Move to file_body in boost

As is, it reads the whole file into memory before sending it.  While
fairly fast for the user, this wastes ram, and makes bmcweb less useful
on less capable systems.

This patch enables using the boost::beast::http::file_body type, which
has more efficient serialization semantics than using a std::string.  To
do this, it adds a openFile() handler to http::Response, which can be
used to properly open a file.  Once the file is opened, the existing
string body is ignored, and the file payload is sent instead.
openFile() also returns success or failure, to allow users to properly
handle 404s and other errors.

To prove that it works, I moved over every instance of direct use of the
body() method over to using this, including the webasset handler.  The
webasset handler specifically should help with system load when doing an
initial page load of the webui.

Tested:
Redfish service validator passes.

Change-Id: Ic7ea9ffefdbc81eb985de7edc0fac114822994ad
Signed-off-by: Ed Tanous <ed@tanous.net>

1 files changed, 22 insertions, 20 deletions

diff --git a/http/http_client.hpp b/http/http_client.hpp
index 046df2e0f0..8c27d6d61a 100644
--- a/http/http_client.hpp
+++ b/http/http_client.hpp
@@ -39,6 +39,8 @@
 #include <boost/beast/version.hpp>
 #include <boost/container/devector.hpp>
 #include <boost/system/error_code.hpp>
+#include <boost/url/format.hpp>
+#include <boost/url/url.hpp>
 #include <boost/url/url_view.hpp>
 
 #include <cstdlib>
@@ -50,9 +52,8 @@
 
 namespace crow
 {
-
-// With Redfish Aggregation it is assumed we will connect to another instance
-// of BMCWeb which can handle 100 simultaneous connections.
+// With Redfish Aggregation it is assumed we will connect to another
+// instance of BMCWeb which can handle 100 simultaneous connections.
 constexpr size_t maxPoolSize = 20;
 constexpr size_t maxRequestQueueSize = 500;
 constexpr unsigned int httpReadBodyLimit = 131072;
@@ -96,8 +97,8 @@ static inline boost::system::error_code
     return boost::system::errc::make_error_code(boost::system::errc::success);
 };
 
-// We need to allow retry information to be set before a message has been sent
-// and a connection pool has been created
+// We need to allow retry information to be set before a message has been
+// sent and a connection pool has been created
 struct ConnectionPolicy
 {
     uint32_t maxRetryAttempts = 5;
@@ -402,7 +403,7 @@ class ConnectionInfo : public std::enable_shared_from_this<ConnectionInfo>
 
         // Copy the response into a Response object so that it can be
         // processed by the callback function.
-        res.stringResponse = parser->release();
+        res.response = parser->release();
         callback(parser->keep_alive(), connId, res);
         res.clear();
     }
@@ -419,8 +420,8 @@ class ConnectionInfo : public std::enable_shared_from_this<ConnectionInfo>
         if (ec)
         {
             BMCWEB_LOG_ERROR("async_wait failed: {}", ec.message());
-            // If the timer fails, we need to close the socket anyway, same as
-            // if it expired.
+            // If the timer fails, we need to close the socket anyway, same
+            // as if it expired.
         }
         std::shared_ptr<ConnectionInfo> self = weakSelf.lock();
         if (self == nullptr)
@@ -454,8 +455,8 @@ class ConnectionInfo : public std::enable_shared_from_this<ConnectionInfo>
             callback(false, connId, res);
             res.clear();
 
-            // Reset the retrycount to zero so that client can try connecting
-            // again if needed
+            // Reset the retrycount to zero so that client can try
+            // connecting again if needed
             retryCount = 0;
             return;
         }
@@ -604,10 +605,11 @@ class ConnectionInfo : public std::enable_shared_from_this<ConnectionInfo>
                 BMCWEB_LOG_ERROR("prepareSSLContext failed - {}, id: {}", host,
                                  connId);
                 // Don't retry if failure occurs while preparing SSL context
-                // such as certificate is invalid or set cipher failure or set
-                // host name failure etc... Setting conn state to sslInitFailed
-                // and connection state will be transitioned to next state
-                // depending on retry policy set by subscription.
+                // such as certificate is invalid or set cipher failure or
+                // set host name failure etc... Setting conn state to
+                // sslInitFailed and connection state will be transitioned
+                // to next state depending on retry policy set by
+                // subscription.
                 state = ConnState::sslInitFailed;
                 waitAndRetry();
                 return;
@@ -742,8 +744,8 @@ class ConnectionPool : public std::enable_shared_from_this<ConnectionPool>
             }
         }
 
-        // All connections in use so create a new connection or add request to
-        // the queue
+        // All connections in use so create a new connection or add request
+        // to the queue
         if (connections.size() < connPolicy->maxConnections)
         {
             BMCWEB_LOG_DEBUG("Adding new connection to pool {}", id);
@@ -760,8 +762,8 @@ class ConnectionPool : public std::enable_shared_from_this<ConnectionPool>
         }
         else
         {
-            // If we can't buffer the request then we should let the callback
-            // handle a 429 Too Many Requests dummy response
+            // If we can't buffer the request then we should let the
+            // callback handle a 429 Too Many Requests dummy response
             BMCWEB_LOG_ERROR("{}:{} request queue full.  Dropping request.",
                              id);
             Response dummyRes;
@@ -875,8 +877,8 @@ class HttpClient
             pool.first->second = std::make_shared<ConnectionPool>(
                 ioc, clientKey, connPolicy, destUrl);
         }
-        // Send the data using either the existing connection pool or the newly
-        // created connection pool
+        // Send the data using either the existing connection pool or the
+        // newly created connection pool
         pool.first->second->sendData(std::move(data), destUrl, httpHeader, verb,
                                      resHandler);
     }