make preview available to peers

oml/node/server.py

@@ -109,7 +109,12 @@ class Handler(http.server.SimpleHTTPRequestHandler):
 
     def do_GET(self):
         import item.models
-        id = self.path.split('/')[-1] if self.path.startswith('/get/') else None
+        parts = self.path.split('/')
+        if len(parts) ==  3 and parts[1] in ('get', 'preview'):
+            id = parts[2]
+            preview = parts[1] == 'preview'
+        else:
+            id = None
         if id and len(id) == 32 and id.isalnum():
             with db.session():
                 i = item.models.Item.get(id)
@@ -119,6 +124,21 @@ class Handler(http.server.SimpleHTTPRequestHandler):
                     self.end_headers()
                     self.wfile.write(b'404 - Not Found')
                     return
+                if preview:
+                    from item.icons import icons
+                    key = 'preview:' + id
+                    data = icons[key]
+                    if data:
+                        self.send_response(200, 'ok')
+                        self.send_header('Content-type', 'image/jpg')
+                    else:
+                        self.send_response(404, 'Not Found')
+                        self.send_header('Content-type', 'text/plain')
+                        data = b'404 - Not Found'
+                    self.send_header('Content-Length', str(len(data)))
+                    self.end_headers()
+                    self.wfile.write(data)
+                    return
                 path = i.get_path()
                 mimetype = {
                     'epub': 'application/epub+zip',

oml/nodes.py

@@ -304,17 +304,19 @@ class Node(Thread):
             trigger_event('peering.%s'%action.replace('Peering', ''), u.json())
             return True
 
+    headers = {
+        'X-Node-Protocol': settings.NODE_PROTOCOL,
+        'User-Agent': settings.USER_AGENT,
+        'Accept-Encoding': 'gzip',
+    }
+
     def download(self, item):
         from item.models import Transfer
         self.resolve()
         url = '%s/get/%s' % (self.url, item.id)
-        headers = {
-            'X-Node-Protocol': settings.NODE_PROTOCOL,
-            'User-Agent': settings.USER_AGENT,
-        }
         t1 = datetime.utcnow()
         logger.debug('download %s', url)
-        self._opener.addheaders = list(zip(headers.keys(), headers.values()))
+        self._opener.addheaders = list(zip(self.headers.keys(), self.headers.values()))
         try:
             r = self._opener.open(url, timeout=self.TIMEOUT*2)
         except:
@@ -363,6 +365,37 @@ class Node(Thread):
             logger.debug('FAILED %s', url)
             return False
 
+    def download_preview(self, item):
+        from item.icons import icons
+        self.resolve()
+        url = '%s/preview/%s' % (self.url, item.id)
+        self._opener.addheaders = list(zip(self.headers.keys(), self.headers.values()))
+        try:
+            r = self._opener.open(url, timeout=self.TIMEOUT*2)
+        except:
+            logger.debug('openurl failed %s', url, exc_info=1)
+            return False
+        code = r.getcode()
+        if code == 200:
+            try:
+                fileobj = r
+                if r.headers.get('content-encoding', None) == 'gzip':
+                    fileobj = gzip.GzipFile(fileobj=r)
+                content = fileobj.read()
+                key = 'preview:' + item.id
+                icons[key] = content
+                for resolution in (128, 256, 512):
+                    del icons['preview:%s' % resolution]
+                return True
+            except:
+                logger.debug('preview download failed %s', url, exc_info=1)
+                return False
+        elif code == 404:
+            pass
+        else:
+            logger.debug('FAILED %s', url)
+            return False
+
     def download_upgrade(self, release):
         for module in release['modules']:
             path = os.path.join(settings.update_path, release['modules'][module]['name'])