Commit my improvement on Rodney Brown's patch to g(un)zip, decreasing

binary size.

1 files changed, 29 insertions, 26 deletions

diff --git a/libbb/unzip.c b/libbb/unzip.c
index a747baea5..6c3f3229a 100644
--- a/libbb/unzip.c
+++ b/libbb/unzip.c
@@ -186,6 +186,8 @@ 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
@@ -201,7 +203,7 @@ static int huft_free(huft_t *t)
  * 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 unsigned short *e, huft_t **t, int *m)
+        const unsigned short *d, const extra_bits_t *e, huft_t **t, int *m)
 {
         unsigned a;             /* counter for codes of length k */
         unsigned c[BMAX + 1];   /* bit length count table */
@@ -489,6 +491,30 @@ static int inflate_codes(huft_t *tl, huft_t *td, int bl, int bd)
         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
+};
+
 /*
  * decompress an inflated block
  * e: last block flag
@@ -500,25 +526,6 @@ 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 */
-        static 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 unsigned short 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 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 unsigned short 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
-        };
 
         /* make local bit buffer */
         b = bb;
@@ -657,12 +664,8 @@ static int inflate_block(int *e)
                 }
         case 2: /* Inflate dynamic */
                 {
-                        /* Tables for deflate from PKZIP's appnote.txt. */
-                        static unsigned 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
-                        };
-                        int dbits = 6;                                  /* bits in base distance lookup table */
-                        int lbits = 9;                                  /* bits in base literal/length lookup table */
+                        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;