1 /* Copyright (c) 2019, 2020, Oracle and/or its affiliates. All rights reserved.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License, version 2.0,
5 as published by the Free Software Foundation.
6
7 This program is also distributed with certain software (including
8 but not limited to OpenSSL) that is licensed under separate terms,
9 as designated in a particular file or component or in included license
10 documentation. The authors of MySQL hereby grant you an additional
11 permission to link the program and your derivative works with the
12 separately licensed software that they have included with MySQL.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License, version 2.0, for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
22
23 #include "sql/hash_join_chunk.h"
24
25 #include <cstring>
26
27 #include "my_base.h"
28 #include "my_dbug.h"
29 #include "my_sys.h"
30 #include "scope_guard.h"
31 #include "sql/hash_join_buffer.h"
32 #include "sql/mysqld.h"
33 #include "sql/sql_base.h"
34 #include "sql/sql_const.h"
35
HashJoinChunk(HashJoinChunk && other)36 HashJoinChunk::HashJoinChunk(HashJoinChunk &&other)
37 : m_tables(std::move(other.m_tables)),
38 m_num_rows(other.m_num_rows),
39 m_file(other.m_file),
40 m_uses_match_flags(other.m_uses_match_flags) {
41 setup_io_cache(&m_file);
42 // Reset the IO_CACHE structure so that the destructor doesn't close/clear the
43 // file contents and it's buffers.
44 new (&other.m_file) IO_CACHE();
45 }
46
operator =(HashJoinChunk && other)47 HashJoinChunk &HashJoinChunk::operator=(HashJoinChunk &&other) {
48 m_tables = std::move(other.m_tables);
49 m_num_rows = other.m_num_rows;
50 m_uses_match_flags = other.m_uses_match_flags;
51
52 // Since the file we are replacing will become unreachable, free all resources
53 // used by it.
54 close_cached_file(&m_file);
55 m_file = other.m_file;
56 setup_io_cache(&m_file);
57
58 // Reset the IO_CACHE structure so that the destructor doesn't close/clear the
59 // file contents and it's buffers.
60 new (&other.m_file) IO_CACHE();
61 return *this;
62 }
63
~HashJoinChunk()64 HashJoinChunk::~HashJoinChunk() { close_cached_file(&m_file); }
65
Init(const hash_join_buffer::TableCollection & tables,bool uses_match_flags)66 bool HashJoinChunk::Init(const hash_join_buffer::TableCollection &tables,
67 bool uses_match_flags) {
68 m_tables = tables;
69 m_file.file_key = key_file_hash_join;
70 m_num_rows = 0;
71 m_uses_match_flags = uses_match_flags;
72 return open_cached_file(&m_file, mysql_tmpdir, TEMP_PREFIX, DISK_BUFFER_SIZE,
73 MYF(MY_WME));
74 }
75
Rewind()76 bool HashJoinChunk::Rewind() {
77 if (my_b_flush_io_cache(&m_file, /*need_append_buffer_lock=*/0) == -1 ||
78 reinit_io_cache(&m_file, READ_CACHE, 0, false, false)) {
79 my_error(ER_TEMP_FILE_WRITE_FAILURE, MYF(0));
80 return true;
81 }
82
83 return false;
84 }
85
WriteRowToChunk(String * buffer,bool matched)86 bool HashJoinChunk::WriteRowToChunk(String *buffer, bool matched) {
87 if (hash_join_buffer::StoreFromTableBuffers(m_tables, buffer)) {
88 my_error(ER_OUTOFMEMORY, MYF(ME_FATALERROR),
89 ComputeRowSizeUpperBound(m_tables));
90 return true;
91 }
92
93 if (m_uses_match_flags) {
94 if (my_b_write(&m_file, pointer_cast<const uchar *>(&matched),
95 sizeof(matched)) != 0) {
96 my_error(ER_TEMP_FILE_WRITE_FAILURE, MYF(0));
97 return true;
98 }
99 }
100
101 // Write out the length of the data.
102 size_t data_length = buffer->length();
103 if (my_b_write(&m_file, pointer_cast<const uchar *>(&data_length),
104 sizeof(data_length)) != 0) {
105 my_error(ER_TEMP_FILE_WRITE_FAILURE, MYF(0));
106 return true;
107 }
108
109 // ... and then write the actual data.
110 if (my_b_write(&m_file, pointer_cast<uchar *>(buffer->ptr()), data_length) !=
111 0) {
112 my_error(ER_TEMP_FILE_WRITE_FAILURE, MYF(0));
113 return true;
114 }
115 m_num_rows++;
116 return false;
117 }
118
LoadRowFromChunk(String * buffer,bool * matched)119 bool HashJoinChunk::LoadRowFromChunk(String *buffer, bool *matched) {
120 if (m_uses_match_flags) {
121 if (my_b_read(&m_file, pointer_cast<uchar *>(matched), sizeof(*matched)) !=
122 0) {
123 my_error(ER_TEMP_FILE_WRITE_FAILURE, MYF(0));
124 return true;
125 }
126 }
127
128 // Read the length of the row.
129 size_t row_length;
130 if (my_b_read(&m_file, pointer_cast<uchar *>(&row_length),
131 sizeof(row_length)) != 0) {
132 my_error(ER_TEMP_FILE_WRITE_FAILURE, MYF(0));
133 return true;
134 }
135
136 // Read the actual data of the row.
137 if (buffer->reserve(row_length)) {
138 my_error(ER_OUTOFMEMORY, MYF(ME_FATALERROR), row_length);
139 return true;
140 }
141
142 buffer->length(row_length);
143 if (my_b_read(&m_file, pointer_cast<uchar *>(buffer->ptr()), row_length) !=
144 0) {
145 my_error(ER_TEMP_FILE_WRITE_FAILURE, MYF(0));
146 return true;
147 }
148
149 hash_join_buffer::LoadIntoTableBuffers(
150 m_tables, {pointer_cast<const uchar *>(buffer->ptr()), buffer->length()});
151
152 return false;
153 }
154