From ra!tut!draken!kth!mcvax!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!purdue!iuvax!bsu-cs!ibmbin Tue May 23 17:14:03 EET DST 1989 Article 292 of comp.binaries.ibm.pc: Path: chyde!ra!tut!draken!kth!mcvax!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!purdue!iuvax!bsu-cs!ibmbin >From: nelson@sun.soe.clarkson.edu (Russ Nelson) Newsgroups: comp.binaries.ibm.pc Subject: v02i098: flzh_rn.c, faster lzhuf Summary: flzh_rn.c, faster lzhuf Message-ID: <7380@bsu-cs.bsu.edu> Date: 23 May 89 08:00:19 GMT Sender: ibmbin@bsu-cs.bsu.edu Followup-To: comp.binaries.ibm.pc.d Lines: 868 Approved: dhesi@bsu-cs.bsu.edu Checksum: 2850493429 (Verify with "brik -cv") Posting-number: Volume 02, Issue 098 Submitted-by: Russ Nelson Archive-name: flzh/flzh_rn.c /* Here is another text posting. It speaks for itself. Just in case others come up with further revisions, I have named this one "flzh_rn.c" after "Faster LZHuf by Russ Nelson". Note that I have added the copyright statement as requested by Kenji Rikitake in an earlier Usenet article. There seems to be a compiler dependency here, because it won't execute correctly if compiled with Turbo C 1.0, but Russ Nelson tells me it does work with later versions of Turbo C, 1.5 or 2, but I don't remember which. -- R.D */ #ifdef USE_ASM #pragma inline #endif /* LZHUF.C (c)1989 by Haruyasu Yoshizaki, Haruhiko Okumura, and Kenji Rikitake. All rights reserved. Permission granted for non-commercial use. */ /* * LZHUF.C English version 1.0 * Based on Japanese version 29-NOV-1988 * LZSS coded by Haruhiko OKUMURA * Adaptive Huffman Coding coded by Haruyasu YOSHIZAKI * Edited and translated to English by Kenji RIKITAKE * Assembly language added by Russell Nelson (nelson@clutx.clarkson.edu) * Makes it 1.56 times faster in compression, * and 1.53 times faster in decompression. * Warning! If you change anything, verify that the register use doesn't * change. * Some C optimization added by Russell Nelson. */ #include #include #inclHTTP/1.0 200 Document Follows Date: Tue, 29 Dec 1998 02:16:37 GMT Server: WinGate Engine Content-Type: application/unknown Content-Length: 20390 ude #include /* These values are Turbo-C dependent; EXIT_SUCCESS, EXIT_FAILURE renamed by Kenji */ #define EXIT_OK 0 #define EXIT_FAILED -1 FILE *infile, *outfile; unsigned long int textsize = 0, codesize = 0, printcount = 0; void Error(char *message) { printf("\n%s\n", message); exit(EXIT_FAILED); } /* LZSS Parameters */ #define N 4096 /* Size of string buffer */ #define F 60 /* Size of look-ahead buffer */ #define THRESHOLD 2 #define NIL N /* End of tree's node */ unsigned char text_buf[N + F - 1]; int match_position, match_length, lson[N + 1], rson[N + 257], dad[N + 1]; void InitTree(void) /* Initializing tree */ { int i; for (i = N + 1; i <= N + 256; i++) rson[i] = NIL; /* root */ for (i = 0; i < N; i++) dad[i] = NIL; /* node */ } void InsertNode(int r) /* Inserting node to the tree */ { int i, p, cmp; unsigned char *key, keychar; unsigned c; cmp = 1; key = &text_buf[r]; keychar = key[1]; p = N + 1 + key[0]; rson[r] = lson[r] = NIL; match_length = 0; #ifdef USE_ASM /* for speed's sake, we use a bunch of hacks. If you change this code, be * sure to tcc -S it before you attempt to run it. If you can't figure * out what something's doing, look at the standard C version of it in the * #else clause. */ #define SF 0x1000 /* 8086 sign flag */ /* We're going to hold p in _SI. Turbo C would ordinarily put it in a * register for us, but it refuses to do so if it sees any mention of * the register, either in a 'asm' statement or the _SI pseudovariable. * When we actually use _SI, we push it first. * * Similarly for r in _DI. Note that the algorithm doesn't change r. */ _SI = p; #define p _SI _DI = r; #define r _DI _ES = _DS; /* we're going to use cmpsb */ asm cld /* many times the initial characters don't match, so we spend a fair amount * of time in the following unstructured code. */ for ( ; ; ) { if ((cmp & SF) == 0) { right: asm mov bx,si asm mov ax,rson[bx+si] if (_AX != NIL) { asm mov si,ax; asm mov al,text_buf[si+1]; asm cmp keychar,al; asm jg right; asm jl left; } else { rson[p] = r; dad[r] = p; return; } } else { left: asm mov bx,si asm mov ax,lson[bx+si] if (_AX != NIL) { asm mov si,ax; asm mov al,text_buf[si+1]; asm cmp keychar,al; asm jg right; asm jl left; } else { lson[p] = r; dad[r] = p; return; } } equal: asm push si asm push di _DI = (unsigned) &text_buf[p+1]; _SI = (unsigned) &key[1]; _CX = F - 1; /* The semantics of cmpsb are not well understood. Every comparison decrements * _CX and bumps _SI and _DI. If the values compared are equal and _CX <> 0 * then the cmpsb repeats. Otherwise the flags are set to the result of the * comparison. The consequence of this is that the only way to determine * whether the entire string was equal is to check the flags. If the two * strings are identical up to the last character, _CX will be zero * whether or not the last characters match. * * The Microsoft Macro Assembler 5.0 Reference Booklet gets it wrong, even * though Intel documents it very precisely and accurately. Boo! Hiss! * * If _CX is zero before the cmpsb, the flags are unchanged. This affects * the interpretation of zero length strings. Are they equal or different? * If you wish them to be equal, you can "or cx,cx". If you wish them to * be different you can "or sp,sp". In a subroutine, sp is guaranteed to * be nonzero. */ asm repe cmpsb /* 7% of runtime is spent here! */ /* remember the sign flag to see if it was larger or smaller */ asm lahf cmp = _AX; /* if it matched, we want _CX to be zero */ asm je matched; _CX++; matched: i = F - _CX; asm pop di; asm pop si; if (i > THRESHOLD) { if (i > match_length) { match_position = ((r - p) & (N - 1)) - 1; if ((match_length = i) >= F) break; } if (i == match_length) { if (((r - p) & (N - 1)) - 1 < match_position) { match_position = _AX; } } } } #else for ( ; ; ) { if (cmp >= 0) { if (rson[p] != NIL) p = rson[p]; else { rson[p] = r; dad[r] = p; return; } } else { if (lson[p] != NIL) p = lson[p]; else { lson[p] = r; dad[r] = p; return; } } for (i = 1; i < F; i++) if ((cmp = key[i] - text_buf[p + i]) != 0) break; if (i > THRESHOLD) { if (i > match_length) { match_position = ((r - p) & (N - 1)) - 1; if ((match_length = i) >= F) break; } if (i == match_length) { if ((c = ((r - p) & (N - 1)) - 1) < match_position) { match_position = c; } } } } #endif dad[r] = dad[p]; lson[r] = lson[p]; rson[r] = rson[p]; dad[lson[p]] = r; dad[rson[p]] = r; if (rson[dad[p]] == p) rson[dad[p]] = r; else lson[dad[p]] = r; dad[p] = NIL; /* remove p */ #undef p #undef r } void DeleteNode(int p) /* Deleting node from the tree */ { int q; if (dad[p] == NIL) return; /* unregistered */ if (rson[p] == NIL) q = lson[p]; else if (lson[p] == NIL) q = rson[p]; else { q = lson[p]; if (rson[q] != NIL) { do { q = rson[q]; } while (rson[q] != NIL); rson[dad[q]] = lson[q]; dad[lson[q]] = dad[q]; lson[q] = lson[p]; dad[lson[p]] = q; } rson[q] = rson[p]; dad[rson[p]] = q; } dad[q] = dad[p]; if (rson[dad[p]] == p) rson[dad[p]] = q; else lson[dad[p]] = q; dad[p] = NIL; } /* Huffman coding parameters */ #define N_CHAR (256 - THRESHOLD + F) /* character code (= 0..N_CHAR-1) */ #define T (N_CHAR * 2 - 1) /* Size of table */ #define R (T - 1) /* root position */ #define MAX_FREQ 0x8000 /* update when cumulative frequency */ /* reaches to this value */ typedef unsigned char uchar; /* * Tables for encoding/decoding upper 6 bits of * sliding dictionary pointer */ /* encoder table */ uchar p_len[64] = { 0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08 }; uchar p_code[64] = { 0x00, 0x20, 0x30, 0x40, 0x50, 0x58, 0x60, 0x68, 0x70, 0x78, 0x80, 0x88, 0x90, 0x94, 0x98, 0x9C, 0xA0, 0xA4, 0xA8, 0xAC, 0xB0, 0xB4, 0xB8, 0xBC, 0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC, 0xCE, 0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA, 0xDC, 0xDE, 0xE0, 0xE2, 0xE4, 0xE6, 0xE8, 0xEA, 0xEC, 0xEE, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF }; /* decoder table */ uchar d_code[256] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0C, 0x0C, 0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0D, 0x0E, 0x0E, 0x0E, 0x0E, 0x0F, 0x0F, 0x0F, 0x0F, 0x10, 0x10, 0x10, 0x10, 0x11, 0x11, 0x11, 0x11, 0x12, 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13, 0x14, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x15, 0x16, 0x16, 0x16, 0x16, 0x17, 0x17, 0x17, 0x17, 0x18, 0x18, 0x19, 0x19, 0x1A, 0x1A, 0x1B, 0x1B, 0x1C, 0x1C, 0x1D, 0x1D, 0x1E, 0x1E, 0x1F, 0x1F, 0x20, 0x20, 0x21, 0x21, 0x22, 0x22, 0x23, 0x23, 0x24, 0x24, 0x25, 0x25, 0x26, 0x26, 0x27, 0x27, 0x28, 0x28, 0x29, 0x29, 0x2A, 0x2A, 0x2B, 0x2B, 0x2C, 0x2C, 0x2D, 0x2D, 0x2E, 0x2E, 0x2F, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, }; uchar d_len[256] = { 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, }; unsigned freq[T + 1]; /* cumulative freq table */ /* * pointing parent nodes. * area [T..(T + N_CHAR - 1)] are pointers for leaves */ int prnt[T + N_CHAR]; /* pointing children nodes (son[], son[] + 1)*/ int son[T]; unsigned getbuf = 0; uchar getlen = 0; int GetBit(void) /* get one bit */ { int i; while (getlen <= 8) { if ((i = getc(infile)) < 0) i = 0; getbuf |= i << (8 - getlen); getlen += 8; } i = getbuf; getbuf <<= 1; getlen--; return (i < 0); } int GetByte(void) /* get a byte */ { unsigned i; while (getlen <= 8) { if ((i = getc(infile)) < 0) i = 0; getbuf |= i << (8 - getlen); getlen += 8; } #ifdef USE_ASM _AX = *(((unsigned char *)&getbuf)+1); _BX = getbuf; _BH = _BL; _BL = 0; asm mov getbuf,bx; getlen -= 8; return _AX; #else i = getbuf; getbuf <<= 8; getlen -= 8; return i >> 8; #endif } unsigned putbuf = 0; uchar putlen = 0; void Putcode(int l, unsigned c) /* output c bits */ { putbuf |= c >> putlen; if ((putlen += l) >= 8) { putc(putbuf >> 8, outfile); if ((putlen -= 8) >= 8) { putc(putbuf, outfile); codesize += 2; putlen -= 8; putbuf = c << (l - putlen); } else { putbuf <<= 8; codesize++; } } } /* initialize freq tree */ void StartHuff() { int i, j; for (i = 0; i < N_CHAR; i++) { freq[i] = 1; son[i] = i + T; prnt[i + T] = i; } i = 0; j = N_CHAR; while (j <= R) { freq[j] = freq[i] + freq[i + 1]; son[j] = i; prnt[i] = prnt[i + 1] = j; i += 2; j++; } freq[T] = 0xffff; prnt[R] = 0; } /* reconstruct freq tree */ void reconst() { int i, j, k; unsigned f, l; /* halven cumulative freq for leaf nodes */ j = 0; for (i = 0; i < T; i++) { if (son[i] >= T) { freq[j] = (freq[i] + 1) / 2; son[j] = son[i]; j++; } } /* make a tree : first, connect children nodes */ for (i = 0, j = N_CHAR; j < T; i += 2, j++) { k = i + 1; f = freq[j] = freq[i] + freq[k]; for (k = j - 1; f < freq[k]; k--); k++; l = (j - k) * 2; (void)memmove(&freq[k + 1], &freq[k], l); freq[k] = f; (void)memmove(&son[k + 1], &son[k], l); son[k] = i; } /* connect parent nodes */ for (i = 0; i < T; i++) { if ((k = son[i]) >= T) { prnt[k] = i; } else { prnt[k] = prnt[k + 1] = i; } } } /* update freq tree */ void update(int c) { register int k, l; int i, j; if (freq[R] == MAX_FREQ) { reconst(); } #ifdef USE_ASM #define k _DX /* _DX is safe to use. */ _SI = prnt[c + T]; #define c _SI do { more_k: k = ++freq[c]; asm cmp dx,word ptr DGROUP:_freq+2[bx]; asm ja start; asm mov si,word ptr DGROUP:_prnt[bx]; asm or si,si; asm jne more_k; break; start: _BX = (unsigned)&freq[c+1]; again: asm cmp dx,[bx] asm jbe done _BX += 4; asm cmp dx,[bx-2] asm ja again _BX -= 2; done: _BX -= (unsigned) &freq; l = _BX >> 1; #else c = prnt[c + T]; do { /* keep the outer loop together so stupid compilers * can optimize. */ do { k = ++freq[c]; /* swap nodes to keep the tree freq-ordered */ if (k > freq[c + 1]) goto start; } while ((c = prnt[c]) != 0); break; start: l = c + 1; /* this is the inner loop -- unroll it a few times */ while (k > freq[++l] && k > freq[++l] && k > freq[++l]); #endif l--; freq[c] = freq[l]; freq[l] = k; i = son[c]; prnt[i] = l; if (i < T) prnt[i + 1] = l; j = son[l]; son[l] = i; prnt[j] = c; if (j < T) prnt[j + 1] = c; son[c] = j; c = l; } while ((c = prnt[c]) != 0); /* do it until reaching the root */ #undef k #undef c } unsigned code, len; void EncodeChar(unsigned c) { unsigned i; int j, k; i = 0; j = 0; k = prnt[c + T]; /* search connections from leaf node to the root */ do { i >>= 1; /* if node's address is odd, output 1 else output 0 */ if (k & 1) i += 0x8000; j++; } while ((k = prnt[k]) != R); Putcode(j, i); code = i; len = j; update(c); } void EncodePosition(unsigned c) { unsigned i; /* output upper 6 bits with encoding */ i = c >> 6; Putcode(p_len[i], (unsigned)p_code[i] << 8); /* output lower 6 bits directly */ Putcode(6, (c & 0x3f) << 10); } void EncodeEnd() { if (putlen) { putc(putbuf >> 8, outfile); codesize++; } } int DecodeChar() { unsigned c; c = son[R]; /* * start searching tree from the root to leaves. * choose node #(son[]) if input bit == 0 * else choose #(son[]+1) (input bit == 1) */ while (c < T) { if(getlen){ getlen--; #ifdef USE_ASM getbuf<<=1; asm jnc zerobit; c++; zerobit:; #else if (getbuf < 0) c++; getbuf<<=1; #endif } else c += GetBit(); c = son[c]; } c -= T; update(c); return c; } int DecodePosition() { unsigned i, j, c; /* decode upper 6 bits from given table */ i = GetByte(); c = (unsigned)d_code[i] << 6; j = d_len[i]; /* input lower 6 bits directly */ j -= 2; while (j--) { i <<= 1; if(getlen){ getlen--; #ifdef USE_ASM getbuf<<=1; asm jnc zerobit; i++; zerobit:; #else if (getbuf < 0) i++; getbuf<<=1; #endif } else i += GetBit(); } return c | i & 0x3f; } /* Compression */ void Encode(void) /* Encoding/Compressing */ { int i, c, len, r, s, last_match_length; fseek(infile, 0L, 2); textsize = ftell(infile); if (fwrite(&textsize, sizeof textsize, 1, outfile) < 1) Error("Unable to write"); /* write size of original text */ if (textsize == 0) return; rewind(infile); textsize = 0; /* rewind and rescan */ StartHuff(); InitTree(); s = 0; r = N - F; for (i = s; i < r; i++) text_buf[i] = ' '; for (len = 0; len < F && (c = getc(infile)) != EOF; len++) text_buf[r + len] = c; textsize = len; for (i = 1; i <= F; i++) InsertNode(r - i); InsertNode(r); do { if (match_length > len) match_length = len; if (match_length <= THRESHOLD) { match_length = 1; EncodeChar(text_buf[r]); } else { EncodeChar(255 - THRESHOLD + match_length); EncodePosition(match_position); } last_match_length = match_length; for (i = 0; i < last_match_length && (c = getc(infile)) != EOF; i++) { DeleteNode(s); text_buf[s] = c; if (s < F - 1) text_buf[s + N] = c; s = (s + 1) & (N - 1); r = (r + 1) & (N - 1); InsertNode(r); } if ((textsize += i) > printcount) { printf("%12ld\r", textsize); printcount += 1024; } while (i++ < last_match_length) { DeleteNode(s); s = (s + 1) & (N - 1); r = (r + 1) & (N - 1); if (--len) InsertNode(r); } } while (len > 0); EncodeEnd(); printf("input: %ld bytes\n", textsize); printf("output: %ld bytes\n", codesize); printf("output/input: %.3f\n", (double)codesize / textsize); } void Decode(void) /* Decoding/Uncompressing */ { int i, j, k, r, c; unsigned long int count; if (fread(&textsize, sizeof textsize, 1, infile) < 1) Error("Unable to read"); /* read size of original text */ if (textsize == 0) return; StartHuff(); for (i = 0; i < N - F; i++) text_buf[i] = ' '; r = N - F; for (count = 0; count < textsize; ) { c = DecodeChar(); if (c < 256) { putc(c, outfile); text_buf[r++] = c; r &= (N - 1); count++; } else { i = (r - DecodePosition() - 1) & (N - 1); j = c - 255 + THRESHOLD; if (r + j < N && i + j < N && (i + j <= r || i >= r) #ifdef __TURBOC__ && outfile->level < -j){ memcpy(outfile->curp, memmove(&text_buf[r],&text_buf[i], j), j); outfile->curp += j; outfile->level += j; #else ){ fwrite(memcpy(&text_buf[r],&text_buf[i], j), 1, j, outfile); #endif r += j; count += j; } else for (k = i, j += i; k < j; k++) { c = text_buf[k & (N - 1)]; putc(c, outfile); text_buf[r++] = c; r &= (N - 1); count++; } } if (count > printcount) { printf("%12ld\r", count); printcount += 4096; } } printf("%12ld\n", count); } int main(int argc, char *argv[]) { char *s; if (argc != 4) { printf("Usage:lzhuf e(compression)|d(uncompression)" " infile outfile\n"); return EXIT_FAILED; } if ((s = argv[1], s[1] || strpbrk(s, "DEde") == NULL) || (s = argv[2], (infile = fopen(s, "rb")) == NULL) || (s = argv[3], (outfile = fopen(s, "wb")) == NULL)) { printf("Trouble with arg %s\n", s); return EXIT_FAILED; } setvbuf(outfile, NULL, _IOFBF, 1<<12); setvbuf(infile, NULL, _IOFBF, 1<<12); if (toupper(*argv[1]) == 'E') Encode(); else Decode(); fclose(infile); fclose(outfile); return EXIT_OK; }