FileBasedStrategy::getStringAtIndex() - Code Metrics - Inspection of "Add Performance tests" - box/spout - Measure and Improve Code Quality continuously with Scrutinizer

Failed Conditions

Push — perf-tests ( 50942d...2fc93e )

by Adrien

created 2016-06-16 17:11 UTC

FileBasedStrategy::getStringAtIndex() B

↳ Parent: FileBasedStrategy

Complexity

Conditions	5
Paths	9

Size

Total Lines	31
Code Lines	16

Duplication

Lines	0
Ratio	0 %

Importance

Changes	2
Bugs	0	Features	0

Metric	Value
c	2
b	0
f	0
dl	0
loc	31
rs	8.439
cc	5
eloc	16
nc	9
nop	1

<?php

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

use Box\Spout\Common\Helper\FileSystemHelper;
use Box\Spout\Common\Helper\GlobalFunctionsHelper;
use Box\Spout\Reader\Exception\SharedStringNotFoundException;

/**
 * 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.
 *
 * @package Box\Spout\Reader\XLSX\Helper\SharedStringsCaching
 */
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|null $tempFolder Temporary folder where the temporary files to store shared strings will be stored
     * @param int $maxNumStringsPerTempFile Maximum number of strings that can be stored in one temp file
     */
    public function __construct($tempFolder, $maxNumStringsPerTempFile)
    {
        $rootTempFolder = ($tempFolder) ?: sys_get_temp_dir();
        $this->fileSystemHelper = new FileSystemHelper($rootTempFolder);
        $this->tempFolder = $this->fileSystemHelper->createFolder($rootTempFolder, uniqid('sharedstrings'));

        $this->maxNumStringsPerTempFile = $maxNumStringsPerTempFile;

        $this->globalFunctionsHelper = new GlobalFunctionsHelper();
        $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)
    {
        $numTempFile = intval($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 $sharedStringIndex Index of the shared string in the sharedStrings.xml file
     * @return string The shared string at the given index
     * @throws \Box\Spout\Reader\Exception\SharedStringNotFoundException If no shared string found for the given index
     */
    public function getStringAtIndex($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\Helper\SharedStringsCaching;
4
5			use Box\Spout\Common\Helper\FileSystemHelper;
6			use Box\Spout\Common\Helper\GlobalFunctionsHelper;
7			use Box\Spout\Reader\Exception\SharedStringNotFoundException;
8
9			/**
10			* Class FileBasedStrategy
11			*
12			* This class implements the file-based caching strategy for shared strings.
13			* Shared strings are stored in small files (with a max number of strings per file).
14			* This strategy is slower than an in-memory strategy but is used to avoid out of memory crashes.
15			*
16			* @package Box\Spout\Reader\XLSX\Helper\SharedStringsCaching
17			*/
18			class FileBasedStrategy implements CachingStrategyInterface
19			{
20			/** Value to use to escape the line feed character ("\n") */
21			const ESCAPED_LINE_FEED_CHARACTER = '_x000A_';
22
23			/** @var \Box\Spout\Common\Helper\GlobalFunctionsHelper Helper to work with global functions */
24			protected $globalFunctionsHelper;
25
26			/** @var \Box\Spout\Common\Helper\FileSystemHelper Helper to perform file system operations */
27			protected $fileSystemHelper;
28
29			/** @var string Temporary folder where the temporary files will be created */
30			protected $tempFolder;
31
32			/**
33			* @var int Maximum number of strings that can be stored in one temp file
34			* @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
35			*/
36			protected $maxNumStringsPerTempFile;
37
38			/** @var resource Pointer to the last temp file a shared string was written to */
39			protected $tempFilePointer;
40
41			/**
42			* @var string Path of the temporary file whose contents is currently stored in memory
43			* @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
44			*/
45			protected $inMemoryTempFilePath;
46
47			/**
48			* @var array Contents of the temporary file that was last read
49			* @see CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE
50			*/
51			protected $inMemoryTempFileContents;
52
53			/**
54			* @param string\|null $tempFolder Temporary folder where the temporary files to store shared strings will be stored
55			* @param int $maxNumStringsPerTempFile Maximum number of strings that can be stored in one temp file
56			*/
57			public function __construct($tempFolder, $maxNumStringsPerTempFile)
58			{
59			$rootTempFolder = ($tempFolder) ?: sys_get_temp_dir();
60			$this->fileSystemHelper = new FileSystemHelper($rootTempFolder);
61			$this->tempFolder = $this->fileSystemHelper->createFolder($rootTempFolder, uniqid('sharedstrings'));
62
63			$this->maxNumStringsPerTempFile = $maxNumStringsPerTempFile;
64
65			$this->globalFunctionsHelper = new GlobalFunctionsHelper();
66			$this->tempFilePointer = null;
67			}
68
69			/**
70			* Adds the given string to the cache.
71			*
72			* @param string $sharedString The string to be added to the cache
73			* @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
74			* @return void
75			*/
76			public function addStringForIndex($sharedString, $sharedStringIndex)
77			{
78			$tempFilePath = $this->getSharedStringTempFilePath($sharedStringIndex);
79
80			if (!$this->globalFunctionsHelper->file_exists($tempFilePath)) {
81			if ($this->tempFilePointer) {
82			$this->globalFunctionsHelper->fclose($this->tempFilePointer);
83			}
84			$this->tempFilePointer = $this->globalFunctionsHelper->fopen($tempFilePath, 'w');
85			}
86
87			// The shared string retrieval logic expects each cell data to be on one line only
88			// Encoding the line feed character allows to preserve this assumption
89			$lineFeedEncodedSharedString = $this->escapeLineFeed($sharedString);
90
91			$this->globalFunctionsHelper->fwrite($this->tempFilePointer, $lineFeedEncodedSharedString . PHP_EOL);
92			}
93
94			/**
95			* Returns the path for the temp file that should contain the string for the given index
96			*
97			* @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
98			* @return string The temp file path for the given index
99			*/
100			protected function getSharedStringTempFilePath($sharedStringIndex)
101			{
102			$numTempFile = intval($sharedStringIndex / $this->maxNumStringsPerTempFile);
103			return $this->tempFolder . '/sharedstrings' . $numTempFile;
104			}
105
106			/**
107			* Closes the cache after the last shared string was added.
108			* This prevents any additional string from being added to the cache.
109			*
110			* @return void
111			*/
112			public function closeCache()
113			{
114			// close pointer to the last temp file that was written
115			if ($this->tempFilePointer) {
116			$this->globalFunctionsHelper->fclose($this->tempFilePointer);
117			}
118			}
119
120
121			/**
122			* Returns the string located at the given index from the cache.
123			*
124			* @param int $sharedStringIndex Index of the shared string in the sharedStrings.xml file
125			* @return string The shared string at the given index
126			* @throws \Box\Spout\Reader\Exception\SharedStringNotFoundException If no shared string found for the given index
127			*/
128			public function getStringAtIndex($sharedStringIndex)
129			{
130			$tempFilePath = $this->getSharedStringTempFilePath($sharedStringIndex);
131			$indexInFile = $sharedStringIndex % $this->maxNumStringsPerTempFile;
132
133			if (!$this->globalFunctionsHelper->file_exists($tempFilePath)) {
134			throw new SharedStringNotFoundException("Shared string temp file not found: $tempFilePath ; for index: $sharedStringIndex");
135			}
136
137			if ($this->inMemoryTempFilePath !== $tempFilePath) {
138			// free memory
139			unset($this->inMemoryTempFileContents);
140
141			$this->inMemoryTempFileContents = explode(PHP_EOL, $this->globalFunctionsHelper->file_get_contents($tempFilePath));
142			$this->inMemoryTempFilePath = $tempFilePath;
143			}
144
145			$sharedString = null;
146
147			// Using isset here because it is way faster than array_key_exists...
148			if (isset($this->inMemoryTempFileContents[$indexInFile])) {
149			$escapedSharedString = $this->inMemoryTempFileContents[$indexInFile];
150			$sharedString = $this->unescapeLineFeed($escapedSharedString);
151			}
152
153			if ($sharedString === null) {
154			throw new SharedStringNotFoundException("Shared string not found for index: $sharedStringIndex");
155			}
156
157			return rtrim($sharedString, PHP_EOL);
158			}
159
160			/**
161			* Escapes the line feed characters (\n)
162			*
163			* @param string $unescapedString
164			* @return string
165			*/
166			private function escapeLineFeed($unescapedString)
167			{
168			return str_replace("\n", self::ESCAPED_LINE_FEED_CHARACTER, $unescapedString);
169			}
170
171			/**
172			* Unescapes the line feed characters (\n)
173			*
174			* @param string $escapedString
175			* @return string
176			*/
177			private function unescapeLineFeed($escapedString)
178			{
179			return str_replace(self::ESCAPED_LINE_FEED_CHARACTER, "\n", $escapedString);
180			}
181
182			/**
183			* Destroys the cache, freeing memory and removing any created artifacts
184			*
185			* @return void
186			*/
187			public function clearCache()
188			{
189			if ($this->tempFolder) {
190			$this->fileSystemHelper->deleteFolderRecursively($this->tempFolder);
191			}
192			}
193			}
194

box / spout

Push — perf-tests ( 50942d...2fc93e )

FileBasedStrategy::getStringAtIndex() B

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