//********************************************
// AEI.h
// -------------------------------------------
// Data types and function declarations of the
// AEI (AE Interface) module
//
// Author: Leiwen Deng
// Date: 12/10/2005
//********************************************

#ifndef AEI_H
#define AEI_H

#include "IPC.h"

// File names
#define AE_PROGRAM "/usr/local/squid/sbin/AE" // The executable file name of the Anti-pollution Engine(AE)
#define LOG_FILE_NAME "/usr/local/squid/var/logs/IPC_AE.log"
#define BLOCKED_ENTRY_FILE_NAME "/usr/local/squid/var/logs/blocked_entry"
#define BLOCKED_CLIENT_FILE_NAME "/usr/local/squid/var/logs/blocked_client"

// Interval in times of printing block-entry events to log file
#define BLOCK_ENTRY_PRINT_INTERVAL 10
// Interval in times of printing block-client events to log file
#define BLOCK_CLIENT_PRINT_INTERVAL 100

typedef unsigned int uint32;

// Record of a blocked entry
typedef struct _BlockedEntry BlockedEntry;

// Record of a blocked client
typedef struct _BlockedClient BlockedClient;

struct _BlockedEntry{
    hash_link hash;
    int block_count;
};

struct _BlockedClient{
    hash_link hash;
    int block_count;
};

// The structure of system parameters
typedef struct{
  FILE * ipc_read;
  FILE * ipc_write;
  FILE * log_file;
  char log_updated;
  pid_t AE_pid;
  hash_table * blocked_entry_table;
  hash_table * blocked_client_table;
}SYS_PARAMETER;

extern SYS_PARAMETER sys_parameter; // system parameters

// ************* Begin *************
// Functions implemented in "main.c"

// Spawn a program and open a pair of pipe file to communicate with it
pid_t IPC_Open2( const char * filename, int * fd_read, int * fd_write );

// Initialize the AEI
char Initialize_AE_Interface( void );

// Close the AEI
char Close_AE_Interface( void );

// Send access information to the AE through the pipe
char SendAccessInfo( const ACCESS_INFO * access_info );

// Send a storage release notification to the AE through the pipe
char SendReleaseNotification( StoreEntry * entry );

// ************* End ***************

// ************* Begin *************
// Functions implemented in "client_side.c"

// Process the feedback from the AE module
void Process_AE_Feedback( void );

// Initialized the hash tables of blocked entries and blocked clients
void AEI_DB_Init( void );

// De-initialize the hash tables of blocked entries and blocked clients
void AEI_DB_FreeMemory( void );

// Create a new entry in the table of the blocked entries
BlockedEntry * BlockedEntryCreate( const cache_key * key );
// Delete an entry from the table of the blocked entries
void BlockedEntryDelete( BlockedEntry * e );
// Look up an entry in the table of the blocked entries
BlockedEntry * BlockedEntryFind( const cache_key * key );
// Dump all blocked entries to a file
void DumpBlockedEntry( void );

// Create a new entry in the table of the blocked clients
BlockedClient * BlockedClientCreate( uint32 client_ip );
// Delete an entry from the table of the blocked clients
void BlockedClientDelete( BlockedClient * e );
// Look up an entry in the table of the blocked clients
BlockedClient * BlockedClientFind( uint32 client_ip );
// Dump all blocked clients to a file
void DumpBlockedClient( void );

// An enhanced version of "hash_join", which allows the size of the hash table to be doubled when necessary
void hash_insert_link( hash_table * hid, hash_link * lnk );

// ************* End ***************

#endif