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-rw-r--r--src/fontfile/decompress.c408
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diff --git a/src/fontfile/decompress.c b/src/fontfile/decompress.c
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+/* $Xorg: decompress.c,v 1.4 2001/02/09 02:04:03 xorgcvs Exp $ */
+/*
+ * Copyright 1985, 1986 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * James A. Woods, derived from original work by Spencer Thomas
+ * and Joseph Orost.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley. The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+/*
+
+Copyright 1993, 1998 The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+
+*/
+/*
+ * decompress - cat a compressed file
+ */
+
+#include "fontmisc.h"
+#include <bufio.h>
+
+#define BITS 16
+
+/*
+ * a code_int must be able to hold 2**BITS values of type int, and also -1
+ */
+#if BITS > 15
+typedef long int code_int;
+#else
+typedef int code_int;
+#endif
+
+typedef long int count_int;
+
+#ifdef NO_UCHAR
+ typedef char char_type;
+#else
+ typedef unsigned char char_type;
+#endif /* UCHAR */
+
+static char_type magic_header[] = { "\037\235" }; /* 1F 9D */
+
+/* Defines for third byte of header */
+#define BIT_MASK 0x1f
+#define BLOCK_MASK 0x80
+/* Masks 0x40 and 0x20 are free. I think 0x20 should mean that there is
+ a fourth header byte (for expansion).
+*/
+
+#define INIT_BITS 9 /* initial number of bits/code */
+
+#ifdef COMPATIBLE /* But wrong! */
+# define MAXCODE(n_bits) (1 << (n_bits) - 1)
+#else
+# define MAXCODE(n_bits) ((1 << (n_bits)) - 1)
+#endif /* COMPATIBLE */
+
+static code_int getcode();
+
+/*
+ * the next two codes should not be changed lightly, as they must not
+ * lie within the contiguous general code space.
+ */
+#define FIRST 257 /* first free entry */
+#define CLEAR 256 /* table clear output code */
+
+#define STACK_SIZE 8192
+
+typedef struct _compressedFILE {
+ BufFilePtr file;
+
+ char_type *stackp;
+ code_int oldcode;
+ char_type finchar;
+
+ int block_compress;
+ int maxbits;
+ code_int maxcode, maxmaxcode;
+
+ code_int free_ent;
+ int clear_flg;
+ int n_bits;
+
+ /* bit buffer */
+ int offset, size;
+ char_type buf[BITS];
+
+ char_type de_stack[STACK_SIZE];
+ char_type *tab_suffix;
+ unsigned short *tab_prefix;
+} CompressedFile;
+
+
+static int hsize_table[] = {
+ 5003, /* 12 bits - 80% occupancy */
+ 9001, /* 13 bits - 91% occupancy */
+ 18013, /* 14 bits - 91% occupancy */
+ 35023, /* 15 bits - 94% occupancy */
+ 69001 /* 16 bits - 95% occupancy */
+};
+
+static int BufCompressedFill(), BufCompressedSkip(), BufCompressedClose();
+
+BufFilePtr
+BufFilePushCompressed (f)
+ BufFilePtr f;
+{
+ int code;
+ int maxbits;
+ int hsize;
+ CompressedFile *file;
+ int extra;
+
+ if ((BufFileGet(f) != (magic_header[0] & 0xFF)) ||
+ (BufFileGet(f) != (magic_header[1] & 0xFF)))
+ {
+ return 0;
+ }
+ code = BufFileGet (f);
+ maxbits = code & BIT_MASK;
+ if (maxbits > BITS || maxbits < 12)
+ return 0;
+ hsize = hsize_table[maxbits - 12];
+ extra = (1 << maxbits) * sizeof (char_type) +
+ hsize * sizeof (unsigned short);
+ file = (CompressedFile *) xalloc (sizeof (CompressedFile) + extra);
+ if (!file)
+ return 0;
+ file->file = f;
+ file->maxbits = maxbits;
+ file->block_compress = code & BLOCK_MASK;
+ file->maxmaxcode = 1 << file->maxbits;
+ file->tab_suffix = (char_type *) &file[1];
+ file->tab_prefix = (unsigned short *) (file->tab_suffix + file->maxmaxcode);
+ /*
+ * As above, initialize the first 256 entries in the table.
+ */
+ file->maxcode = MAXCODE(file->n_bits = INIT_BITS);
+ for ( code = 255; code >= 0; code-- ) {
+ file->tab_prefix[code] = 0;
+ file->tab_suffix[code] = (char_type) code;
+ }
+ file->free_ent = ((file->block_compress) ? FIRST : 256 );
+ file->clear_flg = 0;
+ file->offset = 0;
+ file->size = 0;
+ file->stackp = file->de_stack;
+ bzero(file->buf, BITS);
+ file->finchar = file->oldcode = getcode (file);
+ if (file->oldcode != -1)
+ *file->stackp++ = file->finchar;
+ return BufFileCreate ((char *) file,
+ BufCompressedFill,
+ BufCompressedSkip,
+ BufCompressedClose);
+}
+
+static int
+BufCompressedClose (f, doClose)
+ BufFilePtr f;
+{
+ CompressedFile *file;
+ BufFilePtr raw;
+
+ file = (CompressedFile *) f->private;
+ raw = file->file;
+ xfree (file);
+ BufFileClose (raw, doClose);
+ return 1;
+}
+
+static int
+BufCompressedFill (f)
+ BufFilePtr f;
+{
+ CompressedFile *file;
+ register char_type *stackp, *de_stack;
+ register char_type finchar;
+ register code_int code, oldcode, incode;
+ BufChar *buf, *bufend;
+
+ file = (CompressedFile *) f->private;
+
+ buf = f->buffer;
+ bufend = buf + BUFFILESIZE;
+ stackp = file->stackp;
+ de_stack = file->de_stack;
+ finchar = file->finchar;
+ oldcode = file->oldcode;
+ while (buf < bufend) {
+ while (stackp > de_stack && buf < bufend)
+ *buf++ = *--stackp;
+
+ if (buf == bufend)
+ break;
+
+ if (oldcode == -1)
+ break;
+
+ code = getcode (file);
+ if (code == -1)
+ break;
+
+ if ( (code == CLEAR) && file->block_compress ) {
+ for ( code = 255; code >= 0; code-- )
+ file->tab_prefix[code] = 0;
+ file->clear_flg = 1;
+ file->free_ent = FIRST - 1;
+ if ( (code = getcode (file)) == -1 ) /* O, untimely death! */
+ break;
+ }
+ incode = code;
+ /*
+ * Special case for KwKwK string.
+ */
+ if ( code >= file->free_ent ) {
+ *stackp++ = finchar;
+ code = oldcode;
+ }
+
+ /*
+ * Generate output characters in reverse order
+ */
+ while ( code >= 256 )
+ {
+ *stackp++ = file->tab_suffix[code];
+ code = file->tab_prefix[code];
+ }
+ finchar = file->tab_suffix[code];
+ *stackp++ = finchar;
+
+ /*
+ * Generate the new entry.
+ */
+ if ( (code=file->free_ent) < file->maxmaxcode ) {
+ file->tab_prefix[code] = (unsigned short)oldcode;
+ file->tab_suffix[code] = finchar;
+ file->free_ent = code+1;
+ }
+ /*
+ * Remember previous code.
+ */
+ oldcode = incode;
+ }
+ file->oldcode = oldcode;
+ file->stackp = stackp;
+ file->finchar = finchar;
+ if (buf == f->buffer) {
+ f->left = 0;
+ return BUFFILEEOF;
+ }
+ f->bufp = f->buffer + 1;
+ f->left = (buf - f->buffer) - 1;
+ return f->buffer[0];
+}
+
+/*****************************************************************
+ * TAG( getcode )
+ *
+ * Read one code from the standard input. If BUFFILEEOF, return -1.
+ * Inputs:
+ * stdin
+ * Outputs:
+ * code or -1 is returned.
+ */
+
+static char_type rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
+
+static code_int
+getcode(file)
+ CompressedFile *file;
+{
+ register code_int code;
+ register int r_off, bits;
+ register char_type *bp = file->buf;
+ register BufFilePtr raw;
+
+ if ( file->clear_flg > 0 || file->offset >= file->size ||
+ file->free_ent > file->maxcode )
+ {
+ /*
+ * If the next entry will be too big for the current code
+ * size, then we must increase the size. This implies reading
+ * a new buffer full, too.
+ */
+ if ( file->free_ent > file->maxcode ) {
+ file->n_bits++;
+ if ( file->n_bits == file->maxbits )
+ file->maxcode = file->maxmaxcode; /* won't get any bigger now */
+ else
+ file->maxcode = MAXCODE(file->n_bits);
+ }
+ if ( file->clear_flg > 0) {
+ file->maxcode = MAXCODE (file->n_bits = INIT_BITS);
+ file->clear_flg = 0;
+ }
+ bits = file->n_bits;
+ raw = file->file;
+ while (bits > 0 && (code = BufFileGet (raw)) != BUFFILEEOF)
+ {
+ *bp++ = code;
+ --bits;
+ }
+ bp = file->buf;
+ if (bits == file->n_bits)
+ return -1; /* end of file */
+ file->size = file->n_bits - bits;
+ file->offset = 0;
+ /* Round size down to integral number of codes */
+ file->size = (file->size << 3) - (file->n_bits - 1);
+ }
+ r_off = file->offset;
+ bits = file->n_bits;
+ /*
+ * Get to the first byte.
+ */
+ bp += (r_off >> 3);
+ r_off &= 7;
+ /* Get first part (low order bits) */
+#ifdef NO_UCHAR
+ code = ((*bp++ >> r_off) & rmask[8 - r_off]) & 0xff;
+#else
+ code = (*bp++ >> r_off);
+#endif /* NO_UCHAR */
+ bits -= (8 - r_off);
+ r_off = 8 - r_off; /* now, offset into code word */
+ /* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
+ if ( bits >= 8 ) {
+#ifdef NO_UCHAR
+ code |= (*bp++ & 0xff) << r_off;
+#else
+ code |= *bp++ << r_off;
+#endif /* NO_UCHAR */
+ r_off += 8;
+ bits -= 8;
+ }
+ /* high order bits. */
+ code |= (*bp & rmask[bits]) << r_off;
+ file->offset += file->n_bits;
+
+ return code;
+}
+
+static int
+BufCompressedSkip (f, bytes)
+ BufFilePtr f;
+ int bytes;
+{
+ int c;
+ while (bytes--)
+ {
+ c = BufFileGet(f);
+ if (c == BUFFILEEOF)
+ return BUFFILEEOF;
+ }
+ return 0;
+}
+
+#ifdef TEST
+main (argc, argv)
+ int argc;
+ char **argv;
+{
+ BufFilePtr inputraw, input, output;
+ int c;
+
+ inputraw = BufFileOpenRead (0);
+ input = BufFilePushCompressed (inputraw);
+ output = BufFileOpenWrite (1);
+ while ((c = BufFileGet (input)) != -1)
+ BufFilePut (c, output);
+ BufFileClose (input, FALSE);
+ BufFileClose (output, FALSE);
+}
+#endif
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