->end= character;
 105   string->end++;
 106
 107   return MEMCACHED_SUCCESS;
 108 }
 109
 110 memcached_return_t memcached_string_append(memcached_string_st *string,
 111                                            const char *value, size_t length)
 112 {
 113   memcached_return_t rc;
 114
 115   rc= _string_check(string, length);
 116
 117   if (rc != MEMCACHED_SUCCESS)
 118     return rc;
 119
 120   WATCHPOINT_ASSERT(length <= string->current_size);
 121   WATCHPOINT_ASSERT(string->string);
 122   WATCHPOINT_ASSERT(string->end >= string->string);
 123
 124   memcpy(string->end, value, length);
 125   string->end+= length;
 126
 127   return MEMCACHED_SUCCESS;
 128 }
 129
 130 char *memcached_string_c_copy(memcached_string_st *string)
 131 {
 132   char *c_ptr;
 133
 134   if (memcached_string_length(string) == 0)
 135     return NULL;
 136
 137   c_ptr= libmemcached_malloc(string->root, (memcached_string_length(string)+1) * sizeof(char));
 138
 139   if (c_ptr == NULL)
 140     return NULL;
 141
 142   memcpy(c_ptr, memcached_string_value(string), memcached_string_length(string));
 143   c_ptr[memcached_string_length(string)]= 0;
 144
 145   return c_ptr;
 146 }
 147
 148 memcached_return_t memcached_string_reset(memcached_string_st *string)
 149 {
 150   string->end= string->string;
 151
 152   return MEMCACHED_SUCCESS;
 153 }
 154
 155 void memcached_string_free(memcached_string_st *ptr)
 156 {
 157   if (ptr == NULL)
 158     return;
 159
 160   if (ptr->string)
 161   {
 162     libmemcached_free(ptr->root, ptr->string);
 163   }
 164
 165   if (memcached_is_allocated(ptr))
 166   {
 167     libmemcached_free(ptr->root, ptr);
 168   }
 169   else
 170   {
 171     ptr->options.is_initialized= false;
 172   }
 173 }
 174
 175 memcached_return_t memcached_string_check(memcached_string_st *string, size_t need)
 176 {
 177   return _string_check(string, need);
 178 }
 179