HTTPHelper.h

00001 #pragma once
00002 
00003 #include <mbed.h>
00004 #include "es_wifi.h"
00005 
00006 #define HTTP_200OK "200 OK\r\n"
00007 #define HTTP_CL "Content-Length: "
00008 
00009 class HTTPHelper
00010 {
00011 private:
00012     char m_io_buffer[ES_WIFI_PAYLOAD_SIZE];
00013 
00014 public:
00015 
00016     HTTPHelper() {}
00017     ~HTTPHelper(){}
00018 
00019 
00020     bool HttpParseResponse(TCPConnector *net,uint8_t socket, char *content_buffer, uint32_t content_buffer_size, bool *status_ok, uint32_t *content_size)
00021     {
00022         uint16_t recv_bytes = 0;
00023         uint16_t http_content_len = 0;
00024         char *http_content_pivot = NULL;
00025         uint16_t content_chunk_size;
00026         bool res = false;
00027 
00028         *status_ok = false;
00029         *content_size = 0;
00030 
00031         // receive RESPONSE
00032         m_io_buffer[0] = 0;
00033         if(net->tcp_read(socket,m_io_buffer,ES_WIFI_PAYLOAD_SIZE,&recv_bytes,false))
00034         {
00035             if (recv_bytes > 0)
00036             {
00037                 m_io_buffer[recv_bytes]=0;
00038                 printf("%s\r\n",m_io_buffer);
00039                 http_parse_response(m_io_buffer, recv_bytes, status_ok, &http_content_len);
00040                 printf("> HTTP OK = %d Content len = %d\r\n", *status_ok, http_content_len);
00041                 *content_size = http_content_len;
00042 
00043                 /* fetch content */
00044                 http_content_pivot = strstr(m_io_buffer, "\r\n\r\n");
00045                 if (http_content_pivot != NULL)
00046                 {
00047                     /* copy first content chunk */
00048                     http_content_pivot += 4;
00049                     content_chunk_size = strlen(http_content_pivot);
00050                     if (content_chunk_size < content_buffer_size) strcpy(content_buffer, http_content_pivot);
00051                     http_content_len -= content_chunk_size;
00052                     printf("http_content_len %d content_chunk_size %d\r\n",http_content_len,content_chunk_size);
00053 
00054                     /* continue to fetch content chunck */
00055                     while (http_content_len > 0)
00056                     {
00057                         printf("http_content_len %d\r\n",http_content_len);
00058                         if( net->tcp_read(socket,m_io_buffer,ES_WIFI_PAYLOAD_SIZE,&recv_bytes,true) == false ) break;
00059                         m_io_buffer[recv_bytes] = 0;
00060                         http_content_len -= recv_bytes;
00061                         if (recv_bytes == 0)
00062                         {
00063                             printf("> ERROR : http content len overflow\r\n");
00064                             break;
00065                         }
00066                         strcat(content_buffer,m_io_buffer);
00067                     }
00068                     res = (http_content_len == 0);
00069                 }
00070 
00071             }
00072         }
00073 
00074         return res;
00075 
00076     }
00077 
00078 private:
00079 
00080     void http_parse_response(char *http_chunk, uint16_t http_chunk_len, bool *status_code_ok, uint16_t *content_len)
00081     {
00082         char *line_pivot, *key_pivot;
00083 
00084         *status_code_ok = false;
00085         *content_len = 0;
00086 
00087         line_pivot = strstr(http_chunk, "\r\n");
00088         if (line_pivot == NULL)
00089             return ;
00090 
00091         key_pivot = strstr(http_chunk, HTTP_200OK);
00092         
00093         if (key_pivot != NULL)
00094             *status_code_ok = true;
00095         else
00096             *status_code_ok = false;
00097 
00098         *content_len = 0;
00099         while (1)
00100         {
00101             line_pivot = strstr(line_pivot + 2, "\r\n");
00102             if (line_pivot == NULL)
00103                 break;
00104             key_pivot = strstr(http_chunk, HTTP_CL);
00105             if (key_pivot == NULL)
00106                 continue;
00107             if (key_pivot < line_pivot)
00108             {
00109                 key_pivot += strlen(HTTP_CL);
00110                 *content_len = atoi((char const *)key_pivot);
00111                 break;
00112             }
00113         }
00114     }
00115 
00116 
00117 };