src/server/iotquery.cpp

   1 #include "iotquery.h"
   2 #include <string.h>
   3 #include <sys/stat.h>
   4 #include <sys/types.h>
   5 #include <sys/file.h>
   6 #include <fcntl.h>
   7 #include <unistd.h>
   8 #include <stdlib.h>
   9
  10 using namespace std;
  11
  12 const char * query_str="QUERY_STRING";
  13 const char * uri_str="REQUEST_URI";
  14 const char * method_str="REQUEST_METHOD";
  15 const char * iotcloudroot_str="IOTCLOUD_ROOT";
  16 const char * length_str="CONTENT_LENGTH";
  17
  18 IoTQuery::IoTQuery(FCGX_Request *request) :
  19         request(request),
  20         data(NULL),
  21         directory(NULL),
  22         uri(NULL),
  23         query(NULL),
  24         method(NULL),
  25         iotcloudroot(NULL),
  26         length(0),
  27         oldestentry(0),
  28         newestentry(0),
  29         requestsequencenumber(0),
  30         numqueueentries(DEFAULT_SIZE),
  31         fd(-1) {
  32 }
  33
  34 IoTQuery::~IoTQuery() {
  35         if (fd >= 0)
  36                 close(fd);
  37         if (directory)
  38                 delete directory;
  39         if (data)
  40                 delete data;
  41 }
  42
  43 bool IoTQuery::checkDirectory() {
  44         struct stat s;
  45         int err=stat(directory, &s);
  46         if (-1 == err)
  47                 return false;
  48         return S_ISDIR(s.st_mode);
  49 }
  50
  51 void IoTQuery::decodeQuery() {
  52         int len=strlen(query);
  53         char * str=new char[len+1];
  54         memcpy(str, query, len+1);
  55         char *tok_ptr=str;
  56
  57         /* Parse commands */
  58         char *command=strsep(&tok_ptr, "&");
  59         if (strncmp(command, "putslot", 7) == 0)
  60                 reqPutSlot = true;
  61
  62         if (strncmp(command, "getslot", 7) == 0)
  63                 reqGetSlot = true;
  64
  65         /* Load Sequence Number for request */
  66         char *sequencenumber_str = strsep(&tok_ptr, "&");
  67
  68         if (sequencenumber_str != NULL)
  69                 requestsequencenumber = strtoll(sequencenumber_str, NULL, 10);
  70
  71         /* Update size if we get request */
  72         char * numqueueentries_str = tok_ptr;
  73         if (numqueueentries_str != NULL)
  74                 numqueueentries = strtoll(numqueueentries_str, NULL, 10);
  75
  76         delete str;
  77 }
  78
  79 void doWrite(int fd, char *data, long long length) {
  80         long long offset=0;
  81         do {
  82                 long long byteswritten=write(fd, &data[offset], length);
  83                 if (byteswritten > 0) {
  84                         length -= byteswritten;
  85                         offset += byteswritten;
  86                 } else {
  87                         cerr << "Bytes not written";
  88                         return;
  89                 }
  90         } while(length != 0);
  91 }
  92
  93 void IoTQuery::getSlot() {
  94
  95 }
  96
  97 void IoTQuery::putSlot() {
  98         if (requestsequencenumber!=(newestentry+1)) {
  99                 getSlot();
 100                 return;
 101         }
 102
 103         int numberofliveslots=(int) ((newestentry-oldestentry)+1);
 104         if (numberofliveslots >=  numqueueentries) {
 105                 //need to drop slot
 106                 removeOldestSlot();
 107         }
 108         //write slot data out to file
 109         char *filename = getSlotFileName(requestsequencenumber);
 110         int slotfd = open(filename, O_CREAT|O_WRONLY, S_IRUSR| S_IWUSR);
 111         doWrite(slotfd, data, length);
 112         close(slotfd);
 113         delete filename;
 114         newestentry = requestsequencenumber; // update sequence number
 115         updateStatusFile(); // update counts
 116 }
 117
 118 char * IoTQuery::getSlotFileName(long long slot) {
 119         int directorylen=strlen(directory);
 120         char * filename=new char[25+directorylen];//19 digits for long number + 4 characters for SLOT + 1 character for null termination
 121         snprintf(filename, 24+directorylen+1, "%s/SLOT%lld", directory, slot);
 122         return filename;
 123 }
 124
 125
 126
 127 void IoTQuery::removeOldestSlot() {
 128         if (oldestentry!=0) {
 129                 char * filename=getSlotFileName(oldestentry);
 130                 unlink(filename);
 131                 delete filename;
 132         }
 133         oldestentry++;
 134 }
 135
 136 void IoTQuery::processQuery() {
 137         getQuery();
 138         getDirectory();
 139         readData();
 140
 141         if (strncmp(method, "POST", 4) != 0)
 142                 return;
 143
 144         if (directory == NULL ||
 145                         !checkDirectory())
 146                 return;
 147
 148         if (!openStatusFile())
 149                 return;
 150
 151         flock(fd, LOCK_EX);
 152
 153         decodeQuery();
 154
 155         if (reqGetSlot)
 156                 getSlot();
 157         else if (reqPutSlot)
 158                 putSlot();
 159         else return;
 160 }
 161
 162 void IoTQuery::readData() {
 163         if (length) {
 164                 data = new char[length+1];
 165                 memset(data, 0, length+1);
 166                 cin.read(data, length);
 167         }
 168         do {
 169                 char dummy;
 170                 cin >> dummy;
 171         } while (!cin.eof());
 172 }
 173
 174 void IoTQuery::getQuery() {
 175         uri = FCGX_GetParam(uri_str, request->envp);
 176         query = FCGX_GetParam(query_str, request->envp);
 177         method = FCGX_GetParam(method_str, request->envp);
 178         iotcloudroot = FCGX_GetParam(iotcloudroot_str, request->envp);
 179
 180         char * reqlength = FCGX_GetParam(length_str, request->envp);
 181         if (length) {
 182                 length=strtoll(reqlength, NULL, 10);
 183         } else {
 184                 length=0;
 185         }
 186 }
 187
 188 void IoTQuery::getDirectory() {
 189         char * split = strchr((char *)uri, '?');
 190         if (split == NULL)
 191                 return;
 192         int split_len = (int) (split-uri);
 193         int rootdir_len = strlen(iotcloudroot);
 194         int directory_len = split_len + rootdir_len + 1;
 195         directory = new char[directory_len];
 196         memcpy(directory, iotcloudroot, rootdir_len);
 197         memcpy(directory + rootdir_len, uri, split_len);
 198         directory[directory_len]=0;
 199 }
 200
 201 int doread(int fd, void *ptr, size_t count, off_t offset) {
 202         do {
 203                 size_t bytesread=pread(fd, ptr, count, offset);
 204                 if (bytesread==count) {
 205                         return 1;
 206                 } else if (bytesread==0) {
 207                         return 0;
 208                 }
 209         } while(1);
 210 }
 211
 212 void IoTQuery::updateStatusFile() {
 213         pwrite(fd, &numqueueentries, sizeof(numqueueentries), OFFSET_MAX);
 214         pwrite(fd, &oldestentry, sizeof(oldestentry), OFFSET_OLD);
 215         pwrite(fd, &newestentry, sizeof(newestentry), OFFSET_NEW);
 216 }
 217
 218 bool IoTQuery::openStatusFile() {
 219         char statusfile[]="queuestatus";
 220         int len=strlen(directory);
 221
 222         char * filename=new char[len+sizeof(statusfile)+2];
 223         memcpy(filename, directory, len);
 224         filename[len]='/';
 225         memcpy(filename+len+1, statusfile, sizeof(statusfile));
 226         filename[len+sizeof(statusfile)+1]=0;
 227         fd=open(filename, O_CREAT| O_RDWR, S_IRUSR| S_IWUSR);
 228         delete filename;
 229
 230         if (fd < 0)
 231                 return false;
 232
 233         int size;
 234         int needwrite=0;
 235         if (doread(fd, &size, sizeof(size), OFFSET_MAX))
 236                 numqueueentries=size;
 237         else
 238                 needwrite=1;
 239
 240         long long entry;
 241         if (doread(fd, &entry, sizeof(entry), OFFSET_OLD))
 242                 oldestentry=entry;
 243         else
 244                 needwrite=1;
 245
 246         if (doread(fd, &entry, sizeof(entry), OFFSET_NEW))
 247                 newestentry=entry;
 248         else
 249                 needwrite=1;
 250
 251         if (needwrite)
 252                 updateStatusFile();
 253
 254         return true;
 255 }
 256
 257