1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
/* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008-2009 Sun Microsystems
* Copyright (c) 2010 Jay Pipes <jaypipes@gmail.com>
*
* Authors:
*
* Jay Pipes <jaypipes@gmail.com.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
*
* Defines the implementation of the transaction applier plugin
* for the transaction log.
*
* @see drizzled/plugin/transaction_replicator.h
* @see drizzled/plugin/transaction_applier.h
*
* @details
*
* The TransactionLogApplier::apply() method constructs the entry
* in the transaction log from the supplied Transaction message and
* asks its associated TransactionLog object to write this entry.
*
* Upon a successful write, the applier adds some information about
* the written transaction to the transaction log index.
*/
#include "config.h"
#include "transaction_log.h"
#include "transaction_log_applier.h"
#include "transaction_log_index.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <drizzled/errmsg_print.h>
#include <drizzled/gettext.h>
#include <drizzled/algorithm/crc32.h>
#include <drizzled/message/transaction.pb.h>
#include <google/protobuf/io/coded_stream.h>
using namespace std;
using namespace drizzled;
using namespace google;
TransactionLogApplier *transaction_log_applier= NULL; /* The singleton transaction log applier */
extern TransactionLogIndex *transaction_log_index;
TransactionLogApplier::TransactionLogApplier(const string name_arg,
TransactionLog &in_transaction_log,
bool in_do_checksum) :
plugin::TransactionApplier(name_arg),
transaction_log(in_transaction_log),
do_checksum(in_do_checksum)
{
}
TransactionLogApplier::~TransactionLogApplier()
{
}
void TransactionLogApplier::apply(const message::Transaction &to_apply)
{
uint8_t *buffer; /* Buffer we will write serialized header,
message and trailing checksum to */
uint8_t *orig_buffer;
size_t message_byte_length= to_apply.ByteSize();
size_t total_envelope_length= TransactionLog::HEADER_TRAILER_BYTES + message_byte_length;
/*
* Attempt allocation of raw memory buffer for the header,
* message and trailing checksum bytes.
*/
buffer= static_cast<uint8_t *>(malloc(total_envelope_length));
if (buffer == NULL)
{
errmsg_printf(ERRMSG_LVL_ERROR,
_("Failed to allocate enough memory to buffer header, "
"transaction message, and trailing checksum bytes. Tried to allocate %" PRId64
" bytes. Error: %s\n"),
static_cast<int64_t>(total_envelope_length),
strerror(errno));
return;
}
else
orig_buffer= buffer; /* We will free() orig_buffer, as buffer is moved during write */
/*
* Write the header information, which is the message type and
* the length of the transaction message into the buffer
*/
buffer= protobuf::io::CodedOutputStream::WriteLittleEndian32ToArray(
static_cast<uint32_t>(ReplicationServices::TRANSACTION), buffer);
buffer= protobuf::io::CodedOutputStream::WriteLittleEndian32ToArray(
static_cast<uint32_t>(message_byte_length), buffer);
/*
* Now write the serialized transaction message, followed
* by the optional checksum into the buffer.
*/
buffer= to_apply.SerializeWithCachedSizesToArray(buffer);
uint32_t checksum= 0;
if (do_checksum)
{
checksum= drizzled::algorithm::crc32(
reinterpret_cast<char *>(buffer) - message_byte_length, message_byte_length);
}
/* We always write in network byte order */
buffer= protobuf::io::CodedOutputStream::WriteLittleEndian32ToArray(checksum, buffer);
/* Ask the transaction log to write the entry and return where it wrote it */
off_t written_to= transaction_log.writeEntry(orig_buffer, total_envelope_length);
free(orig_buffer);
/* Add an entry to the index describing what was just applied */
transaction_log_index->addEntry(TransactionLogEntry(ReplicationServices::TRANSACTION,
written_to,
total_envelope_length),
to_apply,
checksum);
}
|