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#include "imemory.h"

#include "idebug.h"

#include "iproc_fs.h"

// General purpose function to support proc file reads

//

// config_data, config_alloc, total_size - static variables in proc function

//		will be managed here to maintain context across multiple read calls to

//		this file.

// func - function to allocate space to text contents and format it

// func_data - will be passed as argument to provide context of what to format

// buf, start, offset, maxlen, eof - standard proc read arguments

IBA_PROC_RET

iba_proc_read_wrapper(char **config_data, char **config_alloc, int *total_size,

		IBA_PROC_FORMAT_FUNC func, void* func_data,

 		char *buf, char **start, IBA_PROC_OFFSET offset, int maxlen,

		int *eof)

{

	int cur_size;

	if (! *config_data) {

		*total_size = 0;	// in case format fails to allocate space

		*config_data = *config_alloc = (*func)(func_data, total_size);

	}

	/*

	 * How much data is available for read: OS spits reads into 512b blocks

	 * and asks each individualy via a separate call to you each time.

	 */

	cur_size = (*total_size <= maxlen ? *total_size : maxlen);

	/*

	 * Is this the last read.. do something to generate

	 * an EOF

	 */

	if (cur_size <= 0) {

		*config_data = NULL;

		if (*config_alloc != NULL)

			MemoryDeallocate(*config_alloc);

		*config_alloc = NULL;

		*eof = 1;

		return 0;

	}

	MemoryCopy((void *)buf, (void *)*config_data, cur_size);

	/*

	 * setup for next call

	 */

	*total_size -= cur_size; // Compute #bytes left to deliver.

	*config_data += cur_size;

	if (*total_size <= 0)

		*eof = 1;

	else

		*eof = 0;

	*start = (char *)(uintn)cur_size;

	return cur_size;

}

void

SimpleProcInitState(SIMPLE_PROC *pProc)

{

	MemoryClear(pProc, sizeof(*pProc));

}

// internal format function if callback occurs for

// /proc object which is uninitialize (eg. being destroyed)

static

char * SimpleProcFormatUninit(void *data, int* total_size)

{

	return NULL;

}

static

IBA_PROC_RET SimpleProcRead(char *buf, char **start, IBA_PROC_OFFSET offset, int maxlen, int *eof, void *data)

{

	SIMPLE_PROC *pProc = (SIMPLE_PROC*)data;

	return iba_proc_read_wrapper(&pProc->config_data, &pProc->config_alloc,

			&pProc->total_size,

			pProc->Initialized ? pProc->FormatFunc

					: SimpleProcFormatUninit,

			pProc->Context,

			buf, start, offset, maxlen, eof);

}

static

IBA_PROC_RET SimpleProcWrite(IBA_PROC_FILE *file, const char *buffer, unsigned long length, void *data)

{

	SIMPLE_PROC *pProc = (SIMPLE_PROC*)data;

	if (pProc->Initialized);

		(*pProc->ClearFunc)(pProc->Context);

	return length;

}

// create and initialize /proc file

// Inputs:

//	pProc - object to initialize

//	Name - relative filename in ProcDir

//	ProcDir - parent directory

//	Context - context to pass to FormatFunc and ClearFunc

//	FormatFunc - function to allocate and format /proc read data

//	ClearFunc - function to clear data in response to /proc write

// Outputs:

//	None

// Returns:

//	true - initialized and callbacks will begin on user access to /proc

//	false - unable to create

//

// must be called in a preemptable context

//

boolean

SimpleProcInit(SIMPLE_PROC *pProc, const char* Name, IBA_PROC_NODE *ProcDir, 

		void *Context, IBA_PROC_FORMAT_FUNC FormatFunc,

		OPTIONAL SIMPLE_PROC_CLEAR_FUNC ClearFunc)

{

	IBA_PROC_NODE 		*entry;

	ASSERT(! pProc->Initialized);

	ASSERT(FormatFunc);

	ASSERT(Name);

	pProc->Context = Context;

	strncpy(pProc->Name, Name, SIMPLE_PROC_NAME_LEN-1);

	pProc->Name[SIMPLE_PROC_NAME_LEN-1] = '\0';

	pProc->ProcDir = ProcDir;

	pProc->FormatFunc = FormatFunc;

	pProc->ClearFunc = ClearFunc;

	entry = iba_create_proc_entry(pProc->Name,

				IBA_PROC_MODE_IFREG | IBA_PROC_MODE_IRUGOWUG,

				pProc->ProcDir);

	if (! entry)

	{

		MsgOut("Cannot create proc entry: %s\n", pProc->Name);

		return FALSE;

	}

	iba_set_proc_data(entry, pProc);

	iba_set_proc_read_func(entry, SimpleProcRead);

	iba_set_proc_write_func(entry, ClearFunc?SimpleProcWrite:NULL);

	pProc->Initialized = TRUE;

	return TRUE;

}

void

SimpleProcDestroy(SIMPLE_PROC *pProc)

{

	if (pProc->Initialized)

		iba_remove_proc_entry(pProc->Name, pProc->ProcDir);

	MemoryClear(pProc, sizeof(*pProc));

}