Jeroen De Dauw has uploaded a new change for review.
https://gerrit.wikimedia.org/r/81254
Change subject: Add code to read in table definitions from the db [DNM, DRAFT]
......................................................................
Add code to read in table definitions from the db [DNM, DRAFT]
Change-Id: I11dd081d1835abbcc978b7f576f90cad4903db6c
---
M src/DBConnectionProvider.php
M src/LazyDBConnectionProvider.php
A src/TableDefinitionReader.php
3 files changed, 224 insertions(+), 0 deletions(-)
git pull
ssh://gerrit.wikimedia.org:29418/mediawiki/extensions/WikibaseDatabase
refs/changes/54/81254/1
diff --git a/src/DBConnectionProvider.php b/src/DBConnectionProvider.php
index 9bac3ab..a65f955 100644
--- a/src/DBConnectionProvider.php
+++ b/src/DBConnectionProvider.php
@@ -7,6 +7,8 @@
/**
* Interface for database connection providers.
*
+ * TODO: specify connection handling requirements
+ *
* @since 0.1
*
* @file
diff --git a/src/LazyDBConnectionProvider.php b/src/LazyDBConnectionProvider.php
index 541a649..0f88755 100644
--- a/src/LazyDBConnectionProvider.php
+++ b/src/LazyDBConnectionProvider.php
@@ -8,6 +8,8 @@
* Lazy database connection provider.
* The connection is fetched when needed using the id provided in the
constructor.
*
+ * TODO: implement connection handling requirements
+ *
* @since 0.1
*
* @file
diff --git a/src/TableDefinitionReader.php b/src/TableDefinitionReader.php
new file mode 100644
index 0000000..8b8c5ad
--- /dev/null
+++ b/src/TableDefinitionReader.php
@@ -0,0 +1,220 @@
+<?php
+
+namespace Wikibase\Database;
+
+use Exception;
+
+/**
+ * Returns the TableDefinition for the specified table,
+ * by reading the information from somewhere.
+ *
+ * @since 0.1
+ *
+ * @licence GNU GPL v2+
+ * @author Jeroen De Dauw < jeroended...@gmail.com >
+ */
+interface TableDefinitionReader {
+
+ /**
+ * @param string $tableName
+ *
+ * @return TableDefinition mixed
+ */
+ public function readDefinition( $tableName );
+
+}
+
+/**
+ * Constructs and returns a TableDefinition for the specified table
+ * based on how it current exists in the database.
+ *
+ * @since 0.1
+ *
+ * @licence GNU GPL v2+
+ * @author Jeroen De Dauw < jeroended...@gmail.com >
+ */
+class MediaWikiTableDefinitionReader implements TableDefinitionReader {
+
+ protected $connectionProvider;
+ protected $explainSqlBuilder;
+ protected $explainSqlInterpreter;
+
+ public function __construct( DBConnectionProvider $connectionProvider,
+ TableExplainSqlBuilder $explainSqlBuilder,
TableExplainSqlInterpreter $explainSqlInterpreter ) {
+ $this->connectionProvider = $connectionProvider;
+ $this->explainSqlBuilder = $explainSqlBuilder;
+ $this->explainSqlInterpreter = $explainSqlInterpreter;
+ }
+
+ /**
+ * @param string $tableName
+ *
+ * @return TableDefinition mixed
+ */
+ public function readDefinition( $tableName ) {
+ $db = $this->connectionProvider->getConnection();
+
+ $queryResult = $db->query(
$this->explainSqlBuilder->getExplainSql( $tableName ) );
+
+ // TODO: handle connection properly
+ // TODO: handle result before passing it along
+
+ return $this->explainSqlInterpreter->buildTableDefinition(
$tableName, $queryResult );
+ }
+
+}
+
+/**
+ * Builds an SQL string to explain/describe the structure of the specified
table.
+ *
+ * @since 0.1
+ *
+ * @licence GNU GPL v2+
+ * @author Jeroen De Dauw < jeroended...@gmail.com >
+ */
+interface TableExplainSqlBuilder {
+
+ /**
+ * @param string $tableName
+ *
+ * @return string
+ */
+ public function getExplainSql( $tableName );
+
+}
+
+class SQLiteTableExplainSqlBuilder implements TableExplainSqlBuilder {
+
+ protected $tableNameFormatter;
+
+ public function __construct( TableNameFormatter $tableNameFormatter ) {
+ $this->tableNameFormatter = $tableNameFormatter;
+ }
+
+ public function getExplainSql( $tableName ) {
+ return 'PRAGMA table_info(' .
$this->tableNameFormatter->formatTableName( $tableName ) . ')';
+ }
+
+}
+
+/**
+ * Does any formatting and escaping of a table name (as for instance obtained
from a TableDefinition)
+ * which needs to be done before using it in an SQL statement.
+ *
+ * @since 0.1
+ *
+ * @licence GNU GPL v2+
+ * @author Jeroen De Dauw < jeroended...@gmail.com >
+ */
+interface TableNameFormatter {
+
+ /**
+ * @param string $tableName
+ *
+ * @return string
+ */
+ public function formatTableName( $tableName );
+
+}
+
+class MediaWikiTableNameFormatter implements TableNameFormatter {
+
+ protected $connectionProvider;
+
+ public function __construct( DBConnectionProvider $connectionProvider )
{
+ $this->connectionProvider = $connectionProvider;
+ }
+
+ public function formatTableName( $tableName ) {
+ $db = $this->connectionProvider->getConnection();
+
+ try {
+ $tableName = $db->tableName( $tableName );
+ }
+ catch ( Exception $ex ) {
+ $this->connectionProvider->releaseConnection();
+ throw $ex;
+ }
+
+ $this->connectionProvider->releaseConnection();
+ return $tableName;
+ }
+
+}
+
+/**
+ * Builds a TableDefinition from the result of a explain/describe query.
+ * TODO: determine exact format of this result
+ *
+ * @since 0.1
+ *
+ * @licence GNU GPL v2+
+ * @author Jeroen De Dauw < jeroended...@gmail.com >
+ */
+interface TableExplainSqlInterpreter {
+
+ /**
+ * @param string $tableName
+ * @param TODO $explainResult
+ *
+ * @return TableDefinition
+ */
+ public function buildTableDefinition( $tableName, $explainResult );
+
+}
+
+class SQLiteTableExplainSqlInterpreter implements TableExplainSqlInterpreter {
+
+ public function buildTableDefinition( $tableName, $explainResult ) {
+ // TODO
+ return new TableDefinition( $tableName, array() );
+ }
+
+}
+
+/**
+ * Updates a tables schema from the old definition to the new one.
+ *
+ * @since 0.1
+ *
+ * @licence GNU GPL v2+
+ * @author Jeroen De Dauw < jeroended...@gmail.com >
+ */
+interface TableSchemaUpdater {
+
+ public function updateTable( TableDefinition $originalTable,
TableDefinition $newTable );
+
+}
+
+// Something like this would be in the SQLStore.
+// TODO: move
+class StoreSchemaUpdater {
+
+ protected $tableDefinitionReader;
+ protected $tableUpdater;
+
+ public function __construct( TableDefinitionReader
$tableDefinitionReader, TableSchemaUpdater $tableUpdater ) {
+ $this->tableDefinitionReader = $tableDefinitionReader;
+ $this->tableUpdater = $tableUpdater;
+ }
+
+ public function updateSchema() {
+ foreach ( $this->getCurrentTables() as $currentTable ) {
+ $this->updateTable( $currentTable );
+ }
+ }
+
+ /**
+ * @return TableDefinition[]
+ */
+ protected function getCurrentTables() {
+ return array(); // TODO
+ }
+
+ protected function updateTable( TableDefinition $currentTable ) {
+ $oldDefinition = $this->tableDefinitionReader->readDefinition(
$currentTable->getName() );
+
+ $this->tableUpdater->updateTable( $oldDefinition, $currentTable
);
+ }
+
+}
\ No newline at end of file
--
To view, visit https://gerrit.wikimedia.org/r/81254
To unsubscribe, visit https://gerrit.wikimedia.org/r/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: I11dd081d1835abbcc978b7f576f90cad4903db6c
Gerrit-PatchSet: 1
Gerrit-Project: mediawiki/extensions/WikibaseDatabase
Gerrit-Branch: master
Gerrit-Owner: Jeroen De Dauw <jeroended...@gmail.com>
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