Initial commit

src/Buffer.php

@@ -0,0 +1,109 @@
+<?php
+
+namespace Shufflingpixels\IO;
+
+use InvalidArgumentException;
+use OutOfBoundsException;
+use Shufflingpixels\IO\Exception\EndOfStreamException;
+
+class Buffer implements StreamInterface
+{
+    private int $position = 0;
+
+    public function __construct(protected string $data)
+    {
+    }
+
+    public function close(): void
+    {
+    }
+
+    public function length(): int
+    {
+        return \strlen($this->data);
+    }
+
+    public function remaining() : int
+    {
+        return $this->length() - $this->position;
+    }
+
+    public function eof(): bool
+    {
+        return $this->remaining() === 0;
+    }
+
+    public function tell() : int
+    {
+        return $this->position;
+    }
+
+    public function isSeekable(): bool
+    {
+        return true;
+    }
+
+    public function seek(int $offset, SeekMode $mode = SeekMode::SET): void
+    {
+        $position = match($mode) {
+            SeekMode::SET => $offset,
+            SeekMode::CUR => $this->position + $offset,
+            SeekMode::END => $this->length() + $offset,
+            default => throw new InvalidArgumentException("Invalid seek mode")
+        };
+
+        if ($position > $this->length()) {
+            throw new OutOfBoundsException("Seek position out of bounds: {$position}");
+        }
+
+        $this->position = $position;
+    }
+
+    public function isReadable(): bool
+    {
+        return true;
+    }
+
+    public function read(int $length): string
+    {
+        if ($length < 0) {
+            throw new InvalidArgumentException("Length must be >= 0");
+        }
+
+        if ($this->remaining() < $length) {
+            throw new EndOfStreamException(
+                "Not enough bytes to read {$length} byte(s), {$this->remaining()} remaining"
+            );
+        }
+
+        $result = substr($this->data, $this->position, $length);
+        $this->position += $length;
+
+        return $result;
+    }
+
+    public function isWriteable(): bool
+    {
+        return true;
+    }
+
+    public function write(string $data): int
+    {
+        $length = \strlen($data);
+
+        if ($length === 0) {
+            return 0;
+        }
+
+        $prefix = \substr($this->data, 0, $this->position);
+        $suffixStart = $this->position + $length;
+        $suffix = $suffixStart < $this->length()
+            ? \substr($this->data, $suffixStart)
+            : '';
+
+        $this->data = $prefix . $data . $suffix;
+        $this->position += $length;
+
+        return $length;
+    }
+}