sbgInterfaceFile.c

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#include "sbgInterfaceFile.h"

//----------------------------------------------------------------------//
//- Internal methods declarations                                      -//
//----------------------------------------------------------------------//

//----------------------------------------------------------------------//
//- Operations methods declarations                                    -//
//----------------------------------------------------------------------//

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileOpen(SbgInterface *pHandle, const char *filePath)
{
        SbgErrorCode     errorCode = SBG_NO_ERROR;
        FILE                    *pInputFile;
        
        assert(pHandle);
        assert(filePath);

        //
        // Always call the underlying zero init method to make sure we can correctly handle SbgInterface evolutions
        //
        sbgInterfaceZeroInit(pHandle);

        //
        // Try to open the file
        //
        pInputFile = fopen(filePath, "rb");

        //
        // Test if the input file has been opened
        //
        if (pInputFile)
        {
                //
                // Define base interface members
                //
                pHandle->handle         = pInputFile;
                pHandle->type           = SBG_IF_TYPE_FILE;

                //
                // Define the interface name
                //
                sbgInterfaceNameSet(pHandle, filePath);
                                
                //
                // Define all overloaded members
                //
                pHandle->pReadFunc      = sbgInterfaceFileRead;
                pHandle->pWriteFunc     = sbgInterfaceFileWriteFake;
                pHandle->pFlushFunc     = sbgInterfaceFileFlush;
        }
        else
        {
                //
                // Unable to open the input file
                //
                errorCode = SBG_INVALID_PARAMETER;
        }

        return errorCode;
}

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileWriteOpen(SbgInterface *pHandle, const char *filePath)
{
        SbgErrorCode     errorCode = SBG_NO_ERROR;
        FILE                    *pInputFile;
                        
        //
        //      Test input arguments
        //
        assert(pHandle);
        assert(filePath);

        //
        // Try to open the file
        //
        pInputFile = fopen(filePath, "wb");

        //
        // Test if the input file has been opened
        //
        if (pInputFile)
        {
                //
                // Define the interface members
                //
                pHandle->handle = pInputFile;
                pHandle->type = SBG_IF_TYPE_FILE;
                pHandle->pReadFunc = sbgInterfaceFileReadFake;
                pHandle->pWriteFunc = sbgInterfaceFileWrite;
                pHandle->pFlushFunc = sbgInterfaceFileFlush;
        }
        else
        {
                //
                // Unable to open the input file
                //
                errorCode = SBG_INVALID_PARAMETER;
        }

        return errorCode;
}

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileClose(SbgInterface *pHandle)
{
        FILE *pInputFile;

        //
        //      Test input arguments
        //
        assert(pHandle);

        //
        // Get the internal FILE handle
        //
        pInputFile = (FILE*)(pHandle->handle);

        //
        // Close the input file only if opened
        //
        if (pInputFile)
        {
                fclose(pInputFile);
                pHandle->handle = NULL;
        }

        return SBG_NO_ERROR;
}

SBG_COMMON_LIB_API size_t sbgInterfaceFileGetSize(SbgInterface *pHandle)
{
        FILE    *pInputFile;
        long     cursorPos;
        long     fileSize;

        //
        //      Test input arguments
        //
        assert(pHandle);

        //
        // Initialize the file size to 0 in case of error
        //
        fileSize = 0;

        //
        // Get the internal FILE handle
        //
        pInputFile = (FILE*)(pHandle->handle);

        //
        // Test if the file handle is valid
        //
        if (pInputFile)
        {
                //
                // Compute the file size
                //
                cursorPos = ftell(pInputFile);
                fseek(pInputFile, 0, SEEK_END);
                fileSize = ftell(pInputFile);
                fseek(pInputFile, cursorPos, SEEK_SET);
        }
        
        return (size_t)fileSize;
}

SBG_COMMON_LIB_API size_t sbgInterfaceFileGetCursor(const SbgInterface *pHandle)
{
        FILE    *pInputFile;

        //
        //      Test input argument
        //
        assert(pHandle);

        //
        // Get the internal FILE handle
        //
        pInputFile = (FILE*)(pHandle->handle);

        //
        // Test if the file handle is valid
        //
        if (pInputFile)
        {
                //
                // Return the current cursor position
                //
                return (size_t)ftell(pInputFile);
        }
        
        return 0;
}


//----------------------------------------------------------------------//
//- Internal interfaces write/read implementations                     -//
//----------------------------------------------------------------------//

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileWrite(SbgInterface *pHandle, const void *pBuffer, size_t bytesToWrite)
{
        FILE *pOutputFile;
        size_t bytesWritten;

        //
        //      Test input argument
        //
        assert(pHandle);
        assert(pBuffer);

        //
        // Get the internal FILE handle
        //
        pOutputFile = (FILE*)(pHandle->handle);

        //
        // Write as much bytes as we can
        //
        bytesWritten = fwrite(pBuffer, sizeof(uint8_t), bytesToWrite, pOutputFile);

        //
        // Check if we could successfuly write our bytes
        //
        if (bytesWritten == bytesToWrite)
        {

                return SBG_NO_ERROR;
        }
        else
        {
                return SBG_WRITE_ERROR;
        }
}

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileRead(SbgInterface *pHandle, void *pBuffer, size_t *pReadBytes, size_t bytesToRead)
{
        FILE *pInputFile;

        //
        //      Test input argument
        //
        assert(pHandle);
        assert(pBuffer);
        assert(pReadBytes);

        //
        // Get the internal FILE handle
        //
        pInputFile = (FILE*)(pHandle->handle);

        //
        // Read some bytes from the file
        //
        *pReadBytes = fread(pBuffer, sizeof(uint8_t), bytesToRead, pInputFile);

        return SBG_NO_ERROR;
}

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileFlush(SbgInterface *pHandle)
{
        SbgErrorCode     errorCode;
        FILE                    *pInputFile;
        int                              ret;

        //
        //      Test input argument
        //
        assert(pHandle);

        //
        // Get the internal FILE handle
        //
        pInputFile = (FILE*)(pHandle->handle);

        //
        // Flush all pending data
        //
        ret = fflush(pInputFile);

        if (ret == 0)
        {
                errorCode = SBG_NO_ERROR;
        }
        else
        {
                errorCode = SBG_ERROR;
        }

        return errorCode;
}

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileWriteFake(SbgInterface *pHandle, const void *pBuffer, size_t bytesToWrite)
{
        //
        // Simply avoid warnings and return an error
        //
        SBG_UNUSED_PARAMETER(pHandle);
        SBG_UNUSED_PARAMETER(pBuffer);
        SBG_UNUSED_PARAMETER(bytesToWrite);

        return SBG_ERROR;
}

SBG_COMMON_LIB_API SbgErrorCode sbgInterfaceFileReadFake(SbgInterface *pHandle, void *pBuffer, size_t *pReadBytes, size_t bytesToRead)
{
        //
        // Simply avoid warnings and return an error
        //
        SBG_UNUSED_PARAMETER(pHandle);
        SBG_UNUSED_PARAMETER(pBuffer);
        SBG_UNUSED_PARAMETER(pReadBytes);
        SBG_UNUSED_PARAMETER(bytesToRead);

        return SBG_ERROR;
}