fluent-cart / vendor / openspout / openspout / src / Reader / XLSX / Manager / SharedStringsCaching / FileBasedStrategy.php

FileBasedStrategy.php in FluentCart A New Era of eCommerce – Faster, Lighter, and Simpler 1.4.1, at vendor/openspout/openspout/src/Reader/XLSX/Manager/SharedStringsCaching/FileBasedStrategy.php

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