Handle parser errors by emitting error and closing connection

src/Io/Buffer.php

@@ -37,7 +37,7 @@ public function prepend($str)
      *
      * @param int $len length in bytes, must be positive or zero
      * @return string
-     * @throws \LogicException
+     * @throws \UnderflowException
      */
     public function read($len)
     {
@@ -53,7 +53,7 @@ public function read($len)
 
         // ensure buffer size contains $len bytes by checking target buffer position
         if ($len < 0 || !isset($this->buffer[$this->bufferPos + $len - 1])) {
-            throw new \LogicException('Not enough data in buffer to read ' . $len . ' bytes');
+            throw new \UnderflowException('Not enough data in buffer to read ' . $len . ' bytes');
         }
         $buffer = \substr($this->buffer, $this->bufferPos, $len);
         $this->bufferPos += $len;
@@ -62,39 +62,58 @@ public function read($len)
     }
 
     /**
-     * Skips binary string data with given byte length from buffer
+     * Reads data with given byte length from buffer into a new buffer
      *
-     * This method can be used instead of `read()` if you do not care about the
-     * bytes that will be skipped.
+     * This class keeps consumed data in memory for performance reasons and only
+     * advances the internal buffer position by default. Reading data into a new
+     * buffer will clear the data from the original buffer to free memory.
      *
-     * @param int $len length in bytes, must be positve and non-zero
-     * @return void
-     * @throws \LogicException
+     * @param int $len length in bytes, must be positive or zero
+     * @return self
+     * @throws \UnderflowException
      */
-    public function skip($len)
+    public function readBuffer($len)
     {
-        if ($len < 1 || !isset($this->buffer[$this->bufferPos + $len - 1])) {
-            throw new \LogicException('Not enough data in buffer');
+        // happy path to return empty buffer without any memory access for zero length string
+        if ($len === 0) {
+            return new self();
         }
-        $this->bufferPos += $len;
+
+        // ensure buffer size contains $len bytes by checking target buffer position
+        if ($len < 0 || !isset($this->buffer[$this->bufferPos + $len - 1])) {
+            throw new \UnderflowException('Not enough data in buffer to read ' . $len . ' bytes');
+        }
+
+        $buffer = new self();
+        $buffer->buffer = $this->read($len);
+
+        if (!isset($this->buffer[$this->bufferPos])) {
+            $this->buffer = '';
+        } else {
+            $this->buffer = \substr($this->buffer, $this->bufferPos);
+        }
+        $this->bufferPos = 0;
+
+        return $buffer;
+
     }
 
     /**
-     * Clears all consumed data from the buffer
+     * Skips binary string data with given byte length from buffer
      *
-     * This class keeps consumed data in memory for performance reasons and only
-     * advances the internal buffer position until this method is called.
+     * This method can be used instead of `read()` if you do not care about the
+     * bytes that will be skipped.
      *
+     * @param int $len length in bytes, must be positve and non-zero
      * @return void
+     * @throws \UnderflowException
      */
-    public function trim()
+    public function skip($len)
     {
-        if (!isset($this->buffer[$this->bufferPos])) {
-            $this->buffer = '';
-        } else {
-            $this->buffer = \substr($this->buffer, $this->bufferPos);
+        if ($len < 1 || !isset($this->buffer[$this->bufferPos + $len - 1])) {
+            throw new \UnderflowException('Not enough data in buffer');
         }
-        $this->bufferPos = 0;
+        $this->bufferPos += $len;
     }
 
     /**
@@ -201,13 +220,13 @@ public function readStringLen()
      * Reads string until NULL character
      *
      * @return string
-     * @throws \LogicException
+     * @throws \UnderflowException
      */
     public function readStringNull()
     {
         $pos = \strpos($this->buffer, "\0", $this->bufferPos);
         if ($pos === false) {
-            throw new \LogicException('Missing NULL character');
+            throw new \UnderflowException('Missing NULL character');
         }
 
         $ret = $this->read($pos - $this->bufferPos);