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Direktori : /home2/selectio/www/limpiar.in.net/vendor/aws/aws-sdk-php/src/Glacier/ |
Current File : //home2/selectio/www/limpiar.in.net/vendor/aws/aws-sdk-php/src/Glacier/TreeHash.php |
<?php namespace Aws\Glacier; use Aws\HashInterface; /** * Encapsulates the creation of a tree hash from streamed data */ class TreeHash implements HashInterface { const MB = 1048576; const EMPTY_HASH = 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855'; /** @var string Algorithm used for hashing. */ private $algorithm; /** @var string Buffered data that has not yet been hashed. */ private $buffer; /** @var array Binary checksums from which the tree hash is derived. */ private $checksums = []; /** @var string Resulting hash in binary form. */ private $hash; public function __construct($algorithm = 'sha256') { $this->algorithm = $algorithm; $this->reset(); } /** * {@inheritdoc} * @throws \LogicException if the root tree hash is already calculated */ public function update($data) { // Error if hash is already calculated. if ($this->hash) { throw new \LogicException('You may not add more data to a ' . 'complete tree hash.'); } // Buffer incoming data. $this->buffer .= $data; // When there is more than a MB of data, create a checksum. while (strlen($this->buffer) >= self::MB) { $data = substr($this->buffer, 0, self::MB); $this->buffer = substr($this->buffer, self::MB) ?: ''; $this->checksums[] = hash($this->algorithm, $data, true); } return $this; } /** * Add a checksum to the tree hash directly * * @param string $checksum The checksum to add * @param bool $inBinaryForm TRUE if checksum is in binary form * * @return self * @throws \LogicException if the root tree hash is already calculated */ public function addChecksum($checksum, $inBinaryForm = false) { // Error if hash is already calculated if ($this->hash) { throw new \LogicException('You may not add more checksums to a ' . 'complete tree hash.'); } // Convert the checksum to binary form if necessary $this->checksums[] = $inBinaryForm ? $checksum : hex2bin($checksum); return $this; } public function complete() { if (!$this->hash) { // Clear out the remaining buffer. if (strlen($this->buffer) > 0) { $this->checksums[] = hash($this->algorithm, $this->buffer, true); $this->buffer = ''; } // If no hashes, add the EMPTY_HASH. if (!$this->checksums) { $this->checksums[] = hex2bin(self::EMPTY_HASH); } // Perform hashes up the tree to arrive at the root checksum. $hashes = $this->checksums; while (count($hashes) > 1) { $sets = array_chunk($hashes, 2); $hashes = array(); foreach ($sets as $set) { $hashes[] = (count($set) === 1) ? $set[0] : hash($this->algorithm, $set[0] . $set[1], true); } } $this->hash = $hashes[0]; } return $this->hash; } public function reset() { $this->hash = null; $this->checksums = []; $this->buffer = ''; } }