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1 | package DBIx::Class::Storage::DBI::Replicated; |
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2 | |
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3 | BEGIN { |
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4 | use DBIx::Class; |
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5 | die('The following modules are required for Replication ' . DBIx::Class::Optional::Dependencies->req_missing_for ('replicated') . "\n" ) |
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6 | unless DBIx::Class::Optional::Dependencies->req_ok_for ('replicated'); |
ecb65397 |
7 | } |
8 | |
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9 | use Moose; |
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10 | use DBIx::Class::Storage::DBI; |
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11 | use DBIx::Class::Storage::DBI::Replicated::Pool; |
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12 | use DBIx::Class::Storage::DBI::Replicated::Balancer; |
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13 | use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSchema DBICStorageDBI/; |
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14 | use MooseX::Types::Moose qw/ClassName HashRef Object/; |
b2e4d522 |
15 | use Scalar::Util 'reftype'; |
e666c5fd |
16 | use Hash::Merge; |
7da56142 |
17 | use List::Util qw/min max reduce/; |
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18 | use Try::Tiny; |
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19 | use namespace::clean; |
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20 | |
21 | use namespace::clean -except => 'meta'; |
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22 | |
23 | =head1 NAME |
24 | |
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25 | DBIx::Class::Storage::DBI::Replicated - BETA Replicated database support |
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26 | |
27 | =head1 SYNOPSIS |
28 | |
29 | The Following example shows how to change an existing $schema to a replicated |
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30 | storage type, add some replicated (read-only) databases, and perform reporting |
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31 | tasks. |
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32 | |
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33 | You should set the 'storage_type attribute to a replicated type. You should |
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34 | also define your arguments, such as which balancer you want and any arguments |
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35 | that the Pool object should get. |
36 | |
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37 | my $schema = Schema::Class->clone; |
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38 | $schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] ); |
ce854fd3 |
39 | $schema->connection(...); |
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40 | |
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41 | Next, you need to add in the Replicants. Basically this is an array of |
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42 | arrayrefs, where each arrayref is database connect information. Think of these |
43 | arguments as what you'd pass to the 'normal' $schema->connect method. |
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44 | |
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45 | $schema->storage->connect_replicants( |
46 | [$dsn1, $user, $pass, \%opts], |
47 | [$dsn2, $user, $pass, \%opts], |
48 | [$dsn3, $user, $pass, \%opts], |
49 | ); |
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50 | |
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51 | Now, just use the $schema as you normally would. Automatically all reads will |
52 | be delegated to the replicants, while writes to the master. |
53 | |
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54 | $schema->resultset('Source')->search({name=>'etc'}); |
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55 | |
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56 | You can force a given query to use a particular storage using the search |
57 | attribute 'force_pool'. For example: |
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58 | |
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59 | my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); |
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60 | |
61 | Now $RS will force everything (both reads and writes) to use whatever was setup |
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62 | as the master storage. 'master' is hardcoded to always point to the Master, |
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63 | but you can also use any Replicant name. Please see: |
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64 | L<DBIx::Class::Storage::DBI::Replicated::Pool> and the replicants attribute for more. |
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65 | |
66 | Also see transactions and L</execute_reliably> for alternative ways to |
67 | force read traffic to the master. In general, you should wrap your statements |
68 | in a transaction when you are reading and writing to the same tables at the |
69 | same time, since your replicants will often lag a bit behind the master. |
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70 | |
71 | See L<DBIx::Class::Storage::DBI::Replicated::Instructions> for more help and |
72 | walkthroughs. |
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73 | |
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74 | =head1 DESCRIPTION |
75 | |
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76 | Warning: This class is marked BETA. This has been running a production |
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77 | website using MySQL native replication as its backend and we have some decent |
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78 | test coverage but the code hasn't yet been stressed by a variety of databases. |
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79 | Individual DBs may have quirks we are not aware of. Please use this in first |
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80 | development and pass along your experiences/bug fixes. |
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81 | |
82 | This class implements replicated data store for DBI. Currently you can define |
83 | one master and numerous slave database connections. All write-type queries |
84 | (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master |
85 | database, all read-type queries (SELECTs) go to the slave database. |
86 | |
87 | Basically, any method request that L<DBIx::Class::Storage::DBI> would normally |
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88 | handle gets delegated to one of the two attributes: L</read_handler> or to |
89 | L</write_handler>. Additionally, some methods need to be distributed |
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90 | to all existing storages. This way our storage class is a drop in replacement |
91 | for L<DBIx::Class::Storage::DBI>. |
92 | |
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93 | Read traffic is spread across the replicants (slaves) occurring to a user |
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94 | selected algorithm. The default algorithm is random weighted. |
95 | |
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96 | =head1 NOTES |
97 | |
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98 | The consistency between master and replicants is database specific. The Pool |
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99 | gives you a method to validate its replicants, removing and replacing them |
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100 | when they fail/pass predefined criteria. Please make careful use of the ways |
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101 | to force a query to run against Master when needed. |
102 | |
103 | =head1 REQUIREMENTS |
104 | |
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105 | Replicated Storage has additional requirements not currently part of |
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106 | L<DBIx::Class>. See L<DBIx::Class::Optional::Dependencies> for more details. |
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107 | |
108 | =head1 ATTRIBUTES |
109 | |
110 | This class defines the following attributes. |
111 | |
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112 | =head2 schema |
113 | |
114 | The underlying L<DBIx::Class::Schema> object this storage is attaching |
115 | |
116 | =cut |
117 | |
118 | has 'schema' => ( |
119 | is=>'rw', |
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120 | isa=>DBICSchema, |
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121 | weak_ref=>1, |
122 | required=>1, |
123 | ); |
124 | |
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125 | =head2 pool_type |
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126 | |
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127 | Contains the classname which will instantiate the L</pool> object. Defaults |
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128 | to: L<DBIx::Class::Storage::DBI::Replicated::Pool>. |
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129 | |
130 | =cut |
131 | |
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132 | has 'pool_type' => ( |
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133 | is=>'rw', |
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134 | isa=>ClassName, |
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135 | default=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
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136 | handles=>{ |
137 | 'create_pool' => 'new', |
138 | }, |
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139 | ); |
140 | |
f068a139 |
141 | =head2 pool_args |
142 | |
143 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
144 | See L<DBIx::Class::Storage::DBI::Replicated::Pool> for available arguments. |
f068a139 |
145 | |
146 | =cut |
147 | |
148 | has 'pool_args' => ( |
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149 | is=>'rw', |
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150 | isa=>HashRef, |
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151 | lazy=>1, |
64cdad22 |
152 | default=>sub { {} }, |
f068a139 |
153 | ); |
154 | |
155 | |
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156 | =head2 balancer_type |
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157 | |
158 | The replication pool requires a balance class to provider the methods for |
159 | choose how to spread the query load across each replicant in the pool. |
160 | |
161 | =cut |
162 | |
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163 | has 'balancer_type' => ( |
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164 | is=>'rw', |
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165 | isa=>BalancerClassNamePart, |
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166 | coerce=>1, |
167 | required=>1, |
168 | default=> 'DBIx::Class::Storage::DBI::Replicated::Balancer::First', |
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169 | handles=>{ |
170 | 'create_balancer' => 'new', |
171 | }, |
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172 | ); |
173 | |
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174 | =head2 balancer_args |
175 | |
176 | Contains a hashref of initialized information to pass to the Balancer object. |
212cc5c2 |
177 | See L<DBIx::Class::Storage::DBI::Replicated::Balancer> for available arguments. |
17b05c13 |
178 | |
179 | =cut |
180 | |
181 | has 'balancer_args' => ( |
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182 | is=>'rw', |
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183 | isa=>HashRef, |
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184 | lazy=>1, |
185 | required=>1, |
186 | default=>sub { {} }, |
17b05c13 |
187 | ); |
188 | |
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189 | =head2 pool |
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190 | |
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191 | Is a L<DBIx::Class::Storage::DBI::Replicated::Pool> or derived class. This is a |
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192 | container class for one or more replicated databases. |
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193 | |
194 | =cut |
195 | |
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196 | has 'pool' => ( |
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197 | is=>'ro', |
198 | isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', |
199 | lazy_build=>1, |
200 | handles=>[qw/ |
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201 | connect_replicants |
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202 | replicants |
203 | has_replicants |
204 | /], |
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205 | ); |
206 | |
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207 | =head2 balancer |
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208 | |
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209 | Is a L<DBIx::Class::Storage::DBI::Replicated::Balancer> or derived class. This |
210 | is a class that takes a pool (L<DBIx::Class::Storage::DBI::Replicated::Pool>) |
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211 | |
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212 | =cut |
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213 | |
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214 | has 'balancer' => ( |
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215 | is=>'rw', |
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216 | isa=>'DBIx::Class::Storage::DBI::Replicated::Balancer', |
217 | lazy_build=>1, |
218 | handles=>[qw/auto_validate_every/], |
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219 | ); |
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220 | |
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221 | =head2 master |
222 | |
223 | The master defines the canonical state for a pool of connected databases. All |
224 | the replicants are expected to match this databases state. Thus, in a classic |
225 | Master / Slaves distributed system, all the slaves are expected to replicate |
226 | the Master's state as quick as possible. This is the only database in the |
227 | pool of databases that is allowed to handle write traffic. |
228 | |
229 | =cut |
230 | |
231 | has 'master' => ( |
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232 | is=> 'ro', |
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233 | isa=>DBICStorageDBI, |
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234 | lazy_build=>1, |
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235 | ); |
236 | |
cb6ec758 |
237 | =head1 ATTRIBUTES IMPLEMENTING THE DBIx::Storage::DBI INTERFACE |
238 | |
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239 | The following methods are delegated all the methods required for the |
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240 | L<DBIx::Class::Storage::DBI> interface. |
241 | |
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242 | =cut |
243 | |
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244 | my $method_dispatch = { |
245 | writer => [qw/ |
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246 | on_connect_do |
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247 | on_disconnect_do |
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248 | on_connect_call |
249 | on_disconnect_call |
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250 | connect_info |
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251 | _connect_info |
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252 | throw_exception |
253 | sql_maker |
254 | sqlt_type |
255 | create_ddl_dir |
256 | deployment_statements |
257 | datetime_parser |
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258 | datetime_parser_type |
259 | build_datetime_parser |
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260 | last_insert_id |
261 | insert |
262 | insert_bulk |
263 | update |
264 | delete |
265 | dbh |
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266 | txn_begin |
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267 | txn_do |
268 | txn_commit |
269 | txn_rollback |
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270 | txn_scope_guard |
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271 | deploy |
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272 | with_deferred_fk_checks |
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273 | dbh_do |
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274 | _prep_for_execute |
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275 | is_datatype_numeric |
276 | _count_select |
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277 | _subq_update_delete |
278 | svp_rollback |
279 | svp_begin |
280 | svp_release |
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281 | relname_to_table_alias |
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282 | _dbh_last_insert_id |
283 | _fix_bind_params |
284 | _default_dbi_connect_attributes |
285 | _dbi_connect_info |
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286 | _dbic_connect_attributes |
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287 | auto_savepoint |
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288 | _query_end |
289 | bind_attribute_by_data_type |
290 | transaction_depth |
291 | _dbh |
292 | _select_args |
293 | _dbh_execute_array |
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294 | _sql_maker |
295 | _query_start |
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296 | _per_row_update_delete |
297 | _dbh_begin_work |
298 | _dbh_execute_inserts_with_no_binds |
299 | _select_args_to_query |
300 | _svp_generate_name |
301 | _multipk_update_delete |
302 | source_bind_attributes |
303 | _normalize_connect_info |
304 | _parse_connect_do |
305 | _dbh_commit |
306 | _execute_array |
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307 | savepoints |
3244fdcc |
308 | _sql_maker_opts |
309 | _conn_pid |
3244fdcc |
310 | _dbh_autocommit |
311 | _native_data_type |
312 | _get_dbh |
313 | sql_maker_class |
314 | _dbh_rollback |
315 | _adjust_select_args_for_complex_prefetch |
316 | _resolve_ident_sources |
317 | _resolve_column_info |
318 | _prune_unused_joins |
319 | _strip_cond_qualifiers |
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320 | _strip_cond_qualifiers_from_array |
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321 | _resolve_aliastypes_from_select_args |
322 | _execute |
323 | _do_query |
402ac1c9 |
324 | _sth |
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325 | _dbh_sth |
326 | _dbh_execute |
64cdad22 |
327 | /], |
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328 | reader => [qw/ |
329 | select |
330 | select_single |
331 | columns_info_for |
332 | _dbh_columns_info_for |
333 | _select |
334 | /], |
335 | unimplemented => [qw/ |
336 | _arm_global_destructor |
337 | _verify_pid |
338 | |
339 | get_use_dbms_capability |
340 | set_use_dbms_capability |
341 | get_dbms_capability |
342 | set_dbms_capability |
343 | _dbh_details |
344 | _dbh_get_info |
345 | |
346 | sql_limit_dialect |
347 | sql_quote_char |
348 | sql_name_sep |
349 | |
350 | _inner_join_to_node |
351 | _group_over_selection |
352 | _extract_order_criteria |
353 | |
354 | _prefetch_autovalues |
355 | |
356 | _max_column_bytesize |
357 | _is_lob_type |
358 | _is_binary_lob_type |
359 | _is_text_lob_type |
402ac1c9 |
360 | |
361 | sth |
4bea1fe7 |
362 | /,( |
363 | # the capability framework |
364 | # not sure if CMOP->initialize does evil things to DBIC::S::DBI, fix if a problem |
365 | grep |
366 | { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x } |
367 | ( Class::MOP::Class->initialize('DBIx::Class::Storage::DBI')->get_all_method_names ) |
368 | )], |
369 | }; |
370 | |
371 | if (DBIx::Class::_ENV_::DBICTEST) { |
372 | |
373 | my $seen; |
374 | for my $type (keys %$method_dispatch) { |
375 | for (@{$method_dispatch->{$type}}) { |
376 | push @{$seen->{$_}}, $type; |
377 | } |
378 | } |
cb6ec758 |
379 | |
4bea1fe7 |
380 | if (my @dupes = grep { @{$seen->{$_}} > 1 } keys %$seen) { |
381 | die(join "\n", '', |
382 | 'The following methods show up multiple times in ::Storage::DBI::Replicated handlers:', |
383 | (map { "$_: " . (join ', ', @{$seen->{$_}}) } sort @dupes), |
384 | '', |
385 | ); |
386 | } |
bbdda281 |
387 | |
4bea1fe7 |
388 | if (my @cant = grep { ! DBIx::Class::Storage::DBI->can($_) } keys %$seen) { |
389 | die(join "\n", '', |
390 | '::Storage::DBI::Replicated specifies handling of the following *NON EXISTING* ::Storage::DBI methods:', |
391 | @cant, |
392 | '', |
393 | ); |
394 | } |
395 | } |
bbdda281 |
396 | |
4bea1fe7 |
397 | for my $method (@{$method_dispatch->{unimplemented}}) { |
398 | __PACKAGE__->meta->add_method($method, sub { |
70c28808 |
399 | my $self = shift; |
400 | $self->throw_exception("$method must not be called on ".(blessed $self).' objects'); |
4bea1fe7 |
401 | }); |
402 | } |
31a8aaaf |
403 | |
4bea1fe7 |
404 | =head2 read_handler |
584ea6e4 |
405 | |
4bea1fe7 |
406 | Defines an object that implements the read side of L<BIx::Class::Storage::DBI>. |
584ea6e4 |
407 | |
4bea1fe7 |
408 | =cut |
409 | |
410 | has 'read_handler' => ( |
411 | is=>'rw', |
412 | isa=>Object, |
413 | lazy_build=>1, |
414 | handles=>$method_dispatch->{reader}, |
e471ab87 |
415 | ); |
416 | |
4bea1fe7 |
417 | =head2 write_handler |
418 | |
419 | Defines an object that implements the write side of L<BIx::Class::Storage::DBI>, |
420 | as well as methods that don't write or read that can be called on only one |
421 | storage, methods that return a C<$dbh>, and any methods that don't make sense to |
422 | run on a replicant. |
423 | |
424 | =cut |
425 | |
426 | has 'write_handler' => ( |
427 | is=>'ro', |
428 | isa=>Object, |
429 | lazy_build=>1, |
430 | handles=>$method_dispatch->{writer}, |
7f4433eb |
431 | ); |
432 | |
4bea1fe7 |
433 | |
6d766626 |
434 | |
b2e4d522 |
435 | has _master_connect_info_opts => |
436 | (is => 'rw', isa => HashRef, default => sub { {} }); |
437 | |
438 | =head2 around: connect_info |
439 | |
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440 | Preserves master's C<connect_info> options (for merging with replicants.) |
441 | Also sets any Replicated-related options from connect_info, such as |
dcdf7b2c |
442 | C<pool_type>, C<pool_args>, C<balancer_type> and C<balancer_args>. |
b2e4d522 |
443 | |
444 | =cut |
445 | |
446 | around connect_info => sub { |
447 | my ($next, $self, $info, @extra) = @_; |
448 | |
282a9a4f |
449 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
450 | |
b2e4d522 |
451 | my %opts; |
452 | for my $arg (@$info) { |
453 | next unless (reftype($arg)||'') eq 'HASH'; |
e666c5fd |
454 | %opts = %{ $merge->merge($arg, \%opts) }; |
b2e4d522 |
455 | } |
b2e4d522 |
456 | delete $opts{dsn}; |
457 | |
dcdf7b2c |
458 | if (@opts{qw/pool_type pool_args/}) { |
459 | $self->pool_type(delete $opts{pool_type}) |
460 | if $opts{pool_type}; |
461 | |
b88b85e7 |
462 | $self->pool_args( |
e666c5fd |
463 | $merge->merge((delete $opts{pool_args} || {}), $self->pool_args) |
b88b85e7 |
464 | ); |
dcdf7b2c |
465 | |
64ae1667 |
466 | ## Since we possibly changed the pool_args, we need to clear the current |
467 | ## pool object so that next time it is used it will be rebuilt. |
468 | $self->clear_pool; |
dcdf7b2c |
469 | } |
470 | |
471 | if (@opts{qw/balancer_type balancer_args/}) { |
472 | $self->balancer_type(delete $opts{balancer_type}) |
473 | if $opts{balancer_type}; |
474 | |
b88b85e7 |
475 | $self->balancer_args( |
e666c5fd |
476 | $merge->merge((delete $opts{balancer_args} || {}), $self->balancer_args) |
b88b85e7 |
477 | ); |
dcdf7b2c |
478 | |
67c43863 |
479 | $self->balancer($self->_build_balancer) |
6f7344b8 |
480 | if $self->balancer; |
dcdf7b2c |
481 | } |
482 | |
b2e4d522 |
483 | $self->_master_connect_info_opts(\%opts); |
484 | |
cca282b6 |
485 | my @res; |
486 | if (wantarray) { |
0ce2d0d5 |
487 | @res = $self->$next($info, @extra); |
488 | } else { |
cca282b6 |
489 | $res[0] = $self->$next($info, @extra); |
0ce2d0d5 |
490 | } |
491 | |
fd4eb9c2 |
492 | # Make sure master is blessed into the correct class and apply role to it. |
493 | my $master = $self->master; |
494 | $master->_determine_driver; |
495 | Moose::Meta::Class->initialize(ref $master); |
cea43436 |
496 | |
ec0946db |
497 | DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); |
cea43436 |
498 | |
499 | # link pool back to master |
500 | $self->pool->master($master); |
0ce2d0d5 |
501 | |
cca282b6 |
502 | wantarray ? @res : $res[0]; |
b2e4d522 |
503 | }; |
504 | |
26ab719a |
505 | =head1 METHODS |
2bf79155 |
506 | |
26ab719a |
507 | This class defines the following methods. |
2bf79155 |
508 | |
c354902c |
509 | =head2 BUILDARGS |
2bf79155 |
510 | |
faaba25f |
511 | L<DBIx::Class::Schema> when instantiating its storage passed itself as the |
2ce6e9a6 |
512 | first argument. So we need to massage the arguments a bit so that all the |
513 | bits get put into the correct places. |
2bf79155 |
514 | |
515 | =cut |
516 | |
c354902c |
517 | sub BUILDARGS { |
fd323bf1 |
518 | my ($class, $schema, $storage_type_args, @args) = @_; |
d4daee7b |
519 | |
c354902c |
520 | return { |
6f7344b8 |
521 | schema=>$schema, |
522 | %$storage_type_args, |
523 | @args |
c354902c |
524 | } |
525 | } |
2bf79155 |
526 | |
cb6ec758 |
527 | =head2 _build_master |
2bf79155 |
528 | |
cb6ec758 |
529 | Lazy builder for the L</master> attribute. |
2bf79155 |
530 | |
531 | =cut |
532 | |
cb6ec758 |
533 | sub _build_master { |
2ce6e9a6 |
534 | my $self = shift @_; |
ee356d00 |
535 | my $master = DBIx::Class::Storage::DBI->new($self->schema); |
ee356d00 |
536 | $master |
106d5f3b |
537 | } |
538 | |
26ab719a |
539 | =head2 _build_pool |
2bf79155 |
540 | |
26ab719a |
541 | Lazy builder for the L</pool> attribute. |
2bf79155 |
542 | |
543 | =cut |
544 | |
26ab719a |
545 | sub _build_pool { |
64cdad22 |
546 | my $self = shift @_; |
547 | $self->create_pool(%{$self->pool_args}); |
2bf79155 |
548 | } |
549 | |
26ab719a |
550 | =head2 _build_balancer |
2bf79155 |
551 | |
cb6ec758 |
552 | Lazy builder for the L</balancer> attribute. This takes a Pool object so that |
553 | the balancer knows which pool it's balancing. |
2bf79155 |
554 | |
555 | =cut |
556 | |
26ab719a |
557 | sub _build_balancer { |
64cdad22 |
558 | my $self = shift @_; |
559 | $self->create_balancer( |
6f7344b8 |
560 | pool=>$self->pool, |
64cdad22 |
561 | master=>$self->master, |
562 | %{$self->balancer_args}, |
563 | ); |
2bf79155 |
564 | } |
565 | |
cb6ec758 |
566 | =head2 _build_write_handler |
2bf79155 |
567 | |
cb6ec758 |
568 | Lazy builder for the L</write_handler> attribute. The default is to set this to |
569 | the L</master>. |
50336325 |
570 | |
571 | =cut |
572 | |
cb6ec758 |
573 | sub _build_write_handler { |
64cdad22 |
574 | return shift->master; |
cb6ec758 |
575 | } |
50336325 |
576 | |
cb6ec758 |
577 | =head2 _build_read_handler |
2bf79155 |
578 | |
cb6ec758 |
579 | Lazy builder for the L</read_handler> attribute. The default is to set this to |
580 | the L</balancer>. |
2bf79155 |
581 | |
582 | =cut |
583 | |
cb6ec758 |
584 | sub _build_read_handler { |
64cdad22 |
585 | return shift->balancer; |
cb6ec758 |
586 | } |
50336325 |
587 | |
cb6ec758 |
588 | =head2 around: connect_replicants |
2bf79155 |
589 | |
cb6ec758 |
590 | All calls to connect_replicants needs to have an existing $schema tacked onto |
b2e4d522 |
591 | top of the args, since L<DBIx::Storage::DBI> needs it, and any C<connect_info> |
592 | options merged with the master, with replicant opts having higher priority. |
955a6df6 |
593 | |
cb6ec758 |
594 | =cut |
955a6df6 |
595 | |
b2e4d522 |
596 | around connect_replicants => sub { |
597 | my ($next, $self, @args) = @_; |
598 | |
599 | for my $r (@args) { |
600 | $r = [ $r ] unless reftype $r eq 'ARRAY'; |
601 | |
1a58752c |
602 | $self->throw_exception('coderef replicant connect_info not supported') |
b2e4d522 |
603 | if ref $r->[0] && reftype $r->[0] eq 'CODE'; |
604 | |
605 | # any connect_info options? |
606 | my $i = 0; |
607 | $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; |
608 | |
6f7344b8 |
609 | # make one if none |
b2e4d522 |
610 | $r->[$i] = {} unless $r->[$i]; |
611 | |
612 | # merge if two hashes |
b88b85e7 |
613 | my @hashes = @$r[$i .. $#{$r}]; |
614 | |
1a58752c |
615 | $self->throw_exception('invalid connect_info options') |
b88b85e7 |
616 | if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; |
617 | |
1a58752c |
618 | $self->throw_exception('too many hashrefs in connect_info') |
b88b85e7 |
619 | if @hashes > 2; |
620 | |
282a9a4f |
621 | my $merge = Hash::Merge->new('LEFT_PRECEDENT'); |
e666c5fd |
622 | my %opts = %{ $merge->merge(reverse @hashes) }; |
b88b85e7 |
623 | |
624 | # delete them |
b2e4d522 |
625 | splice @$r, $i+1, ($#{$r} - $i), (); |
626 | |
0bd8e058 |
627 | # make sure master/replicants opts don't clash |
628 | my %master_opts = %{ $self->_master_connect_info_opts }; |
629 | if (exists $opts{dbh_maker}) { |
630 | delete @master_opts{qw/dsn user password/}; |
631 | } |
632 | delete $master_opts{dbh_maker}; |
633 | |
b2e4d522 |
634 | # merge with master |
e666c5fd |
635 | %opts = %{ $merge->merge(\%opts, \%master_opts) }; |
b2e4d522 |
636 | |
637 | # update |
638 | $r->[$i] = \%opts; |
639 | } |
640 | |
641 | $self->$next($self->schema, @args); |
955a6df6 |
642 | }; |
2bf79155 |
643 | |
2bf79155 |
644 | =head2 all_storages |
645 | |
646 | Returns an array of of all the connected storage backends. The first element |
647 | in the returned array is the master, and the remainings are each of the |
648 | replicants. |
649 | |
650 | =cut |
651 | |
652 | sub all_storages { |
64cdad22 |
653 | my $self = shift @_; |
654 | return grep {defined $_ && blessed $_} ( |
655 | $self->master, |
6412a592 |
656 | values %{ $self->replicants }, |
64cdad22 |
657 | ); |
2bf79155 |
658 | } |
659 | |
c4d3fae2 |
660 | =head2 execute_reliably ($coderef, ?@args) |
661 | |
662 | Given a coderef, saves the current state of the L</read_handler>, forces it to |
48580715 |
663 | use reliable storage (e.g. sets it to the master), executes a coderef and then |
c4d3fae2 |
664 | restores the original state. |
665 | |
666 | Example: |
667 | |
64cdad22 |
668 | my $reliably = sub { |
669 | my $name = shift @_; |
670 | $schema->resultset('User')->create({name=>$name}); |
fd323bf1 |
671 | my $user_rs = $schema->resultset('User')->find({name=>$name}); |
64cdad22 |
672 | return $user_rs; |
673 | }; |
c4d3fae2 |
674 | |
64cdad22 |
675 | my $user_rs = $schema->storage->execute_reliably($reliably, 'John'); |
c4d3fae2 |
676 | |
677 | Use this when you must be certain of your database state, such as when you just |
678 | inserted something and need to get a resultset including it, etc. |
679 | |
680 | =cut |
681 | |
682 | sub execute_reliably { |
64cdad22 |
683 | my ($self, $coderef, @args) = @_; |
d4daee7b |
684 | |
64cdad22 |
685 | unless( ref $coderef eq 'CODE') { |
686 | $self->throw_exception('Second argument must be a coderef'); |
687 | } |
d4daee7b |
688 | |
64cdad22 |
689 | ##Get copy of master storage |
690 | my $master = $self->master; |
d4daee7b |
691 | |
64cdad22 |
692 | ##Get whatever the current read hander is |
693 | my $current = $self->read_handler; |
d4daee7b |
694 | |
64cdad22 |
695 | ##Set the read handler to master |
696 | $self->read_handler($master); |
d4daee7b |
697 | |
64cdad22 |
698 | ## do whatever the caller needs |
699 | my @result; |
700 | my $want_array = wantarray; |
d4daee7b |
701 | |
ed7ab0f4 |
702 | try { |
64cdad22 |
703 | if($want_array) { |
704 | @result = $coderef->(@args); |
705 | } elsif(defined $want_array) { |
706 | ($result[0]) = ($coderef->(@args)); |
ed213e85 |
707 | } else { |
64cdad22 |
708 | $coderef->(@args); |
6f7344b8 |
709 | } |
ed7ab0f4 |
710 | } catch { |
711 | $self->throw_exception("coderef returned an error: $_"); |
712 | } finally { |
713 | ##Reset to the original state |
714 | $self->read_handler($current); |
64cdad22 |
715 | }; |
d4daee7b |
716 | |
cca282b6 |
717 | return wantarray ? @result : $result[0]; |
c4d3fae2 |
718 | } |
719 | |
cb6ec758 |
720 | =head2 set_reliable_storage |
721 | |
722 | Sets the current $schema to be 'reliable', that is all queries, both read and |
723 | write are sent to the master |
d4daee7b |
724 | |
cb6ec758 |
725 | =cut |
726 | |
727 | sub set_reliable_storage { |
64cdad22 |
728 | my $self = shift @_; |
729 | my $schema = $self->schema; |
730 | my $write_handler = $self->schema->storage->write_handler; |
d4daee7b |
731 | |
64cdad22 |
732 | $schema->storage->read_handler($write_handler); |
cb6ec758 |
733 | } |
734 | |
735 | =head2 set_balanced_storage |
736 | |
737 | Sets the current $schema to be use the </balancer> for all reads, while all |
48580715 |
738 | writes are sent to the master only |
d4daee7b |
739 | |
cb6ec758 |
740 | =cut |
741 | |
742 | sub set_balanced_storage { |
64cdad22 |
743 | my $self = shift @_; |
744 | my $schema = $self->schema; |
bd5da369 |
745 | my $balanced_handler = $self->schema->storage->balancer; |
d4daee7b |
746 | |
bd5da369 |
747 | $schema->storage->read_handler($balanced_handler); |
cb6ec758 |
748 | } |
2bf79155 |
749 | |
750 | =head2 connected |
751 | |
752 | Check that the master and at least one of the replicants is connected. |
753 | |
754 | =cut |
755 | |
756 | sub connected { |
64cdad22 |
757 | my $self = shift @_; |
758 | return |
759 | $self->master->connected && |
760 | $self->pool->connected_replicants; |
2bf79155 |
761 | } |
762 | |
2bf79155 |
763 | =head2 ensure_connected |
764 | |
765 | Make sure all the storages are connected. |
766 | |
767 | =cut |
768 | |
769 | sub ensure_connected { |
64cdad22 |
770 | my $self = shift @_; |
771 | foreach my $source ($self->all_storages) { |
772 | $source->ensure_connected(@_); |
773 | } |
2bf79155 |
774 | } |
775 | |
2bf79155 |
776 | =head2 limit_dialect |
777 | |
778 | Set the limit_dialect for all existing storages |
779 | |
780 | =cut |
781 | |
782 | sub limit_dialect { |
64cdad22 |
783 | my $self = shift @_; |
784 | foreach my $source ($self->all_storages) { |
785 | $source->limit_dialect(@_); |
786 | } |
f3e9f010 |
787 | return $self->master->limit_dialect; |
2bf79155 |
788 | } |
789 | |
2bf79155 |
790 | =head2 quote_char |
791 | |
792 | Set the quote_char for all existing storages |
793 | |
794 | =cut |
795 | |
796 | sub quote_char { |
64cdad22 |
797 | my $self = shift @_; |
798 | foreach my $source ($self->all_storages) { |
799 | $source->quote_char(@_); |
800 | } |
3fbe08e3 |
801 | return $self->master->quote_char; |
2bf79155 |
802 | } |
803 | |
2bf79155 |
804 | =head2 name_sep |
805 | |
806 | Set the name_sep for all existing storages |
807 | |
808 | =cut |
809 | |
810 | sub name_sep { |
64cdad22 |
811 | my $self = shift @_; |
812 | foreach my $source ($self->all_storages) { |
813 | $source->name_sep(@_); |
814 | } |
3fbe08e3 |
815 | return $self->master->name_sep; |
2bf79155 |
816 | } |
817 | |
2bf79155 |
818 | =head2 set_schema |
819 | |
820 | Set the schema object for all existing storages |
821 | |
822 | =cut |
823 | |
824 | sub set_schema { |
64cdad22 |
825 | my $self = shift @_; |
826 | foreach my $source ($self->all_storages) { |
827 | $source->set_schema(@_); |
828 | } |
2bf79155 |
829 | } |
830 | |
2bf79155 |
831 | =head2 debug |
832 | |
833 | set a debug flag across all storages |
834 | |
835 | =cut |
836 | |
837 | sub debug { |
64cdad22 |
838 | my $self = shift @_; |
3fbe08e3 |
839 | if(@_) { |
840 | foreach my $source ($self->all_storages) { |
841 | $source->debug(@_); |
6f7344b8 |
842 | } |
64cdad22 |
843 | } |
3fbe08e3 |
844 | return $self->master->debug; |
2bf79155 |
845 | } |
846 | |
2bf79155 |
847 | =head2 debugobj |
848 | |
cea43436 |
849 | set a debug object |
2bf79155 |
850 | |
851 | =cut |
852 | |
853 | sub debugobj { |
64cdad22 |
854 | my $self = shift @_; |
cea43436 |
855 | return $self->master->debugobj(@_); |
2bf79155 |
856 | } |
857 | |
2bf79155 |
858 | =head2 debugfh |
859 | |
cea43436 |
860 | set a debugfh object |
2bf79155 |
861 | |
862 | =cut |
863 | |
864 | sub debugfh { |
64cdad22 |
865 | my $self = shift @_; |
cea43436 |
866 | return $self->master->debugfh(@_); |
2bf79155 |
867 | } |
868 | |
2bf79155 |
869 | =head2 debugcb |
870 | |
cea43436 |
871 | set a debug callback |
2bf79155 |
872 | |
873 | =cut |
874 | |
875 | sub debugcb { |
64cdad22 |
876 | my $self = shift @_; |
cea43436 |
877 | return $self->master->debugcb(@_); |
2bf79155 |
878 | } |
879 | |
2bf79155 |
880 | =head2 disconnect |
881 | |
882 | disconnect everything |
883 | |
884 | =cut |
885 | |
886 | sub disconnect { |
64cdad22 |
887 | my $self = shift @_; |
888 | foreach my $source ($self->all_storages) { |
889 | $source->disconnect(@_); |
890 | } |
2bf79155 |
891 | } |
892 | |
b2e4d522 |
893 | =head2 cursor_class |
894 | |
895 | set cursor class on all storages, or return master's |
896 | |
897 | =cut |
898 | |
899 | sub cursor_class { |
900 | my ($self, $cursor_class) = @_; |
901 | |
902 | if ($cursor_class) { |
903 | $_->cursor_class($cursor_class) for $self->all_storages; |
904 | } |
905 | $self->master->cursor_class; |
906 | } |
d4daee7b |
907 | |
3244fdcc |
908 | =head2 cursor |
909 | |
910 | set cursor class on all storages, or return master's, alias for L</cursor_class> |
911 | above. |
912 | |
913 | =cut |
914 | |
915 | sub cursor { |
916 | my ($self, $cursor_class) = @_; |
917 | |
918 | if ($cursor_class) { |
919 | $_->cursor($cursor_class) for $self->all_storages; |
920 | } |
921 | $self->master->cursor; |
922 | } |
923 | |
924 | =head2 unsafe |
925 | |
926 | sets the L<DBIx::Class::Storage::DBI/unsafe> option on all storages or returns |
927 | master's current setting |
928 | |
929 | =cut |
930 | |
931 | sub unsafe { |
932 | my $self = shift; |
933 | |
934 | if (@_) { |
935 | $_->unsafe(@_) for $self->all_storages; |
936 | } |
937 | |
938 | return $self->master->unsafe; |
939 | } |
940 | |
941 | =head2 disable_sth_caching |
942 | |
943 | sets the L<DBIx::Class::Storage::DBI/disable_sth_caching> option on all storages |
944 | or returns master's current setting |
945 | |
946 | =cut |
947 | |
948 | sub disable_sth_caching { |
949 | my $self = shift; |
950 | |
951 | if (@_) { |
952 | $_->disable_sth_caching(@_) for $self->all_storages; |
953 | } |
954 | |
955 | return $self->master->disable_sth_caching; |
956 | } |
957 | |
958 | =head2 lag_behind_master |
959 | |
960 | returns the highest Replicant L<DBIx::Class::Storage::DBI/lag_behind_master> |
961 | setting |
962 | |
963 | =cut |
964 | |
965 | sub lag_behind_master { |
966 | my $self = shift; |
967 | |
968 | return max map $_->lag_behind_master, $self->replicants; |
fd323bf1 |
969 | } |
3244fdcc |
970 | |
971 | =head2 is_replicating |
972 | |
973 | returns true if all replicants return true for |
974 | L<DBIx::Class::Storage::DBI/is_replicating> |
975 | |
976 | =cut |
977 | |
978 | sub is_replicating { |
979 | my $self = shift; |
980 | |
981 | return (grep $_->is_replicating, $self->replicants) == ($self->replicants); |
982 | } |
983 | |
984 | =head2 connect_call_datetime_setup |
985 | |
986 | calls L<DBIx::Class::Storage::DBI/connect_call_datetime_setup> for all storages |
987 | |
988 | =cut |
989 | |
990 | sub connect_call_datetime_setup { |
991 | my $self = shift; |
992 | $_->connect_call_datetime_setup for $self->all_storages; |
993 | } |
994 | |
995 | sub _populate_dbh { |
996 | my $self = shift; |
997 | $_->_populate_dbh for $self->all_storages; |
998 | } |
999 | |
1000 | sub _connect { |
1001 | my $self = shift; |
1002 | $_->_connect for $self->all_storages; |
1003 | } |
1004 | |
1005 | sub _rebless { |
1006 | my $self = shift; |
1007 | $_->_rebless for $self->all_storages; |
1008 | } |
1009 | |
1010 | sub _determine_driver { |
1011 | my $self = shift; |
1012 | $_->_determine_driver for $self->all_storages; |
1013 | } |
1014 | |
1015 | sub _driver_determined { |
1016 | my $self = shift; |
fd323bf1 |
1017 | |
3244fdcc |
1018 | if (@_) { |
1019 | $_->_driver_determined(@_) for $self->all_storages; |
1020 | } |
1021 | |
1022 | return $self->master->_driver_determined; |
1023 | } |
1024 | |
1025 | sub _init { |
1026 | my $self = shift; |
fd323bf1 |
1027 | |
3244fdcc |
1028 | $_->_init for $self->all_storages; |
1029 | } |
1030 | |
1031 | sub _run_connection_actions { |
1032 | my $self = shift; |
fd323bf1 |
1033 | |
3244fdcc |
1034 | $_->_run_connection_actions for $self->all_storages; |
1035 | } |
1036 | |
1037 | sub _do_connection_actions { |
1038 | my $self = shift; |
fd323bf1 |
1039 | |
3244fdcc |
1040 | if (@_) { |
1041 | $_->_do_connection_actions(@_) for $self->all_storages; |
1042 | } |
1043 | } |
1044 | |
1045 | sub connect_call_do_sql { |
1046 | my $self = shift; |
1047 | $_->connect_call_do_sql(@_) for $self->all_storages; |
1048 | } |
1049 | |
1050 | sub disconnect_call_do_sql { |
1051 | my $self = shift; |
1052 | $_->disconnect_call_do_sql(@_) for $self->all_storages; |
1053 | } |
1054 | |
1055 | sub _seems_connected { |
1056 | my $self = shift; |
1057 | |
1058 | return min map $_->_seems_connected, $self->all_storages; |
1059 | } |
1060 | |
1061 | sub _ping { |
1062 | my $self = shift; |
1063 | |
1064 | return min map $_->_ping, $self->all_storages; |
1065 | } |
1066 | |
bbdda281 |
1067 | # not using the normalized_version, because we want to preserve |
1068 | # version numbers much longer than the conventional xxx.yyyzzz |
7da56142 |
1069 | my $numify_ver = sub { |
1070 | my $ver = shift; |
1071 | my @numparts = split /\D+/, $ver; |
bbdda281 |
1072 | my $format = '%d.' . (join '', ('%06d') x (@numparts - 1)); |
7da56142 |
1073 | |
1074 | return sprintf $format, @numparts; |
1075 | }; |
fecb38cb |
1076 | sub _server_info { |
1077 | my $self = shift; |
1078 | |
bbdda281 |
1079 | if (not $self->_dbh_details->{info}) { |
1080 | $self->_dbh_details->{info} = ( |
fd323bf1 |
1081 | reduce { $a->[0] < $b->[0] ? $a : $b } |
7da56142 |
1082 | map [ $numify_ver->($_->{dbms_version}), $_ ], |
1083 | map $_->_server_info, $self->all_storages |
1084 | )->[1]; |
fecb38cb |
1085 | } |
1086 | |
bbdda281 |
1087 | return $self->next::method; |
fecb38cb |
1088 | } |
1089 | |
1090 | sub _get_server_version { |
1091 | my $self = shift; |
1092 | |
1093 | return $self->_server_info->{dbms_version}; |
1094 | } |
1095 | |
7e38d850 |
1096 | =head1 GOTCHAS |
1097 | |
1098 | Due to the fact that replicants can lag behind a master, you must take care to |
1099 | make sure you use one of the methods to force read queries to a master should |
1100 | you need realtime data integrity. For example, if you insert a row, and then |
1101 | immediately re-read it from the database (say, by doing $row->discard_changes) |
1102 | or you insert a row and then immediately build a query that expects that row |
1103 | to be an item, you should force the master to handle reads. Otherwise, due to |
1104 | the lag, there is no certainty your data will be in the expected state. |
1105 | |
1106 | For data integrity, all transactions automatically use the master storage for |
1107 | all read and write queries. Using a transaction is the preferred and recommended |
1108 | method to force the master to handle all read queries. |
1109 | |
1110 | Otherwise, you can force a single query to use the master with the 'force_pool' |
1111 | attribute: |
1112 | |
1113 | my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); |
1114 | |
1115 | This attribute will safely be ignore by non replicated storages, so you can use |
1116 | the same code for both types of systems. |
1117 | |
1118 | Lastly, you can use the L</execute_reliably> method, which works very much like |
1119 | a transaction. |
1120 | |
1121 | For debugging, you can turn replication on/off with the methods L</set_reliable_storage> |
1122 | and L</set_balanced_storage>, however this operates at a global level and is not |
1123 | suitable if you have a shared Schema object being used by multiple processes, |
1124 | such as on a web application server. You can get around this limitation by |
1125 | using the Schema clone method. |
1126 | |
1127 | my $new_schema = $schema->clone; |
1128 | $new_schema->set_reliable_storage; |
d4daee7b |
1129 | |
7e38d850 |
1130 | ## $new_schema will use only the Master storage for all reads/writes while |
1131 | ## the $schema object will use replicated storage. |
1132 | |
f5d3a5de |
1133 | =head1 AUTHOR |
1134 | |
64cdad22 |
1135 | John Napiorkowski <john.napiorkowski@takkle.com> |
f5d3a5de |
1136 | |
c4d3fae2 |
1137 | Based on code originated by: |
f5d3a5de |
1138 | |
64cdad22 |
1139 | Norbert Csongrádi <bert@cpan.org> |
1140 | Peter Siklósi <einon@einon.hu> |
2156bbdd |
1141 | |
f5d3a5de |
1142 | =head1 LICENSE |
1143 | |
1144 | You may distribute this code under the same terms as Perl itself. |
1145 | |
1146 | =cut |
1147 | |
c354902c |
1148 | __PACKAGE__->meta->make_immutable; |
1149 | |
f5d3a5de |
1150 | 1; |