From 18eecbfda25b608526d8999f2577e8c286a8785d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kucha=C5=99?= <honza.kuchar@grifart.cz>
Date: Fri, 6 May 2016 20:54:47 +0200
Subject: [PATCH] Cursor now has boundary checks
---
src/PostgresDriver/CursorException.php | 6 ++
src/PostgresDriver/FastCursor.php | 23 ++++++--
src/PostgresDriver/ICursor.php | 2 +-
.../Store/PostgresDriver/FastCursorTest.phpt | 59 +++++++++++++++++++
4 files changed, 85 insertions(+), 5 deletions(-)
diff --git a/src/PostgresDriver/CursorException.php b/src/PostgresDriver/CursorException.php
index 268f278..b5fa8e4 100644
--- a/src/PostgresDriver/CursorException.php
+++ b/src/PostgresDriver/CursorException.php
@@ -10,6 +10,7 @@ use Exception;
class CursorException extends \LogicException
{
const MESSAGE_NO_DATA_TO_FETCH = "There was not data to fetch. Haven't you reached end of cursor?";
+ const MESSAGE_OVERFLOW = "Cursor overflow. You've hit end or beginning of the cursor.";
/**
* @inheritDoc
@@ -24,4 +25,9 @@ class CursorException extends \LogicException
return new static(self::MESSAGE_NO_DATA_TO_FETCH);
}
+ public static function cursorOverflow()
+ {
+ return new static(self::MESSAGE_OVERFLOW);
+ }
+
}
\ No newline at end of file
diff --git a/src/PostgresDriver/FastCursor.php b/src/PostgresDriver/FastCursor.php
index 36c68bf..808309f 100644
--- a/src/PostgresDriver/FastCursor.php
+++ b/src/PostgresDriver/FastCursor.php
@@ -52,20 +52,26 @@ class FastCursor implements ICursor
public function moveTo(int $index)
{
- $this->getConnection()->query(
+ $result = $this->getConnection()->query(
"MOVE ABSOLUTE %i IN %n",
$index,
$this->getCursorName()
);
+ if($result !== 1) {
+ throw CursorException::cursorOverflow();
+ }
}
public function moveBy(int $rows)
{
- $this->getConnection()->query(
+ $result = $this->getConnection()->query(
"MOVE RELATIVE %i IN %n",
$rows,
$this->getCursorName()
);
+ if($result !== 1) {
+ throw CursorException::cursorOverflow();
+ }
}
public function moveToBeginning()
@@ -78,18 +84,24 @@ class FastCursor implements ICursor
public function moveToFirst()
{
- $this->getConnection()->query(
+ $result = $this->getConnection()->query(
"MOVE FIRST IN %n;", // == ABSOLUTE 1
$this->getCursorName()
);
+ if($result !== 1) {
+ throw CursorException::cursorOverflow();
+ }
}
public function moveToLast()
{
- $this->getConnection()->query(
+ $result = $this->getConnection()->query(
"MOVE LAST IN %n", // == ABSOLUTE -1
$this->getCursorName()
);
+ if($result !== 1) {
+ throw CursorException::cursorOverflow();
+ }
}
public function moveToEnd()
@@ -101,6 +113,8 @@ class FastCursor implements ICursor
);
}
+ // ----------------- FETCH ---------------------
+
public function fetch(int $rows)
{
$forward = $rows >= 0;
@@ -110,6 +124,7 @@ class FastCursor implements ICursor
$rows,
$this->getCursorName()
)->fetchAll();
+
}
public function fetchNext()
diff --git a/src/PostgresDriver/ICursor.php b/src/PostgresDriver/ICursor.php
index 8f2aa04..1fe4f8e 100644
--- a/src/PostgresDriver/ICursor.php
+++ b/src/PostgresDriver/ICursor.php
@@ -56,7 +56,7 @@ interface ICursor
* @return void
*/
public function moveToEnd();
-
+
/**
* Fetch the next/previous count rows. FORWARD 0 re-fetches the current row.
* @param int $rows
diff --git a/tests/Store/PostgresDriver/FastCursorTest.phpt b/tests/Store/PostgresDriver/FastCursorTest.phpt
index 9066b2f..7d6da26 100644
--- a/tests/Store/PostgresDriver/FastCursorTest.phpt
+++ b/tests/Store/PostgresDriver/FastCursorTest.phpt
@@ -233,7 +233,66 @@ class FastCursorTest extends BaseTest
$this->uut->fetchCurrentSingle();
}, CursorException::class, CursorException::MESSAGE_NO_DATA_TO_FETCH);
}
+
+
+ // edge cases:
+ public function test_givenInitialPosition_whenMoveToLeft_thenGetError()
+ {
+ // start: index === 0
+ Assert::exception(function() {
+ $this->uut->moveBy(-1);
+ }, CursorException::class, CursorException::MESSAGE_OVERFLOW);
+
+ // index === 0
+ $data = $this->uut->fetch(-1);
+ Assert::count(0, $data);
+
+ $firstValue = $this->uut->fetchNextSingle();
+ Assert::equal(1, $firstValue);
+
+ }
+
+ public function test_givenEndPosition_whenMoveToRight_thenGetError()
+ {
+ $this->uut->moveToEnd();
+
+ Assert::exception(function() {
+ $this->uut->moveBy(1);
+ }, CursorException::class, CursorException::MESSAGE_OVERFLOW);
+ }
+
+ public function test_givenFirstPosition_whenMoveToLeft_thenGetError()
+ {
+ $this->uut->moveToFirst();
+
+ Assert::exception(function() {
+ $this->uut->moveBy(-1);
+ }, CursorException::class, CursorException::MESSAGE_OVERFLOW);
+
+ // todo: unfortunately moveBy moved cursor into index=0 even when exception occured
+ // todo: this should be supported or should not modify state
+
+ Assert::exception(function() {
+ $this->uut->fetchCurrentSingle();
+ }, CursorException::class, CursorException::MESSAGE_NO_DATA_TO_FETCH);
+ }
+ public function test_givenLastPosition_whenMoveToRight_thenGetError()
+ {
+ $this->uut->moveToLast();
+
+ Assert::exception(function() {
+ $this->uut->moveBy(1);
+ }, CursorException::class, CursorException::MESSAGE_OVERFLOW);
+
+ // todo: unfortunately moveBy moved cursor into index=0 even when exception occured
+ // todo: this should be supported or should not modify state
+
+ Assert::exception(function() {
+ $this->uut->fetchCurrentSingle();
+ }, CursorException::class, CursorException::MESSAGE_NO_DATA_TO_FETCH);
+ }
+
}
(new FastCursorTest())->run();
--
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