duskos

commit 9d269a11bbd53ee10ada1dacb993fed989fa5922
parent 7a619571ed1a12ec43fa28372a67b561febada36
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Wed, 30 Nov 2022 18:33:50 -0500

ar/puff: stream input from StdIn

Diffstat:
M
fs/ar/puff.c
 | 
38
++++++++++++++++----------------------
M
fs/ar/ungz.fs
 | 
13
+++----------

2 files changed, 19 insertions(+), 32 deletions(-)
diff --git a/fs/ar/puff.c b/fs/ar/puff.c
@@ -54,9 +54,6 @@ struct state {
 	unsigned char out[OUTBUFLEN];	/* output buffer */
 	unsigned int outptr;        /* current position in output buffer */
 	unsigned int outcnt;		/* total bytes written to out so far */
-	unsigned char *in;			/* input buffer */
-	unsigned int inlen;			/* available input at in */
-	unsigned int incnt;			/* bytes read so far */
 	int bitbuf;					/* bit buffer */
 	int bitcnt;					/* number of bits in bit buffer */
 };
@@ -74,6 +71,16 @@ static void spit(unsigned char c) {
 	}
 }
 
+static unsigned char getc() {
+	int c;
+	c = stdin();
+	if (c < 0) {
+		fputs("out of input\n", ConsoleOut());
+		abort();
+	}
+	return c;
+}
+
 /*
  * Return need bits from the input stream.	This always leaves less than
  * eight bits in the buffer.  bits() works properly for need == 0.
@@ -92,11 +99,7 @@ static int bits(int need)
 	/* load at least need bits into val */
 	val = s.bitbuf;
 	while (s.bitcnt < need) {
-		if (s.incnt == s.inlen) {
-			fputs("out of input\n", ConsoleOut());
-			abort();
-		}
-		val |= (s.in[s.incnt++]) << s.bitcnt; /* load eight bits */
+		val |= getc() << s.bitcnt; /* load eight bits */
 		s.bitcnt += 8;
 	}
 
@@ -134,19 +137,13 @@ static int stored()
 	s.bitcnt = 0;
 
 	/* get length and check against its one's complement */
-	if (s.incnt + 4 > s.inlen)
-		return 2;								/* not enough input */
-	len = s.in[s.incnt++];
-	len |= s.in[s.incnt++] << 8;
-	if (s.in[s.incnt++] != (~len & $ff) ||
-		s.in[s.incnt++] != ((~len >> 8) & $ff))
+	len = getc();
+	len |= getc() << 8;
+	if (getc() != (~len & $ff) || getc() != ((~len >> 8) & $ff))
 		return -2;								/* didn't match complement! */
 
 	/* copy len bytes from in to out */
-	if (s.incnt + len > s.inlen)
-		return 2;								/* not enough input */
-	while (len--)
-		spit(s.in[s.incnt++]);
+	while (len--) spit(getc());
 
 	/* done with a valid stored block */
 	return 0;
@@ -673,7 +670,7 @@ static int dynamic()
  *	 block (if it was a fixed or dynamic block) are undefined and have no
  *	 expected values to check.
  */
-int puff(unsigned char *source, unsigned int sourcelen)
+int puff()
 {
 	int last, type;				/* block information */
 	int err;					/* return value */
@@ -681,9 +678,6 @@ int puff(unsigned char *source, unsigned int sourcelen)
 
 	s.outptr = 0;
 	s.outcnt = 0;
-	s.in = source;
-	s.inlen = sourcelen;
-	s.incnt = 0;
 	s.bitbuf = 0;
 	s.bitcnt = 0;
 
diff --git a/fs/ar/ungz.fs b/fs/ar/ungz.fs
@@ -7,25 +7,18 @@ cc<< /ar/puff.c
 
 : _skiptonull begin stdin not until ;
 
-\ Make it work, then make it work well. puff.c as ported is memory oriented.
-\ Creating huge buffers for gzip is ugly, but I just want to make it work.
-\ Streaming is coming soon...
-$1000 const INBUFSZ
-create _inbuf INBUFSZ allot
-
 \ Take a gzip file from stdin and spit the deflated version on stdout
 : ungz ( -- err )
   stdin $1f = _assert stdin $8b = _assert \ ID1+ID2
   stdin 8 = _assert \ CM
   stdin >r \ V1=FLG
-  _inbuf 6 StdIn IO :read \ useless stuff
+  here 6 StdIn IO :read \ useless stuff
   V1 $04 and if \ FLG.EXTRA
     stdin stdin 8 lshift or ( xlen )
-    _inbuf swap StdIn IO :read \ read extra
+    here swap StdIn IO :read \ read extra
   then
   V1 $08 and if \ FLG.NAME
     _skiptonull then
   r> $10 and if \ FLG.COMMENT
     _skiptonull then
-  _inbuf StdIn IO :readall
-  _inbuf INBUFSZ puff ;
+  puff ;