Drizzled Public API Documentation

repeat.cc
1 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
2  * vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
3  *
4  * Copyright (C) 2008 Sun Microsystems, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 of the License.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 #include <config.h>
21 
22 #include <drizzled/function/str/repeat.h>
23 #include <drizzled/error.h>
24 #include <drizzled/function/str/alloc_buffer.h>
25 #include <drizzled/session.h>
26 #include <drizzled/system_variables.h>
27 
28 namespace drizzled {
29 
30 void Item_func_repeat::fix_length_and_dec()
31 {
32  collation.set(args[0]->collation);
33  if (args[1]->const_item())
34  {
35  /* must be int64_t to avoid truncation */
36  int64_t count= args[1]->val_int();
37 
38  /* Assumes that the maximum length of a String is < INT32_MAX. */
39  /* Set here so that rest of code sees out-of-bound value as such. */
40  if (count > INT32_MAX)
41  count= INT32_MAX;
42 
43  uint64_t max_result_length= (uint64_t) args[0]->max_length * count;
44  if (max_result_length >= MAX_BLOB_WIDTH)
45  {
46  max_result_length= MAX_BLOB_WIDTH;
47  maybe_null= 1;
48  }
49  max_length= (ulong) max_result_length;
50  }
51  else
52  {
53  max_length= MAX_BLOB_WIDTH;
54  maybe_null= 1;
55  }
56 }
57 
64 {
65  assert(fixed == 1);
66  uint32_t length,tot_length;
67  char *to;
68  /* must be int64_t to avoid truncation */
69  int64_t count= args[1]->val_int();
70  String *res= args[0]->val_str(str);
71 
72  if (args[0]->null_value || args[1]->null_value)
73  goto err; // string and/or delim are null
74  null_value= 0;
75 
76  if (count <= 0 && (count == 0 || !args[1]->unsigned_flag))
77  return &my_empty_string;
78 
79  /* Assumes that the maximum length of a String is < INT32_MAX. */
80  /* Bounds check on count: If this is triggered, we will error. */
81  if ((uint64_t) count > INT32_MAX)
82  count= INT32_MAX;
83  if (count == 1) // To avoid reallocs
84  return res;
85  length=res->length();
86  // Safe length check
87  if (length > session.variables.max_allowed_packet / (uint) count)
88  {
89  push_warning_printf(&session, DRIZZLE_ERROR::WARN_LEVEL_WARN,
90  ER_WARN_ALLOWED_PACKET_OVERFLOWED,
91  ER(ER_WARN_ALLOWED_PACKET_OVERFLOWED),
92  func_name(), session.variables.max_allowed_packet);
93  goto err;
94  }
95  tot_length= length*(uint) count;
96  if (!(res= alloc_buffer(res,str,&tmp_value,tot_length)))
97  goto err;
98 
99  to=(char*) res->ptr()+length;
100  while (--count)
101  {
102  memcpy(to,res->ptr(),length);
103  to+=length;
104  }
105  return (res);
106 
107 err:
108  null_value=1;
109  return 0;
110 }
111 
112 } /* namespace drizzled */
String * val_str(String *)
Definition: repeat.cc:63
virtual int64_t val_int()=0
bool fixed
Definition: item.h:120
bool null_value
Definition: item.h:122
virtual bool const_item() const
Definition: func.h:108
bool maybe_null
Definition: item.h:121
virtual String * val_str(String *str)=0
drizzle_system_variables & variables
Definition: session.h:199