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authorDenis Vlasenko <vda.linux@googlemail.com>2007-01-07 19:38:42 +0000
committerDenis Vlasenko <vda.linux@googlemail.com>2007-01-07 19:38:42 +0000
commitf824136f6b21558ac023bc53bcb69294e0676103 (patch)
treef168544e67c3c8c5dae57c5a58ffa7e8b16e92f3 /archival/gzip.c
parented0f6db35e02ccd0d8c22337639463a05e3efea1 (diff)
downloadbusybox-f824136f6b21558ac023bc53bcb69294e0676103.tar.gz
gzip cleanup part #4
Diffstat (limited to 'archival/gzip.c')
-rw-r--r--archival/gzip.c74
1 files changed, 39 insertions, 35 deletions
diff --git a/archival/gzip.c b/archival/gzip.c
index dcbcae0b3..4f47a2782 100644
--- a/archival/gzip.c
+++ b/archival/gzip.c
@@ -61,12 +61,6 @@ aa: 85.1% -- replaced with aa.gz
# endif
#endif
-#define PACK_MAGIC "\037\036" /* Magic header for packed files */
-#define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
-#define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
-#define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files */
-#define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */
-
/* gzip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
@@ -142,9 +136,9 @@ aa: 85.1% -- replaced with aa.gz
# define Assert(cond,msg) {if(!(cond)) bb_error_msg(msg);}
# define Trace(x) fprintf x
# define Tracev(x) {if (verbose) fprintf x ;}
-# define Tracevv(x) {if (verbose>1) fprintf x ;}
+# define Tracevv(x) {if (verbose > 1) fprintf x ;}
# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
-# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
+# define Tracecv(c,x) {if (verbose > 1 && (c)) fprintf x ;}
#else
# define Assert(cond,msg)
# define Trace(x)
@@ -313,7 +307,7 @@ static void clear_bufs(void)
* pointer, then initialize the crc shift register contents instead.
* Return the current crc in either case.
*/
-static uint32_t crc = ~0; /* shift register contents */
+static uint32_t crc; /* shift register contents */
static uint32_t updcrc(uch * s, unsigned n)
{
uint32_t c; /* temporary variable */
@@ -1414,17 +1408,18 @@ static void set_file_type(void);
#ifndef DEBUG
+/* Send a code of the given tree. c and tree must not have side effects */
# define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
- /* Send a code of the given tree. c and tree must not have side effects */
-
#else /* DEBUG */
# define send_code(c, tree) \
- { if (verbose>1) bb_error_msg("\ncd %3d ",(c)); \
- send_bits(tree[c].Code, tree[c].Len); }
+{ \
+ if (verbose > 1) bb_error_msg("\ncd %3d ",(c)); \
+ send_bits(tree[c].Code, tree[c].Len); \
+}
#endif
#define d_code(dist) \
- ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
+ ((dist) < 256 ? dist_code[dist] : dist_code[256 + ((dist)>>7)])
/* Mapping from a distance to a distance code. dist is the distance - 1 and
* must not have side effects. dist_code[256] and dist_code[257] are never
* used.
@@ -1432,6 +1427,7 @@ static void set_file_type(void);
/* the arguments must not have side effects */
+
/* ===========================================================================
* Allocate the match buffer, initialize the various tables and save the
* location of the internal file attribute (ascii/binary) and method
@@ -1513,12 +1509,13 @@ static void ct_init(ush * attr, int *methodp)
init_block();
}
+
/* ===========================================================================
* Initialize a new block.
*/
static void init_block(void)
{
- int n; /* iterates over tree elements */
+ int n; /* iterates over tree elements */
/* Initialize the trees. */
for (n = 0; n < L_CODES; n++)
@@ -1535,28 +1532,22 @@ static void init_block(void)
flag_bit = 1;
}
-#define SMALLEST 1
-/* Index within the heap array of least frequent node in the Huffman tree */
-
/* ===========================================================================
* Remove the smallest element from the heap and recreate the heap with
* one less element. Updates heap and heap_len.
*/
+
+#define SMALLEST 1
+/* Index within the heap array of least frequent node in the Huffman tree */
+
#define pqremove(tree, top) \
-{\
- top = heap[SMALLEST]; \
- heap[SMALLEST] = heap[heap_len--]; \
- pqdownheap(tree, SMALLEST); \
+{ \
+ top = heap[SMALLEST]; \
+ heap[SMALLEST] = heap[heap_len--]; \
+ pqdownheap(tree, SMALLEST); \
}
-/* ===========================================================================
- * Compares to subtrees, using the tree depth as tie breaker when
- * the subtrees have equal frequency. This minimizes the worst case length.
- */
-#define smaller(tree, n, m) \
- (tree[n].Freq < tree[m].Freq || \
- (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
/* ===========================================================================
* Restore the heap property by moving down the tree starting at node k,
@@ -1564,6 +1555,14 @@ static void init_block(void)
* when the heap property is re-established (each father smaller than its
* two sons).
*/
+
+/* Compares to subtrees, using the tree depth as tie breaker when
+ * the subtrees have equal frequency. This minimizes the worst case length.
+ */
+#define smaller(tree, n, m) \
+ (tree[n].Freq < tree[m].Freq \
+ || (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
+
static void pqdownheap(ct_data * tree, int k)
{
int v = heap[k];
@@ -1588,6 +1587,7 @@ static void pqdownheap(ct_data * tree, int k)
heap[k] = v;
}
+
/* ===========================================================================
* Compute the optimal bit lengths for a tree and update the total bit length
* for the current block.
@@ -1624,8 +1624,10 @@ static void gen_bitlen(tree_desc * desc)
for (h = heap_max + 1; h < HEAP_SIZE; h++) {
n = heap[h];
bits = tree[tree[n].Dad].Len + 1;
- if (bits > max_length)
- bits = max_length, overflow++;
+ if (bits > max_length) {
+ bits = max_length;
+ overflow++;
+ }
tree[n].Len = (ush) bits;
/* We overwrite tree[n].Dad which is no longer needed */
@@ -2151,7 +2153,7 @@ static void compress_block(ct_data * ltree, ct_data * dtree)
unsigned code; /* the code to send */
int extra; /* number of extra bits to send */
- if (last_lit != 0)
+ if (last_lit != 0) {
do {
if ((lx & 7) == 0)
flag = flag_buf[fx++];
@@ -2182,6 +2184,7 @@ static void compress_block(ct_data * ltree, ct_data * dtree)
} /* literal or match pair ? */
flag >>= 1;
} while (lx < last_lit);
+ }
send_code(END_BLOCK, ltree);
}
@@ -2204,7 +2207,7 @@ static void set_file_type(void)
ascii_freq += dyn_ltree[n++].Freq;
while (n < LITERALS)
bin_freq += dyn_ltree[n++].Freq;
- *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
+ *file_type = (bin_freq > (ascii_freq >> 2)) ? BINARY : ASCII;
if (*file_type == BINARY && translate_eol) {
bb_error_msg("-l used on binary file");
}
@@ -2228,8 +2231,9 @@ static int zip(int in, int out)
/* Write the header to the gzip file. See algorithm.doc for the format */
method = DEFLATED;
- put_header_byte(GZIP_MAGIC[0]); /* magic header */
- put_header_byte(GZIP_MAGIC[1]);
+ put_header_byte(0x1f); /* magic header for gzip files, 1F 8B */
+ put_header_byte(0x8b);
+
put_header_byte(DEFLATED); /* compression method */
put_header_byte(my_flags); /* general flags */