parent
69bda25bbb
commit
fabc3ad24e
GPG Key ID:
2C5FD5035250423D
@ -0,0 +1,52 @@ |
||||
<?php |
||||
|
||||
|
||||
namespace App\Tables; |
||||
|
||||
use App\Models\Row; |
||||
use MightyPork\Utils\Utils; |
||||
|
||||
/** |
||||
* Generates a sequence of string codes for internal naming of columns |
||||
* |
||||
* Produces database-unique lowercase identifiers for created or proposed columns. |
||||
* Column identifiers are used in row objects to uniquely identify data even if the |
||||
* revision header (columns object) is modified, such as reordering, changing name, |
||||
* adding new column in concurrent proposals, etc. |
||||
* |
||||
* Thanks to this uniqueness, it could even be possible to compare or merge forks |
||||
* of the same table. |
||||
*/ |
||||
class ColumnNumerator |
||||
{ |
||||
const ALPHABET = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', |
||||
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']; |
||||
|
||||
/** @var int */ |
||||
private $next; |
||||
/** @var int */ |
||||
private $last; |
||||
|
||||
/** |
||||
* Create numerator for the given number of columns |
||||
*/ |
||||
public function __construct($capacity) |
||||
{ |
||||
list($this->next, $this->last) = Row::allocateColIDs($capacity); |
||||
} |
||||
|
||||
/** |
||||
* Get next column name, incrementing the internal state |
||||
* |
||||
* @return string |
||||
*/ |
||||
public function next() |
||||
{ |
||||
if ($this->next > $this->last) |
||||
throw new \OutOfBoundsException("Column numerator has run out of allocated GCID slots"); |
||||
|
||||
$key = Utils::alphabetEncode($this->next, self::ALPHABET); |
||||
$this->next++; |
||||
return $key; |
||||
} |
||||
} |
||||
@ -0,0 +1,32 @@ |
||||
<?php |
||||
|
||||
|
||||
namespace App\Tables; |
||||
|
||||
use App\Models\Row; |
||||
|
||||
class RowNumerator |
||||
{ |
||||
/** @var int */ |
||||
private $next; |
||||
/** @var int */ |
||||
private $last; |
||||
|
||||
/** |
||||
* Create a numerator for the given number of rows. |
||||
* |
||||
* @param int $capacity |
||||
*/ |
||||
public function __construct($capacity) |
||||
{ |
||||
list($this->next, $this->last) = Row::allocateRowIDs($capacity); |
||||
} |
||||
|
||||
public function next() |
||||
{ |
||||
if ($this->next > $this->last) |
||||
throw new \OutOfBoundsException("Row numerator has run out of allocated GRID slots"); |
||||
|
||||
return $this->next++; |
||||
} |
||||
} |
||||
@ -0,0 +1,30 @@ |
||||
<?php |
||||
|
||||
use Illuminate\Support\Facades\Schema; |
||||
use Illuminate\Database\Schema\Blueprint; |
||||
use Illuminate\Database\Migrations\Migration; |
||||
|
||||
class AddColumnSequence extends Migration |
||||
{ |
||||
/** |
||||
* Run the migrations. |
||||
* |
||||
* @return void |
||||
*/ |
||||
public function up() |
||||
{ |
||||
DB::unprepared('CREATE SEQUENCE IF NOT EXISTS global_column_id_seq START 0 MINVALUE 0;'); |
||||
// mandatory first increment to make the multi_nextval function work |
||||
DB::select("SELECT nextval('global_column_id_seq') as nv;"); |
||||
} |
||||
|
||||
/** |
||||
* Reverse the migrations. |
||||
* |
||||
* @return void |
||||
*/ |
||||
public function down() |
||||
{ |
||||
DB::unprepared('DROP SEQUENCE IF EXISTS global_column_id_seq;'); |
||||
} |
||||
} |
||||
@ -0,0 +1,72 @@ |
||||
<?php |
||||
|
||||
namespace Tests\Unit; |
||||
|
||||
use App\Tables\ColumnNumerator; |
||||
use Tests\TestCase; |
||||
use Illuminate\Foundation\Testing\RefreshDatabase; |
||||
|
||||
class ColumnNumeratorTest extends TestCase |
||||
{ |
||||
public function testIncrementsWithDefaultInit() |
||||
{ |
||||
$n = new ColumnNumerator(); |
||||
|
||||
self::assertEquals('a', $n->next()); |
||||
self::assertEquals('b', $n->next()); |
||||
self::assertEquals('c', $n->next()); |
||||
} |
||||
|
||||
public function testIncrementsWithCustomInit() |
||||
{ |
||||
$n = new ColumnNumerator('r'); |
||||
|
||||
self::assertEquals('r', $n->next()); |
||||
self::assertEquals('s', $n->next()); |
||||
self::assertEquals('t', $n->next()); |
||||
} |
||||
|
||||
public function testIncrementsMultiChar() |
||||
{ |
||||
$n = new ColumnNumerator('aaa'); |
||||
|
||||
self::assertEquals('aaa', $n->next()); |
||||
self::assertEquals('aab', $n->next()); |
||||
self::assertEquals('aac', $n->next()); |
||||
} |
||||
|
||||
public function testOverflowGrow() |
||||
{ |
||||
$n = new ColumnNumerator('y'); |
||||
|
||||
self::assertEquals('y', $n->next()); |
||||
self::assertEquals('z', $n->next()); |
||||
self::assertEquals('aa', $n->next()); |
||||
self::assertEquals('ab', $n->next()); |
||||
} |
||||
|
||||
public function testOverflowNoGrow() |
||||
{ |
||||
$n = new ColumnNumerator('yy'); |
||||
|
||||
self::assertEquals('yy', $n->next()); |
||||
self::assertEquals('yz', $n->next()); |
||||
self::assertEquals('za', $n->next()); |
||||
self::assertEquals('zb', $n->next()); |
||||
} |
||||
|
||||
public function testResume() |
||||
{ |
||||
$n = new ColumnNumerator('yy'); |
||||
self::assertEquals('yy', $n->next()); |
||||
self::assertEquals('yz', $n->next()); |
||||
|
||||
$n2 = new ColumnNumerator($n->getState()); |
||||
unset($n); |
||||
|
||||
self::assertEquals('za', $n2->next(), 'recreated numerator continues'); |
||||
self::assertEquals('zb', $n2->next()); |
||||
|
||||
self::assertEquals($n2->getState(), 'zc', 'State is next string'); |
||||
} |
||||
} |
||||
@ -1,19 +0,0 @@ |
||||
<?php |
||||
|
||||
namespace Tests\Unit; |
||||
|
||||
use Tests\TestCase; |
||||
use Illuminate\Foundation\Testing\RefreshDatabase; |
||||
|
||||
class ExampleTest extends TestCase |
||||
{ |
||||
/** |
||||
* A basic test example. |
||||
* |
||||
* @return void |
||||
*/ |
||||
public function testBasicTest() |
||||
{ |
||||
$this->assertTrue(true); |
||||
} |
||||
} |
||||
Loading…
Reference in new issue