ppcrcd/trunk/yaboot/gunzip.c
sparky
cvs at pld-linux.org
Thu Jan 5 23:14:51 CET 2006
Author: sparky
Date: Thu Jan 5 23:14:47 2006
New Revision: 6746
Modified:
ppcrcd/trunk/yaboot/gunzip.c
Log:
- spaces -> tabs
Modified: ppcrcd/trunk/yaboot/gunzip.c
==============================================================================
--- ppcrcd/trunk/yaboot/gunzip.c (original)
+++ ppcrcd/trunk/yaboot/gunzip.c Thu Jan 5 23:14:47 2006
@@ -1,4 +1,4 @@
-/*
+/*
* yaboot for ppcrcd
* PLD Linux Distribution
*
@@ -32,101 +32,101 @@
*/
/* inflate.c -- Not copyrighted 1992 by Mark Adler
- version c10p1, 10 January 1993 */
+ version c10p1, 10 January 1993 */
/* You can do whatever you like with this source file, though I would
- prefer that if you modify it and redistribute it that you include
- comments to that effect with your name and the date. Thank you.
+ prefer that if you modify it and redistribute it that you include
+ comments to that effect with your name and the date. Thank you.
*/
/*
- Inflate deflated (PKZIP's method 8 compressed) data. The compression
- method searches for as much of the current string of bytes (up to a
- length of 258) in the previous 32K bytes. If it doesn't find any
- matches (of at least length 3), it codes the next byte. Otherwise, it
- codes the length of the matched string and its distance backwards from
- the current position. There is a single Huffman code that codes both
- single bytes (called "literals") and match lengths. A second Huffman
- code codes the distance information, which follows a length code. Each
- length or distance code actually represents a base value and a number
- of "extra" (sometimes zero) bits to get to add to the base value. At
- the end of each deflated block is a special end-of-block (EOB) literal/
- length code. The decoding process is basically: get a literal/length
- code; if EOB then done; if a literal, emit the decoded byte; if a
- length then get the distance and emit the referred-to bytes from the
- sliding window of previously emitted data.
-
- There are (currently) three kinds of inflate blocks: stored, fixed, and
- dynamic. The compressor deals with some chunk of data at a time, and
- decides which method to use on a chunk-by-chunk basis. A chunk might
- typically be 32K or 64K. If the chunk is uncompressible, then the
- "stored" method is used. In this case, the bytes are simply stored as
- is, eight bits per byte, with none of the above coding. The bytes are
- preceded by a count, since there is no longer an EOB code.
-
- If the data is compressible, then either the fixed or dynamic methods
- are used. In the dynamic method, the compressed data is preceded by
- an encoding of the literal/length and distance Huffman codes that are
- to be used to decode this block. The representation is itself Huffman
- coded, and so is preceded by a description of that code. These code
- descriptions take up a little space, and so for small blocks, there is
- a predefined set of codes, called the fixed codes. The fixed method is
- used if the block codes up smaller that way (usually for quite small
- chunks), otherwise the dynamic method is used. In the latter case, the
- codes are customized to the probabilities in the current block, and so
- can code it much better than the pre-determined fixed codes.
-
- The Huffman codes themselves are decoded using a mutli-level table
- lookup, in order to maximize the speed of decoding plus the speed of
- building the decoding tables. See the comments below that precede the
- lbits and dbits tuning parameters.
- */
+ Inflate deflated (PKZIP's method 8 compressed) data. The compression
+ method searches for as much of the current string of bytes (up to a
+ length of 258) in the previous 32K bytes. If it doesn't find any
+ matches (of at least length 3), it codes the next byte. Otherwise, it
+ codes the length of the matched string and its distance backwards from
+ the current position. There is a single Huffman code that codes both
+ single bytes (called "literals") and match lengths. A second Huffman
+ code codes the distance information, which follows a length code. Each
+ length or distance code actually represents a base value and a number
+ of "extra" (sometimes zero) bits to get to add to the base value. At
+ the end of each deflated block is a special end-of-block (EOB) literal/
+ length code. The decoding process is basically: get a literal/length
+ code; if EOB then done; if a literal, emit the decoded byte; if a
+ length then get the distance and emit the referred-to bytes from the
+ sliding window of previously emitted data.
+
+ There are (currently) three kinds of inflate blocks: stored, fixed, and
+ dynamic. The compressor deals with some chunk of data at a time, and
+ decides which method to use on a chunk-by-chunk basis. A chunk might
+ typically be 32K or 64K. If the chunk is uncompressible, then the
+ "stored" method is used. In this case, the bytes are simply stored as
+ is, eight bits per byte, with none of the above coding. The bytes are
+ preceded by a count, since there is no longer an EOB code.
+
+ If the data is compressible, then either the fixed or dynamic methods
+ are used. In the dynamic method, the compressed data is preceded by
+ an encoding of the literal/length and distance Huffman codes that are
+ to be used to decode this block. The representation is itself Huffman
+ coded, and so is preceded by a description of that code. These code
+ descriptions take up a little space, and so for small blocks, there is
+ a predefined set of codes, called the fixed codes. The fixed method is
+ used if the block codes up smaller that way (usually for quite small
+ chunks), otherwise the dynamic method is used. In the latter case, the
+ codes are customized to the probabilities in the current block, and so
+ can code it much better than the pre-determined fixed codes.
+
+ The Huffman codes themselves are decoded using a mutli-level table
+ lookup, in order to maximize the speed of decoding plus the speed of
+ building the decoding tables. See the comments below that precede the
+ lbits and dbits tuning parameters.
+*/
/*
- Notes beyond the 1.93a appnote.txt:
-
- 1. Distance pointers never point before the beginning of the output
- stream.
- 2. Distance pointers can point back across blocks, up to 32k away.
- 3. There is an implied maximum of 7 bits for the bit length table and
- 15 bits for the actual data.
- 4. If only one code exists, then it is encoded using one bit. (Zero
- would be more efficient, but perhaps a little confusing.) If two
- codes exist, they are coded using one bit each (0 and 1).
- 5. There is no way of sending zero distance codes--a dummy must be
- sent if there are none. (History: a pre 2.0 version of PKZIP would
- store blocks with no distance codes, but this was discovered to be
- too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
- zero distance codes, which is sent as one code of zero bits in
- length.
- 6. There are up to 286 literal/length codes. Code 256 represents the
- end-of-block. Note however that the static length tree defines
- 288 codes just to fill out the Huffman codes. Codes 286 and 287
- cannot be used though, since there is no length base or extra bits
- defined for them. Similarly, there are up to 30 distance codes.
- However, static trees define 32 codes (all 5 bits) to fill out the
- Huffman codes, but the last two had better not show up in the data.
- 7. Unzip can check dynamic Huffman blocks for complete code sets.
- The exception is that a single code would not be complete (see #4).
- 8. The five bits following the block type is really the number of
- literal codes sent minus 257.
- 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
- (1+6+6). Therefore, to output three times the length, you output
- three codes (1+1+1), whereas to output four times the same length,
- you only need two codes (1+3). Hmm.
- 10. In the tree reconstruction algorithm, Code = Code + Increment
- only if BitLength(i) is not zero. (Pretty obvious.)
- 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
- 12. Note: length code 284 can represent 227-258, but length code 285
- really is 258. The last length deserves its own, short code
- since it gets used a lot in very redundant files. The length
- 258 is special since 258 - 3 (the min match length) is 255.
- 13. The literal/length and distance code bit lengths are read as a
- single stream of lengths. It is possible (and advantageous) for
- a repeat code (16, 17, or 18) to go across the boundary between
- the two sets of lengths.
- */
+ Notes beyond the 1.93a appnote.txt:
+
+ 1. Distance pointers never point before the beginning of the output
+ stream.
+ 2. Distance pointers can point back across blocks, up to 32k away.
+ 3. There is an implied maximum of 7 bits for the bit length table and
+ 15 bits for the actual data.
+ 4. If only one code exists, then it is encoded using one bit. (Zero
+ would be more efficient, but perhaps a little confusing.) If two
+ codes exist, they are coded using one bit each (0 and 1).
+ 5. There is no way of sending zero distance codes--a dummy must be
+ sent if there are none. (History: a pre 2.0 version of PKZIP would
+ store blocks with no distance codes, but this was discovered to be
+ too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
+ zero distance codes, which is sent as one code of zero bits in
+ length.
+ 6. There are up to 286 literal/length codes. Code 256 represents the
+ end-of-block. Note however that the static length tree defines
+ 288 codes just to fill out the Huffman codes. Codes 286 and 287
+ cannot be used though, since there is no length base or extra bits
+ defined for them. Similarly, there are up to 30 distance codes.
+ However, static trees define 32 codes (all 5 bits) to fill out the
+ Huffman codes, but the last two had better not show up in the data.
+ 7. Unzip can check dynamic Huffman blocks for complete code sets.
+ The exception is that a single code would not be complete (see #4).
+ 8. The five bits following the block type is really the number of
+ literal codes sent minus 257.
+ 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
+ (1+6+6). Therefore, to output three times the length, you output
+ three codes (1+1+1), whereas to output four times the same length,
+ you only need two codes (1+3). Hmm.
+ 10. In the tree reconstruction algorithm, Code = Code + Increment
+ only if BitLength(i) is not zero. (Pretty obvious.)
+ 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
+ 12. Note: length code 284 can represent 227-258, but length code 285
+ really is 258. The last length deserves its own, short code
+ since it gets used a lot in very redundant files. The length
+ 258 is special since 258 - 3 (the min match length) is 255.
+ 13. The literal/length and distance code bit lengths are read as a
+ single stream of lengths. It is possible (and advantageous) for
+ a repeat code (16, 17, or 18) to go across the boundary between
+ the two sets of lengths.
+*/
#include "stdlib.h"
#include "string.h"
@@ -159,13 +159,15 @@
static char *gzmalloc_start = 0;
static char *gzmalloc_top = 0;
-void gzmalloc_init(void *bottom, unsigned long size)
+void
+gzmalloc_init(void *bottom, unsigned long size)
{
- gzmalloc_start = gzmalloc_ptr = bottom;
- gzmalloc_top = bottom + size;
+ gzmalloc_start = gzmalloc_ptr = bottom;
+ gzmalloc_top = bottom + size;
}
-void *gzmalloc (unsigned int size)
+void *
+gzmalloc (unsigned int size)
{
char *caddr;
@@ -182,7 +184,8 @@
return caddr;
}
-void reset_gzmalloc(void) {
+void
+reset_gzmalloc(void) {
gzmalloc_ptr = gzmalloc_start;
}
@@ -191,56 +194,56 @@
static int
bad_field (int len)
{
- char ch = 1;
- int not_retval = 1;
+ char ch = 1;
+ int not_retval = 1;
- do
- {
- if (len >= 0)
+ do
{
- if (!(len--))
- break;
- }
- else
- {
- if (!ch)
- break;
+ if (len >= 0)
+ {
+ if (!(len--))
+ break;
+ }
+ else
+ {
+ if (!ch)
+ break;
+ }
}
- }
- while ((not_retval = gunzip_file.fs->read(&gunzip_file, 1, &ch)) == 1);
+ while ((not_retval = gunzip_file.fs->read(&gunzip_file, 1, &ch)) == 1);
- return (!not_retval);
+ return (!not_retval);
}
/* Big-Endian defines for the 2-byte magic number for gzip files */
-#define GZIP_HDR_BE 0x1F8B
-#define OLD_GZIP_HDR_BE 0x1F9E
+#define GZIP_HDR_BE 0x1F8B
+#define OLD_GZIP_HDR_BE 0x1F9E
/* Compression methods (see algorithm.doc) */
-#define STORED 0
-#define COMPRESSED 1
-#define PACKED 2
-#define LZHED 3
+#define STORED 0
+#define COMPRESSED 1
+#define PACKED 2
+#define LZHED 3
/* methods 4 to 7 reserved */
-#define DEFLATED 8
-#define MAX_METHODS 9
+#define DEFLATED 8
+#define MAX_METHODS 9
/* gzip flag byte */
-#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
+#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
-#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 ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
-#define RESERVED 0xC0 /* bit 6,7: reserved */
+#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 ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
+#define RESERVED 0xC0 /* bit 6,7: reserved */
#define UNSUPP_FLAGS (CONTINUATION|ENCRYPTED|RESERVED)
/* inflate block codes */
-#define INFLATE_STORED 0
-#define INFLATE_FIXED 1
-#define INFLATE_DYNAMIC 2
+#define INFLATE_STORED 0
+#define INFLATE_FIXED 1
+#define INFLATE_DYNAMIC 2
typedef unsigned char uch;
typedef unsigned short ush;
@@ -259,75 +262,75 @@
int
gunzip_test_header (void)
{
- unsigned char buf[10];
-
- compressed_file = 0;
-
- /*
- * This checks if the file is gzipped. If a problem occurs here
- * (other than a real error with the disk) then we don't think it
- * is a compressed file, and simply mark it as such.
- */
- if ( gunzip_file.fs->read(&gunzip_file, 10, &buf) != 10
- || ((*((unsigned short *) buf) != GZIP_HDR_BE)
- && (*((unsigned short *) buf) != OLD_GZIP_HDR_BE)))
- {
- gunzip_file.fs->seek(&gunzip_file, 0);
- return 1;
- }
-
- /*
- * This does consistency checking on the header data. If a
- * problem occurs from here on, then we have corrupt or otherwise
- * bad data, and the error should be reported to the user.
- */
- if (buf[2] != DEFLATED
- || (buf[3] & UNSUPP_FLAGS)
- || ((buf[3] & EXTRA_FIELD)
- && (gunzip_file.fs->read(&gunzip_file, 2, &buf) != 2
- || bad_field (*((unsigned short *) buf))))
- || ((buf[3] & ORIG_NAME) && bad_field (-1))
- || ((buf[3] & COMMENT) && bad_field (-1)))
- {
- gunzip_file.fs->seek(&gunzip_file, 0);
- return 10;
- }
-
- gzip_data_offset = gunzip_file.pos;
-
- if (!initialized_gzmalloc)
- {
- void* gzmalloc_base = NULL;
-
- gzmalloc_base = prom_claim((void *)GZMALLOCADDR, GZMALLOCSIZE, 0);
- if (gzmalloc_base == (void *)-1) {
- prom_printf("Can't claim malloc buffer (%d bytes at 0x%08x)\n",
- GZMALLOCSIZE, GZMALLOCADDR);
- return -1;
- }
- gzmalloc_init(gzmalloc_base, GZMALLOCSIZE);
- initialized_gzmalloc = 1;
- }
-
- initialize_tables ();
-
- compressed_file = 1;
-
- gzip_filepos = 0;
+ unsigned char buf[10];
+
+ compressed_file = 0;
+
+ /*
+ * This checks if the file is gzipped. If a problem occurs here
+ * (other than a real error with the disk) then we don't think it
+ * is a compressed file, and simply mark it as such.
+ */
+ if ( gunzip_file.fs->read(&gunzip_file, 10, &buf) != 10
+ || ((*((unsigned short *) buf) != GZIP_HDR_BE)
+ && (*((unsigned short *) buf) != OLD_GZIP_HDR_BE)))
+ {
+ gunzip_file.fs->seek(&gunzip_file, 0);
+ return 1;
+ }
- return 0;
+ /*
+ * This does consistency checking on the header data. If a
+ * problem occurs from here on, then we have corrupt or otherwise
+ * bad data, and the error should be reported to the user.
+ */
+ if (buf[2] != DEFLATED
+ || (buf[3] & UNSUPP_FLAGS)
+ || ((buf[3] & EXTRA_FIELD)
+ && (gunzip_file.fs->read(&gunzip_file, 2, &buf) != 2
+ || bad_field (*((unsigned short *) buf))))
+ || ((buf[3] & ORIG_NAME) && bad_field (-1))
+ || ((buf[3] & COMMENT) && bad_field (-1)))
+ {
+ gunzip_file.fs->seek(&gunzip_file, 0);
+ return 10;
+ }
+
+ gzip_data_offset = gunzip_file.pos;
+
+ if (!initialized_gzmalloc)
+ {
+ void* gzmalloc_base = NULL;
+
+ gzmalloc_base = prom_claim((void *)GZMALLOCADDR, GZMALLOCSIZE, 0);
+ if (gzmalloc_base == (void *)-1) {
+ prom_printf("Can't claim malloc buffer (%d bytes at 0x%08x)\n",
+ GZMALLOCSIZE, GZMALLOCADDR);
+ return -1;
+ }
+ gzmalloc_init(gzmalloc_base, GZMALLOCSIZE);
+ initialized_gzmalloc = 1;
+ }
+
+ initialize_tables ();
+
+ compressed_file = 1;
+
+ gzip_filepos = 0;
+
+ return 0;
}
/* The inflate algorithm uses a sliding 32K byte window on the uncompressed
- stream to find repeated byte strings. This is implemented here as a
- circular buffer. The index is updated simply by incrementing and then
- and'ing with 0x7fff (32K-1). */
+ stream to find repeated byte strings. This is implemented here as a
+ circular buffer. The index is updated simply by incrementing and then
+ and'ing with 0x7fff (32K-1). */
/* It is left to other modules to supply the 32K area. It is assumed
- to be usable as if it were declared "uch slide[32768];" or as just
- "uch *slide;" and then malloc'ed in the latter case. The definition
- must be in unzip.h, included above. */
+ to be usable as if it were declared "uch slide[32768];" or as just
+ "uch *slide;" and then malloc'ed in the latter case. The definition
+ must be in unzip.h, included above. */
/* sliding window in uncompressed data */
@@ -339,60 +342,70 @@
/* Tables for deflate from PKZIP's appnote.txt. */
static unsigned bitorder[] =
-{ /* 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};
+{
+ /* 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 ush 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. */
+{
+ /* 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 ush 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 */
+{
+ /* 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 ush 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};
+{
+ /* 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 ush 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};
+{
+ /* 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
+};
/*
- Huffman code decoding is performed using a multi-level table lookup.
- The fastest way to decode is to simply build a lookup table whose
- size is determined by the longest code. However, the time it takes
- to build this table can also be a factor if the data being decoded
- is not very long. The most common codes are necessarily the
- shortest codes, so those codes dominate the decoding time, and hence
- the speed. The idea is you can have a shorter table that decodes the
- shorter, more probable codes, and then point to subsidiary tables for
- the longer codes. The time it costs to decode the longer codes is
- then traded against the time it takes to make longer tables.
-
- This results of this trade are in the variables lbits and dbits
- below. lbits is the number of bits the first level table for literal/
- length codes can decode in one step, and dbits is the same thing for
- the distance codes. Subsequent tables are also less than or equal to
- those sizes. These values may be adjusted either when all of the
- codes are shorter than that, in which case the longest code length in
- bits is used, or when the shortest code is *longer* than the requested
- table size, in which case the length of the shortest code in bits is
- used.
-
- There are two different values for the two tables, since they code a
- different number of possibilities each. The literal/length table
- codes 286 possible values, or in a flat code, a little over eight
- bits. The distance table codes 30 possible values, or a little less
- than five bits, flat. The optimum values for speed end up being
- about one bit more than those, so lbits is 8+1 and dbits is 5+1.
- The optimum values may differ though from machine to machine, and
- possibly even between compilers. Your mileage may vary.
- */
+ Huffman code decoding is performed using a multi-level table lookup.
+ The fastest way to decode is to simply build a lookup table whose
+ size is determined by the longest code. However, the time it takes
+ to build this table can also be a factor if the data being decoded
+ is not very long. The most common codes are necessarily the
+ shortest codes, so those codes dominate the decoding time, and hence
+ the speed. The idea is you can have a shorter table that decodes the
+ shorter, more probable codes, and then point to subsidiary tables for
+ the longer codes. The time it costs to decode the longer codes is
+ then traded against the time it takes to make longer tables.
+
+ This results of this trade are in the variables lbits and dbits
+ below. lbits is the number of bits the first level table for literal/
+ length codes can decode in one step, and dbits is the same thing for
+ the distance codes. Subsequent tables are also less than or equal to
+ those sizes. These values may be adjusted either when all of the
+ codes are shorter than that, in which case the longest code length in
+ bits is used, or when the shortest code is *longer* than the requested
+ table size, in which case the length of the shortest code in bits is
+ used.
+
+ There are two different values for the two tables, since they code a
+ different number of possibilities each. The literal/length table
+ codes 286 possible values, or in a flat code, a little over eight
+ bits. The distance table codes 30 possible values, or a little less
+ than five bits, flat. The optimum values for speed end up being
+ about one bit more than those, so lbits is 8+1 and dbits is 5+1.
+ The optimum values may differ though from machine to machine, and
+ possibly even between compilers. Your mileage may vary.
+*/
static int lbits = 9; /* bits in base literal/length lookup table */
@@ -404,46 +417,47 @@
#define N_MAX 288 /* maximum number of codes in any set */
/* Macros for inflate() bit peeking and grabbing.
- The usage is:
+ The usage is:
- NEEDBITS(j)
- x = b & mask_bits[j];
- DUMPBITS(j)
-
- where NEEDBITS makes sure that b has at least j bits in it, and
- DUMPBITS removes the bits from b. The macros use the variable k
- for the number of bits in b. Normally, b and k are register
- variables for speed, and are initialized at the beginning of a
- routine that uses these macros from a global bit buffer and count.
-
- If we assume that EOB will be the longest code, then we will never
- ask for bits with NEEDBITS that are beyond the end of the stream.
- So, NEEDBITS should not read any more bytes than are needed to
- meet the request. Then no bytes need to be "returned" to the buffer
- at the end of the last block.
-
- However, this assumption is not true for fixed blocks--the EOB code
- is 7 bits, but the other literal/length codes can be 8 or 9 bits.
- (The EOB code is shorter than other codes because fixed blocks are
- generally short. So, while a block always has an EOB, many other
- literal/length codes have a significantly lower probability of
- showing up at all.) However, by making the first table have a
- lookup of seven bits, the EOB code will be found in that first
- lookup, and so will not require that too many bits be pulled from
- the stream.
- */
+ NEEDBITS(j)
+ x = b & mask_bits[j];
+ DUMPBITS(j)
+
+ where NEEDBITS makes sure that b has at least j bits in it, and
+ DUMPBITS removes the bits from b. The macros use the variable k
+ for the number of bits in b. Normally, b and k are register
+ variables for speed, and are initialized at the beginning of a
+ routine that uses these macros from a global bit buffer and count.
+
+ If we assume that EOB will be the longest code, then we will never
+ ask for bits with NEEDBITS that are beyond the end of the stream.
+ So, NEEDBITS should not read any more bytes than are needed to
+ meet the request. Then no bytes need to be "returned" to the buffer
+ at the end of the last block.
+
+ However, this assumption is not true for fixed blocks--the EOB code
+ is 7 bits, but the other literal/length codes can be 8 or 9 bits.
+ (The EOB code is shorter than other codes because fixed blocks are
+ generally short. So, while a block always has an EOB, many other
+ literal/length codes have a significantly lower probability of
+ showing up at all.) However, by making the first table have a
+ lookup of seven bits, the EOB code will be found in that first
+ lookup, and so will not require that too many bits be pulled from
+ the stream.
+*/
static ulg bb; /* bit buffer */
static unsigned bk; /* bits in bit buffer */
static ush mask_bits[] =
{
- 0x0000,
- 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
- 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
+ 0x0000,
+ 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+ 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
};
-#define NEEDBITS(n) { while( k<(n) ) { b |= ( (ulg)get_byte() ) << k; k += 8; } }
+#define NEEDBITS(n) { while( k<(n) ) { \
+ b |= ( (ulg)get_byte() ) << k; k += 8; } }
#define DUMPBITS(n) { b >>= (n); k -= (n); }
#define INBUFSIZ 0x2000
@@ -454,33 +468,33 @@
static int
get_byte (void)
{
- if (gunzip_file.pos == gzip_data_offset || bufloc == INBUFSIZ)
- {
- bufloc = 0;
- gunzip_file.fs->read(&gunzip_file, INBUFSIZ, &inbuf);
- }
+ if (gunzip_file.pos == gzip_data_offset || bufloc == INBUFSIZ)
+ {
+ bufloc = 0;
+ gunzip_file.fs->read(&gunzip_file, INBUFSIZ, &inbuf);
+ }
- return inbuf[bufloc++];
+ return inbuf[bufloc++];
}
/* Huffman code lookup table entry--this entry is four bytes for machines
- that have 16-bit pointers (e.g. PC's in the small or medium model).
- Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
- means that v is a literal, 16 < e < 32 means that v is a pointer to
- the next table, which codes e - 16 bits, and lastly e == 99 indicates
- an unused code. If a code with e == 99 is looked up, this implies an
- error in the data. */
+ that have 16-bit pointers (e.g. PC's in the small or medium model).
+ Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
+ means that v is a literal, 16 < e < 32 means that v is a pointer to
+ the next table, which codes e - 16 bits, and lastly e == 99 indicates
+ an unused code. If a code with e == 99 is looked up, this implies an
+ error in the data. */
struct huft
{
- uch e; /* number of extra bits or operation */
- uch b; /* number of bits in this code or subcode */
- union
- {
- ush n; /* literal, length base, or distance base */
- struct huft *t; /* pointer to next level of table */
- }
- v;
+ uch e; /* number of extra bits or operation */
+ uch b; /* number of bits in this code or subcode */
+ union
+ {
+ ush n; /* literal, length base, or distance base */
+ struct huft *t; /* pointer to next level of table */
+ }
+ v;
};
@@ -493,340 +507,340 @@
/* more function prototypes */
static int huft_build (unsigned *, unsigned, unsigned, ush *, ush *,
- struct huft **, int *);
+ struct huft **, int *);
static int inflate_codes_in_window (void);
/* 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
- case), two if the input is invalid (all zero length codes or an
- oversubscribed set of lengths), and three if not enough memory. */
+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
+case), two if the input is invalid (all zero length codes or an
+oversubscribed set of lengths), and three if not enough memory. */
static int
huft_build (unsigned *b, /* code lengths in bits (all assumed <= BMAX) */
- unsigned n, /* number of codes (assumed <= N_MAX) */
- unsigned s, /* number of simple-valued codes (0..s-1) */
- ush * d, /* list of base values for non-simple codes */
- ush * e, /* list of extra bits for non-simple codes */
- struct huft **t, /* result: starting table */
- int *m) /* maximum lookup bits, returns actual */
-{
- 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 */
- 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[] */
- register struct huft *q; /* points to current table */
- struct huft r; /* table entry for structure assignment */
- struct huft *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 */
-
- /* Generate counts for each bit length */
- memset ((char *) c, 0, sizeof (c));
- p = b;
- i = n;
- do
- {
- 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 = (struct huft *) NULL;
- *m = 0;
- return 0;
- }
-
- /* Find minimum and maximum length, bound *m by those */
- l = *m;
- for (j = 1; j <= BMAX; j++)
- if (c[j])
- break;
- k = j; /* minimum code length */
- if ((unsigned) l < j)
- l = j;
- for (i = BMAX; i; i--)
- if (c[i])
- break;
- g = i; /* maximum code length */
- 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)
- return 2; /* bad input: more codes than bits */
- 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 */
- *xp++ = (j += *p++);
- }
-
- /* Make a table of values in order of bit lengths */
- p = b;
- i = 0;
- do
- {
- 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 */
- p = v; /* grab values in bit order */
- h = -1; /* no tables yet--level -1 */
- w = -l; /* bits decoded == (l * h) */
- u[0] = (struct huft *) NULL; /* just to keep compilers happy */
- q = (struct huft *) NULL; /* ditto */
- z = 0; /* ditto */
-
- /* go through the bit lengths (k already is bits in shortest code) */
- for (; k <= g; k++)
- {
- a = c[k];
- while (a--)
- {
- /* here i is the Huffman code of length k bits for value *p */
- /* make tables up to required level */
- while (k > w + l)
- {
- h++;
- 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 */
- if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
- { /* too few codes for k-w bit table */
- 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)
- break; /* enough codes to use up j bits */
- f -= *xp; /* else deduct codes from patterns */
- }
- }
- z = 1 << j; /* table entries for j-bit table */
+ unsigned n, /* number of codes (assumed <= N_MAX) */
+ unsigned s, /* number of simple-valued codes (0..s-1) */
+ ush * d, /* list of base values for non-simple codes */
+ ush * e, /* list of extra bits for non-simple codes */
+ struct huft **t, /* result: starting table */
+ int *m) /* maximum lookup bits, returns actual */
+{
+ 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 */
+ 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[] */
+ register struct huft *q; /* points to current table */
+ struct huft r; /* table entry for structure assignment */
+ struct huft *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 */
+
+ /* Generate counts for each bit length */
+ memset ((char *) c, 0, sizeof (c));
+ p = b;
+ i = n;
+ do
+ {
+ 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 = (struct huft *) NULL;
+ *m = 0;
+ return 0;
+ }
- /* allocate and link in new table */
- if ((q = (struct huft *)gzmalloc( (z + 1)*sizeof(struct huft) )) ==
- (struct huft *)NULL)
- {
- prom_printf("\ngunzip: malloc failed; not enought memory ?\n");
- return 3; /* not enough memory */
- }
-
- *t = q + 1; /* link to list for huft_free() */
- *(t = &(q->v.t)) = (struct huft *) NULL;
- u[h] = ++q; /* table starts after link */
+ /* Find minimum and maximum length, bound *m by those */
+ l = *m;
+ for (j = 1; j <= BMAX; j++)
+ if (c[j])
+ break;
+ k = j; /* minimum code length */
+ if ((unsigned) l < j)
+ l = j;
+ for (i = BMAX; i; i--)
+ if (c[i])
+ break;
+ g = i; /* maximum code length */
+ 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)
+ return 2; /* bad input: more codes than bits */
+ 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 */
+ *xp++ = (j += *p++);
+ }
- /* connect to last table, if there is one */
- if (h)
+ /* Make a table of values in order of bit lengths */
+ p = b;
+ i = 0;
+ do
+ {
+ 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 */
+ p = v; /* grab values in bit order */
+ h = -1; /* no tables yet--level -1 */
+ w = -l; /* bits decoded == (l * h) */
+ u[0] = (struct huft *) NULL; /* just to keep compilers happy */
+ q = (struct huft *) NULL; /* ditto */
+ z = 0; /* ditto */
+
+ /* go through the bit lengths (k already is bits in shortest code) */
+ for (; k <= g; k++)
+ {
+ a = c[k];
+ while (a--)
{
- x[h] = i; /* save pattern for backing up */
- r.b = (uch) l; /* bits to dump before this table */
- r.e = (uch) (16 + j); /* bits in this table */
- r.v.t = q; /* pointer to this table */
- j = i >> (w - l); /* (get around Turbo C bug) */
- u[h - 1][j] = r; /* connect to last table */
+ /* here i is the Huffman code of length k bits for value *p */
+ /* make tables up to required level */
+ while (k > w + l)
+ {
+ h++;
+ 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 */
+ if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
+ { /* too few codes for k-w bit table */
+ 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)
+ break; /* enough codes to use up j bits */
+ f -= *xp; /* else deduct codes from patterns */
+ }
+ }
+ z = 1 << j; /* table entries for j-bit table */
+
+ /* allocate and link in new table */
+ if ((q = (struct huft *)gzmalloc( (z + 1)*sizeof(struct huft) )) ==
+ (struct huft *)NULL)
+ {
+ prom_printf("\ngunzip: malloc failed; not enought memory ?\n");
+ return 3; /* not enough memory */
+ }
+
+ *t = q + 1; /* link to list for huft_free() */
+ *(t = &(q->v.t)) = (struct huft *) NULL;
+ u[h] = ++q; /* table starts after link */
+
+ /* connect to last table, if there is one */
+ if (h)
+ {
+ x[h] = i; /* save pattern for backing up */
+ r.b = (uch) l; /* bits to dump before this table */
+ r.e = (uch) (16 + j); /* bits in this table */
+ r.v.t = q; /* pointer to this table */
+ j = i >> (w - l); /* (get around Turbo C bug) */
+ u[h - 1][j] = r; /* connect to last table */
+ }
+ }
+
+ /* set up table entry in r */
+ r.b = (uch) (k - w);
+ if (p >= v + n)
+ r.e = 99; /* out of values--invalid code */
+ else if (*p < s)
+ {
+ r.e = (uch) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
+ r.v.n = (ush) (*p); /* simple code is just the value */
+ p++; /* one compiler does not like *p++ */
+ }
+ else
+ {
+ r.e = (uch) e[*p - s]; /* non-simple--look up in lists */
+ r.v.n = d[*p++ - s];
+ }
+
+ /* fill code-like entries with r */
+ f = 1 << (k - w);
+ 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)
+ i ^= j;
+ i ^= j;
+
+ /* backup over finished tables */
+ while ((i & ((1 << w) - 1)) != x[h])
+ {
+ h--; /* don't need to update q */
+ w -= l;
+ }
}
- }
-
- /* set up table entry in r */
- r.b = (uch) (k - w);
- if (p >= v + n)
- r.e = 99; /* out of values--invalid code */
- else if (*p < s)
- {
- r.e = (uch) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
- r.v.n = (ush) (*p); /* simple code is just the value */
- p++; /* one compiler does not like *p++ */
- }
- else
- {
- r.e = (uch) e[*p - s]; /* non-simple--look up in lists */
- r.v.n = d[*p++ - s];
- }
-
- /* fill code-like entries with r */
- f = 1 << (k - w);
- 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)
- i ^= j;
- i ^= j;
-
- /* backup over finished tables */
- while ((i & ((1 << w) - 1)) != x[h])
- {
- h--; /* don't need to update q */
- w -= l;
- }
}
- }
- /* Return true (1) if we were given an incomplete table */
- return y != 0 && g != 1;
+ /* Return true (1) if we were given an incomplete table */
+ return y != 0 && g != 1;
}
/*
- * inflate (decompress) the codes in a deflated (compressed) block.
- * Return an error code or zero if it all goes ok.
- */
+* inflate (decompress) the codes in a deflated (compressed) block.
+* Return an error code or zero if it all goes ok.
+*/
static unsigned inflate_n, inflate_d;
static int
inflate_codes_in_window (void)
{
- register unsigned e; /* table entry flag/number of extra bits */
- unsigned n, d; /* length and index for copy */
- unsigned w; /* current window position */
- struct huft *t; /* pointer to table entry */
- unsigned ml, md; /* masks for bl and bd bits */
- register ulg b; /* bit buffer */
- register unsigned k; /* number of bits in bit buffer */
-
- /* make local copies of globals */
- d = inflate_d;
- n = inflate_n;
- b = bb; /* initialize bit buffer */
- k = bk;
- w = wp; /* 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 */
- {
- if (!code_state)
- {
- NEEDBITS ((unsigned) bl);
- if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
- do
- {
- if (e == 99)
- {
- prom_printf("ERR_BAD_GZIP_DATA: inflate_codes_in_window 1\n");
- return 0;
- }
- DUMPBITS (t->b);
- e -= 16;
- NEEDBITS (e);
- }
- while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
- DUMPBITS (t->b);
-
- if (e == 16) /* then it's a literal */
- {
- slide[w++] = (uch) t->v.n;
- if (w == WSIZE)
- break;
- }
- else
- /* it's an EOB or a length */
- {
- /* exit if end of block */
- if (e == 15)
+ register unsigned e; /* table entry flag/number of extra bits */
+ unsigned n, d; /* length and index for copy */
+ unsigned w; /* current window position */
+ struct huft *t; /* pointer to table entry */
+ unsigned ml, md; /* masks for bl and bd bits */
+ register ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
+
+ /* make local copies of globals */
+ d = inflate_d;
+ n = inflate_n;
+ b = bb; /* initialize bit buffer */
+ k = bk;
+ w = wp; /* 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 */
+ {
+ if (!code_state)
{
- block_len = 0;
- break;
+ NEEDBITS ((unsigned) bl);
+ if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
+ do
+ {
+ if (e == 99)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: inflate_codes_in_window 1\n");
+ return 0;
+ }
+ DUMPBITS (t->b);
+ e -= 16;
+ NEEDBITS (e);
+ }
+ while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
+ DUMPBITS (t->b);
+
+ if (e == 16) /* then it's a literal */
+ {
+ slide[w++] = (uch) t->v.n;
+ if (w == WSIZE)
+ break;
+ }
+ else
+ /* it's an EOB or a length */
+ {
+ /* exit if end of block */
+ if (e == 15)
+ {
+ block_len = 0;
+ break;
+ }
+
+ /* get length of block to copy */
+ NEEDBITS (e);
+ n = t->v.n + ((unsigned) b & mask_bits[e]);
+ DUMPBITS (e);
+
+ /* decode distance of block to copy */
+ NEEDBITS ((unsigned) bd);
+ if ((e = (t = td + ((unsigned) b & md))->e) > 16)
+ do
+ {
+ if (e == 99)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: inflate_codes_in_window 2\n");
+ return 0;
+ }
+ DUMPBITS (t->b);
+ e -= 16;
+ NEEDBITS (e);
+ }
+ while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e)
+ > 16);
+ DUMPBITS (t->b);
+ NEEDBITS (e);
+ d = w - t->v.n - ((unsigned) b & mask_bits[e]);
+ DUMPBITS (e);
+ code_state++;
+ }
}
- /* get length of block to copy */
- NEEDBITS (e);
- n = t->v.n + ((unsigned) b & mask_bits[e]);
- DUMPBITS (e);
-
- /* decode distance of block to copy */
- NEEDBITS ((unsigned) bd);
- if ((e = (t = td + ((unsigned) b & md))->e) > 16)
- do
- {
- if (e == 99)
- {
- prom_printf("ERR_BAD_GZIP_DATA: inflate_codes_in_window 2\n");
- return 0;
- }
- DUMPBITS (t->b);
- e -= 16;
- NEEDBITS (e);
- }
- while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e)
- > 16);
- DUMPBITS (t->b);
- NEEDBITS (e);
- d = w - t->v.n - ((unsigned) b & mask_bits[e]);
- DUMPBITS (e);
- code_state++;
- }
- }
-
- if (code_state)
- {
- /* do the copy */
- do
- {
- n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n
- : e);
- if (w - d >= e)
- {
- memmove (slide + w, slide + d, e);
- w += e;
- d += e;
- }
- else
- /* purposefully use the overlap for extra copies here!! */
+ if (code_state)
{
- while (e--)
- slide[w++] = slide[d++];
+ /* do the copy */
+ do
+ {
+ n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n
+ : e);
+ if (w - d >= e)
+ {
+ memmove (slide + w, slide + d, e);
+ w += e;
+ d += e;
+ }
+ else
+ /* purposefully use the overlap for extra copies here!! */
+ {
+ while (e--)
+ slide[w++] = slide[d++];
+ }
+ if (w == WSIZE)
+ break;
+ }
+ while (n);
+
+ if (!n)
+ code_state--;
+
+ /* did we break from the loop too soon? */
+ if (w == WSIZE)
+ break;
}
- if (w == WSIZE)
- break;
- }
- while (n);
-
- if (!n)
- code_state--;
-
- /* did we break from the loop too soon? */
- if (w == WSIZE)
- break;
- }
- }
-
- /* restore the globals from the locals */
- inflate_d = d;
- inflate_n = n;
- wp = w; /* restore global window pointer */
- bb = b; /* restore global bit buffer */
- bk = k;
+ }
+
+ /* restore the globals from the locals */
+ inflate_d = d;
+ inflate_n = n;
+ wp = w; /* restore global window pointer */
+ bb = b; /* restore global bit buffer */
+ bk = k;
- return !block_len;
+ return !block_len;
}
@@ -835,70 +849,70 @@
static void
init_stored_block (void)
{
- register ulg b; /* bit buffer */
- register unsigned k; /* number of bits in bit buffer */
+ register ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
- /* make local copies of globals */
- b = bb; /* initialize bit buffer */
- k = bk;
-
- /* go to byte boundary */
- DUMPBITS (k & 7);
-
- /* get the length and its complement */
- NEEDBITS (16);
- block_len = ((unsigned) b & 0xffff);
- DUMPBITS (16);
- NEEDBITS (16);
- if (block_len != (unsigned) ((~b) & 0xffff))
- prom_printf("ERR_BAD_GZIP_DATA: init_stored_block");
- DUMPBITS (16);
-
- /* restore global variables */
- bb = b;
- bk = k;
+ /* make local copies of globals */
+ b = bb; /* initialize bit buffer */
+ k = bk;
+
+ /* go to byte boundary */
+ DUMPBITS (k & 7);
+
+ /* get the length and its complement */
+ NEEDBITS (16);
+ block_len = ((unsigned) b & 0xffff);
+ DUMPBITS (16);
+ NEEDBITS (16);
+ if (block_len != (unsigned) ((~b) & 0xffff))
+ prom_printf("ERR_BAD_GZIP_DATA: init_stored_block");
+ DUMPBITS (16);
+
+ /* restore global variables */
+ bb = b;
+ bk = k;
}
/* get header for an inflated type 1 (fixed Huffman codes) block. We should
- either replace this with a custom decoder, or at least precompute the
- Huffman tables. */
+ either replace this with a custom decoder, or at least precompute the
+ Huffman tables. */
static void
init_fixed_block ()
{
- int i; /* temporary variable */
- unsigned l[288]; /* length list for huft_build */
+ int i; /* temporary variable */
+ unsigned 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)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_fixed_block 1\n");
+ return;
+ }
- /* 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)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_fixed_block 1\n");
- return;
- }
-
- /* 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)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_fixed_block 2\n");
- return;
- }
-
- /* indicate we're now working on a block */
- code_state = 0;
- block_len++;
+ /* 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)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_fixed_block 2\n");
+ return;
+ }
+
+ /* indicate we're now working on a block */
+ code_state = 0;
+ block_len++;
}
@@ -907,292 +921,292 @@
static void
init_dynamic_block (void)
{
- int i; /* temporary variables */
- unsigned j;
- unsigned l; /* last length */
- unsigned m; /* mask for bit lengths table */
- unsigned n; /* number of lengths to get */
- 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 ulg b; /* bit buffer */
- register unsigned k; /* number of bits in bit buffer */
-
- /* make local bit buffer */
- b = bb;
- k = bk;
-
- /* read in table lengths */
- NEEDBITS (5);
- nl = 257 + ((unsigned) b & 0x1f); /* number of literal/length codes */
- DUMPBITS (5);
- NEEDBITS (5);
- nd = 1 + ((unsigned) b & 0x1f); /* number of distance codes */
- DUMPBITS (5);
- NEEDBITS (4);
- nb = 4 + ((unsigned) b & 0xf); /* number of bit length codes */
- DUMPBITS (4);
- if (nl > 286 || nd > 30)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 1\n");
- return;
- }
-
- /* read in bit-length-code lengths */
- for (j = 0; j < nb; j++)
- {
- NEEDBITS (3);
- ll[bitorder[j]] = (unsigned) b & 7;
- DUMPBITS (3);
- }
- for (; j < 19; j++)
- ll[bitorder[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)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 2\n");
- return;
- }
-
- /* read in literal and distance code lengths */
- n = nl + nd;
- m = mask_bits[bl];
- i = l = 0;
- while ((unsigned) i < n)
- {
- NEEDBITS ((unsigned) bl);
- j = (td = tl + ((unsigned) b & m))->b;
- DUMPBITS (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 */
- {
- NEEDBITS (2);
- j = 3 + ((unsigned) b & 3);
- DUMPBITS (2);
- if ((unsigned) i + j > n)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 3\n");
- return;
- }
- while (j--)
- ll[i++] = l;
- }
- else if (j == 17) /* 3 to 10 zero length codes */
- {
- NEEDBITS (3);
- j = 3 + ((unsigned) b & 7);
- DUMPBITS (3);
- if ((unsigned) i + j > n)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 4\n");
- return;
- }
- while (j--)
- ll[i++] = 0;
- l = 0;
- }
- else
- /* j == 18: 11 to 138 zero length codes */
- {
- NEEDBITS (7);
- j = 11 + ((unsigned) b & 0x7f);
- DUMPBITS (7);
- if ((unsigned) i + j > n)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 5\n");
- return;
- }
- while (j--)
- ll[i++] = 0;
- l = 0;
- }
- }
-
- /* free decoding table for trees */
- reset_gzmalloc();
-
- /* restore the global bit buffer */
- bb = b;
- bk = k;
-
- /* build the decoding tables for literal/length and distance codes */
- bl = lbits;
- if ((i = huft_build (ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 6\n");
- return;
- }
- bd = dbits;
- if ((i = huft_build (ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
- {
- prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 7\n");
- return;
- }
-
- /* indicate we're now working on a block */
- code_state = 0;
- block_len++;
+ int i; /* temporary variables */
+ unsigned j;
+ unsigned l; /* last length */
+ unsigned m; /* mask for bit lengths table */
+ unsigned n; /* number of lengths to get */
+ 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 ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
+
+ /* make local bit buffer */
+ b = bb;
+ k = bk;
+
+ /* read in table lengths */
+ NEEDBITS (5);
+ nl = 257 + ((unsigned) b & 0x1f); /* number of literal/length codes */
+ DUMPBITS (5);
+ NEEDBITS (5);
+ nd = 1 + ((unsigned) b & 0x1f); /* number of distance codes */
+ DUMPBITS (5);
+ NEEDBITS (4);
+ nb = 4 + ((unsigned) b & 0xf); /* number of bit length codes */
+ DUMPBITS (4);
+ if (nl > 286 || nd > 30)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 1\n");
+ return;
+ }
+
+ /* read in bit-length-code lengths */
+ for (j = 0; j < nb; j++)
+ {
+ NEEDBITS (3);
+ ll[bitorder[j]] = (unsigned) b & 7;
+ DUMPBITS (3);
+ }
+ for (; j < 19; j++)
+ ll[bitorder[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)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 2\n");
+ return;
+ }
+
+ /* read in literal and distance code lengths */
+ n = nl + nd;
+ m = mask_bits[bl];
+ i = l = 0;
+ while ((unsigned) i < n)
+ {
+ NEEDBITS ((unsigned) bl);
+ j = (td = tl + ((unsigned) b & m))->b;
+ DUMPBITS (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 */
+ {
+ NEEDBITS (2);
+ j = 3 + ((unsigned) b & 3);
+ DUMPBITS (2);
+ if ((unsigned) i + j > n)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 3\n");
+ return;
+ }
+ while (j--)
+ ll[i++] = l;
+ }
+ else if (j == 17) /* 3 to 10 zero length codes */
+ {
+ NEEDBITS (3);
+ j = 3 + ((unsigned) b & 7);
+ DUMPBITS (3);
+ if ((unsigned) i + j > n)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 4\n");
+ return;
+ }
+ while (j--)
+ ll[i++] = 0;
+ l = 0;
+ }
+ else
+ /* j == 18: 11 to 138 zero length codes */
+ {
+ NEEDBITS (7);
+ j = 11 + ((unsigned) b & 0x7f);
+ DUMPBITS (7);
+ if ((unsigned) i + j > n)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 5\n");
+ return;
+ }
+ while (j--)
+ ll[i++] = 0;
+ l = 0;
+ }
+ }
+
+ /* free decoding table for trees */
+ reset_gzmalloc();
+
+ /* restore the global bit buffer */
+ bb = b;
+ bk = k;
+
+ /* build the decoding tables for literal/length and distance codes */
+ bl = lbits;
+ if ((i = huft_build (ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 6\n");
+ return;
+ }
+ bd = dbits;
+ if ((i = huft_build (ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
+ {
+ prom_printf("ERR_BAD_GZIP_DATA: init_dynamic_block 7\n");
+ return;
+ }
+
+ /* indicate we're now working on a block */
+ code_state = 0;
+ block_len++;
}
static void
get_new_block (void)
{
- register ulg b; /* bit buffer */
- register unsigned k; /* number of bits in bit buffer */
+ register ulg b; /* bit buffer */
+ register unsigned k; /* number of bits in bit buffer */
- /* make local bit buffer */
- b = bb;
- k = bk;
-
- /* read in last block bit */
- NEEDBITS (1);
- last_block = (int) b & 1;
- DUMPBITS (1);
-
- /* read in block type */
- NEEDBITS (2);
- block_type = (unsigned) b & 3;
- DUMPBITS (2);
-
- /* restore the global bit buffer */
- bb = b;
- bk = k;
-
- if (block_type == INFLATE_STORED)
- init_stored_block ();
- if (block_type == INFLATE_FIXED)
- init_fixed_block ();
- if (block_type == INFLATE_DYNAMIC)
- init_dynamic_block ();
+ /* make local bit buffer */
+ b = bb;
+ k = bk;
+
+ /* read in last block bit */
+ NEEDBITS (1);
+ last_block = (int) b & 1;
+ DUMPBITS (1);
+
+ /* read in block type */
+ NEEDBITS (2);
+ block_type = (unsigned) b & 3;
+ DUMPBITS (2);
+
+ /* restore the global bit buffer */
+ bb = b;
+ bk = k;
+
+ if (block_type == INFLATE_STORED)
+ init_stored_block ();
+ if (block_type == INFLATE_FIXED)
+ init_fixed_block ();
+ if (block_type == INFLATE_DYNAMIC)
+ init_dynamic_block ();
}
static void
inflate_window (void)
{
- /* initialize window */
- wp = 0;
+ /* initialize window */
+ wp = 0;
- /*
- * Main decompression loop.
- */
+ /*
+ * Main decompression loop.
+ */
- while (wp < WSIZE)
- {
- if (!block_len)
+ while (wp < WSIZE)
{
- if (last_block)
- break;
+ if (!block_len)
+ {
+ if (last_block)
+ break;
- get_new_block ();
- }
+ get_new_block ();
+ }
- if (block_type > INFLATE_DYNAMIC) {
- prom_printf("ERR_BAD_GZIP_DATA: init_window 1\n");
- return;
- }
+ if (block_type > INFLATE_DYNAMIC) {
+ prom_printf("ERR_BAD_GZIP_DATA: init_window 1\n");
+ return;
+ }
- /*
- * Expand stored block here.
- */
- if (block_type == INFLATE_STORED)
- {
- int w = wp;
+ /*
+ * Expand stored block here.
+ */
+ if (block_type == INFLATE_STORED)
+ {
+ int w = wp;
- /*
- * This is basically a glorified pass-through
- */
+ /*
+ * This is basically a glorified pass-through
+ */
- while (block_len && w < WSIZE)
- {
- slide[w++] = get_byte ();
- block_len--;
- }
+ while (block_len && w < WSIZE)
+ {
+ slide[w++] = get_byte ();
+ block_len--;
+ }
- wp = w;
+ wp = w;
- continue;
- }
+ continue;
+ }
- /*
- * Expand other kind of block.
- */
+ /*
+ * Expand other kind of block.
+ */
- if ( inflate_codes_in_window() )
- reset_gzmalloc();
- }
+ if ( inflate_codes_in_window() )
+ reset_gzmalloc();
+ }
- saved_filepos += WSIZE;
+ saved_filepos += WSIZE;
- /* XXX do CRC calculation here! */
+ /* XXX do CRC calculation here! */
}
static void
initialize_tables (void)
{
- saved_filepos = 0;
-
- if (gunzip_file.fs->seek(&gunzip_file, gzip_data_offset) != FILE_ERR_OK )
- prom_printf("Error seeking !!!\n");
-
-
- /* initialize window, bit buffer */
- bk = 0;
- bb = 0;
-
- /* reset partial decompression code */
- last_block = 0;
- block_len = 0;
+ saved_filepos = 0;
+
+ if (gunzip_file.fs->seek(&gunzip_file, gzip_data_offset) != FILE_ERR_OK )
+ prom_printf("Error seeking !!!\n");
+
+
+ /* initialize window, bit buffer */
+ bk = 0;
+ bb = 0;
+
+ /* reset partial decompression code */
+ last_block = 0;
+ block_len = 0;
- /* reset memory allocation stuff */
- reset_gzmalloc();
+ /* reset memory allocation stuff */
+ reset_gzmalloc();
}
int
gunzip_read (void *buf, unsigned int len)
{
- int ret = 0;
+ int ret = 0;
- /* do we reset decompression to the beginning of the file? */
- if (saved_filepos > gzip_filepos + WSIZE)
- initialize_tables ();
-
- /*
- * This loop operates upon uncompressed data only. The only
- * special thing it does is to make sure the decompression
- * window is within the range of data it needs.
- */
-
- while (len > 0)
- {
- register int size;
- register char *srcaddr;
-
- while (gzip_filepos >= saved_filepos)
- inflate_window ();
-
- srcaddr = (char *) ((gzip_filepos & (WSIZE - 1)) + slide);
- size = saved_filepos - gzip_filepos;
- if (size > len)
- size = len;
-
- memmove (buf, srcaddr, size);
-
- buf += size;
- len -= size;
- gzip_filepos += size;
- ret += size;
- }
+ /* do we reset decompression to the beginning of the file? */
+ if (saved_filepos > gzip_filepos + WSIZE)
+ initialize_tables ();
+
+ /*
+ * This loop operates upon uncompressed data only. The only
+ * special thing it does is to make sure the decompression
+ * window is within the range of data it needs.
+ */
- return ret;
+ while (len > 0)
+ {
+ register int size;
+ register char *srcaddr;
+
+ while (gzip_filepos >= saved_filepos)
+ inflate_window ();
+
+ srcaddr = (char *) ((gzip_filepos & (WSIZE - 1)) + slide);
+ size = saved_filepos - gzip_filepos;
+ if (size > len)
+ size = len;
+
+ memmove (buf, srcaddr, size);
+
+ buf += size;
+ len -= size;
+ gzip_filepos += size;
+ ret += size;
+ }
+
+ return ret;
}
int
@@ -1202,3 +1216,6 @@
return FILE_ERR_OK;
}
+/*
+ * vim: ts=4
+ */
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