// hash.cpp

#include "hash.h"

//===========================================================================
HashItem::HashItem(char *s, int v) {
  if (strlen(s) > STR_LEN) {
    cout<<endl<<"Hash item string too long";
    exit(-1);
  }
  strcpy(str, s); value = v;
}
//===========================================================================
void HashItem::Set(char *s, int v) {
  if (strlen(s) > STR_LEN) {
    cout<<endl<<"Hash item string too long";
    exit(-1);
  }
  strcpy(str, s); value = v;
}
//===========================================================================
void HashTable::Insert(HashItem &h_item) {
  int hash_index = HashFunc(h_item.str);
  #ifdef DBG
  cout<<hash_index;cout.flush();
  #endif
  data[hash_index].Insert(h_item);
}
//===========================================================================
int HashTable::Retrieve(HashItem &h_item) {
  int hash_index = HashFunc(h_item.str);
  HashItem *temp_item_ptr = data[hash_index].Search(h_item);
  if (!temp_item_ptr) return 0;
  else {
    h_item = *temp_item_ptr;
    return 1;
  }
}
//===========================================================================
unsigned HashTable::HashFunc(char *str) {
  unsigned k = 0;
  for (int i = 0; i < strlen(str); i++) {
    k += (unsigned)str[i] << (i * 8);
  }
  return (k % data.Size());
}
//=============================================================================
ostream &operator<<(ostream &s, HashTable &ht) {
  for (int i = 0; i < ht.data.Size(); i++) {
    if (!ht.data[i].Empty()) {
      ht.data[i].Write(s);
      s<<endl;
    }
  }    
  return s;
}
//===========================================================================
// for int hash tables
//===========================================================================
HashItemInt &HashItemInt::operator = (const HashItemInt &h_item) {
  key = h_item.key; 
  value = h_item.value;
  return *this;
}
//===========================================================================
void HashTableInt::Insert(HashItemInt &h_item) {
  int hash_index = HashFunc(h_item.key);
  data[hash_index].Insert(h_item);
}
//===========================================================================
int HashTableInt::Retrieve(HashItemInt &h_item) {
  int hash_index = HashFunc(h_item.key);
  HashItemInt *temp_item_ptr;
  temp_item_ptr = data[hash_index].Search(h_item);
  if (!temp_item_ptr) return 0;
  else {
    h_item = *temp_item_ptr;
    return 1;
  }
}
//===========================================================================
unsigned HashTableInt::HashFunc(int key) {
  return (key % data.Size());
}
//=============================================================================
ostream &operator<<(ostream &s, HashTableInt &ht) {
  for (int i = 0; i < ht.data.Size(); i++) {
    if (!ht.data[i].Empty()) {
      ht.data[i].Write(s);
      s<<endl;
    }
  }    
  return s;
}
//===========================================================================
void HashTableInt::PutInArray(Array<HashItemInt> &h_array, int &num_items) {
  num_items = 0;
  HashItemInt h_item;
  for (int i = 0; i < data.Size(); i++) {
    if (!data[i].Empty()) { // now iterate through the linked list
      int start = 1; 
      while (data[i].GetNext(h_item, start)) {
        h_array[num_items].Set(h_item.key, h_item.value); 
	start = 0;
	num_items++;
      }
    }
  }    
}
//===========================================================================
int HashTableInt::ExtToInt(int key, int next_value)
{
  HashItemInt h_item(key, 0);

  // Check to see if we know this one.  0 matches any number.  If we
  // do know this one, h_item.value gets set to what we knew it to be.
  if (!Retrieve(h_item)) { 
    h_item.Set(key, next_value);
    Insert(h_item);
  }
  return (h_item.value);
}

/*
// to test out the hash table
#include <stdlib.h>
#include <string.h>
#include <fstream.h>

#define MAX_SYS_CALLS 255
//============================================================================
int GetCalls(HashTable &ht) {
  ifstream calls_file("calls.txt");
  char buff[255];
  int buff_len;
  int num_sys_calls = 0;
  HashItem h_item;
  while (!calls_file.eof() && num_sys_calls < MAX_SYS_CALLS) {
    calls_file.getline(buff, 254);
    buff_len = strlen(buff);
    if (buff_len) {
      // cat on a parenth to make sure only calls are matched
      strcat(buff, "(");
      #ifdef DBG
      cout<<endl<<buff; cout.flush();
      #endif
      h_item.Set(buff, num_sys_calls);
      ht.Insert(h_item);
      num_sys_calls++;
    }
  }
  calls_file.close();
  if (num_sys_calls == MAX_SYS_CALLS) return 0;
  else return 1;
}
//============================================================================
void main(void) {
  HashTable hashtable(701);
  HashItem h_item("unlink(", 0);
  if (GetCalls(hashtable)) {
    cout<<endl<<hashtable;
    h_item.Set("unlink(", 0);
    if (hashtable.Retrieve(h_item))
      cout<<endl<<" unlink found, index = "<<h_item.value;
    else cout<<endl<<" unlink not found";
    h_item.Set("get_kernel_syms(", 0);
    if (hashtable.Retrieve(h_item))
      cout<<endl<<" get_kernel_syms found, index = "<<h_item.value;
    else cout<<endl<<" get_kernel_syms not found";
    h_item.Set("hello(", 0);
    if (hashtable.Retrieve(h_item))
      cout<<endl<<" hello found, index = "<<h_item.value;
    else cout<<endl<<" hello not found";
    h_item.Set("setsockopt(", 0);
    if (hashtable.Retrieve(h_item))
      cout<<endl<<" setsockopt found, index = "<<h_item.value;
    else cout<<endl<<" setsockopt not found";
  }
}
*/