flate

commit e2c36cb2b784ab7ded4dcd79925bb2291058108a
parent 8fba42f347be7bb505324c2d57847807a7ba26a3
Author: nsz <nszabolcs@gmail.com>
Date:   Tue,  9 Jun 2009 11:41:36 +0200

cleanup
Diffstat:
inflate.c
 | 
45
+++++++++++++++++++--------------------------

1 file changed, 19 insertions(+), 26 deletions(-)
diff --git a/inflate.c b/inflate.c
@@ -37,6 +37,7 @@ enum {
 	DynamicHuff,
 	DynamicHuffClen,
 	DynamicHuffLitlenDist,
+	DynamicHuffContinue,
 	DecodeBlock,
 	DecodeBlockLenBits,
 	DecodeBlockDist,
@@ -423,7 +424,7 @@ decode_distbits:
 						pos++;
 					}
 				}
-			} else {
+			} else { /* rare */
 decode_copy:
 				while (len--) {
 					win[pos] = win[(pos - dist) & WinMask];
@@ -472,12 +473,14 @@ int inflate(State *s) {
 		case BlockHead:
 			if (s->final) {
 				if (s->pos)
-					goto hasoutput;
-				else
-					goto finish;
+					return FlateHasOutput;
+				else {
+					free(s->win);
+					return FlateOk;
+				}
 			}
 			if (!fillbits(s, 3))
-				goto needinput;
+				return FlateNeedInput;
 			s->final = getbits(s, 1);
 			n = getbits(s, 2);
 			if (n == 0)
@@ -494,7 +497,7 @@ int inflate(State *s) {
 			s->bits >>= s->nbits & 7;
 			s->nbits &= ~7;
 			if (!fillbits(s, 32))
-				goto needinput;
+				return FlateNeedInput;
 			s->lenpos = getbits(s, 16);
 			n = getbits(s, 16);
 			if (s->lenpos != (~n & 0xffff))
@@ -505,11 +508,11 @@ int inflate(State *s) {
 			/* s->nbits should be 0 here */
 			while (s->lenpos) {
 				if (s->src == s->srcend)
-					goto needinput;
+					return FlateNeedInput;
 				s->lenpos--;
 				s->win[s->pos++] = *s->src++;
 				if (s->pos == WinSize)
-					goto hasoutput;
+					return FlateHasOutput;
 			}
 			s->state = BlockHead;
 			break;
@@ -522,7 +525,7 @@ int inflate(State *s) {
 		case DynamicHuff:
 			/* decode dynamic huffman code trees */
 			if (!fillbits(s, 14))
-				goto needinput;
+				return FlateNeedInput;
 			s->nlit = 257 + getbits(s, 5);
 			s->ndist = 1 + getbits(s, 5);
 			s->nclen = 4 + getbits(s, 4);
@@ -540,17 +543,14 @@ int inflate(State *s) {
 					s->lens[clenorder[n]] = getbits(s, 3);
 				} else {
 					s->lenpos = n;
-					goto needinput;
+					return FlateNeedInput;
 				}
 			/* using lhuff for code length huff code */
 			if (build_huff(&s->lhuff, s->lens, Nclen, ClenTableBits) < 0)
 				goto error;
 			s->state = DynamicHuffLitlenDist;
 			s->lenpos = 0;
-			s->nclen = -1; /* decoded symbol is stored in clen or -1 */
 		case DynamicHuffLitlenDist:
-			if (s->nclen >= 0)
-				goto dynhuff_continue;
 			/* decode code lengths for the dynamic trees */
 			for (n = s->lenpos; n < s->nlit + s->ndist; ) {
 				uint sym = decode_symbol(s, &s->lhuff);
@@ -561,10 +561,9 @@ int inflate(State *s) {
 					s->lens[n++] = sym;
 					continue;
 				} else if (sym == (uint)FlateNeedInput) {
-					s->nclen = -1;
 					s->lenpos = n;
-					goto needinput;
-dynhuff_continue:
+					return FlateNeedInput;
+		case DynamicHuffContinue:
 					n = s->lenpos;
 					sym = s->nclen;
 				}
@@ -574,7 +573,8 @@ dynhuff_continue:
 						goto error;
 					s->nclen = sym;
 					s->lenpos = n;
-					goto needinput;
+					s->state = DynamicHuffContinue;
+					return FlateNeedInput;
 				}
 				if (sym == 16) {
 					/* copy previous code length 3-6 times */
@@ -608,9 +608,9 @@ dynhuff_continue:
 			else
 				n = decode_block(s, &s->lhuff, &s->dhuff);
 			if (n == FlateNeedInput)
-				goto needinput;
+				return FlateNeedInput;
 			if (n == FlateHasOutput)
-				goto hasoutput;
+				return FlateHasOutput;
 			if (n == FlateError)
 				goto error;
 			s->state = BlockHead;
@@ -619,16 +619,9 @@ dynhuff_continue:
 			goto error;
 		}
 	}
-needinput:
-	return FlateNeedInput;
-hasoutput:
-	return FlateHasOutput;
 error:
 	free(s->win);
 	return FlateError;
-finish:
-	free(s->win);
-	return FlateOk;
 }
 
 int inflate_callback(int (*r)(void *, int, void *), void *rdata, int (*w)(void *, int, void *), void *wdata) {