Cache streams from report output

3 files changed, 78 insertions, 3 deletions

diff --git a/library/SSRS/Object/RenderStream.php b/library/SSRS/Object/RenderStream.php
index 58482b6..02cbb33 100755
--- a/library/SSRS/Object/RenderStream.php
+++ b/library/SSRS/Object/RenderStream.php
@@ -7,9 +7,11 @@ class RenderStream extends ObjectAbstract {
     public $Result;
     public $MimeType;
 
-    public function __construct(\stdClass $stream) {
-        $this->Result = $stream->Result;
-        $this->MimeType = $stream->MimeType;
+    public function __construct(\stdClass $stream = null) {
+        if ($stream) {
+            $this->Result = $stream->Result;
+            $this->MimeType = $stream->MimeType;
+        }
     }
 
     public function __toString() {
diff --git a/library/SSRS/Object/ReportOutput.php b/library/SSRS/Object/ReportOutput.php
index 0500525..ac17fe4 100755
--- a/library/SSRS/Object/ReportOutput.php
+++ b/library/SSRS/Object/ReportOutput.php
@@ -2,8 +2,26 @@
 
 namespace SSRS\Object;
 
+use SSRS\Report;
+use SSRS\Report\CachedStreamResource;
+
 class ReportOutput extends ObjectAbstract {
 
+    public function preCacheStreams(Report $report, $localCachePath, $format = 'HTML4.0') {
+        $this->verifyCachePath($localCachePath);
+
+        $rootPath = rtrim($localCachePath, '/');
+        foreach ($this->StreamIds->string as $streamId) {
+            $path = $rootPath . '/' . $streamId;
+            $stream = $report->renderStream($format, $streamId);
+
+            $cachedResource = new CachedStreamResource($streamId, $path);
+            $cachedResource->store($stream);
+        }
+
+        return $this;
+    }
+
     public function download($filename) {
         header("Cache-control: max-age=3600, must-revalidate");
         header("Pragma: public");
@@ -22,4 +40,16 @@ class ReportOutput extends ObjectAbstract {
         return (string) $this->Result;
     }
 
+    protected function verifyCachePath($path) {
+        if (false === file_exists($path) || false === is_dir($path)) {
+            throw new \RuntimeException('Stream cache path does not exist');
+        }
+
+        if (false === is_writable($path)) {
+            throw new \RuntimeException('Stream cache path is not writeable');
+        }
+
+        return $this;
+    }
+
 }
diff --git a/library/SSRS/Report/CachedStreamResource.php b/library/SSRS/Report/CachedStreamResource.php
new file mode 100644
index 0000000..08e9dbb
--- /dev/null
+++ b/library/SSRS/Report/CachedStreamResource.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace SSRS\Report;
+
+use \SSRS\Object\RenderStream;
+
+class CachedStreamResource {
+
+    public $streamId;
+    public $filePath;
+
+    public function __construct($streamId, $filePath) {
+        $this->streamId = $streamId;
+        $this->filePath = $filePath;
+    }
+
+    public function read() {
+        $data = file_get_contents($this->filePath);
+        $parts = explode("\n", $data, 2);
+
+        $stream = new RenderStream();
+        $stream->MimeType = $parts[0];
+        $stream->Result = $parts[1];
+
+        return $stream;
+    }
+
+    public function store(RenderStream $renderStream) {
+        $data = trim($renderStream->MimeType) . "\n";
+        $data .= $renderStream->Result;
+
+        file_put_contents($this->filePath, $data);
+        return $this;
+    }
+
+    public function send() {
+        $stream = $this->read();
+
+        header('Content-Type: ' . $stream->MimeType);
+        echo $stream->Result;
+    }
+
+}