Speed and memory usage improvements from Laurence Adnerson
[oweals/busybox.git] / archival / libunarchive / unzip.c
index 6c3f3229a1ed15669e89de8b8a5bfff328187075..d8d5b77b1f4281c18f5afafe6a97b4b1d0852e77 100644 (file)
@@ -7,13 +7,15 @@
  * Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
  * based on gzip sources
  *
- * Adjusted further by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
- * to support files as well as stdin/stdout, and to generally behave itself wrt
+ * Adjusted further by Erik Andersen <andersee@debian.org> to support
+ * files as well as stdin/stdout, and to generally behave itself wrt
  * command line handling.
  *
  * General cleanup to better adhere to the style guide and make use of standard
  * busybox functions by Glenn McGrath <bug1@optushome.com.au>
  * 
+ * read_gz interface + associated hacking by Laurence Anderson
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -65,105 +67,118 @@ static char *license_msg[] = {
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
-#include "libbb.h"
+#include <unistd.h>
+#include <fcntl.h>
+#include "config.h"
+#include "busybox.h"
+#include "unarchive.h"
 
-static FILE *in_file, *out_file;
+typedef struct huft_s {
+       unsigned char e;        /* number of extra bits or operation */
+       unsigned char b;        /* number of bits in this code or subcode */
+       union {
+               unsigned short n;       /* literal, length base, or distance base */
+               struct huft_s *t;       /* pointer to next level of table */
+       } v;
+} huft_t;
 
-/* these are freed by gz_close */
-static unsigned char *window;
-static unsigned long *crc_table;
+static int gunzip_src_fd;
+unsigned int gunzip_bytes_out; /* number of output bytes */
+static unsigned int gunzip_outbuf_count;       /* bytes in output buffer */
 
-static unsigned long crc = 0xffffffffL;        /* shift register contents */
+/* This is used to sanify any unused bits from the bitbuffer 
+ * so they arent skipped when reading trailers (trailing headers) */
+unsigned char gunzip_in_buffer_count;
+unsigned char *gunzip_in_buffer;
 
-/* Return codes from gzip */
-static const int ERROR = 1;
+/* gunzip_window size--must be a power of two, and
+ *  at least 32K for zip's deflate method */
+static const int gunzip_wsize = 0x8000;
 
-/*
- * window size--must be a power of two, and
- *  at least 32K for zip's deflate method 
- */
-static const int WSIZE = 0x8000;
+static unsigned char *gunzip_window;
+static unsigned int *gunzip_crc_table;
+unsigned int gunzip_crc;
 
 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
-static const int BMAX = 16;            /* maximum bit length of any code (16 for explode) */
-static const int N_MAX = 288;          /* maximum number of codes in any set */
-
-static long bytes_out;         /* number of output bytes */
-static unsigned long outcnt;   /* bytes in output buffer */
-
-static unsigned hufts;         /* track memory usage */
-static unsigned long bb;                       /* bit buffer */
-static unsigned bk;            /* bits in bit buffer */
+#define BMAX 16        /* maximum bit length of any code (16 for explode) */
+#define N_MAX 288      /* maximum number of codes in any set */
 
-typedef struct huft_s {
-       unsigned char e;                /* number of extra bits or operation */
-       unsigned char b;                /* number of bits in this code or subcode */
-       union {
-               unsigned short n;               /* literal, length base, or distance base */
-               struct huft_s *t;       /* pointer to next level of table */
-       } v;
-} huft_t;
+static unsigned int gunzip_bb; /* bit buffer */
+static unsigned char gunzip_bk;        /* bits in bit buffer */
 
 static const unsigned short mask_bits[] = {
-       0x0000,
-       0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+       0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
        0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
 };
 
-//static int error_number = 0;
-/* ========================================================================
- * Signal and error handler.
- */
-static void abort_gzip(void)
+/* Copy lengths for literal codes 257..285 */
+static const unsigned short cplens[] = {
+       3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
+               67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
+};
+
+/* note: see note #13 above about the 258 in this list. */
+/* Extra bits for literal codes 257..285 */
+static const unsigned char cplext[] = {
+       0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5,
+               5, 5, 5, 0, 99, 99
+};                                             /* 99==invalid */
+
+/* Copy offsets for distance codes 0..29 */
+static const unsigned short cpdist[] = {
+       1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
+               769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
+};
+
+/* Extra bits for distance codes */
+static const unsigned char cpdext[] = {
+       0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
+               11, 11, 12, 12, 13, 13
+};
+
+/* Tables for deflate from PKZIP's appnote.txt. */
+/* Order of the bit length code lengths */
+static const unsigned char border[] = {
+       16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
+};
+
+static unsigned int fill_bitbuffer(unsigned int bitbuffer, unsigned int *current, const unsigned int required)
 {
-       error_msg("gzip aborted\n");
-       exit(ERROR);
+       while (*current < required) {
+               bitbuffer |= ((unsigned int) xread_char(gunzip_src_fd)) << *current;
+               *current += 8;
+       }
+
+       return(bitbuffer);
 }
 
-static void make_crc_table(void)
+static void make_gunzip_crc_table(void)
 {
-       const unsigned long poly = 0xedb88320;      /* polynomial exclusive-or pattern */
-       unsigned short i;                /* counter for all possible eight bit values */
+       const unsigned int poly = 0xedb88320;   /* polynomial exclusive-or pattern */
+       unsigned short i;       /* counter for all possible eight bit values */
 
-       crc_table = (unsigned long *) malloc(256 * sizeof(unsigned long));
+       /* initial shift register value */
+       gunzip_crc = 0xffffffffL;
+       gunzip_crc_table = (unsigned int *) malloc(256 * sizeof(unsigned int));
 
        /* Compute and print table of CRC's, five per line */
        for (i = 0; i < 256; i++) {
-               unsigned long table_entry;      /* crc shift register */
-               char k; /* byte being shifted into crc apparatus */
+               unsigned int table_entry;       /* crc shift register */
+               unsigned char k;        /* byte being shifted into crc apparatus */
 
                table_entry = i;
-          /* The idea to initialize the register with the byte instead of
-            * zero was stolen from Haruhiko Okumura's ar002
-            */
+               /* The idea to initialize the register with the byte instead of
+                  * zero was stolen from Haruhiko Okumura's ar002
+                */
                for (k = 8; k; k--) {
-                       table_entry = table_entry & 1 ? (table_entry >> 1) ^ poly : table_entry >> 1;
-               }
-               crc_table[i]=table_entry;
+                       if (table_entry & 1) {
+                               table_entry = (table_entry >> 1) ^ poly;
+                       } else {
+                               table_entry >>= 1;
        }
-}
-
-/* ===========================================================================
- * Write the output window window[0..outcnt-1] and update crc and bytes_out.
- * (Used for the decompressed data only.)
- */
-static void flush_window(void)
-{
-       int n;
-
-       if (outcnt == 0)
-               return;
-
-       for (n = 0; n < outcnt; n++) {
-               crc = crc_table[((int) crc ^ (window[n])) & 0xff] ^ (crc >> 8);
        }
-
-       if (fwrite(window, 1, outcnt, out_file) != outcnt) {
-               error_msg_and_die("Couldnt write");
+               gunzip_crc_table[i] = table_entry;
        }
-       bytes_out += (unsigned long) outcnt;
-       outcnt = 0;
 }
 
 /*
@@ -172,9 +187,10 @@ static void flush_window(void)
  * each table. 
  * t: table to free
  */
-static int huft_free(huft_t *t)
+static int huft_free(huft_t * t)
 {
-       huft_t *p, *q;
+       huft_t *p;
+       huft_t *q;
 
        /* Go through linked list, freeing from the malloced (t[-1]) address. */
        p = t;
@@ -186,8 +202,6 @@ static int huft_free(huft_t *t)
        return 0;
 }
 
-typedef unsigned char extra_bits_t;
-
 /* Given a list of code lengths and a maximum table size, make a set of
  * tables to decode that set of codes.  Return zero on success, one if
  * the given code set is incomplete (the tables are still built in this
@@ -202,36 +216,37 @@ typedef unsigned char extra_bits_t;
  * t:  result: starting table
  * m:  maximum lookup bits, returns actual
  */
-static int huft_build(unsigned int *b, const unsigned int n, const unsigned int s, 
-       const unsigned short *d, const extra_bits_t *e, huft_t **t, int *m)
+static int huft_build(unsigned int *b, const unsigned int n,
+                                         const unsigned int s, const unsigned short *d,
+                                         const unsigned char *e, huft_t ** t, int *m)
 {
-       unsigned a;             /* counter for codes of length k */
+       unsigned a;                     /* counter for codes of length k */
        unsigned c[BMAX + 1];   /* bit length count table */
-       unsigned f;             /* i repeats in table every f entries */
-       int g;                  /* maximum code length */
-       int h;                  /* table level */
+       unsigned f;                     /* i repeats in table every f entries */
+       int g;                          /* maximum code length */
+       int h;                          /* table level */
        register unsigned i;    /* counter, current code */
        register unsigned j;    /* counter */
        register int k;         /* number of bits in current code */
-       int l;                  /* bits per table (returned in m) */
-       register unsigned *p;           /* pointer into c[], b[], or v[] */
+       int l;                          /* bits per table (returned in m) */
+       register unsigned *p;   /* pointer into c[], b[], or v[] */
        register huft_t *q;     /* points to current table */
-       huft_t r;               /* table entry for structure assignment */
+       huft_t r;                       /* table entry for structure assignment */
        huft_t *u[BMAX];        /* table stack */
        unsigned v[N_MAX];      /* values in order of bit length */
        register int w;         /* bits before this table == (l * h) */
        unsigned x[BMAX + 1];   /* bit offsets, then code stack */
        unsigned *xp;           /* pointer into x */
-       int y;                  /* number of dummy codes added */
-       unsigned z;             /* number of entries in current table */
+       int y;                          /* number of dummy codes added */
+       unsigned z;                     /* number of entries in current table */
 
        /* Generate counts for each bit length */
-       memset ((void *)(c), 0, sizeof(c));
+       memset((void *) (c), 0, sizeof(c));
        p = b;
        i = n;
        do {
-               c[*p]++;        /* assume all entries <= BMAX */
-               p++;            /* Can't combine with above line (Solaris bug) */
+               c[*p]++;                /* assume all entries <= BMAX */
+               p++;                    /* Can't combine with above line (Solaris bug) */
        } while (--i);
        if (c[0] == n) {        /* null input--all zero length codes */
                *t = (huft_t *) NULL;
@@ -241,33 +256,42 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
 
        /* Find minimum and maximum length, bound *m by those */
        l = *m;
-       for (j = 1; j <= BMAX; j++)
-               if (c[j])
+       for (j = 1; j <= BMAX; j++) {
+               if (c[j]) {
                        break;
+               }
+       }
        k = j;                          /* minimum code length */
-       if ((unsigned) l < j)
+       if ((unsigned) l < j) {
                l = j;
-       for (i = BMAX; i; i--)
-               if (c[i])
+       }
+       for (i = BMAX; i; i--) {
+               if (c[i]) {
                        break;
+               }
+       }
        g = i;                          /* maximum code length */
-       if ((unsigned) l > i)
+       if ((unsigned) l > i) {
                l = i;
+       }
        *m = l;
 
        /* Adjust last length count to fill out codes, if needed */
-       for (y = 1 << j; j < i; j++, y <<= 1)
-               if ((y -= c[j]) < 0)
+       for (y = 1 << j; j < i; j++, y <<= 1) {
+               if ((y -= c[j]) < 0) {
                        return 2;       /* bad input: more codes than bits */
-       if ((y -= c[i]) < 0)
+               }
+       }
+       if ((y -= c[i]) < 0) {
                return 2;
+       }
        c[i] += y;
 
        /* Generate starting offsets into the value table for each length */
        x[1] = j = 0;
        p = c + 1;
        xp = x + 2;
-       while (--i) {                   /* note that i == g from above */
+       while (--i) {           /* note that i == g from above */
                *xp++ = (j += *p++);
        }
 
@@ -275,12 +299,13 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
        p = b;
        i = 0;
        do {
-               if ((j = *p++) != 0)
+               if ((j = *p++) != 0) {
                        v[x[j]++] = i;
+               }
        } while (++i < n);
 
        /* Generate the Huffman codes and for each, make the table entries */
-       x[0] = i = 0;                   /* first Huffman code is zero */
+       x[0] = i = 0;           /* first Huffman code is zero */
        p = v;                          /* grab values in bit order */
        h = -1;                         /* no tables yet--level -1 */
        w = -l;                         /* bits decoded == (l * h) */
@@ -296,7 +321,7 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
                        /* make tables up to required level */
                        while (k > w + l) {
                                h++;
-                               w += l;         /* previous table always l bits */
+                               w += l; /* previous table always l bits */
 
                                /* compute minimum size table less than or equal to l bits */
                                z = (z = g - w) > (unsigned) l ? l : z; /* upper limit on table size */
@@ -304,20 +329,20 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
                                        f -= a + 1;     /* deduct codes from patterns left */
                                        xp = c + k;
                                        while (++j < z) {       /* try smaller tables up to z bits */
-                                               if ((f <<= 1) <= *++xp)
+                                               if ((f <<= 1) <= *++xp) {
                                                        break;  /* enough codes to use up j bits */
+                                               }
                                                f -= *xp;       /* else deduct codes from patterns */
                                        }
                                }
-                               z = 1 << j;             /* table entries for j-bit table */
+                               z = 1 << j;     /* table entries for j-bit table */
 
                                /* allocate and link in new table */
                                q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t));
 
-                               hufts += z + 1; /* track memory usage */
-                               *t = q + 1;             /* link to list for huft_free() */
+                               *t = q + 1;     /* link to list for huft_free() */
                                *(t = &(q->v.t)) = NULL;
-                               u[h] = ++q;             /* table starts after link */
+                               u[h] = ++q;     /* table starts after link */
 
                                /* connect to last table, if there is one */
                                if (h) {
@@ -332,12 +357,12 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
 
                        /* set up table entry in r */
                        r.b = (unsigned char) (k - w);
-                       if (p >= v + n)
-                               r.e = 99;               /* out of values--invalid code */
-                       else if (*p < s) {
+                       if (p >= v + n) {
+                               r.e = 99;       /* out of values--invalid code */
+                       else if (*p < s) {
                                r.e = (unsigned char) (*p < 256 ? 16 : 15);     /* 256 is end-of-block code */
                                r.v.n = (unsigned short) (*p);  /* simple code is just the value */
-                               p++;                    /* one compiler does not like *p++ */
+                               p++;    /* one compiler does not like *p++ */
                        } else {
                                r.e = (unsigned char) e[*p - s];        /* non-simple--look up in lists */
                                r.v.n = d[*p++ - s];
@@ -345,17 +370,19 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
 
                        /* fill code-like entries with r */
                        f = 1 << (k - w);
-                       for (j = i >> w; j < z; j += f)
+                       for (j = i >> w; j < z; j += f) {
                                q[j] = r;
+                       }
 
                        /* backwards increment the k-bit code i */
-                       for (j = 1 << (k - 1); i & j; j >>= 1)
+                       for (j = 1 << (k - 1); i & j; j >>= 1) {
                                i ^= j;
+                       }
                        i ^= j;
 
                        /* backup over finished tables */
                        while ((i & ((1 << w) - 1)) != x[h]) {
-                               h--;                    /* don't need to update q */
+                               h--;    /* don't need to update q */
                                w -= l;
                        }
                }
@@ -371,52 +398,61 @@ static int huft_build(unsigned int *b, const unsigned int n, const unsigned int
  * tl, td: literal/length and distance decoder tables
  * bl, bd: number of bits decoded by tl[] and td[]
  */
-static int inflate_codes(huft_t *tl, huft_t *td, int bl, int bd)
+static int inflate_codes(huft_t * my_tl, huft_t * my_td, const unsigned int my_bl, const unsigned int my_bd, int setup)
 {
-       register unsigned long e;               /* table entry flag/number of extra bits */
-       unsigned long n, d;                             /* length and index for copy */
-       unsigned long w;                                /* current window position */
-       huft_t *t;                              /* pointer to table entry */
-       unsigned ml, md;                        /* masks for bl and bd bits */
-       register unsigned long b;                               /* bit buffer */
-       register unsigned k;            /* number of bits in bit buffer */
-
-       /* make local copies of globals */
-       b = bb;                                 /* initialize bit buffer */
-       k = bk;
-       w = outcnt;                             /* initialize window position */
-
-       /* inflate the coded data */
-       ml = mask_bits[bl];                     /* precompute masks for speed */
-       md = mask_bits[bd];
-       for (;;) {                              /* do until end of block */
-               while (k < (unsigned) bl) {
-                       b |= ((unsigned long)fgetc(in_file)) << k;
-                       k += 8;
-               }
+       static unsigned int e;  /* table entry flag/number of extra bits */
+       static unsigned int n, d;       /* length and index for copy */
+       static unsigned int w;  /* current gunzip_window position */
+       static huft_t *t;                       /* pointer to table entry */
+       static unsigned int ml, md;     /* masks for bl and bd bits */
+       static unsigned int b;  /* bit buffer */
+       static unsigned int k;                  /* number of bits in bit buffer */
+       static huft_t *tl, *td;
+       static unsigned int bl, bd;
+       static int resumeCopy = 0;
+
+       if (setup) { // 1st time we are called, copy in variables
+               tl = my_tl;
+               td = my_td;
+               bl = my_bl;
+               bd = my_bd;
+               /* make local copies of globals */
+               b = gunzip_bb;                          /* initialize bit buffer */
+               k = gunzip_bk;
+               w = gunzip_outbuf_count;                        /* initialize gunzip_window position */
+
+               /* inflate the coded data */
+               ml = mask_bits[bl];     /* precompute masks for speed */
+               md = mask_bits[bd];
+               return 0; // Don't actually do anything the first time
+       }
+       
+       if (resumeCopy) goto do_copy;
+       
+       while (1) {                     /* do until end of block */
+               b = fill_bitbuffer(b, &k, bl);
                if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
-               do {
-                       if (e == 99) {
-                               return 1;
-                       }
-                       b >>= t->b;
-                       k -= t->b;
-                       e -= 16;
-                       while (k < e) {
-                               b |= ((unsigned long)fgetc(in_file)) << k;
-                               k += 8;
-                       }
-               } while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
+                       do {
+                               if (e == 99) {
+                                       error_msg_and_die("inflate_codes error 1");;
+                               }
+                               b >>= t->b;
+                               k -= t->b;
+                               e -= 16;
+                               b = fill_bitbuffer(b, &k, e);
+                       } while ((e =
+                                         (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
                b >>= t->b;
                k -= t->b;
-               if (e == 16) {          /* then it's a literal */
-                       window[w++] = (unsigned char) t->v.n;
-                       if (w == WSIZE) {
-                               outcnt=(w),
-                               flush_window();
+               if (e == 16) {  /* then it's a literal */
+                       gunzip_window[w++] = (unsigned char) t->v.n;
+                       if (w == gunzip_wsize) {
+                               gunzip_outbuf_count = (w);
+                               //flush_gunzip_window();
                                w = 0;
+                               return 1; // We have a block to read
                        }
-               } else {                                /* it's an EOB or a length */
+               } else {                /* it's an EOB or a length */
 
                        /* exit if end of block */
                        if (e == 15) {
@@ -424,96 +460,108 @@ static int inflate_codes(huft_t *tl, huft_t *td, int bl, int bd)
                        }
 
                        /* get length of block to copy */
-                       while (k < e) {
-                               b |= ((unsigned long)fgetc(in_file)) << k;
-                               k += 8;
-                       }
+                       b = fill_bitbuffer(b, &k, e);
                        n = t->v.n + ((unsigned) b & mask_bits[e]);
                        b >>= e;
                        k -= e;
 
                        /* decode distance of block to copy */
-                       while (k < (unsigned) bd) {
-                               b |= ((unsigned long)fgetc(in_file)) << k;
-                               k += 8;
-                       }
-
+                       b = fill_bitbuffer(b, &k, bd);
                        if ((e = (t = td + ((unsigned) b & md))->e) > 16)
                                do {
                                        if (e == 99)
-                                               return 1;
+                                               error_msg_and_die("inflate_codes error 2");;
                                        b >>= t->b;
                                        k -= t->b;
                                        e -= 16;
-                                       while (k < e) {
-                                               b |= ((unsigned long)fgetc(in_file)) << k;
-                                               k += 8;
-                                       }
-                               } while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
+                                       b = fill_bitbuffer(b, &k, e);
+                               } while ((e =
+                                                 (t =
+                                                  t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
                        b >>= t->b;
                        k -= t->b;
-                       while (k < e) {
-                               b |= ((unsigned long)fgetc(in_file)) << k;
-                               k += 8;
-                       }
+                       b = fill_bitbuffer(b, &k, e);
                        d = w - t->v.n - ((unsigned) b & mask_bits[e]);
                        b >>= e;
                        k -= e;
 
                        /* do the copy */
-                       do {
-                               n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n : e);
-#if !defined(NOMEMCPY) && !defined(DEBUG)
+do_copy:               do {
+                               n -= (e =
+                                         (e =
+                                          gunzip_wsize - ((d &= gunzip_wsize - 1) > w ? d : w)) > n ? n : e);
+                          /* copy to new buffer to prevent possible overwrite */
                                if (w - d >= e) {       /* (this test assumes unsigned comparison) */
-                                       memcpy(window + w, window + d, e);
+                                       memcpy(gunzip_window + w, gunzip_window + d, e);
                                        w += e;
                                        d += e;
-                               } else                  /* do it slow to avoid memcpy() overlap */
-#endif                                                 /* !NOMEMCPY */
+                               } else {
+                                  /* do it slow to avoid memcpy() overlap */
+                                  /* !NOMEMCPY */
                                        do {
-                                               window[w++] = window[d++];
+                                               gunzip_window[w++] = gunzip_window[d++];
                                        } while (--e);
-                               if (w == WSIZE) {
-                                       outcnt=(w),
-                                       flush_window();
+                               }
+                               if (w == gunzip_wsize) {
+                                       gunzip_outbuf_count = (w);
+                                       if (n) resumeCopy = 1;
+                                       else resumeCopy = 0;
+                                       //flush_gunzip_window();
                                        w = 0;
+                                       return 1;
                                }
                        } while (n);
+                       resumeCopy = 0;
                }
        }
 
        /* restore the globals from the locals */
-       outcnt = w;                     /* restore global window pointer */
-       bb = b;                         /* restore global bit buffer */
-       bk = k;
-
+       gunzip_outbuf_count = w;                        /* restore global gunzip_window pointer */
+       gunzip_bb = b;                          /* restore global bit buffer */
+       gunzip_bk = k;
+
+       /* normally just after call to inflate_codes, but save code by putting it here */
+       /* free the decoding tables, return */
+       huft_free(tl);
+       huft_free(td);
+       
        /* done */
        return 0;
 }
 
-static const unsigned short cplens[] = {     /* Copy lengths for literal codes 257..285 */
-    3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
-    35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
-};
-/* note: see note #13 above about the 258 in this list. */
-static const extra_bits_t cplext[] = {  /* Extra bits for literal codes 257..285 */
-    0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
-    3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
-};                 /* 99==invalid */
-static const unsigned short cpdist[] = {     /* Copy offsets for distance codes 0..29 */
-    1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
-    257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
-    8193, 12289, 16385, 24577
-};
-static const extra_bits_t cpdext[] = {  /* Extra bits for distance codes */
-    0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
-    7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
-    12, 12, 13, 13
-};
-/* Tables for deflate from PKZIP's appnote.txt. */
-static const extra_bits_t border[] = {  /* Order of the bit length code lengths */
-    16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
-};
+static int inflate_stored(int my_n, int my_b_stored, int my_k_stored, int setup)
+{
+       static int n, b_stored, k_stored, w;
+       if (setup) {
+               n = my_n;
+               b_stored = my_b_stored;
+               k_stored = my_k_stored;
+               w = gunzip_outbuf_count;                /* initialize gunzip_window position */
+               return 0; // Don't do anything first time
+       }
+       
+       /* read and output the compressed data */
+       while (n--) {
+               b_stored = fill_bitbuffer(b_stored, &k_stored, 8);
+               gunzip_window[w++] = (unsigned char) b_stored;
+               if (w == (unsigned int) gunzip_wsize) {
+                       gunzip_outbuf_count = (w);
+                       //flush_gunzip_window();
+                       w = 0;
+                       b_stored >>= 8;
+                       k_stored -= 8;
+                       return 1; // We have a block
+               }
+               b_stored >>= 8;
+               k_stored -= 8;
+       }
+
+       /* restore the globals from the locals */
+       gunzip_outbuf_count = w;                /* restore global gunzip_window pointer */
+       gunzip_bb = b_stored;   /* restore global bit buffer */
+       gunzip_bk = k_stored;
+       return 0; // Finished
+}
 
 /*
  * decompress an inflated block
@@ -521,487 +569,424 @@ static const extra_bits_t border[] = {  /* Order of the bit length code lengths
  *
  * GLOBAL VARIABLES: bb, kk,
  */
+ // Return values: -1 = inflate_stored, -2 = inflate_codes
 static int inflate_block(int *e)
 {
        unsigned t;                     /* block type */
-       register unsigned long b;                       /* bit buffer */
-       register unsigned k;            /* number of bits in bit buffer */
+       register unsigned int b;        /* bit buffer */
+       unsigned int k; /* number of bits in bit buffer */
 
        /* make local bit buffer */
-       b = bb;
-       k = bk;
+
+       b = gunzip_bb;
+       k = gunzip_bk;
 
        /* read in last block bit */
-       while (k < 1) {
-               b |= ((unsigned long)fgetc(in_file)) << k;
-               k += 8;
-       }
+       b = fill_bitbuffer(b, &k, 1);
        *e = (int) b & 1;
        b >>= 1;
        k -= 1;
 
        /* read in block type */
-       while (k < 2) {
-               b |= ((unsigned long)fgetc(in_file)) << k;
-               k += 8;
-       }
+       b = fill_bitbuffer(b, &k, 2);
        t = (unsigned) b & 3;
        b >>= 2;
        k -= 2;
 
        /* restore the global bit buffer */
-       bb = b;
-       bk = k;
+       gunzip_bb = b;
+       gunzip_bk = k;
 
        /* inflate that block type */
        switch (t) {
-       case 0: /* Inflate stored */
-               {
-                       unsigned long n;                        /* number of bytes in block */
-                       unsigned long w;                        /* current window position */
-                       register unsigned long b_stored;                        /* bit buffer */
-                       register unsigned long k_stored;                /* number of bits in bit buffer */
-
-                       /* make local copies of globals */
-                       b_stored = bb;                          /* initialize bit buffer */
-                       k_stored = bk;
-                       w = outcnt;                     /* initialize window position */
-
-                       /* go to byte boundary */
-                       n = k_stored & 7;
-                       b_stored >>= n;
-                       k_stored -= n;
-
-                       /* get the length and its complement */
-                       while (k_stored < 16) {
-                               b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
-                               k_stored += 8;
-                       }
-                       n = ((unsigned) b_stored & 0xffff);
-                       b_stored >>= 16;
-                       k_stored -= 16;
-                       while (k_stored < 16) {
-                               b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
-                               k_stored += 8;
-                       }
-                       if (n != (unsigned) ((~b_stored) & 0xffff)) {
-                               return 1;               /* error in compressed data */
-                       }
-                       b_stored >>= 16;
-                       k_stored -= 16;
-
-                       /* read and output the compressed data */
-                       while (n--) {
-                               while (k_stored < 8) {
-                                       b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
-                                       k_stored += 8;
-                               }
-                               window[w++] = (unsigned char) b_stored;
-                               if (w == (unsigned long)WSIZE) {
-                                       outcnt=(w),
-                                       flush_window();
-                                       w = 0;
-                               }
-                               b_stored >>= 8;
-                               k_stored -= 8;
-                       }
+       case 0:                 /* Inflate stored */
+       {
+               unsigned int n; /* number of bytes in block */
+               unsigned int b_stored;  /* bit buffer */
+               unsigned int k_stored;  /* number of bits in bit buffer */
+
+               /* make local copies of globals */
+               b_stored = gunzip_bb;   /* initialize bit buffer */
+               k_stored = gunzip_bk;
+
+               /* go to byte boundary */
+               n = k_stored & 7;
+               b_stored >>= n;
+               k_stored -= n;
+
+               /* get the length and its complement */
+               b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
+               n = ((unsigned) b_stored & 0xffff);
+               b_stored >>= 16;
+               k_stored -= 16;
+
+               b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
+               if (n != (unsigned) ((~b_stored) & 0xffff)) {
+                       return 1;       /* error in compressed data */
+               }
+               b_stored >>= 16;
+               k_stored -= 16;
 
-                       /* restore the globals from the locals */
-                       outcnt = w;                     /* restore global window pointer */
-                       bb = b_stored;                          /* restore global bit buffer */
-                       bk = k_stored;
-                       return 0;
+               inflate_stored(n, b_stored, k_stored, 1); // Setup inflate_stored
+               return -1;
+       }
+       case 1:                 /* Inflate fixed 
+                                                  * decompress an inflated type 1 (fixed Huffman codes) block.  We should
+                                                  * either replace this with a custom decoder, or at least precompute the
+                                                  * Huffman tables.
+                                                */
+       {
+               int i;                  /* temporary variable */
+               huft_t *tl;             /* literal/length code table */
+               huft_t *td;             /* distance code table */
+               unsigned int bl;                        /* lookup bits for tl */
+               unsigned int bd;                        /* lookup bits for td */
+               unsigned int l[288];    /* length list for huft_build */
+
+               /* set up literal table */
+               for (i = 0; i < 144; i++) {
+                       l[i] = 8;
+               }
+               for (; i < 256; i++) {
+                       l[i] = 9;
+               }
+               for (; i < 280; i++) {
+                       l[i] = 7;
+               }
+               for (; i < 288; i++) {  /* make a complete, but wrong code set */
+                       l[i] = 8;
+               }
+               bl = 7;
+               if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) {
+                       return i;
                }
-       case 1: /* Inflate fixed 
-                        * decompress an inflated type 1 (fixed Huffman codes) block.  We should
-                        * either replace this with a custom decoder, or at least precompute the
-                        * Huffman tables.
-                        */
-               {
-                       int i;                                  /* temporary variable */
-                       huft_t *tl;                             /* literal/length code table */
-                       huft_t *td;                             /* distance code table */
-                       int bl;                                 /* lookup bits for tl */
-                       int bd;                                 /* lookup bits for td */
-                       unsigned int l[288];    /* length list for huft_build */
-
-                       /* set up literal table */
-                       for (i = 0; i < 144; i++) {
-                               l[i] = 8;
-                       }
-                       for (; i < 256; i++) {
-                               l[i] = 9;
-                       }
-                       for (; i < 280; i++) {
-                               l[i] = 7;
-                       }
-                       for (; i < 288; i++) {  /* make a complete, but wrong code set */
-                               l[i] = 8;
-                       }
-                       bl = 7;
-                       if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) {
-                               return i;
-                       }
 
-                       /* set up distance table */
-                       for (i = 0; i < 30; i++) {      /* make an incomplete code set */
-                               l[i] = 5;
-                       }
-                       bd = 5;
-                       if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
-                               huft_free(tl);
-                               return i;
-                       }
+               /* set up distance table */
+               for (i = 0; i < 30; i++) {      /* make an incomplete code set */
+                       l[i] = 5;
+               }
+               bd = 5;
+               if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
+                       huft_free(tl);
+                       return i;
+               }
 
-                       /* decompress until an end-of-block code */
-                       if (inflate_codes(tl, td, bl, bd))
-                               return 1;
+               /* decompress until an end-of-block code */
+               inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes
+               
+               /* huft_free code moved into inflate_codes */
+               
+               return -2;
+       }
+       case 2:                 /* Inflate dynamic */
+       {
+               const int dbits = 6;    /* bits in base distance lookup table */
+               const int lbits = 9;    /* bits in base literal/length lookup table */
+
+               huft_t *tl;             /* literal/length code table */
+               huft_t *td;             /* distance code table */
+               unsigned int i;                 /* temporary variables */
+               unsigned int j;
+               unsigned int l;         /* last length */
+               unsigned int m;         /* mask for bit lengths table */
+               unsigned int n;         /* number of lengths to get */
+               unsigned int bl;                        /* lookup bits for tl */
+               unsigned int bd;                        /* lookup bits for td */
+               unsigned int nb;        /* number of bit length codes */
+               unsigned int nl;        /* number of literal/length codes */
+               unsigned int nd;        /* number of distance codes */
+
+               unsigned int ll[286 + 30];      /* literal/length and distance code lengths */
+               unsigned int b_dynamic; /* bit buffer */
+               unsigned int k_dynamic; /* number of bits in bit buffer */
+
+               /* make local bit buffer */
+               b_dynamic = gunzip_bb;
+               k_dynamic = gunzip_bk;
+
+               /* read in table lengths */
+               b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
+               nl = 257 + ((unsigned int) b_dynamic & 0x1f);   /* number of literal/length codes */
+
+               b_dynamic >>= 5;
+               k_dynamic -= 5;
+               b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
+               nd = 1 + ((unsigned int) b_dynamic & 0x1f);     /* number of distance codes */
+
+               b_dynamic >>= 5;
+               k_dynamic -= 5;
+               b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 4);
+               nb = 4 + ((unsigned int) b_dynamic & 0xf);      /* number of bit length codes */
+
+               b_dynamic >>= 4;
+               k_dynamic -= 4;
+               if (nl > 286 || nd > 30) {
+                       return 1;       /* bad lengths */
+               }
 
-                       /* free the decoding tables, return */
-                       huft_free(tl);
-                       huft_free(td);
-                       return 0;
+               /* read in bit-length-code lengths */
+               for (j = 0; j < nb; j++) {
+                       b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
+                       ll[border[j]] = (unsigned int) b_dynamic & 7;
+                       b_dynamic >>= 3;
+                       k_dynamic -= 3;
                }
-       case 2: /* Inflate dynamic */
-               {
-                       const int dbits = 6;                                    /* bits in base distance lookup table */
-                       const int lbits = 9;                                    /* bits in base literal/length lookup table */
-
-                       int i;                                          /* temporary variables */
-                       unsigned j;
-                       unsigned l;                                     /* last length */
-                       unsigned m;                                     /* mask for bit lengths table */
-                       unsigned n;                                     /* number of lengths to get */
-                       huft_t *tl;                     /* literal/length code table */
-                       huft_t *td;                     /* distance code table */
-                       int bl;                                         /* lookup bits for tl */
-                       int bd;                                         /* lookup bits for td */
-                       unsigned nb;                            /* number of bit length codes */
-                       unsigned nl;                            /* number of literal/length codes */
-                       unsigned nd;                            /* number of distance codes */
-
-                       unsigned ll[286 + 30];          /* literal/length and distance code lengths */
-                       register unsigned long b_dynamic;       /* bit buffer */
-                       register unsigned k_dynamic;            /* number of bits in bit buffer */
-
-                       /* make local bit buffer */
-                       b_dynamic = bb;
-                       k_dynamic = bk;
-
-                       /* read in table lengths */
-                       while (k_dynamic < 5) {
-                               b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                               k_dynamic += 8;
-                       }
-                       nl = 257 + ((unsigned) b_dynamic & 0x1f);       /* number of literal/length codes */
-                       b_dynamic >>= 5;
-                       k_dynamic -= 5;
-                       while (k_dynamic < 5) {
-                               b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                               k_dynamic += 8;
-                       }
-                       nd = 1 + ((unsigned) b_dynamic & 0x1f); /* number of distance codes */
-                       b_dynamic >>= 5;
-                       k_dynamic -= 5;
-                       while (k_dynamic < 4) {
-                               b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                               k_dynamic += 8;
-                       }
-                       nb = 4 + ((unsigned) b_dynamic & 0xf);  /* number of bit length codes */
-                       b_dynamic >>= 4;
-                       k_dynamic -= 4;
-                       if (nl > 286 || nd > 30) {
-                               return 1;       /* bad lengths */
+               for (; j < 19; j++) {
+                       ll[border[j]] = 0;
+               }
+
+               /* build decoding table for trees--single level, 7 bit lookup */
+               bl = 7;
+               i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl);
+               if (i != 0) {
+                       if (i == 1) {
+                               huft_free(tl);
                        }
+                       return i;       /* incomplete code set */
+               }
 
-                       /* read in bit-length-code lengths */
-                       for (j = 0; j < nb; j++) {
-                               while (k_dynamic < 3) {
-                                       b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                                       k_dynamic += 8;
+               /* read in literal and distance code lengths */
+               n = nl + nd;
+               m = mask_bits[bl];
+               i = l = 0;
+               while ((unsigned int) i < n) {
+                       b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, (unsigned int)bl);
+                       j = (td = tl + ((unsigned int) b_dynamic & m))->b;
+                       b_dynamic >>= j;
+                       k_dynamic -= j;
+                       j = td->v.n;
+                       if (j < 16) {   /* length of code in bits (0..15) */
+                               ll[i++] = l = j;        /* save last length in l */
+                       } else if (j == 16) {   /* repeat last length 3 to 6 times */
+                               b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 2);
+                               j = 3 + ((unsigned int) b_dynamic & 3);
+                               b_dynamic >>= 2;
+                               k_dynamic -= 2;
+                               if ((unsigned int) i + j > n) {
+                                       return 1;
                                }
-                               ll[border[j]] = (unsigned) b_dynamic & 7;
+                               while (j--) {
+                                       ll[i++] = l;
+                               }
+                       } else if (j == 17) {   /* 3 to 10 zero length codes */
+                               b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
+                               j = 3 + ((unsigned int) b_dynamic & 7);
                                b_dynamic >>= 3;
                                k_dynamic -= 3;
-                       }
-                       for (; j < 19; j++) {
-                               ll[border[j]] = 0;
-                       }
-
-                       /* build decoding table for trees--single level, 7 bit lookup */
-                       bl = 7;
-                       if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0) {
-                               if (i == 1) {
-                                       huft_free(tl);
+                               if ((unsigned int) i + j > n) {
+                                       return 1;
                                }
-                               return i;                       /* incomplete code set */
-                       }
-
-                       /* read in literal and distance code lengths */
-                       n = nl + nd;
-                       m = mask_bits[bl];
-                       i = l = 0;
-                       while ((unsigned) i < n) {
-                               while (k_dynamic < (unsigned) bl) {
-                                       b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                                       k_dynamic += 8;
+                               while (j--) {
+                                       ll[i++] = 0;
                                }
-                               j = (td = tl + ((unsigned) b_dynamic & m))->b;
-                               b_dynamic >>= j;
-                               k_dynamic -= j;
-                               j = td->v.n;
-                               if (j < 16) {                   /* length of code in bits (0..15) */
-                                       ll[i++] = l = j;        /* save last length in l */
+                               l = 0;
+                       } else {        /* j == 18: 11 to 138 zero length codes */
+                               b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 7);
+                               j = 11 + ((unsigned int) b_dynamic & 0x7f);
+                               b_dynamic >>= 7;
+                               k_dynamic -= 7;
+                               if ((unsigned int) i + j > n) {
+                                       return 1;
                                }
-                               else if (j == 16) {             /* repeat last length 3 to 6 times */
-                                       while (k_dynamic < 2) {
-                                               b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                                               k_dynamic += 8;
-                                       }
-                                       j = 3 + ((unsigned) b_dynamic & 3);
-                                       b_dynamic >>= 2;
-                                       k_dynamic -= 2;
-                                       if ((unsigned) i + j > n) {
-                                               return 1;
-                                       }
-                                       while (j--) {
-                                               ll[i++] = l;
-                                       }
-                               } else if (j == 17) {   /* 3 to 10 zero length codes */
-                                       while (k_dynamic < 3) {
-                                               b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                                               k_dynamic += 8;
-                                       }
-                                       j = 3 + ((unsigned) b_dynamic & 7);
-                                       b_dynamic >>= 3;
-                                       k_dynamic -= 3;
-                                       if ((unsigned) i + j > n) {
-                                               return 1;
-                                       }
-                                       while (j--) {
-                                               ll[i++] = 0;
-                                       }
-                                       l = 0;
-                               } else {                /* j == 18: 11 to 138 zero length codes */
-                                       while (k_dynamic < 7) {
-                                               b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
-                                               k_dynamic += 8;
-                                       }
-                                       j = 11 + ((unsigned) b_dynamic & 0x7f);
-                                       b_dynamic >>= 7;
-                                       k_dynamic -= 7;
-                                       if ((unsigned) i + j > n) {
-                                               return 1;
-                                       }
-                                       while (j--) {
-                                               ll[i++] = 0;
-                                       }
-                                       l = 0;
+                               while (j--) {
+                                       ll[i++] = 0;
                                }
+                               l = 0;
                        }
+               }
 
-                       /* free decoding table for trees */
-                       huft_free(tl);
+               /* free decoding table for trees */
+               huft_free(tl);
 
-                       /* restore the global bit buffer */
-                       bb = b_dynamic;
-                       bk = k_dynamic;
+               /* restore the global bit buffer */
+               gunzip_bb = b_dynamic;
+               gunzip_bk = k_dynamic;
 
-                       /* build the decoding tables for literal/length and distance codes */
-                       bl = lbits;
-                       if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
-                               if (i == 1) {
-                                       error_msg("Incomplete literal tree");
-                                       huft_free(tl);
-                               }
-                               return i;                       /* incomplete code set */
-                       }
-                       bd = dbits;
-                       if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
-                               if (i == 1) {
-                                       error_msg("incomplete distance tree");
-                                       huft_free(td);
-                               }
+               /* build the decoding tables for literal/length and distance codes */
+               bl = lbits;
+
+               if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
+                       if (i == 1) {
+                               error_msg_and_die("Incomplete literal tree");
                                huft_free(tl);
-                               return i;                       /* incomplete code set */
                        }
+                       return i;       /* incomplete code set */
+               }
 
-                       /* decompress until an end-of-block code */
-                       if (inflate_codes(tl, td, bl, bd))
-                               return 1;
-
-                       /* free the decoding tables, return */
+               bd = dbits;
+               if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
+                       if (i == 1) {
+                               error_msg_and_die("incomplete distance tree");
+                               huft_free(td);
+                       }
                        huft_free(tl);
-                       huft_free(td);
-                       return 0;
+                       return i;       /* incomplete code set */
                }
+
+               /* decompress until an end-of-block code */
+               inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes
+
+               /* huft_free code moved into inflate_codes */
+               
+               return -2;
+       }
        default:
                /* bad block type */
-               return 2;
+               error_msg_and_die("bad block type %d\n", t);
        }
 }
 
-/*
- * decompress an inflated entry
- *
- * GLOBAL VARIABLES: outcnt, bk, bb, hufts, inptr
- */
-static int inflate(void)
+static void calculate_gunzip_crc(void)
 {
-       int e;                          /* last block flag */
-       int r;                          /* result code */
-       unsigned h = 0;         /* maximum struct huft's malloc'ed */
-
-       /* initialize window, bit buffer */
-       outcnt = 0;
-       bk = 0;
-       bb = 0;
-
-       /* Create the crc table */
-       make_crc_table();
+       int n;
+       for (n = 0; n < gunzip_outbuf_count; n++) {
+               gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8);
+       }
+       gunzip_bytes_out += gunzip_outbuf_count;
+}
 
-       /* decompress until the last block */
-       do {
-               hufts = 0;
-               if ((r = inflate_block(&e)) != 0) {
-                       return r;
+static int inflate_get_next_window(void)
+{
+       static int needAnotherBlock = 1;
+       static int method = -1; // Method == -1 for stored, -2 for codes
+       static int e = 0;
+       
+       gunzip_outbuf_count = 0;
+
+       while(1) {
+               int ret;
+       
+               if (needAnotherBlock) {
+                       if(e) { calculate_gunzip_crc(); return 0; } // Last block
+                       method = inflate_block(&e);
+                       needAnotherBlock = 0;
                }
-               if (hufts > h) {
-                       h = hufts;
+       
+               switch (method) {
+                       case -1:        ret = inflate_stored(0,0,0,0);
+                                       break;
+                       case -2:        ret = inflate_codes(0,0,0,0,0);
+                                       break;
+                       default:        error_msg_and_die("inflate error %d", method);
                }
-       } while (!e);
-
-       /* Undo too much lookahead. The next read will be byte aligned so we
-        * can discard unused bits in the last meaningful byte.
-        */
-       while (bk >= 8) {
-               bk -= 8;
-               ungetc((bb << bk), in_file);
-       }
 
-       /* flush out window */
-       flush_window();
-
-       /* return success */
-       return 0;
+               if (ret == 1) {
+                       calculate_gunzip_crc();
+                       return 1; // More data left
+               } else needAnotherBlock = 1; // End of that block
+       }
 }
 
-/* ===========================================================================
- * Unzip in to out.  This routine works on both gzip and pkzip files.
+/*
+ * User functions
  *
- * IN assertions: the buffer inbuf contains already the beginning of
- *   the compressed data, from offsets inptr to insize-1 included.
- *   The magic header has already been checked. The output buffer is cleared.
- * in, out: input and output file descriptors
+ * read_gz, GZ_gzReadOpen, GZ_gzReadClose, inflate
  */
-extern int unzip(FILE *l_in_file, FILE *l_out_file)
-{
-       unsigned char buf[8];   /* extended local header */
-       unsigned char flags;    /* compression flags */
-       typedef void (*sig_type) (int);
-       unsigned short i;
 
-       in_file = l_in_file;
-       out_file = l_out_file;
-
-       if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
-               (void) signal(SIGINT, (sig_type) abort_gzip);
-       }
-#ifdef SIGTERM
-//     if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
-//             (void) signal(SIGTERM, (sig_type) abort_gzip);
-//     }
-#endif
-#ifdef SIGHUP
-       if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
-               (void) signal(SIGHUP, (sig_type) abort_gzip);
-       }
-#endif
-
-       /* Allocate all global buffers (for DYN_ALLOC option) */
-       window = xmalloc((size_t)(((2L*WSIZE)+1L)*sizeof(unsigned char)));
-       outcnt = 0;
-       bytes_out = 0L;
-
-       /* Magic header for gzip files, 1F 8B = \037\213 */
-       if ((fgetc(in_file) != 0x1F) || (fgetc(in_file) != 0x8b)) { 
-               error_msg("Invalid gzip magic");
-               return EXIT_FAILURE;
-       }
-
-       /* Check the compression method */
-       if (fgetc(in_file) != 8) {
-               error_msg("Unknown compression method");
-               return(-1);
-       }
-
-       flags = (unsigned char) fgetc(in_file);
-
-       /* Ignore time stamp(4), extra flags(1), OS type(1) */
-       for (i = 0; i < 6; i++) {
-               fgetc(in_file);
+extern ssize_t read_gz(int fd, void *buf, size_t count)
+{
+       static int morebytes = 0, finished = 0;
+       
+       if (morebytes) {
+               int bytesRead = morebytes > count ? count : morebytes;
+               memcpy(buf, gunzip_window + (gunzip_outbuf_count - morebytes), bytesRead);
+               morebytes -= bytesRead;
+               return bytesRead;
+       } else if (finished) {
+               return 0;
+       } else if (count >= 0x8000) { // We can decompress direcly to the buffer, 32k at a time
+               // Could decompress to larger buffer, but it must be a power of 2, and calculating that is probably more expensive than the benefit
+               unsigned char *old_gunzip_window = gunzip_window; // Save old window
+               gunzip_window = buf;
+               if (inflate_get_next_window() == 0) finished = 1;
+               gunzip_window = old_gunzip_window; // Restore old window
+               return gunzip_outbuf_count;
+       } else { // Oh well, need to split up the gunzip_window
+               int bytesRead;
+               if (inflate_get_next_window() == 0) finished = 1;
+               morebytes = gunzip_outbuf_count;
+               bytesRead = morebytes > count ? count : morebytes;
+               memcpy(buf, gunzip_window, bytesRead);
+               morebytes -= bytesRead;
+               return bytesRead;
        }
+       
+}
 
-       if (flags & 0x04) {
-               /* bit 2 set: extra field present */
-               const unsigned short extra = fgetc(in_file) + (fgetc(in_file) << 8);
-
-               for (i = 0; i < extra; i++) {
-                       fgetc(in_file);
-               }
-       }
+extern void GZ_gzReadOpen(int fd, void *unused, int nUnused)
+{
+       typedef void (*sig_type) (int);
 
-       /* Discard original name if any */
-       if (flags & 0x08) {
-               /* bit 3 set: original file name present */
-               while (fgetc(in_file) != 0);    /* null */
-       }
+       /* Allocate all global buffers (for DYN_ALLOC option) */
+       gunzip_window = xmalloc(gunzip_wsize);
+       gunzip_outbuf_count = 0;
+       gunzip_bytes_out = 0;
+       gunzip_src_fd = fd;
 
-       /* Discard file comment if any */
-       if (flags & 0x10) {
-               /* bit 4 set: file comment present */
-               while (fgetc(in_file) != 0);    /* null */
-       }
+       gunzip_in_buffer = malloc(8);
 
-       /* Decompress */
-       if (inflate() != 0) {
-               error_msg("invalid compressed data--format violated");
-       }
+       /* initialize gunzip_window, bit buffer */
+       gunzip_bk = 0;
+       gunzip_bb = 0;
 
-       /* Get the crc and original length
-        * crc32  (see algorithm.doc)
-        * uncompressed input size modulo 2^32
-        */
-       fread(buf, 1, 8, in_file);
+       /* Create the crc table */
+       make_gunzip_crc_table();
+}
 
-       /* Validate decompression - crc */
-       if ((unsigned int)((buf[0] | (buf[1] << 8)) |((buf[2] | (buf[3] << 8)) << 16)) != (crc ^ 0xffffffffL)) {
-               error_msg("invalid compressed data--crc error");
-       }
-       /* Validate decompression - size */
-       if (((buf[4] | (buf[5] << 8)) |((buf[6] | (buf[7] << 8)) << 16)) != (unsigned long) bytes_out) {
-               error_msg("invalid compressed data--length error");
+extern void GZ_gzReadClose(void)
+{
+       /* Cleanup */
+       free(gunzip_window);
+       free(gunzip_crc_table);
+
+       /* Store unused bytes in a global buffer so calling applets can access it */
+       gunzip_in_buffer_count = 0;
+       if (gunzip_bk >= 8) {
+               /* Undo too much lookahead. The next read will be byte aligned
+                * so we can discard unused bits in the last meaningful byte. */
+               gunzip_in_buffer[gunzip_in_buffer_count] = gunzip_bb & 0xff;
+               gunzip_in_buffer_count++;
+               gunzip_bb >>= 8;
+               gunzip_bk -= 8;
        }
-
-       free(window);
-       free(crc_table);
-
-       return 0;
 }
 
-/*
- * This needs access to global variables wondow and crc_table, so its not in its own file.
- */
-extern void gz_close(int gunzip_pid)
+/*extern int inflate(int in, int out) // Useful for testing read_gz
 {
-       if (kill(gunzip_pid, SIGTERM) == -1) {
-               error_msg_and_die("***  Couldnt kill old gunzip process *** aborting");
+       char buf[8192];
+       ssize_t nread, nwrote;
+
+       GZ_gzReadOpen(in, 0, 0);
+       while(1) { // Robbed from copyfd.c
+               nread = read_gz(in, buf, sizeof(buf));
+               if (nread == 0) break; // no data to write
+               else if (nread == -1) {
+                       perror_msg("read");
+                       return -1;
+               }
+               nwrote = full_write(out, buf, nread);
+               if (nwrote == -1) {
+                       perror_msg("write");
+                       return -1;
+               }
        }
+       GZ_gzReadClose();
+       return 0;
+}*/
 
-       if (waitpid(gunzip_pid, NULL, 0) == -1) {
-               printf("Couldnt wait ?");
+extern int inflate(int in, int out)
+{
+       ssize_t nwrote;
+       GZ_gzReadOpen(in, 0, 0);
+       while(1) {
+               int ret = inflate_get_next_window();
+               nwrote = full_write(out, gunzip_window, gunzip_outbuf_count);
+               if (nwrote == -1) {
+                       perror_msg("write");
+                       return -1;
+               }
+               if (ret == 0) break;
        }
-
-       free(window);
-       free(crc_table);
+       GZ_gzReadClose();
+       return 0;
 }