<?php

declare(strict_types=1);

namespace GuzzleHttp\Psr7;

use Psr\Http\Message\StreamInterface;

/**
 * Stream decorator that can cache previously read bytes from a sequentially
 * read stream.
 */
final class CachingStream implements StreamInterface
{
    use StreamDecoratorTrait;

    /** @var StreamInterface Stream being wrapped */
    private $remoteStream;

    /** @var int Number of bytes to skip reading due to a write on the buffer */
    private $skipReadBytes = 0;

    /**
     * @var StreamInterface
     */
    private $stream;

    /**
     * We will treat the buffer object as the body of the stream
     *
     * @param StreamInterface $stream Stream to cache. The cursor is assumed to be at the beginning of the stream.
     * @param StreamInterface $target Optionally specify where data is cached
     */
    public function __construct(
        StreamInterface $stream,
        StreamInterface $target = null
    ) {
        $this->remoteStream = $stream;
        $this->stream = $target ?: new Stream(Utils::tryFopen('php://temp', 'r+'));
    }

    public function getSize(): ?int
    {
        $remoteSize = $this->remoteStream->getSize();

        if (null === $remoteSize) {
            return null;
        }

        return max($this->stream->getSize(), $remoteSize);
    }

    public function rewind(): void
    {
        $this->seek(0);
    }

    public function seek($offset, $whence = SEEK_SET): void
    {
        if ($whence === SEEK_SET) {
            $byte = $offset;
        } elseif ($whence === SEEK_CUR) {
            $byte = $offset + $this->tell();
        } elseif ($whence === SEEK_END) {
            $size = $this->remoteStream->getSize();
            if ($size === null) {
                $size = $this->cacheEntireStream();
            }
            $byte = $size + $offset;
        } else {
            throw new \InvalidArgumentException('Invalid whence');
        }

        $diff = $byte - $this->stream->getSize();

        if ($diff > 0) {
            // Read the remoteStream until we have read in at least the amount
            // of bytes requested, or we reach the end of the file.
            while ($diff > 0 && !$this->remoteStream->eof()) {
                $this->read($diff);
                $diff = $byte - $this->stream->getSize();
            }
        } else {
            // We can just do a normal seek since we've already seen this byte.
            $this->stream->seek($byte);
        }
    }

    public function read($length): string
    {
        // Perform a regular read on any previously read data from the buffer
        $data = $this->stream->read($length);
        $remaining = $length - strlen($data);

        // More data was requested so read from the remote stream
        if ($remaining) {
            // If data was written to the buffer in a position that would have
            // been filled from the remote stream, then we must skip bytes on
            // the remote stream to emulate overwriting bytes from that
            // position. This mimics the behavior of other PHP stream wrappers.
            $remoteData = $this->remoteStream->read(
                $remaining + $this->skipReadBytes
            );

            if ($this->skipReadBytes) {
                $len = strlen($remoteData);
                $remoteData = substr($remoteData, $this->skipReadBytes);
                $this->skipReadBytes = max(0, $this->skipReadBytes - $len);
            }

            $data .= $remoteData;
            $this->stream->write($remoteData);
        }

        return $data;
    }

    public function write($string): int
    {
        // When appending to the end of the currently read stream, you'll want
        // to skip bytes from being read from the remote stream to emulate
        // other stream wrappers. Basically replacing bytes of data of a fixed
        // length.
        $overflow = (strlen($string) + $this->tell()) - $this->remoteStream->tell();
        if ($overflow > 0) {
            $this->skipReadBytes += $overflow;
        }

        return $this->stream->write($string);
    }

    public function eof(): bool
    {
        return $this->stream->eof() && $this->remoteStream->eof();
    }

    /**
     * Close both the remote stream and buffer stream
     */
    public function close(): void
    {
        $this->remoteStream->close();
        $this->stream->close();
    }

    private function cacheEntireStream(): int
    {
        $target = new FnStream(['write' => 'strlen']);
        Utils::copyToStream($this, $target);

        return $this->tell();
    }
}

• [D] Exception
• [F] AppendStream.php
  Delete
• [F] BufferStream.php
  Delete
• [F] CachingStream.php
  Delete
• [F] DroppingStream.php
  Delete
• [F] FnStream.php
  Delete
• [F] Header.php
  Delete
• [F] HttpFactory.php
  Delete
• [F] InflateStream.php
  Delete
• [F] LazyOpenStream.php
  Delete
• [F] LimitStream.php
  Delete
• [F] Message.php
  Delete
• [F] MessageTrait.php
  Delete
• [F] MimeType.php
  Delete
• [F] MultipartStream.php
  Delete
• [F] NoSeekStream.php
  Delete
• [F] PumpStream.php
  Delete
• [F] Query.php
  Delete
• [F] Request.php
  Delete
• [F] Response.php
  Delete
• [F] Rfc7230.php
  Delete
• [F] ServerRequest.php
  Delete
• [F] Stream.php
  Delete
• [F] StreamDecoratorTrait.php
  Delete
• [F] StreamWrapper.php
  Delete
• [F] UploadedFile.php
  Delete
• [F] Uri.php
  Delete
• [F] UriComparator.php
  Delete
• [F] UriNormalizer.php
  Delete
• [F] UriResolver.php
  Delete
• [F] Utils.php
  Delete

About Section

About NFC Pay: Our Story and Mission

NFC Pay was founded with a vision to transform the way people handle transactions. Our journey is defined by a commitment to innovation, security, and convenience. We strive to deliver seamless, user-friendly payment solutions that make everyday transactions effortless and secure. Our mission is to empower you to pay with ease and confidence, anytime, anywhere.

• Simplifying Payments, One Tap at a Time.
• Reinventing Your Wallet for Modern Convenience.
• Smart Payments for a Effortless Lifestyle.
• Experience the Ease of Tap and Pay.
• Innovative Solutions for Your Daily Transactions.

FAQ Section

Frequently Asked Questions About NFC Pay

Here are answers to some common questions about NFC Pay. We aim to provide clear and concise information to help you understand how our platform works and how it can benefit you. If you have any further inquiries, please don’t hesitate to contact our support team.

How do I register for NFC Pay?

Download the app and sign up using your email or phone number, then complete the verification process.

Is my payment information secure?

Yes, we use advanced encryption and security protocols to protect your payment details.

Can I add multiple cards to my NFC Pay wallet?

Absolutely, you can link multiple debit or credit cards to your wallet.

How do I transfer money to another user?

Go to the transfer section, select the recipient, enter the amount, and authorize the transfer.

What should I do if I forget my PIN?

Use the “Forgot PIN” feature in the app to reset it following the provided instructions.

How can I activate my merchant account?

Sign up for a merchant account through the app and follow the setup instructions to start accepting payments.

Can I track my payment status?

Yes, you can view and track your payment status in the account dashboard