/* $Id: kDbgHlpCrt.cpp 77 2016-06-22 17:03:55Z bird $ */
/** @file
 * kDbg - The Debug Info Reader, Helpers, CRT Based Implementation.
 */

/*
 * Copyright (c) 2006-2007 Knut St. Osmundsen <bird-kStuff-spamix@anduin.net>
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/*******************************************************************************
*   Header Files                                                               *
*******************************************************************************/
#include "kDbgHlp.h"
#include "kDbg.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#ifdef _MSC_VER
# include <io.h>
#endif



/**
 * The stdio base implementation of KDBGHLPFILE.
 */
typedef struct KDBGHLPFILE
{
    /** Pointer to the stdio file stream. */
    FILE *pStrm;
} KDBGHLPFILE;

/** @def HAVE_FSEEKO
 * Define HAVE_FSEEKO to indicate that fseeko and ftello should be used. */
#if !defined(_MSC_VER)
# define HAVE_FSEEKO
#endif


void *kDbgHlpAlloc(size_t cb)
{
    return malloc(cb);
}


void *kDbgHlpAllocZ(size_t cb)
{
    return calloc(1, cb);
}


void *kDbgHlpAllocDup(const void *pv, size_t cb)
{
    void *pvNew = malloc(cb);
    if (pvNew)
        memcpy(pvNew, pv, cb);
    return pvNew;
}


void *kDbgHlpReAlloc(void *pv, size_t cb)
{
    return realloc(pv, cb);
}


void kDbgHlpFree(void *pv)
{
    free(pv);
}


int kDbgHlpCrtConvErrno(int rc)
{
    switch (rc)
    {
        case 0:             return 0;
        case EINVAL:        return KERR_INVALID_PARAMETER;
        case ENOMEM:        return KERR_NO_MEMORY;
        case EISDIR:
        case ENOENT:        return KERR_FILE_NOT_FOUND;
        default:            return KERR_GENERAL_FAILURE;
    }
}


int kDbgHlpOpenRO(const char *pszFilename, PKDBGHLPFILE *ppFile)
{
    PKDBGHLPFILE pFile = (PKDBGHLPFILE)kDbgHlpAlloc(sizeof(*pFile));
    if (!pFile)
        return KERR_NO_MEMORY;

    pFile->pStrm = fopen(pszFilename, "rb");
    if (pFile->pStrm)
    {
        *ppFile = pFile;
        return 0;
    }
    return kDbgHlpCrtConvErrno(errno);
}


void kDbgHlpClose(PKDBGHLPFILE pFile)
{
    if (pFile)
    {
        fclose(pFile->pStrm);
        pFile->pStrm = NULL;
        kDbgHlpFree(pFile);
    }
}


uintptr_t kDbgHlpNativeFileHandle(PKDBGHLPFILE pFile)
{
    int fd = fileno(pFile->pStrm);
#ifdef _MSC_VER
    return _get_osfhandle(fd);
#else
    return fd;
#endif
}


int64_t kDbgHlpFileSize(PKDBGHLPFILE pFile)
{
    int64_t cbFile;
    int64_t offCur = kDbgHlpTell(pFile);
    if (offCur >= 0)
    {
        if (kDbgHlpSeekByEnd(pFile, 0) == 0)
            cbFile = kDbgHlpTell(pFile);
        else
            cbFile = -1;
        kDbgHlpSeek(pFile, offCur);
    }
    else
        cbFile = -1;
    return cbFile;
}


int kDbgHlpReadAt(PKDBGHLPFILE pFile, int64_t off, void *pv, size_t cb)
{
    int rc  = kDbgHlpSeek(pFile, off);
    if (!rc)
        rc = kDbgHlpRead(pFile, pv, cb);
    return rc;
}


int kDbgHlpRead(PKDBGHLPFILE pFile, void *pv, size_t cb)
{
    if (fread(pv, cb, 1, pFile->pStrm) == 1)
        return 0;
    return -1;
}


int kDbgHlpSeek(PKDBGHLPFILE pFile, int64_t off)
{
#ifdef HAVE_FSEEKO
    if (!fseeko(pFile->pStrm, off, SEEK_SET))
        return 0;
#else
    long l = (long)off;
    if (l != off)
        return KERR_OUT_OF_RANGE;
    if (!fseek(pFile->pStrm, l, SEEK_SET))
        return 0;
#endif
    return kDbgHlpCrtConvErrno(errno);
}


int kDbgHlpSeekByCur(PKDBGHLPFILE pFile, int64_t off)
{
#ifdef HAVE_FSEEKO
    if (!fseeko(pFile->pStrm, off, SEEK_CUR))
        return 0;
#else
    long l = (long)off;
    if (l != off)
        return KERR_OUT_OF_RANGE;
    if (!fseek(pFile->pStrm, l, SEEK_CUR))
        return 0;
#endif
    return kDbgHlpCrtConvErrno(errno);
}


int kDbgHlpSeekByEnd(PKDBGHLPFILE pFile, int64_t off)
{
#ifdef HAVE_FSEEKO
    if (!fseeko(pFile->pStrm, -off, SEEK_END))
        return 0;
#else
    long l = (long)off;
    if (l != off)
        return KERR_OUT_OF_RANGE;
    if (!fseek(pFile->pStrm, -l, SEEK_END))
        return 0;
#endif
    return kDbgHlpCrtConvErrno(errno);
}


int64_t kDbgHlpTell(PKDBGHLPFILE pFile)
{
#ifdef HAVE_FSEEKO
    return ftello(pFile->pStrm);
#else
    return ftell(pFile->pStrm);
#endif
}