1 files changed, 65 insertions, 0 deletions
diff --git a/packet_reader/rle.ha b/packet_reader/rle.ha
new file mode 100644
index 0000000..af9f080
--- /dev/null
+++ b/packet_reader/rle.ha
@@ -0,0 +1,65 @@
+
+use fmt;
+
+fn item_encode(count: int, val: u32) u32 =
+	((count-1)<<24):u32 | (val&0xffffff);
+fn item_decode(c: u32) (int, u32) =
+	((((c&0xff000000)>>24)+1):int,   c&0xffffff);
+
+// caller freeeee
+export fn rle_encode(d: []u32) []u32 = {
+	let out: []u32 = [];
+	let start = 0z;
+	for (start < len(d)) {
+		let this = d[start];
+		let ix = start + 1;
+		for (ix < len(d) && d[ix] == this) ix += 1;
+		const val = this;
+		let count = (ix - start): int;
+		fmt::printfln("#{:_06x} x{}",val, count)!;
+		for (count > 0) {
+			append(out, item_encode(count%256, val));
+			count -= 256;
+		};
+		start = ix;
+	};
+	return out;
+};
+
+// ooooo    caller freeeeeee meee
+export fn rle_decode(d: []u32) []u32 = {
+	let out: []u32 = [];
+	for (const k .. d) {
+		const (count, val) = item_decode(k);
+		append(out, [val...], count: size);
+	};
+	return out;
+};
+
+fn dotest(eu: []u32) void = {
+	const ee = rle_encode(eu);
+	defer free(ee);
+	// for (const k .. ee) {
+	// 	const (count, val) = item_decode(k);
+	// 	fmt::printfln("0x{:_08x} | #{:_06x} x{}", k, val, count)!;
+	// };
+
+	const dd = rle_decode(ee);
+	defer free(dd);
+
+	assert(len(eu) == len(dd), "length mismatch??");
+	let good = true;
+	for (let i = 0z; i < len(eu); i += 1) {
+		assert(eu[i] == dd[i], "value wrong");
+		// fmt::printfln("{} vs {}",eu[i], dd[i])!;
+		// if (eu[i] != dd[i]) { good=false; fmt::println("uh oh")!; };
+	};
+	// if (good) fmt::printfln("good yay")!;
+
+};
+
+@test fn euou() void = dotest([1,1,1,1,1,2,2,2,3,3,3,3,3,4,4,5,5,5,666,69,9,9]);
+@test fn oeuoeu2() void = dotest([1,2,3,4,5]);
+@test fn oeuoeu2() void = dotest([1,1,1]);
+@test fn oeuoeu2() void = dotest([1,6]);
+@test fn oeuoeu2() void = dotest([1]);