Eliminate race conditions; verify hashes to prevent TOCTOU

src/Alerts/FileModified.php

@@ -0,0 +1,7 @@
+<?php
+namespace ParagonIE\Halite\Alerts;
+
+class FileModified extends HaliteAlert
+{
+
+}

src/Alerts/InvalidType.php

@@ -0,0 +1,7 @@
+<?php
+namespace ParagonIE\Halite\Alerts;
+
+class InvalidType extends HaliteAlert
+{
+
+}

src/Contract/StreamInterface.php

@@ -0,0 +1,26 @@
+<?php
+namespace ParagonIE\Halite\Contract;
+
+/**
+ * 
+ */
+interface StreamInterface
+{
+    /**
+     * Read from a stream; prevent partial reads
+     * 
+     * @param int $num
+     * @return string
+     * @throws FileAlert\AccessDenied
+     */
+    public function readBytes($num);
+
+    /**
+     * Write to a stream; prevent partial writes
+     * 
+     * @param string $buf
+     * @param int $num (number of bytes)
+     * @throws FileAlert\AccessDenied
+     */
+    public function writeBytes($buf, $num = null);
+}