--- /dev/null
+/* $XConsortium: gunzip.c /main/1 1996/11/03 19:33:23 kaleb $ */
+/* lib/font/fontfile/gunzip.c
+ written by Mark Eichin <eichin@kitten.gen.ma.us> September 1996.
+ intended for inclusion in X11 public releases. */
+
+#include "fontmisc.h"
+#include <bufio.h>
+#include <zlib.h>
+
+typedef struct _xzip_buf {
+ z_stream z;
+ int zstat;
+ BufChar b[BUFFILESIZE];
+ BufChar b_in[BUFFILESIZE];
+ BufFilePtr f;
+} xzip_buf;
+
+static int BufZipFileSkip(); /* f, count */
+static int BufZipFileFill(); /* read: f; write: char, f */
+static int BufZipFileClose(); /* f, flag */
+static int BufCheckZipHeader(); /* f */
+
+BufFilePtr
+BufFilePushZIP (f)
+ BufFilePtr f;
+{
+ xzip_buf *x;
+
+ x = (xzip_buf *) xalloc (sizeof (xzip_buf));
+ if (!x) return 0;
+ /* these are just for raw calloc/free */
+ x->z.zalloc = Z_NULL;
+ x->z.zfree = Z_NULL;
+ x->z.opaque = Z_NULL;
+ x->f = f;
+
+ /* force inflateInit to allocate it's own history buffer */
+ x->z.next_in = Z_NULL;
+ x->z.next_out = Z_NULL;
+ x->z.avail_in = x->z.avail_out = 0;
+
+ /* using negative windowBits sets "nowrap" mode, which turns off
+ zlib header checking [undocumented, for gzip compatibility only?] */
+ x->zstat = inflateInit2(&(x->z), -MAX_WBITS);
+ if (x->zstat != Z_OK) {
+ xfree(x);
+ return 0;
+ }
+
+ /* now that the history buffer is allocated, we provide the data buffer */
+ x->z.next_out = x->b;
+ x->z.avail_out = BUFFILESIZE;
+ x->z.next_out = x->b_in;
+ x->z.avail_in = 0;
+
+ if (BufCheckZipHeader(x->f)) {
+ xfree(x);
+ return 0;
+ }
+
+ return BufFileCreate(x,
+ BufZipFileFill,
+ BufZipFileSkip,
+ BufZipFileClose);
+}
+
+static int BufZipFileClose(f, flag)
+ BufFilePtr f;
+ int flag;
+{
+ xzip_buf *x = (xzip_buf *)f->private;
+ inflateEnd (&(x->z));
+ BufFileClose (x->f, flag);
+ xfree (x);
+ return 1;
+}
+
+/* here's the real work.
+ -- we need to put stuff in f.buffer, update f.left and f.bufp,
+ then return the first byte (or BUFFILEEOF).
+ -- to do this, we need to get stuff into avail_in, and next_in,
+ and call inflate appropriately.
+ -- we may also need to add CRC maintenance - if inflate tells us
+ Z_STREAM_END, we then have 4bytes CRC and 4bytes length...
+ gzio.c:gzread shows most of the mechanism.
+ */
+static int BufZipFileFill (f)
+ BufFilePtr f;
+{
+ xzip_buf *x = (xzip_buf *)f->private;
+
+ /* we only get called when left == 0... */
+ /* but just in case, deal */
+ if (f->left >= 0) {
+ f->left--;
+ return *(f->bufp++);
+ }
+ /* did we run out last time? */
+ switch (x->zstat) {
+ case Z_OK:
+ break;
+ case Z_STREAM_END:
+ case Z_DATA_ERROR:
+ case Z_ERRNO:
+ return BUFFILEEOF;
+ default:
+ return BUFFILEEOF;
+ }
+ /* now we work to consume what we can */
+ /* let zlib know what we can handle */
+ x->z.next_out = x->b;
+ x->z.avail_out = BUFFILESIZE;
+
+ /* and try to consume all of it */
+ while (x->z.avail_out > 0) {
+ /* if we don't have anything to work from... */
+ if (x->z.avail_in == 0) {
+ /* ... fill the z buf from underlying file */
+ int i, c;
+ for (i = 0; i < sizeof(x->b_in); i++) {
+ c = BufFileGet(x->f);
+ if (c == BUFFILEEOF) break;
+ x->b_in[i] = c;
+ }
+ x->z.avail_in += i;
+ x->z.next_in = x->b_in;
+ }
+ /* so now we have some output space and some input data */
+ x->zstat = inflate(&(x->z), Z_NO_FLUSH);
+ /* the inflation output happens in the f buffer directly... */
+ if (x->zstat == Z_STREAM_END) {
+ /* deal with EOF, crc */
+ break;
+ }
+ if (x->zstat != Z_OK) {
+ break;
+ }
+ }
+ f->bufp = x->b;
+ f->left = BUFFILESIZE - x->z.avail_out;
+
+ if (f->left >= 0) {
+ f->left--;
+ return *(f->bufp++);
+ } else {
+ return BUFFILEEOF;
+ }
+}
+
+/* there should be a BufCommonSkip... */
+static int BufZipFileSkip (f, c)
+ BufFilePtr f;
+ int c;
+{
+ /* BufFileRawSkip returns the count unchanged.
+ BufCompressedSkip returns 0.
+ That means it probably never gets called... */
+ int retval = c;
+ while(c--) {
+ int get = BufFileGet(f);
+ if (get == BUFFILEEOF) return get;
+ }
+ return retval;
+}
+
+/* now we need to duplicate check_header */
+/* contents:
+ 0x1f, 0x8b -- magic number
+ 1 byte -- method (Z_DEFLATED)
+ 1 byte -- flags (mask with RESERVED -> fail)
+ 4 byte -- time (discard)
+ 1 byte -- xflags (discard)
+ 1 byte -- "os" code (discard)
+ [if flags & EXTRA_FIELD:
+ 2 bytes -- LSBfirst length n
+ n bytes -- extra data (discard)]
+ [if flags & ORIG_NAME:
+ n bytes -- null terminated name (discard)]
+ [if flags & COMMENT:
+ n bytes -- null terminated comment (discard)]
+ [if flags & HEAD_CRC:
+ 2 bytes -- crc of headers? (discard)]
+ */
+
+/* gzip flag byte -- from gzio.c */
+#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
+#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
+#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
+#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
+#define COMMENT 0x10 /* bit 4 set: file comment present */
+#define RESERVED 0xE0 /* bits 5..7: reserved */
+
+#define GET(f) do {c = BufFileGet(f); if (c == BUFFILEEOF) return c;} while(0)
+static int BufCheckZipHeader(f)
+ BufFilePtr f;
+{
+ int c, flags;
+ GET(f); if (c != 0x1f) return 1; /* magic 1 */
+ GET(f); if (c != 0x8b) return 2; /* magic 2 */
+ GET(f); if (c != Z_DEFLATED) return 3; /* method */
+ GET(f); if (c & RESERVED) return 4; /* reserved flags */
+ flags = c;
+ GET(f); GET(f); GET(f); GET(f); /* time */
+ GET(f); /* xflags */
+ GET(f); /* os code */
+ if (flags & EXTRA_FIELD) {
+ int len;
+ GET(f); len = c;
+ GET(f); len += (c<<8);
+ while (len-- >= 0) {
+ GET(f);
+ }
+ }
+ if (flags & ORIG_NAME) {
+ do { GET(f); } while (c != 0);
+ }
+ if (flags & COMMENT) {
+ do { GET(f); } while (c != 0);
+ }
+ if (flags & HEAD_CRC) {
+ GET(f); GET(f); /* header crc */
+ }
+ return 0;
+}
projects / rdpsrv / blobdiff