MeshAgent/microscript/ILibDuktape_MemoryStream.c

#include "duktape.h"
#include "ILibDuktapeModSearch.h"
#include "ILibDuktape_Helpers.h"
#include "ILibDuktape_DuplexStream.h"
#include "../microstack/ILibParsers.h"


#define ILibDuktape_MemoryStream_Internal		"\xFF_MemoryStream_Internal"

#ifdef __DOXY__
/*! 
\implements DuplexStream
\brief Buffer Accumulator object, sort of like StringBuilder, etc. <b>Note:</b> To use, must <b>require('MemoryStream')</b> and then <b>new</b> it.
*
* To utilize MemoryStream, you must require('MemoryStream')
*/
class MemoryStream
{
public:
	
	/*! 
	\brief Returns a new MemoryStream object
	*
	MemoryStream([initialSize]);
	\param initialSize <integer> Optional parameter specifying the initial size of the internal buffer. Default size is 4096 bytes.
	*/
	MemoryStream([initialSize]);

	/*! property buffer
	\brief Property returning the accumulated byte[] buffer object
	*/
	Buffer buffer;
};
#endif


typedef struct ILibDuktape_MemoryStream
{
	duk_context *ctx;
	size_t initial;
	ILibDuktape_DuplexStream *s;

	char *buffer;
	size_t bufferLen;
	size_t bufferSize;
}ILibDuktape_MemoryStream;

ILibTransport_DoneState ILibDuktape_MemoryStream_OnWrite(struct ILibDuktape_DuplexStream *stream, char *buffer, int bufferLen, void *user)
{
	ILibDuktape_MemoryStream *ms = (ILibDuktape_MemoryStream*)user;

	if (ms->bufferSize - ms->bufferLen < (size_t)bufferLen)
	{
		if ((size_t)bufferLen > ms->bufferSize)
		{
			if ((ms->buffer = (char*)realloc(ms->buffer, ms->bufferSize + bufferLen)) == NULL) { ILIBCRITICALEXITMSG(254, "OUT OF MEMORY"); }
			ms->bufferSize += bufferLen;
		}
		else
		{
			if((ms->buffer = (char*)realloc(ms->buffer, 2*ms->bufferSize)) == NULL) { ILIBCRITICALEXITMSG(254, "OUT OF MEMORY"); }
			ms->bufferSize = (2 * ms->bufferSize);
		}
	}

	memcpy_s(ms->buffer + ms->bufferLen, ms->bufferSize - ms->bufferLen, buffer, bufferLen);
	ms->bufferLen += bufferLen;

	return(ILibTransport_DoneState_COMPLETE);
}
void ILibDuktape_MemoryStream_OnEnd(struct ILibDuktape_DuplexStream *stream, void *user)
{
	ILibDuktape_MemoryStream *ms = (ILibDuktape_MemoryStream*)user;
	ILibDuktape_DuplexStream_WriteEnd(ms->s);
}
duk_ret_t ILibDuktape_MemoryStream_buffer(duk_context *ctx)
{
	duk_push_this(ctx);
	duk_get_prop_string(ctx, -1, ILibDuktape_MemoryStream_Internal);
	ILibDuktape_MemoryStream *ms = (ILibDuktape_MemoryStream*)Duktape_GetBuffer(ctx, -1, NULL);

	duk_push_external_buffer(ctx);
	duk_config_buffer(ctx, -1, ms->buffer, ms->bufferLen);
	duk_push_buffer_object(ctx, -1, 0, ms->bufferLen, DUK_BUFOBJ_NODEJS_BUFFER);

	return(1);
}
duk_ret_t ILibDuktape_MemoryStream_Finalizer(duk_context *ctx)
{
	duk_get_prop_string(ctx, 0, ILibDuktape_MemoryStream_Internal);
	ILibDuktape_MemoryStream *ms = (ILibDuktape_MemoryStream*)Duktape_GetBuffer(ctx, -1, NULL);

	free(ms->buffer);
	return(0);
}

duk_ret_t ILibDuktape_MemoryStream_writeBE(duk_context *ctx)
{
	duk_push_current_function(ctx);
	int size = Duktape_GetIntPropertyValue(ctx, -1, "size", 0);
	char buffer[16];
	int value = duk_require_int(ctx, 0);

	switch (size)
	{
		case 1:
			buffer[0] = (char)value;
			break;
		case 2:
			((unsigned short*)buffer)[0] = htons((unsigned short)value);
			break;
		case 4:
			((unsigned int*)buffer)[0] = htonl((unsigned int)value);
			break;
		default:
			break;
	}

	if (size > 0)
	{
		duk_push_this(ctx);							// [ms]
		duk_get_prop_string(ctx, -1, "write");		// [ms][write]
		duk_swap_top(ctx, -2);						// [write][this]
		duk_push_external_buffer(ctx);				// [write][this][buffer]
		duk_config_buffer(ctx, -1, buffer, size);
		duk_call_method(ctx, 1);					// [retVal]
		return(1);
	}
	else
	{
		return(ILibDuktape_Error(ctx, "MemoryStream.writeBE() Unknown Error"));
	}
}
duk_ret_t ILibDuktape_MemoryStream_new(duk_context *ctx)
{
	int initial = duk_get_top(ctx) > 0 ? duk_require_int(ctx, 0) : 4096;

	ILibDuktape_MemoryStream *ms;
	duk_push_object(ctx);												// [ms]
	duk_push_fixed_buffer(ctx, sizeof(ILibDuktape_MemoryStream));		// [ms][internal]
	ms = (ILibDuktape_MemoryStream*)Duktape_GetBuffer(ctx, -1, NULL);
	memset(ms, 0, sizeof(ILibDuktape_MemoryStream));
	duk_put_prop_string(ctx, -2, ILibDuktape_MemoryStream_Internal);	// [ms]
	ms->buffer = (char*)ILibMemory_Allocate(initial, 0, NULL, NULL);
	ms->bufferSize = (size_t)initial;
	ms->ctx = ctx;

	ms->s = ILibDuktape_DuplexStream_Init(ctx, ILibDuktape_MemoryStream_OnWrite, ILibDuktape_MemoryStream_OnEnd, NULL, NULL, ms);
	ILibDuktape_CreateEventWithGetter(ctx, "buffer", ILibDuktape_MemoryStream_buffer);
	ILibDuktape_CreateFinalizer(ctx, ILibDuktape_MemoryStream_Finalizer);

	ILibDuktape_CreateInstanceMethodWithIntProperty(ctx, "size", 4, "writeUInt32BE", ILibDuktape_MemoryStream_writeBE, 1);
	ILibDuktape_CreateInstanceMethodWithIntProperty(ctx, "size", 2, "writeUInt16BE", ILibDuktape_MemoryStream_writeBE, 1);
	ILibDuktape_CreateInstanceMethodWithIntProperty(ctx, "size", 1, "writeUInt8", ILibDuktape_MemoryStream_writeBE, 1);

	return(1);
}
void ILibDuktape_MemoryStream_PUSH(duk_context *ctx, void *chain)
{
	duk_push_c_function(ctx, ILibDuktape_MemoryStream_new, DUK_VARARGS);
}

void ILibDuktape_MemoryStream_Init(duk_context *ctx)
{
	ILibDuktape_ModSearch_AddHandler(ctx, "MemoryStream", ILibDuktape_MemoryStream_PUSH);
}