Diff: HTTPServer/HTTPRPC.h

Revision:

0:7a64fbb4069d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HTTPServer/HTTPRPC.h	Mon Aug 06 09:23:14 2012 +0000
@@ -0,0 +1,114 @@
+#ifndef HTTPRPC_H
+#define HTTPRPC_H
+
+#include "HTTPServer.h"
+#include "platform.h"
+#ifdef MBED_RPC
+#include "rpc.h"
+
+/**
+ * A datastorage helper for the HTTPRPC class
+ */
+class HTTPRPCData : public HTTPData {
+  public: char result[255];
+};
+
+/**
+ * Thsi class enables you to make rpc calls to your mbed.
+ * Furthermore it is a good example how to write a HTTPHandler for small data chunks.
+ */
+class HTTPRPC : public HTTPHandler {
+  public:
+    /**
+     * We have to know the prefix for the RPCHandler.
+     * A good default choice is /rpc so we made this default.
+     */
+    HTTPRPC(const char *path = "/rpc") : HTTPHandler(path) {}
+    
+  private:
+    /**
+     * If you need some Headerfeelds you have tor register the feelds here.
+     */
+//    virtual void reg(HTTPServer *svr) {
+//      svr->registerField("Content-Length");
+//    }
+
+    /**
+     * If a new RPCRequest Header is complete received the server will call this function.
+     * This is the right place for preparing our datastructures.
+     * Furthermore we will execute the rpc call and store the anwere.
+     * But we will not send a response. This will be hapen in the send method.
+     */
+    virtual HTTPStatus init(HTTPConnection *con) const {
+      HTTPRPCData *data = new HTTPRPCData();
+      con->data = data;
+      char *query = con->getURL()+strlen(_prefix);
+      clean(query);
+      rpc(query, data->result);
+
+      const char *nfields = "Cache-Control: no-cache, no-store, must-revalidate\r\nPragma: no-cache\r\nExpires: Thu, 01 Dec 1994 16:00:00 GM";
+      char *old = (char *)con->getHeaderFields();
+      int oldlen = strlen(old);
+      int atrlen = strlen(nfields);
+      char *fields = new char[atrlen+oldlen+3];
+      strcpy(fields,old);
+      fields[oldlen+0] = '\r';
+      fields[oldlen+1] = '\n';
+      strcpy(&fields[oldlen+2], nfields);
+      fields[atrlen+2+oldlen] = '\0';
+      con->setHeaderFields(fields);
+      if(*old) {
+        delete old;
+      }
+
+      con->setLength(strlen(data->result));
+      return HTTP_OK;
+    }
+
+    /**
+     * If we got an POST request the send method will not be executed.
+     * If we want to send data we have to trigger it the first time by ourself.
+     * So we execute the send method.
+     *
+     * If the rpc call is the content of the POST body we would not be able to execute it.
+     * Were parsing only the URL.
+     */
+    virtual HTTPHandle data(HTTPConnection *con, void *, int) const {
+      return send(con, con->sndbuf());
+    }
+
+    /**
+     * Send the result back to the client.
+     * If we have not enought space wait for next time.
+     */
+    virtual HTTPHandle send(HTTPConnection *con, int maximum) const {
+      HTTPRPCData *data = static_cast<HTTPRPCData *>(con->data);    
+      if(maximum>64) {
+        con->write(data->result, con->getLength());
+        return HTTP_SuccessEnded;
+      } else {
+        // To less memory.
+        return HTTP_SenderMemory;
+      }
+    }
+
+    /**
+     * To reduce memory usage we sodify the URL directly 
+     * and replace '%20',',','+','=' with spaces.
+     */
+    inline void clean(char *str) const {
+      while(*str++) {
+        if(*str=='%'&&*(str+1)=='2'&&*(str+2)=='0') {
+          *str = ' ';
+          *(str+1) = ' ';
+          *(str+2) = ' ';
+        }
+        if(*str==','||*str=='+'||*str=='=') {
+          *str = ' ';
+        }
+      }
+    }
+};
+#endif
+
+#endif