From 906eb92f5a59995a5b5a977ee2667b9a47b3ddec Mon Sep 17 00:00:00 2001
From: DTB <trinity@trinity.moe>
Date: Thu, 4 Jul 2024 20:27:31 -0600
Subject: [PATCH] dj(1): (broken) move hard skipping to the main loop

---
 src/dj.c | 31 ++++++++++++++-----------------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/src/dj.c b/src/dj.c
index aee9c38..7b3bb0a 100644
--- a/src/dj.c
+++ b/src/dj.c
@@ -72,7 +72,8 @@ Io_read(struct Io *io){
 
 	assert(io->bs > 0);
 
-	io->bytes += (io->bufuse = read(io->fd, io->buf, io->bs));
+	io->bytes += (io->bufuse = read(io->fd, &(io->buf)[io->bufuse],
+		io->bs - io->bufuse));
 
 	assert(io->bufuse <= io->bs);
 
@@ -233,19 +234,6 @@ int main(int argc, char *argv[]){
 			io[i].seek = 0;
 	}
 
-	/* hard skipping */
-	if(io[0].seek > 0){
-		do{
-			if((io[0].bufuse = read(
-						io[0].fd, io[0].buf, MIN(io[0].bs, io[0].seek)))
-					== 0)
-				/* second chance */
-				io->bufuse = read(
-					io[0].fd, io[0].buf, MIN(io[0].bs, io[0].seek));
-		}while((io[0].seek -= io[0].bufuse) > 0 && io[0].bufuse != 0);
-		io[0].bufuse = 0;
-	}
-
 	/* hard seeking */
 	if(io[1].seek > 0){
 		memset(io[1].buf, '\0', io[1].bs);
@@ -265,9 +253,8 @@ int main(int argc, char *argv[]){
 
 	/* Sought bytes aren't counted in the statistics because successful seeking
 	 * is guaranteed here. */
-	for(i = 0; i < 2; ++i)
-		if(io[i].seek > 0)
-			return oserr(io[i].fn);
+	if(io[1].seek > 0)
+		return oserr(io[1].fn);
 
 	do{
 		assert(io[0].bufuse == 0);
@@ -279,6 +266,9 @@ int main(int argc, char *argv[]){
 			if(io[0].seek > 0)
 				skipping = 1;
 
+			if(skipping && io[0].seek < io[0].bs)
+				io[0].bufuse = io[0].bs - io[0].seek;
+
 			t = io[0].bufuse;
 			if(Io_read(&io[0])->bufuse == t && !noerror)
 				Io_read(&io[0]); /* second chance */
@@ -297,6 +287,13 @@ int main(int argc, char *argv[]){
 					io->bufuse = io->bs;
 				}
 			}
+
+			if(skipping){
+				skipping = (io[0].seek -= io[0].bufuse - t) > 0;
+				io[0].bufuse = 0;
+				count += (count != 0);
+				continue;
+			}
 		}
 
 		/* write */