git.maemo.org Git - stockwidget/blob - stockgetter.c

   1 /*
   2  * Simple wrapper for curl and Yahoo finance queries
   3  * to enable grabbing stock data.
   4  * Jon Parr
   5  */
   6 #include "stockgetter.h"
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11
  12 /* Current maximum query return size */
  13 #define SG_MAX_BUFFER 512
  14
  15 /* Current query string, note the %s for the stock ticker name */
  16 #define SG_QUERY_STRING "http://finance.yahoo.com/d/quotes.csv?s=%s&f=l1c"
  17
  18 static size_t write_data(void *buffer, size_t size, size_t nmemb, void *userp)
  19 {
  20         StockBuffer *psContext = (StockBuffer*)userp;
  21         int nBytes = size * nmemb;
  22
  23         /*TODO: Write extendable buffer */
  24         if(nBytes > psContext->nCount - psContext->nCurr)
  25         {
  26                 fprintf(stderr,"Ran out of buffer space! (Bytes %d, %d/%d)\n",nBytes,psContext->nCurr,psContext->nCount);
  27                 return 0;
  28         }
  29
  30         memcpy((void*)(psContext->pszBuffer + psContext->nCurr),buffer,nBytes);
  31         psContext->nCurr += nBytes;
  32
  33         return nmemb;
  34 }
  35
  36 SGHandle
  37 InitStockGetter(void)
  38 {
  39         SGHandle hSG;
  40         CURL *curl_handle;
  41
  42         hSG = (SGHandle)malloc(sizeof(struct _SGHandle));
  43
  44         if(!hSG)
  45                 return NULL;
  46
  47         memset(hSG,0,sizeof(struct _SGHandle));
  48
  49         if(curl_global_init(CURL_GLOBAL_ALL) != 0)
  50                 goto err_cleanup;
  51
  52         curl_handle = curl_easy_init();
  53
  54         if(!curl_handle)
  55                 goto err_cleanup;
  56
  57         if(curl_easy_setopt(curl_handle,CURLOPT_WRITEFUNCTION,write_data) != 0)
  58                 goto err_cleanup;
  59
  60         if(curl_easy_setopt (curl_handle, CURLOPT_FOLLOWLOCATION, 1) != 0)
  61                 goto err_cleanup;
  62
  63         if(curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA,&hSG->sData) != 0)
  64                 goto err_cleanup;
  65
  66         hSG->hCurlHandle = curl_handle;
  67
  68         return hSG;
  69
  70 err_cleanup:
  71
  72         if(hSG)
  73                 free(hSG);
  74
  75         return NULL;
  76 }
  77
  78 int
  79 RetrieveStockPrice(SGHandle              hSG,
  80                                    char                 *szTicker,
  81                                    float                *pfValue,
  82                                    float                *pfChangeReal,
  83                                    float                *pfChangePercent)
  84 {
  85         const char      *pszQueryString = SG_QUERY_STRING;
  86         char aszQuery[255]              = {0};
  87         float           fValue          = 0.0f;
  88         float           fChangeReal = 0.0f;
  89         float           fChangePer      = 0.0f;
  90
  91         if(!hSG || !pfValue || !szTicker || strlen(szTicker) > 10)
  92                 return SG_INVALID_PARAMS;
  93
  94         /* On first lookup setup output buffer */
  95         if(!hSG->sData.pszBuffer)
  96         {
  97                 hSG->sData.pszBuffer = (char*)malloc(sizeof(char)*SG_MAX_BUFFER);
  98
  99                 if(!hSG->sData.pszBuffer)
 100                         return SG_BAD_ALLOC;
 101
 102                 memset(hSG->sData.pszBuffer,0,SG_MAX_BUFFER);
 103
 104                 hSG->sData.nCount = SG_MAX_BUFFER;
 105         }
 106
 107         sprintf(aszQuery,pszQueryString,szTicker);
 108
 109         if(curl_easy_setopt(hSG->hCurlHandle, CURLOPT_URL,aszQuery) != 0)
 110                 return SG_LOOKUP_FAILURE;
 111
 112         if(curl_easy_perform(hSG->hCurlHandle) != 0)
 113                 return SG_LOOKUP_FAILURE;
 114
 115         hSG->sData.nCurr = 0;
 116
 117         if(sscanf(hSG->sData.pszBuffer,"%f,\"%f - %f\"\n",&fValue,&fChangeReal,&fChangePer) != 3)
 118                 return SG_LOOKUP_FAILURE;
 119
 120         if(pfValue)
 121                 *pfValue = fValue;
 122
 123         if(pfChangeReal)
 124                 *pfChangeReal = fChangeReal;
 125
 126         if(pfChangePercent)
 127                 *pfChangePercent = fChangePer;
 128
 129         return SG_OK;
 130 }
 131
 132 int
 133 FreeStockGetter(SGHandle hSG)
 134 {
 135         if(!hSG)
 136                 return SG_INVALID_PARAMS;
 137
 138         curl_easy_cleanup(hSG->hCurlHandle);
 139         curl_global_cleanup();
 140
 141         free(hSG);
 142
 143         return SG_OK;
 144 }
 145