Drizzled Public API Documentation

sql_sort.h
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4  * Copyright (C) 2008 Sun Microsystems, Inc.
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19 
20 #pragma once
21 
22 #include <unistd.h>
23 #include <drizzled/base.h>
24 #include <drizzled/common_fwd.h>
25 #include <drizzled/qsort_cmp.h>
26 
27 namespace drizzled {
28 
29 /*
30  The structure sort_addon_field describes a fixed layout
31  for field values appended to sorted values in records to be sorted
32  in the sort buffer.
33  Only fixed layout is supported now.
34  Null bit maps for the appended values is placed before the values
35  themselves. Offsets are from the last sorted field, that is from the
36  record referefence, which is still last component of sorted records.
37  It is preserved for backward compatiblility.
38  The structure is used tp store values of the additional fields
39  in the sort buffer. It is used also when these values are read
40  from a temporary file/buffer. As the reading procedures are beyond the
41  scope of the 'filesort' code the values have to be retrieved via
42  the callback function 'unpack_addon_fields'.
43 */
44 
45 class sort_addon_field { /* Sort addon packed field */
46 public:
47  Field *field; /* Original field */
48  uint32_t offset; /* Offset from the last sorted field */
49  uint32_t null_offset; /* Offset to to null bit from the last sorted field */
50  uint32_t length; /* Length in the sort buffer */
51  uint8_t null_bit; /* Null bit mask for the field */
52 
54  field(NULL),
55  offset(0),
56  null_offset(0),
57  length(0),
58  null_bit(0)
59  { }
60 
61 };
62 
63 class buffpek { /* Struktur om sorteringsbuffrarna */
64 public:
65  off_t file_pos; /* Where we are in the sort file */
66  unsigned char *base; /* key pointers */
67  unsigned char *key; /* key pointers */
68  ha_rows count; /* Number of rows in table */
69  size_t mem_count; /* numbers of keys in memory */
70  size_t max_keys; /* Max keys in buffert */
71 
72  buffpek() :
73  file_pos(0),
74  base(0),
75  key(0),
76  count(0),
77  mem_count(0),
78  max_keys(0)
79  { }
80 
81 };
82 
83 } /* namespace drizzled */
84 
TODO: Rename this file - func.h is stupid.