示例#1
0
文件: rmq.go 项目: glycerine/rmq
//export ReadMsgpackFrame
//
// ReadMsgpackFrame reads the msgpack frame at byteOffset in rawStream, decodes the
// 2-5 bytes of a msgpack binary array (either bin8, bin16, or bin32), and returns
// and the decoded-into-R object and the next byteOffset to use.
//
func ReadMsgpackFrame(rawStream C.SEXP, byteOffset C.SEXP) C.SEXP {

	var start int
	if C.TYPEOF(byteOffset) == C.REALSXP {
		start = int(C.get_real_elt(byteOffset, 0))
	} else if C.TYPEOF(byteOffset) == C.INTSXP {
		start = int(C.get_int_elt(byteOffset, 0))
	} else {
		C.ReportErrorToR_NoReturn(C.CString("read.msgpack.frame(x, byteOffset) requires byteOffset to be a numeric byte-offset number."))
	}

	// rawStream must be a RAWSXP
	if C.TYPEOF(rawStream) != C.RAWSXP {
		C.ReportErrorToR_NoReturn(C.CString("read.msgpack.frame(x, byteOffset) requires x be a RAW vector of bytes."))
	}

	n := int(C.Rf_xlength(rawStream))
	if n == 0 {
		return C.R_NilValue
	}

	if start >= n {
		C.ReportErrorToR_NoReturn(C.CString(fmt.Sprintf("read.msgpack.frame(x, byteOffset) error: byteOffset(%d) is beyond the length of x (x has len %d).", start, n)))
	}

	var decoder [5]byte
	C.memcpy(unsafe.Pointer(&decoder[0]), unsafe.Pointer(C.get_raw_elt_ptr(rawStream, C.ulonglong(start))), C.size_t(5))
	headerSz, _, totalSz, err := DecodeMsgpackBinArrayHeader(decoder[:])
	if err != nil {
		C.ReportErrorToR_NoReturn(C.CString(fmt.Sprintf("ReadMsgpackFrame error trying to decode msgpack frame: %s", err)))
	}

	if start+totalSz > n {
		C.ReportErrorToR_NoReturn(C.CString(fmt.Sprintf("read.msgpack.frame(x, byteOffset) error: byteOffset(%d) plus the frames size(%d) goes beyond the length of x (x has len %d).", start, totalSz, n)))
	}

	bytes := make([]byte, totalSz)
	C.memcpy(unsafe.Pointer(&bytes[0]), unsafe.Pointer(C.get_raw_elt_ptr(rawStream, C.ulonglong(start))), C.size_t(totalSz))

	rObject := decodeMsgpackToR(bytes[headerSz:])
	C.Rf_protect(rObject)
	returnList := C.allocVector(C.VECSXP, C.R_xlen_t(2))
	C.Rf_protect(returnList)
	C.SET_VECTOR_ELT(returnList, C.R_xlen_t(0), C.Rf_ScalarReal(C.double(float64(start+totalSz))))
	C.SET_VECTOR_ELT(returnList, C.R_xlen_t(1), rObject)
	C.Rf_unprotect_ptr(rObject)
	C.Rf_unprotect_ptr(returnList)
	return returnList
}
示例#2
0
文件: rmq.go 项目: glycerine/rmq
//export ReadNewlineDelimJson
//
// ReadNewlineDelimJson reads a json object at byteOffset in rawStream, expects
// it to be newline terminated, and returns the
// decoded-into-R object and the next byteOffset to use (the byte just after
// the terminating newline).
//
func ReadNewlineDelimJson(rawStream C.SEXP, byteOffset C.SEXP) C.SEXP {
	C.Rf_protect(rawStream)

	var start int
	if C.TYPEOF(byteOffset) == C.REALSXP {
		start = int(C.get_real_elt(byteOffset, 0))
	} else if C.TYPEOF(byteOffset) == C.INTSXP {
		start = int(C.get_int_elt(byteOffset, 0))
	} else {
		C.ReportErrorToR_NoReturn(C.CString("read.ndjson(x, byteOffset) requires byteOffset to be a numeric byte-offset number."))
	}
	// rawStream must be a RAWSXP
	if C.TYPEOF(rawStream) != C.RAWSXP {
		C.ReportErrorToR_NoReturn(C.CString("read.ndjson(x, byteOffset) requires x be a RAW vector of bytes."))
	}

	n := int(C.Rf_xlength(rawStream))
	if n == 0 {
		return C.R_NilValue
	}

	if start >= n {
		C.ReportErrorToR_NoReturn(C.CString(fmt.Sprintf("read.ndjson(x, byteOffset) error: byteOffset(%d) is at or beyond the length of x (x has len %d).", start, n)))
	}
	// INVAR: start < n

	// find the next newline or end of raw array
	next := int(C.next_newline_pos(rawStream, C.ulonglong(start+1), C.ulonglong(n)))
	totalSz := next - start

	bytes := make([]byte, totalSz)
	fromPtr := unsafe.Pointer(C.get_raw_elt_ptr(rawStream, C.ulonglong(start)))
	C.memcpy(unsafe.Pointer(&bytes[0]), fromPtr, C.size_t(totalSz))
	rObject := decodeJsonToR(bytes)
	C.Rf_protect(rObject)
	returnList := C.allocVector(C.VECSXP, C.R_xlen_t(2))
	C.Rf_protect(returnList)
	C.SET_VECTOR_ELT(returnList, C.R_xlen_t(0), C.Rf_ScalarReal(C.double(float64(start+totalSz))))
	C.SET_VECTOR_ELT(returnList, C.R_xlen_t(1), rObject)
	C.Rf_unprotect_ptr(rObject)
	C.Rf_unprotect_ptr(returnList)
	C.Rf_unprotect_ptr(rawStream)
	return returnList
}