FileBasedStrategy::clearCache() - Code Metrics - Inspection of "Add docs to gitattrs" - box/spout - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#557)

by Adrien

created 2018-06-03 19:08 UTC

FileBasedStrategy::clearCache() A

↳ Parent: FileBasedStrategy

Complexity

Conditions	2
Paths	2

Size

Total Lines	6
Code Lines	3

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	4
CRAP Score	2

Importance

Changes

Metric	Value
dl	0
loc	6
ccs	4
cts	4
cp	1
rs	9.4285
c	0
b	0
f	0
cc	2
eloc	3
nc	2
nop	0
crap	2

<?php

namespace Box\Spout\Reader\XLSX\Manager\SharedStringsCaching;

use Box\Spout\Reader\Exception\SharedStringNotFoundException;
use Box\Spout\Reader\XLSX\Creator\HelperFactory;

/**
 * Class FileBasedStrategy
 *
 * This class implements the file-based caching strategy for shared strings.
 * Shared strings are stored in small files (with a max number of strings per file).
 * This strategy is slower than an in-memory strategy but is used to avoid out of memory crashes.
 */
class FileBasedStrategy implements CachingStrategyInterface
{
    /** Value to use to escape the line feed character ("\n") */
    const ESCAPED_LINE_FEED_CHARACTER = '_x000A_';

    /** @var \Box\Spout\Common\Helper\GlobalFunctionsHelper Helper to work with global functions */
    protected $globalFunctionsHelper;

    /** @var \Box\Spout\Common\Helper\FileSystemHelper Helper to perform file system operations */
    protected $fileSystemHelper;

    /** @var string Temporary folder where the temporary files will be created */
    protected $tempFolder;

    /**
     * @var int Maximum number of strings that can be stored in one temp file
     * @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
     */
    protected $maxNumStringsPerTempFile;

    /** @var resource Pointer to the last temp file a shared string was written to */
    protected $tempFilePointer;

    /**
     * @var string Path of the temporary file whose contents is currently stored in memory
     * @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
     */
    protected $inMemoryTempFilePath;

    /**
     * @var array Contents of the temporary file that was last read
     * @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
     */
    protected $inMemoryTempFileContents;

    /**
     * @param string $tempFolder Temporary folder where the temporary files to store shared strings will be stored
     * @param int $maxNumStringsPerTempFile Maximum number of strings that can be stored in one temp file
     * @param HelperFactory $helperFactory Factory to create helpers
     */
    public function __construct($tempFolder, $maxNumStringsPerTempFile, $helperFactory)
    {
        $this->fileSystemHelper = $helperFactory->createFileSystemHelper($tempFolder);
        $this->tempFolder = $this->fileSystemHelper->createFolder($tempFolder, uniqid('sharedstrings'));

        $this->maxNumStringsPerTempFile = $maxNumStringsPerTempFile;

        $this->globalFunctionsHelper = $helperFactory->createGlobalFunctionsHelper();
        $this->tempFilePointer = null;
    }

    /**
     * Adds the given string to the cache.
     *
     * @param string $sharedString The string to be added to the cache
     * @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
     * @return void
     */
    public function addStringForIndex($sharedString, $sharedStringIndex)
    {
        $tempFilePath = $this->getSharedStringTempFilePath($sharedStringIndex);

        if (!$this->globalFunctionsHelper->file_exists($tempFilePath)) {
            if ($this->tempFilePointer) {
                $this->globalFunctionsHelper->fclose($this->tempFilePointer);
            }
            $this->tempFilePointer = $this->globalFunctionsHelper->fopen($tempFilePath, 'w');
        }

        // The shared string retrieval logic expects each cell data to be on one line only
        // Encoding the line feed character allows to preserve this assumption
        $lineFeedEncodedSharedString = $this->escapeLineFeed($sharedString);

        $this->globalFunctionsHelper->fwrite($this->tempFilePointer, $lineFeedEncodedSharedString . PHP_EOL);
    }

    /**
     * Returns the path for the temp file that should contain the string for the given index
     *
     * @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
     * @return string The temp file path for the given index
     */
    protected function getSharedStringTempFilePath($sharedStringIndex)
    {
        $numTempFile = (int) ($sharedStringIndex / $this->maxNumStringsPerTempFile);

        return $this->tempFolder . '/sharedstrings' . $numTempFile;
    }

    /**
     * Closes the cache after the last shared string was added.
     * This prevents any additional string from being added to the cache.
     *
     * @return void
     */
    public function closeCache()
    {
        // close pointer to the last temp file that was written
        if ($this->tempFilePointer) {
            $this->globalFunctionsHelper->fclose($this->tempFilePointer);
        }
    }

    /**
     * Returns the string located at the given index from the cache.
     *
     * @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
     * @throws \Box\Spout\Reader\Exception\SharedStringNotFoundException If no shared string found for the given index
     * @return string The shared string at the given index
     */
    public function getStringAtIndex($sharedStringIndex)
    {
        $tempFilePath = $this->getSharedStringTempFilePath($sharedStringIndex);
        $indexInFile = $sharedStringIndex % $this->maxNumStringsPerTempFile;

        if (!$this->globalFunctionsHelper->file_exists($tempFilePath)) {
            throw new SharedStringNotFoundException("Shared string temp file not found: $tempFilePath ; for index: $sharedStringIndex");
        }

        if ($this->inMemoryTempFilePath !== $tempFilePath) {
            // free memory
            unset($this->inMemoryTempFileContents);

            $this->inMemoryTempFileContents = explode(PHP_EOL, $this->globalFunctionsHelper->file_get_contents($tempFilePath));
            $this->inMemoryTempFilePath = $tempFilePath;
        }

        $sharedString = null;

        // Using isset here because it is way faster than array_key_exists...
        if (isset($this->inMemoryTempFileContents[$indexInFile])) {
            $escapedSharedString = $this->inMemoryTempFileContents[$indexInFile];
            $sharedString = $this->unescapeLineFeed($escapedSharedString);
        }

        if ($sharedString === null) {
            throw new SharedStringNotFoundException("Shared string not found for index: $sharedStringIndex");
        }

        return rtrim($sharedString, PHP_EOL);
    }

    /**
     * Escapes the line feed characters (\n)
     *
     * @param string $unescapedString
     * @return string
     */
    private function escapeLineFeed($unescapedString)
    {
        return str_replace("\n", self::ESCAPED_LINE_FEED_CHARACTER, $unescapedString);
    }

    /**
     * Unescapes the line feed characters (\n)
     *
     * @param string $escapedString
     * @return string
     */
    private function unescapeLineFeed($escapedString)
    {
        return str_replace(self::ESCAPED_LINE_FEED_CHARACTER, "\n", $escapedString);
    }

    /**
     * Destroys the cache, freeing memory and removing any created artifacts
     *
     * @return void
     */
    public function clearCache()
    {
        if ($this->tempFolder) {
            $this->fileSystemHelper->deleteFolderRecursively($this->tempFolder);
        }
    }
}


1		<?php
2
3		namespace Box\Spout\Reader\XLSX\Manager\SharedStringsCaching;
4
5		use Box\Spout\Reader\Exception\SharedStringNotFoundException;
6		use Box\Spout\Reader\XLSX\Creator\HelperFactory;
7
8		/**
9		* Class FileBasedStrategy
10		*
11		* This class implements the file-based caching strategy for shared strings.
12		* Shared strings are stored in small files (with a max number of strings per file).
13		* This strategy is slower than an in-memory strategy but is used to avoid out of memory crashes.
14		*/
15		class FileBasedStrategy implements CachingStrategyInterface
16		{
17		/** Value to use to escape the line feed character ("\n") */
18		const ESCAPED_LINE_FEED_CHARACTER = '_x000A_';
19
20		/** @var \Box\Spout\Common\Helper\GlobalFunctionsHelper Helper to work with global functions */
21		protected $globalFunctionsHelper;
22
23		/** @var \Box\Spout\Common\Helper\FileSystemHelper Helper to perform file system operations */
24		protected $fileSystemHelper;
25
26		/** @var string Temporary folder where the temporary files will be created */
27		protected $tempFolder;
28
29		/**
30		* @var int Maximum number of strings that can be stored in one temp file
31		* @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
32		*/
33		protected $maxNumStringsPerTempFile;
34
35		/** @var resource Pointer to the last temp file a shared string was written to */
36		protected $tempFilePointer;
37
38		/**
39		* @var string Path of the temporary file whose contents is currently stored in memory
40		* @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
41		*/
42		protected $inMemoryTempFilePath;
43
44		/**
45		* @var array Contents of the temporary file that was last read
46		* @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
47		*/
48		protected $inMemoryTempFileContents;
49
50		/**
51		* @param string $tempFolder Temporary folder where the temporary files to store shared strings will be stored
52		* @param int $maxNumStringsPerTempFile Maximum number of strings that can be stored in one temp file
53		* @param HelperFactory $helperFactory Factory to create helpers
54		*/
55	9	public function __construct($tempFolder, $maxNumStringsPerTempFile, $helperFactory)
56		{
57	9	$this->fileSystemHelper = $helperFactory->createFileSystemHelper($tempFolder);
58	9	$this->tempFolder = $this->fileSystemHelper->createFolder($tempFolder, uniqid('sharedstrings'));
59
60	9	$this->maxNumStringsPerTempFile = $maxNumStringsPerTempFile;
61
62	9	$this->globalFunctionsHelper = $helperFactory->createGlobalFunctionsHelper();
63	9	$this->tempFilePointer = null;
64	9	}
65
66		/**
67		* Adds the given string to the cache.
68		*
69		* @param string $sharedString The string to be added to the cache
70		* @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
71		* @return void
72		*/
73	2	public function addStringForIndex($sharedString, $sharedStringIndex)
74		{
75	2	$tempFilePath = $this->getSharedStringTempFilePath($sharedStringIndex);
76
77	2	if (!$this->globalFunctionsHelper->file_exists($tempFilePath)) {
78	2	if ($this->tempFilePointer) {
79	1	$this->globalFunctionsHelper->fclose($this->tempFilePointer);
80		}
81	2	$this->tempFilePointer = $this->globalFunctionsHelper->fopen($tempFilePath, 'w');
82		}
83
84		// The shared string retrieval logic expects each cell data to be on one line only
85		// Encoding the line feed character allows to preserve this assumption
86	2	$lineFeedEncodedSharedString = $this->escapeLineFeed($sharedString);
87
88	2	$this->globalFunctionsHelper->fwrite($this->tempFilePointer, $lineFeedEncodedSharedString . PHP_EOL);
89	2	}
90
91		/**
92		* Returns the path for the temp file that should contain the string for the given index
93		*
94		* @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
95		* @return string The temp file path for the given index
96		*/
97	2	protected function getSharedStringTempFilePath($sharedStringIndex)
98		{
99	2	$numTempFile = (int) ($sharedStringIndex / $this->maxNumStringsPerTempFile);
100
101	2	return $this->tempFolder . '/sharedstrings' . $numTempFile;
102		}
103
104		/**
105		* Closes the cache after the last shared string was added.
106		* This prevents any additional string from being added to the cache.
107		*
108		* @return void
109		*/
110	4	public function closeCache()
111		{
112		// close pointer to the last temp file that was written
113	4	if ($this->tempFilePointer) {
114	2	$this->globalFunctionsHelper->fclose($this->tempFilePointer);
115		}
116	4	}
117
118		/**
119		* Returns the string located at the given index from the cache.
120		*
121		* @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
122		* @throws \Box\Spout\Reader\Exception\SharedStringNotFoundException If no shared string found for the given index
123		* @return string The shared string at the given index
124		*/
125	2	public function getStringAtIndex($sharedStringIndex)
126		{
127	2	$tempFilePath = $this->getSharedStringTempFilePath($sharedStringIndex);
128	2	$indexInFile = $sharedStringIndex % $this->maxNumStringsPerTempFile;
129
130	2	if (!$this->globalFunctionsHelper->file_exists($tempFilePath)) {
131		throw new SharedStringNotFoundException("Shared string temp file not found: $tempFilePath ; for index: $sharedStringIndex");
132		}
133
134	2	if ($this->inMemoryTempFilePath !== $tempFilePath) {
135		// free memory
136	2	unset($this->inMemoryTempFileContents);
137
138	2	$this->inMemoryTempFileContents = explode(PHP_EOL, $this->globalFunctionsHelper->file_get_contents($tempFilePath));
139	2	$this->inMemoryTempFilePath = $tempFilePath;
140		}
141
142	2	$sharedString = null;
143
144		// Using isset here because it is way faster than array_key_exists...
145	2	if (isset($this->inMemoryTempFileContents[$indexInFile])) {
146	2	$escapedSharedString = $this->inMemoryTempFileContents[$indexInFile];
147	2	$sharedString = $this->unescapeLineFeed($escapedSharedString);
148		}
149
150	2	if ($sharedString === null) {
151		throw new SharedStringNotFoundException("Shared string not found for index: $sharedStringIndex");
152		}
153
154	2	return rtrim($sharedString, PHP_EOL);
155		}
156
157		/**
158		* Escapes the line feed characters (\n)
159		*
160		* @param string $unescapedString
161		* @return string
162		*/
163	2	private function escapeLineFeed($unescapedString)
164		{
165	2	return str_replace("\n", self::ESCAPED_LINE_FEED_CHARACTER, $unescapedString);
166		}
167
168		/**
169		* Unescapes the line feed characters (\n)
170		*
171		* @param string $escapedString
172		* @return string
173		*/
174	2	private function unescapeLineFeed($escapedString)
175		{
176	2	return str_replace(self::ESCAPED_LINE_FEED_CHARACTER, "\n", $escapedString);
177		}
178
179		/**
180		* Destroys the cache, freeing memory and removing any created artifacts
181		*
182		* @return void
183		*/
184	9	public function clearCache()
185		{
186	9	if ($this->tempFolder) {
187	9	$this->fileSystemHelper->deleteFolderRecursively($this->tempFolder);
188		}
189	9	}
190		}
191

box / spout

Pull Request — master (#557)

FileBasedStrategy::clearCache() A

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