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-rw-r--r--packet_reader/packet_reader.ha52
1 files changed, 52 insertions, 0 deletions
diff --git a/packet_reader/packet_reader.ha b/packet_reader/packet_reader.ha
new file mode 100644
index 0000000..43b85d1
--- /dev/null
+++ b/packet_reader/packet_reader.ha
@@ -0,0 +1,52 @@
+use io;
+use fmt;
+
+export type packet = []u8;
+def PCKSZ: size = 8;
+
+export type packet_reader = struct {
+ buf: [256]u8,
+ good: []u8,
+};
+
+export fn new() packet_reader = {
+ let pr = packet_reader {
+ buf = [0...],
+ ...
+ };
+ pr.good = pr.buf[0..0];
+ return pr;
+
+};
+
+// call when input is ready. could block otherwise
+export fn read(pr: *packet_reader, sock: io::handle) (void | io::error | io::EOF) = {
+ const remaining_amt = len(pr.good);
+ const read_pos = if (remaining_amt > 0) {
+ // still some unconsumed content in the buffer
+ // move unconsumed stuff to start of buffer
+ fmt::printfln("moving {} remaining bytes",remaining_amt)!;
+ pr.buf[0..remaining_amt] = pr.good;
+ yield remaining_amt;
+ } else 0z;
+ const nread = match(io::read(sock, pr.buf[read_pos..])?) {
+ case io::EOF => return io::EOF;
+ case let n: size => yield n;
+ };
+ fmt::printfln("read {} bytes",nread)!;
+ const total_amt = read_pos + nread;
+ pr.good = pr.buf[0..total_amt];
+ fmt::printfln("now {} bytes in buffer",total_amt)!;
+};
+
+
+export fn next(pr: *packet_reader) (packet | done) = {
+ // either parse a full packet out of the front of good,
+ // move good along that many bytes,
+ // and return the packet,
+ // or, ascertain there is no full packet, and return done
+ if (len(pr.good) < PCKSZ) return done;
+ const packet_bytes = pr.good[..PCKSZ];
+ pr.good = pr.good[PCKSZ..];
+ return packet_bytes;
+};