MySQL 8.1.0
Source Code Documentation
binlog_istream.h
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1/* Copyright (c) 2018, 2023, Oracle and/or its affiliates.
2
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4 it under the terms of the GNU General Public License, version 2.0,
5 as published by the Free Software Foundation.
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9 as designated in a particular file or component or in included license
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12 separately licensed software that they have included with MySQL.
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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#ifndef BINLOG_ISTREAM_INCLUDED
24#define BINLOG_ISTREAM_INCLUDED
25#include "my_sys.h"
26#include "sql/basic_istream.h"
28
29/**
30 It defines the error types which could happen when reading binlog files or
31 deserializing binlog events. String error message of the error types are
32 defined as well. It has a member variable to store an error type and
33 provides a few functions to check the error type stored in the member
34 variable.
35 */
37 public:
38 /**
39 Possible errors which happens when reading an event.
40 */
42 // No error happens
44 /*
45 Arrive at the end of the stream. Nothing was read. It is smaller than any
46 other errors. Because READ_EOF is often not an error, and others are
47 usually errors.
48 */
50 // malformed event
52 // IO error while reading
54 // Failed to allocate memory
56 // Only a partial event could be read
58 // Only a partial Format_description_log_event could be read
62 // Event's is_valid returned false
64 // Cannot open the binlog file
66 // System IO error happened while reading the binlog magic
68 // The binlog magic is incorrect
74 };
75
76 Binlog_read_error() = default;
78
79 bool has_error() const { return m_type != SUCCESS; }
80 bool has_fatal_error() const { return m_type > READ_EOF; }
81
82 /**
83 Return the error encountered when reading events.
84 */
85 Error_type get_type() const { return m_type; }
86
87 /**
88 Return error message of the error type.
89
90 @return It will return nullptr if m_type is SUCCESS. In practice, it should
91 never be called if m_type is SUCCESS. So an assertion is added in
92 debug mode which predicts m_type is not SUCCESS.
93 */
94 const char *get_str() const;
95
96 /**
97 Set m_error to error.
98
99 @param[in] type The error type will be set
100 @retval false If error is SUCCESS
101 @retval true If error is not SUCCESS.
102 */
104 m_type = type;
105 return has_error();
106 }
107
108 private:
110};
111
112/**
113 Seekable_istream with decryption feature. It can be setup into an stream
114 pipeline. In the pipeline, it decrypts the data from down stream and then
115 feeds the decrypted data into up stream.
116*/
118 public:
120
121 /**
122 Initialize the context used in the decryption stream.
123
124 @param[in] down_istream The down stream where the encrypted data is stored.
125 @param[in] binlog_read_error Binlog_encryption_istream doesn't own a
126 Binlog_read_error. So the caller should provide
127 one to it. When error happens, the error type
128 will be set into 'binlog_read_error'.
129
130 @retval false Succeed.
131 @retval true Error.
132 */
133 bool open(std::unique_ptr<Basic_seekable_istream> down_istream,
134 Binlog_read_error *binlog_read_error);
135 /**
136 Closes the stream. It also closes the down stream and the decryptor.
137 */
138 void close();
139
140 ssize_t read(unsigned char *buffer, size_t length) override;
141 bool seek(my_off_t offset) override;
142 my_off_t length() override;
143
144 private:
145 /* The decryptor cypher to decrypt the content read from down stream */
146 std::unique_ptr<Stream_cipher> m_decryptor;
147 /* The down stream containing the encrypted content */
148 std::unique_ptr<Basic_seekable_istream> m_down_istream;
149};
150
151/**
152 Base class of binlog input files. It is a logical binlog file which wraps
153 and hides the detail of lower layer storage implementation. Binlog reader and
154 other binlog code just uses this class to control real storage.
155*/
157 public:
158 /**
159 @param[in] binlog_read_error Basic_binlog_ifile doesn't own an
160 Binlog_read_error. So the caller should
161 provide one to it. When error happens,
162 the error type will be set into 'error'.
163 */
164 Basic_binlog_ifile(Binlog_read_error *binlog_read_error);
167 ~Basic_binlog_ifile() override;
168 /**
169 Open a binlog file.
170
171 @param[in] file_name name of the binlog file which will be opened.
172 */
173 bool open(const char *file_name);
174 /**
175 Close the binlog file it is reading.
176 */
177 void close();
178
179 ssize_t read(unsigned char *buffer, size_t length) override;
180 bool seek(my_off_t position) override;
181
182 my_off_t position() const { return m_position; }
183 bool is_open() const { return m_istream != nullptr; }
184
185 const std::string &file_name() const { return m_file_name; }
186 /**
187 Get length of the binlog file. It is not os file length. The content maybe
188 encrypted or compressed. It is the total length of BINLOG_MAGIC and all
189 raw binlog events.
190 */
191 my_off_t length() override;
192
193 protected:
194 /**
195 Open the system layer file. It is the entry of the stream pipeline.
196 Implementation is delegated to sub-classes. Sub-classes opens system layer
197 files in different way.
198
199 @param[in] file_name name of the binlog file which will be opened.
200 */
201 virtual std::unique_ptr<Basic_seekable_istream> open_file(
202 const char *file_name) = 0;
203
204 /**
205 It is convenient for caller to share a Binlog_read_error object between
206 streams. So Binlog_read_error pointer is defined here. It should be
207 initialized in constructor by caller.
208 */
210
211 private:
212 /**
213 The binlog's position where it is reading. It is the position in logical
214 binlog file, but not the position of system file.
215 */
217 /** It is the entry of the low level stream pipeline. */
218 std::unique_ptr<Basic_seekable_istream> m_istream;
219 /** Name of the file opened */
220 std::string m_file_name;
221 /**
222 Read binlog magic from binlog file and check if it is valid binlog magic.
223
224 This function also takes care of setting up any other stream layer (i.e.
225 encryption) when needed.
226
227 @retval false The high level stream layer was recognized as a binary log.
228 @retval true Failure identifying the high level stream layer.
229 */
230 bool read_binlog_magic();
231};
232
233#ifdef MYSQL_SERVER
234/**
235 Binlog input file. It is responsible for opening binlog files generated by
236 the server itself, but not relaylog files.
237*/
239 public:
241
242 protected:
243 std::unique_ptr<Basic_seekable_istream> open_file(
244 const char *file_name) override;
245};
246
247/**
248 Relaylog input file. It is responsible for opening relay log files.
249*/
251 public:
253
254 protected:
255 std::unique_ptr<Basic_seekable_istream> open_file(
256 const char *file_name) override;
257};
258#endif
259
260#endif // BINLOG_ISTREAM_INCLUDED
Base class of binlog input files.
Definition: binlog_istream.h:156
bool open(const char *file_name)
Open a binlog file.
Definition: binlog_istream.cc:182
bool seek(my_off_t position) override
Puts the read position to a given offset.
Definition: binlog_istream.cc:203
virtual std::unique_ptr< Basic_seekable_istream > open_file(const char *file_name)=0
Open the system layer file.
bool read_binlog_magic()
Read binlog magic from binlog file and check if it is valid binlog magic.
Definition: binlog_istream.cc:134
ssize_t read(unsigned char *buffer, size_t length) override
Read some bytes from the input stream.
Definition: binlog_istream.cc:197
Basic_binlog_ifile & operator=(const Basic_binlog_ifile &)=delete
my_off_t length() override
Get length of the binlog file.
Definition: binlog_istream.cc:212
const std::string & file_name() const
Definition: binlog_istream.h:185
my_off_t position() const
Definition: binlog_istream.h:182
my_off_t m_position
The binlog's position where it is reading.
Definition: binlog_istream.h:216
Binlog_read_error * m_error
It is convenient for caller to share a Binlog_read_error object between streams.
Definition: binlog_istream.h:209
~Basic_binlog_ifile() override
Definition: binlog_istream.cc:177
bool is_open() const
Definition: binlog_istream.h:183
std::string m_file_name
Name of the file opened.
Definition: binlog_istream.h:220
Basic_binlog_ifile(Binlog_read_error *binlog_read_error)
Definition: binlog_istream.cc:172
std::unique_ptr< Basic_seekable_istream > m_istream
It is the entry of the low level stream pipeline.
Definition: binlog_istream.h:218
void close()
Close the binlog file it is reading.
Definition: binlog_istream.cc:190
Basic_binlog_ifile(const Basic_binlog_ifile &)=delete
The abstract class for seekable input streams which have fixed length and provide seek operation.
Definition: basic_istream.h:59
Seekable_istream with decryption feature.
Definition: binlog_istream.h:117
bool seek(my_off_t offset) override
Puts the read position to a given offset.
Definition: binlog_istream.cc:120
~Binlog_encryption_istream() override
Definition: binlog_istream.cc:132
bool open(std::unique_ptr< Basic_seekable_istream > down_istream, Binlog_read_error *binlog_read_error)
Initialize the context used in the decryption stream.
Definition: binlog_istream.cc:77
ssize_t read(unsigned char *buffer, size_t length) override
Read some bytes from the input stream.
Definition: binlog_istream.cc:113
void close()
Closes the stream.
Definition: binlog_istream.cc:107
std::unique_ptr< Basic_seekable_istream > m_down_istream
Definition: binlog_istream.h:148
my_off_t length() override
The total length of the stream.
Definition: binlog_istream.cc:128
std::unique_ptr< Stream_cipher > m_decryptor
Definition: binlog_istream.h:146
Binlog input file.
Definition: binlog_istream.h:238
std::unique_ptr< Basic_seekable_istream > open_file(const char *file_name) override
Open the system layer file.
Definition: binlog_istream.cc:216
It defines the error types which could happen when reading binlog files or deserializing binlog event...
Definition: binlog_istream.h:36
bool has_error() const
Definition: binlog_istream.h:79
Error_type get_type() const
Return the error encountered when reading events.
Definition: binlog_istream.h:85
Binlog_read_error(Error_type type)
Definition: binlog_istream.h:77
Error_type
Possible errors which happens when reading an event.
Definition: binlog_istream.h:41
@ EVENT_TOO_LARGE
Definition: binlog_istream.h:60
@ MEM_ALLOCATE
Definition: binlog_istream.h:55
@ BOGUS
Definition: binlog_istream.h:51
@ SUCCESS
Definition: binlog_istream.h:43
@ SYSTEM_IO
Definition: binlog_istream.h:53
@ READ_ENCRYPTED_LOG_FILE_IS_NOT_SUPPORTED
Definition: binlog_istream.h:72
@ CANNOT_GET_FILE_PASSWORD
Definition: binlog_istream.h:71
@ ERROR_DECRYPTING_FILE
Definition: binlog_istream.h:73
@ READ_EOF
Definition: binlog_istream.h:49
@ HEADER_IO_FAILURE
Definition: binlog_istream.h:67
@ TRUNC_EVENT
Definition: binlog_istream.h:57
@ CANNOT_OPEN
Definition: binlog_istream.h:65
@ BAD_BINLOG_MAGIC
Definition: binlog_istream.h:69
@ INVALID_EVENT
Definition: binlog_istream.h:63
@ TRUNC_FD_EVENT
Definition: binlog_istream.h:59
@ CHECKSUM_FAILURE
Definition: binlog_istream.h:61
@ INVALID_ENCRYPTION_HEADER
Definition: binlog_istream.h:70
Binlog_read_error()=default
bool set_type(Error_type type)
Set m_error to error.
Definition: binlog_istream.h:103
Error_type m_type
Definition: binlog_istream.h:109
const char * get_str() const
Return error message of the error type.
Definition: binlog_istream.cc:33
bool has_fatal_error() const
Definition: binlog_istream.h:80
Relaylog input file.
Definition: binlog_istream.h:250
std::unique_ptr< Basic_seekable_istream > open_file(const char *file_name) override
Open the system layer file.
Definition: binlog_istream.cc:227
ulonglong my_off_t
Definition: my_inttypes.h:71
Common header for many mysys elements.
mutable_buffer buffer(void *p, size_t n) noexcept
Definition: buffer.h:419
required string type
Definition: replication_group_member_actions.proto:33
This file includes the major components for encrypting/decrypting binary log files.