X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=epclust%2FR%2Fde_serialize.R;fp=epclust%2FR%2Fde_serialize.R;h=682db53c18a2c129af70431b5d9dc85b0c192331;hb=56857861dc15088cf58e7438968fe5714b22168e;hp=0000000000000000000000000000000000000000;hpb=62deb4244895a20a35397dfb062f0b9fe94c5012;p=epclust.git

diff --git a/epclust/R/de_serialize.R b/epclust/R/de_serialize.R
new file mode 100644
index 0000000..682db53
--- /dev/null
+++ b/epclust/R/de_serialize.R
@@ -0,0 +1,73 @@
+#data: matrix of double or connection
+serialize = function(data_ascii, data_bin_file, nb_per_chunk,
+	sep=",", nbytes=4, endian=.Platform$endian)
+{
+	if (is.character(data_ascii))
+		data_ascii = file(data_ascii, open="r")
+	else if (is(data_ascii,"connection") && !isOpen(data_ascii))
+		open(data_ascii)
+
+	first_write = (!file.exists(data_bin_file) || file.info(data_bin_file)$size == 0)
+	data_bin = file(data_bin_file, open=ifelse(first_write,"wb","ab"))
+
+	#write data length on first call
+	if (first_write)
+	{
+		#number of items always on 8 bytes
+		writeBin(0L, data_bin, size=8) #,endian="little")
+		if (is.matrix(data_ascii))
+			data_length = ncol(data_ascii)
+		else #if (is(data, "connection"))
+		{
+			data_line = scan(data_ascii, double(), sep=sep, nlines=1, quiet=TRUE)
+			writeBin(data_line, data_bin, size=nbytes)
+			data_length = length(data_line)
+		}
+	}
+
+	if (is.matrix(data_ascii))
+		index = 1
+	repeat
+	{
+		if (is.matrix(data_ascii))
+		{
+			range = index:min(nrow(data_ascii),index+nb_per_chunk)
+			data_chunk =
+				if (range[1] <= nrow(data_ascii))
+					as.double(t(data_ascii[range,]))
+				else
+					integer(0)
+			index = index + nb_per_chunk
+		}
+		else
+			data_chunk = scan(data_ascii, double(), sep=sep, nlines=nb_per_chunk, quiet=TRUE)
+		if (length(data_chunk)==0)
+			break
+		writeBin(data_chunk, data_bin, size=nbytes)
+	}
+
+	if (first_write)
+	{
+		#ecrire file_size-1 / (nbytes*nbWritten) en 0 dans bin_data ! ignored == file_size
+		ignored = seek(data_bin, 0)
+		writeBin(data_length, data_bin, size=8)
+	}
+	close(data_bin)
+
+	if (is(data_ascii,"connection"))
+		close(data_ascii)
+}
+
+#read in binary file, always same structure
+getDataInFile = function(indices, data_bin_file, nbytes=4, endian=.Platform$endian)
+{
+	data_bin = file(data_bin_file, "rb")
+	data_length = readBin(data_bin, "integer", 1, 8, endian)
+	#Ou t(sapply(...)) (+ rapide ?)
+	data_ascii = do.call( rbind, lapply( indices, function(i) {
+		ignored = seek(data_bin, 8+((i-1)*data_length*nbytes))
+		readBin(data_bin, "double", n=data_length, size=nbytes)
+	} ) )
+	close(data_bin)
+	data_ascii
+}