final change modulus

temp.c

@@ -23,47 +23,47 @@ int readercount = 0;
 
 unsigned modulus( unsigned char *num, size_t size, unsigned divisor) {
   unsigned rem = 0;
-  
- while(size>0)
+  int i=0;
+ while(i<divisor)
  {
-     rem+=num[size--]%divisor;
+     rem+=num[i]%divisor;
+     i++;
  }
   return rem%divisor;
 }
 
-
-int file_search(char *key, cahr *value, int index) {
-    lseek(fds[index], 0, SEEK_SET);
-    int offset = 0;
-    char fkey[256];
-    char fval[256];
-    do {
-        if( read(fds[index], fkey, sizeof(fkey)) < 0 )
-            break; 
-        if( read(fds[index], fval, sizeof(fval)) < 0 )
-            break; 
-        if( strcmp(fkey, key)==0 ) {
-            memcpy(value, fval, sizeof(fval));
-            return offset;
-        }
-        offset += sizeof(fkey) + sizeof(fval);
-    } while (1);
-    return -1;
-}
-
 void file_del( char *key)
 {   
-    int offset;
     int index=modulus(key,256,setSize);
+    fflush(stdout);
+    int length=0;
     sem_wait(&mutex[index]);
+    char blankspace[512];
+     char ch;
+    int k=-1;
+    lseek(fds[index], 0, SEEK_SET);
+    memset(blankspace,0,512);
+     char *line;
+     char temp[514];
+    size_t len=0;
+    off_t position=0;
+    FILE *fp=fdopen(fds[index],"rb+");
+    while ((getline(&line, &len, fp)) != -1)
+    {
+        memcpy(temp,line,strlen(line)-1);
+        char *fkey=strtok(line,":");
+        char *fvalue=strtok(NULL,":");
+        
+        if(strcmp(key,fkey)==0){
+            lseek(fds[index],position,SEEK_SET);
+            write(fds[index],blankspace,strlen(temp));
            
-    offset = file_search(key, value, index) 
-    if(offset >= 0) {
-        lseek(fds[index], offset, SEEK_SET);
-        write(fds[index], 0, 256);
-        write(fds[index], 0, 256);
+            break;
         }
+        position=ftell(fp);
         
+    }
+    printf("length %d",length);
     sem_post(&mutex[index]);
     
 }
@@ -72,17 +72,28 @@ int file_get(char *key, char *value)
     /* Gets the value stored at offset */
     /* Does not depend on key argument */
     int found =0;
-    int index = modulus(key,strlen(key),setSize);
+    
+    int index=modulus(key,strlen(key),setSize);
+    lseek(fds[index],0,SEEK_SET);
     sem_wait(&readerLocks[index]);
     readCounters[index]+=1;
     if(readCounters[index]==1)
         sem_wait(&mutex[index]);
     sem_post(&readerLocks[index]);
-    
-    if(file_search(key, value, index)>=0) {
-        found = 1;
+    char *line;
+    size_t len=0;
+    FILE *fp=fdopen(fds[index],"rb+");
+    while ((getline(&line, &len, fp)) != -1)
+    {
+        char *fkey=strtok(line,":");
+        char *fvalue=strtok(NULL,":");
+        if(strcmp(key,fkey)==0){
+            memcpy(value,fvalue,strlen(fvalue)-1);
+            found=1;
+            break;
         }
         
+    }
     sem_wait(&readerLocks[index]);
     readCounters[index]-=1;
     if(readCounters[index]==0)
@@ -93,7 +104,8 @@ int file_get(char *key, char *value)
     return found;
 }
 
-off_t file_put(char *key,char *value) {
+off_t file_put(char *key,char *value)
+ {
      /*
         if found then ask the offset where it is present and if the value noy matches with the present value ,update the given line
         if not present then search for empty line and insert there!
@@ -128,7 +140,7 @@ off_t file_put(char *key,char *value) {
     //sem_post(&mutex[index]);
     return position;
 }
-int storage_init()
+int main()
 {
     /*
         define the array of file descriptors  depending on the prefix 
@@ -137,6 +149,20 @@ int storage_init()
         GET would use read lock
         each write should return the line number
     */
+    int n2=0;
+    char prevkey[256];
+    memset(prevkey,0,sizeof(prevkey));
+    memcpy(prevkey,"w",1);
+    char newkey[256];
+    memset(newkey,0,sizeof(newkey));
+    memcpy(newkey,"x",1);
+    
+    printf("key:%s\n",prevkey);
+    char key[256]="25";
+    char value[256]="value2";
+    off_t offset;
+    bzero(key+strlen(key),sizeof(key)-strlen(key));
+    bzero(value+strlen(value),sizeof(value)-strlen(value));
     fds=(int *)malloc(sizeof(int)*setSize);
     readCounters=(int *)malloc(sizeof(int)*setSize);
     readerLocks=(sem_t *)malloc(sizeof(sem_t)*setSize);
@@ -155,7 +181,12 @@ int storage_init()
         sem_init(&mutex[i],0,1);
         readCounters[i]=0;
     }
-    printf("%u",modulus("99",256,setSize));
+
+    i=0;
+  
+   printf("%d",modulus(prevkey,256,2));
+    printf("%d",modulus(newkey,256,2));
+
 
     //offset = file_put("24", "value245");
     //offset = file_put("24", "value1");