Overload of getTiger() that accepts a buffer, so

there is no need to reallocate a new buffer at every call.

src/sums.d

@@ -25,6 +25,8 @@ import std.exception;
 import std.format;
 import std.array : appender;
 
+mixin(import("tigersumConfig.d"));
+
 private void writeError (string parFile, string parMessage) {
 	stderr.writefln("tigersum: %s: %s", parFile, parMessage);
 }
@@ -34,6 +36,8 @@ private void writeWarning (string parMessage) {
 }
 
 void calculateSums (in string[] parFiles, in string parCWD, bool parTiger2, string parFileMode, bool parBsdStyle) {
+	ulong[] read_buff = new ulong[READ_BUFF_BLOCKS * 64 / ulong.sizeof];
+
 	foreach (file_name; parFiles) {
 		const auto curr_path = parCWD ~ file_name;
 		File curr_file;
@@ -46,7 +50,7 @@ void calculateSums (in string[] parFiles, in string parCWD, bool parTiger2, stri
 		}
 
 		if (!isDir(curr_path)) {
-			const string hash = tigerToString(getTiger(curr_file, parTiger2));
+			const string hash = tigerToString(getTiger(curr_file, parTiger2, cast(char[])read_buff));
 			if (parBsdStyle) {
 				writefln("tiger (%s) = %s", file_name, hash);
 			}

src/tiger.d

@@ -49,6 +49,35 @@ public ulong[3] getTiger (in string parData, bool parV2) {
 	return retval;
 }
 
+public ulong[3] getTiger (ref File parData, bool parV2, char[] parBuffer) {
+	assert(parBuffer.length == 64 * READ_BUFF_BLOCKS);
+	assert((cast(size_t)parBuffer.ptr & cast(size_t)(ulong.alignof - 1)) == 0);
+
+	ulong[3] retval;
+	auto data_left = parData.size;
+	const auto buff_length = 64 * READ_BUFF_BLOCKS;
+
+	tiger_init(retval);
+	while (data_left >= buff_length) {
+		parData.rawRead(parBuffer);
+		tiger_chunk(parBuffer.ptr, buff_length, retval);
+		data_left -= buff_length;
+	}
+
+	const char padding = (parV2 ? 0x80 : 0x01);
+	if (data_left) {
+		parData.rawRead(parBuffer[0 .. data_left]);
+		const ulong proc_length = data_left & ~0x3fUL;
+		tiger_chunk(parBuffer.ptr, proc_length, retval);
+		tiger_last_chunk(parBuffer.ptr + proc_length, data_left - proc_length, parData.size, retval, padding);
+	}
+	else {
+		tiger_last_chunk(null, 0, parData.size, retval, padding);
+	}
+
+	return retval;
+}
+
 public ulong[3] getTiger (ref File parData, bool parV2) {
 	const auto buff_length = 64 * READ_BUFF_BLOCKS;
 	char[] unaligned = new char[buff_length + ulong.alignof - 1];
@@ -59,27 +88,7 @@ public ulong[3] getTiger (ref File parData, bool parV2) {
 	char[] aligned = unaligned[offset .. buff_length];
 	assert(aligned.length == buff_length);
 
-	ulong[3] retval;
+	return getTiger(parData, parV2, aligned);
-	auto data_left = parData.size;
-	tiger_init(retval);
-	while (data_left >= buff_length) {
-		parData.rawRead(aligned);
-		tiger_chunk(aligned.ptr, buff_length, retval);
-		data_left -= buff_length;
-	}
-
-	const char padding = (parV2 ? 0x80 : 0x01);
-	if (data_left) {
-		parData.rawRead(aligned[0 .. data_left]);
-		const ulong proc_length = data_left & ~0x3fUL;
-		tiger_chunk(aligned.ptr, proc_length, retval);
-		tiger_last_chunk(aligned.ptr + proc_length, data_left - proc_length, parData.size, retval, padding);
-	}
-	else {
-		tiger_last_chunk(null, 0, parData.size, retval, padding);
-	}
-
-	return retval;
 }
 
 public string tigerToString (in ulong[3] parTiger) {