porthelp.mm

/*
 * porthelp.c
 *
 *  Created on: Jul 21, 2011
 *      Author: erich
 * Description: Implements some tools that might come in handy when writing a
 * port
 */

#include "porthelp.h"
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct
{
    handleType type;
    void *pointer;
    int Handle;

} HandleListEntry, *PHandleListEntry;

volatile HandleListEntry *HandleList;
int HandleList_max;

int CreateHandleFromPointer(void *p, handleType type)
{
    if (HandleList == NULL)
    {
        // Initialize the handlelist
        HandleList_max = 256;
        HandleList = (PHandleListEntry)malloc(256 * sizeof(HandleListEntry));

        memset((void *)HandleList, 0, sizeof(HandleListEntry) * 256);
    }

    // find a empty handle spot, if none are found, relocate (shouldn't happen
    // since ce doesn't open that many handles (of the type provided here), and
    // tends to close them)
    int i;
    for (i = 1; i < HandleList_max; i++)  // start from 1, just sacrifice 0
    {
        if (HandleList[i].type == htEmpty)
        {
            HandleList[i].pointer = p;
            HandleList[i].type = type;
            return i;
        }
    }

    // still here so not a single spot was free (wtf?)

    printf("Reached max amount of handles (%d). Leaking some memory to make a "
           "larger list (hope for the best, and fix this handle leak that is "
           "going on)\n",
           HandleList_max);
    HandleListEntry *NewHandleList =
        (HandleListEntry *)malloc(HandleList_max * 2 * sizeof(HandleListEntry));
    memset((void *)NewHandleList, 0, HandleList_max * 2 * sizeof(HandleListEntry));
    memcpy(NewHandleList, (const void *)HandleList,
           sizeof(HandleList_max * sizeof(HandleListEntry)));

    HandleList = NewHandleList;
    i = HandleList_max;
    HandleList_max = HandleList_max * 2;

    HandleList[i].pointer = p;
    HandleList[i].type = type;
    return i;
}

void *GetPointerFromHandle(int handle)
{
    if ((handle > 0) && (handle < HandleList_max) && (HandleList[handle].type != htEmpty))
        return HandleList[handle].pointer;
    else
        return NULL;
}

handleType GetHandleType(int handle)
{
    if ((handle > 0) && (handle < HandleList_max))
        return HandleList[handle].type;
    else
        return htEmpty;
}

void RemoveHandle(int handle)
{
    if ((handle > 0) && (handle < HandleList_max) && (HandleList[handle].type != htEmpty))
        HandleList[handle].type = htEmpty;
}

int SearchHandleList(int type, HANDLESEARCHCALLBACK cb, void *searchdata)
/*
 * go through the handle list and call cb(data, searchdata) for each handle of
 * the specified type if cb(data,searchdata) returns true then return that
 * handle, else return 0
 */
{
    int i;

    for (i = 1; i < HandleList_max; i++)
    {
        if (HandleList[i].type == type)
        {
            if (cb(HandleList[i].pointer, searchdata)) return i;
        }
    }

    return 0;
}