use a string based buffer for Read/Write streams

src/Native/NativeReadStream.php

@@ -7,22 +7,21 @@
 
 namespace Icewind\SMB\Native;
 
+use Icewind\SMB\StringBuffer;
+
 /**
  * Stream optimized for read only usage
  */
 class NativeReadStream extends NativeStream {
 	const CHUNK_SIZE = 1048576; // 1MB chunks
-	/**
-	 * @var resource
-	 */
-	private $readBuffer = null;
 
-	private $bufferSize = 0;
+	/** @var StringBuffer */
+	private $readBuffer;
 
 	private $pos = 0;
 
 	public function stream_open($path, $mode, $options, &$opened_path) {
-		$this->readBuffer = fopen('php://memory', 'r+');
+		$this->readBuffer = new StringBuffer();
 
 		return parent::stream_open($path, $mode, $options, $opened_path);
 	}
@@ -54,17 +53,11 @@ class NativeReadStream extends NativeStream {
 		// php reads 8192 bytes at once
 		// however due to network latency etc, it's faster to read in larger chunks
 		// and buffer the result
-		if (!parent::stream_eof() && $this->bufferSize < $count) {
-			$remaining = $this->readBuffer;
-			$this->readBuffer = fopen('php://memory', 'r+');
-			$this->bufferSize = 0;
-			stream_copy_to_stream($remaining, $this->readBuffer);
-			$this->bufferSize += fwrite($this->readBuffer, parent::stream_read(self::CHUNK_SIZE));
-			fseek($this->readBuffer, 0);
+		if (!parent::stream_eof() && $this->readBuffer->remaining() < $count) {
+			$this->readBuffer->push(parent::stream_read(self::CHUNK_SIZE));
 		}
 
-		$result = fread($this->readBuffer, $count);
-		$this->bufferSize -= $count;
+		$result = $this->readBuffer->read($count);
 
 		$read = strlen($result);
 		$this->pos += $read;
@@ -75,15 +68,14 @@ class NativeReadStream extends NativeStream {
 	public function stream_seek($offset, $whence = SEEK_SET) {
 		$result = parent::stream_seek($offset, $whence);
 		if ($result) {
-			$this->readBuffer = fopen('php://memory', 'r+');
-			$this->bufferSize = 0;
+			$this->readBuffer->clear();
 			$this->pos = parent::stream_tell();
 		}
 		return $result;
 	}
 
 	public function stream_eof() {
-		return $this->bufferSize <= 0 && parent::stream_eof();
+		return $this->readBuffer->remaining() <= 0 && parent::stream_eof();
 	}
 
 	public function stream_tell() {

src/Native/NativeWriteStream.php

@@ -7,22 +7,21 @@
 
 namespace Icewind\SMB\Native;
 
+use Icewind\SMB\StringBuffer;
+
 /**
  * Stream optimized for write only usage
  */
 class NativeWriteStream extends NativeStream {
 	const CHUNK_SIZE = 1048576; // 1MB chunks
-	/**
-	 * @var resource
-	 */
-	private $writeBuffer = null;
 
-	private $bufferSize = 0;
+	/** @var StringBuffer */
+	private $writeBuffer;
 
 	private $pos = 0;
 
 	public function stream_open($path, $mode, $options, &$opened_path) {
-		$this->writeBuffer = fopen('php://memory', 'r+');
+		$this->writeBuffer = new StringBuffer();
 
 		return parent::stream_open($path, $mode, $options, $opened_path);
 	}
@@ -60,18 +59,14 @@ class NativeWriteStream extends NativeStream {
 	}
 
 	private function flushWrite() {
-		rewind($this->writeBuffer);
-		$this->state->write($this->handle, stream_get_contents($this->writeBuffer), $this->url);
-		$this->writeBuffer = fopen('php://memory', 'r+');
-		$this->bufferSize = 0;
+		$this->state->write($this->handle, $this->writeBuffer->flush(), $this->url);
 	}
 
 	public function stream_write($data) {
-		$written = fwrite($this->writeBuffer, $data);
-		$this->bufferSize += $written;
+		$written = $this->writeBuffer->push($data);
 		$this->pos += $written;
 
-		if ($this->bufferSize >= self::CHUNK_SIZE) {
+		if ($this->writeBuffer->remaining() >= self::CHUNK_SIZE) {
 			$this->flushWrite();
 		}
 

src/StringBuffer.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Icewind\SMB;
+
+class StringBuffer {
+	private $buffer = "";
+	private $pos = 0;
+
+	public function clear() {
+		$this->buffer = "";
+		$this->pos = 0;
+	}
+
+	public function push(string $data) {
+		$this->buffer = $this->flush() . $data;
+		return strlen($data);
+	}
+
+	public function remaining(): int {
+		return strlen($this->buffer) - $this->pos;
+	}
+
+	public function read(int $count): string {
+		$chunk = substr($this->buffer, $this->pos, $this->pos + $count);
+		$this->pos += strlen($chunk);
+		return $chunk;
+	}
+
+	public function flush(): string {
+		if ($this->pos === 0) {
+			$remaining = $this->buffer;
+		} else {
+			$remaining = substr($this->buffer, $this->pos);
+		}
+
+		$this->clear();
+
+		return $remaining;
+	}
+}