commit dbf1f13b3a6e9ee0c3c2ee77238b0d7783601479
parent 1bfe2f94456c9d9f816b11019a7b200aabb800f6
Author: Virgil Dupras <hsoft@hardcoded.net>
Date: Mon, 28 Nov 2022 16:22:54 -0500
ar/puff: replace ar/ungz
See https://lists.sr.ht/~vdupras/duskos-discuss/%3C69cfdb97-49d6-dccd-c7bb-df3b40eab7e6%2540gmx.de%3E
Diffstat:
9 files changed, 764 insertions(+), 985 deletions(-)
diff --git a/fs/ar/puff.c b/fs/ar/puff.c
@@ -0,0 +1,736 @@
+/* Source: https://github.com/madler/zlib
+ * License: /license/madler-puff.txt
+ *
+ * puff.c is a simple inflate written to be an unambiguous way to specify the
+ * deflate format. It is not written for speed but rather simplicity. As a
+ * side benefit, this code might actually be useful when small code is more
+ * important than speed, such as bootstrap applications. For typical deflate
+ * data, zlib's inflate() is about four times as fast as puff(). zlib's
+ * inflate compiles to around 20K on my machine, whereas puff.c compiles to
+ * around 4K on my machine (a PowerPC using GNU cc). If the faster decode()
+ * function here is used, then puff() is only twice as slow as zlib's
+ * inflate().
+ *
+ * All dynamically allocated memory comes from the stack. The stack required
+ * is less than 2K bytes. This code is compatible with 16-bit int's and
+ * assumes that long's are at least 32 bits. puff.c uses the short data type,
+ * assumed to be 16 bits, for arrays in order to conserve memory. The code
+ * works whether integers are stored big endian or little endian.
+ *
+ * In the comments below are "Format notes" that describe the inflate process
+ * and document some of the less obvious aspects of the format. This source
+ * code is meant to supplement RFC 1951, which formally describes the deflate
+ * format:
+ *
+ * http://www.zlib.org/rfc-deflate.html
+ */
+
+/*
+ * Maximums for allocations and loops. It is not useful to change these --
+ * they are fixed by the deflate format.
+ */
+/* maximum bits in a code */
+#define MAXBITS 15
+/* TODO: allow constant expressions array typedefs, for example MAXBITS+1 */
+#define MAXBITSPLUSONE 16
+/* maximum number of literal/length codes */
+#define MAXLCODES 286
+/* maximum number of distance codes */
+#define MAXDCODES 30
+/* maximum codes lengths to read */
+
+// TODO: same here
+//#define MAXCODES (MAXLCODES+MAXDCODES)
+
+#define MAXCODES 316
+/* number of fixed literal/length codes */
+#define FIXLCODES 288
+// TODO: can't #define right after a // comment
+
+/* input and output state */
+struct state {
+ /* output state */
+ unsigned char *out; /* output buffer */
+ unsigned int outlen; /* available space at out */
+ unsigned int outcnt; /* bytes written to out so far */
+
+ /* input state */
+ unsigned char *in; /* input buffer */
+ unsigned int inlen; /* available input at in */
+ unsigned int incnt; /* bytes read so far */
+ int bitbuf; /* bit buffer */
+ int bitcnt; /* number of bits in bit buffer */
+};
+
+/*
+ * Return need bits from the input stream. This always leaves less than
+ * eight bits in the buffer. bits() works properly for need == 0.
+ *
+ * Format notes:
+ *
+ * - Bits are stored in bytes from the least significant bit to the most
+ * significant bit. Therefore bits are dropped from the bottom of the bit
+ * buffer, using shift right, and new bytes are appended to the top of the
+ * bit buffer, using shift left.
+ */
+static int bits(state *s, int need)
+{
+ int val; /* bit accumulator (can use up to 20 bits) */
+
+ /* load at least need bits into val */
+ val = s->bitbuf;
+ while (s->bitcnt < need) {
+ if (s->incnt == s->inlen) {
+ fputs("out of input\n", ConsoleOut());
+ abort();
+ }
+ val |= (s->in[s->incnt++]) << s->bitcnt; /* load eight bits */
+ s->bitcnt += 8;
+ }
+
+ /* drop need bits and update buffer, always zero to seven bits left */
+ s->bitbuf = (val >> need);
+ s->bitcnt -= need;
+
+ /* return need bits, zeroing the bits above that */
+ return (val & ((1 << need) - 1));
+}
+
+/*
+ * Process a stored block.
+ *
+ * Format notes:
+ *
+ * - After the two-bit stored block type (00), the stored block length and
+ * stored bytes are byte-aligned for fast copying. Therefore any leftover
+ * bits in the byte that has the last bit of the type, as many as seven, are
+ * discarded. The value of the discarded bits are not defined and should not
+ * be checked against any expectation.
+ *
+ * - The second inverted copy of the stored block length does not have to be
+ * checked, but it's probably a good idea to do so anyway.
+ *
+ * - A stored block can have zero length. This is sometimes used to byte-align
+ * subsets of the compressed data for random access or partial recovery.
+ */
+static int stored(state *s)
+{
+ unsigned int len; /* length of stored block */
+
+ /* discard leftover bits from current byte (assumes s->bitcnt < 8) */
+ s->bitbuf = 0;
+ s->bitcnt = 0;
+
+ /* get length and check against its one's complement */
+ if (s->incnt + 4 > s->inlen)
+ return 2; /* not enough input */
+ len = s->in[s->incnt++];
+ len |= s->in[s->incnt++] << 8;
+ if (s->in[s->incnt++] != (~len & $ff) ||
+ s->in[s->incnt++] != ((~len >> 8) & $ff))
+ return -2; /* didn't match complement! */
+
+ /* copy len bytes from in to out */
+ if (s->incnt + len > s->inlen)
+ return 2; /* not enough input */
+ if (s->out != NULL) {
+ if (s->outcnt + len > s->outlen)
+ return 1; /* not enough output space */
+ while (len--)
+ s->out[s->outcnt++] = s->in[s->incnt++];
+ }
+ else { /* just scanning */
+ s->outcnt += len;
+ s->incnt += len;
+ }
+
+ /* done with a valid stored block */
+ return 0;
+}
+
+/*
+ * Huffman code decoding tables. count[1..MAXBITS] is the number of symbols of
+ * each length, which for a canonical code are stepped through in order.
+ * symbol[] are the symbol values in canonical order, where the number of
+ * entries is the sum of the counts in count[]. The decoding process can be
+ * seen in the function decode() below.
+ */
+struct huffman {
+ short *count; /* number of symbols of each length */
+ short *symbol; /* canonically ordered symbols */
+};
+
+/*
+ * Decode a code from the stream s using huffman table h. Return the symbol or
+ * a negative value if there is an error. If all of the lengths are zero, i.e.
+ * an empty code, or if the code is incomplete and an invalid code is received,
+ * then -10 is returned after reading MAXBITS bits.
+ *
+ * Format notes:
+ *
+ * - The codes as stored in the compressed data are bit-reversed relative to
+ * a simple integer ordering of codes of the same lengths. Hence below the
+ * bits are pulled from the compressed data one at a time and used to
+ * build the code value reversed from what is in the stream in order to
+ * permit simple integer comparisons for decoding. A table-based decoding
+ * scheme (as used in zlib) does not need to do this reversal.
+ *
+ * - The first code for the shortest length is all zeros. Subsequent codes of
+ * the same length are simply integer increments of the previous code. When
+ * moving up a length, a zero bit is appended to the code. For a complete
+ * code, the last code of the longest length will be all ones.
+ *
+ * - Incomplete codes are handled by this decoder, since they are permitted
+ * in the deflate format. See the format notes for fixed() and dynamic().
+ */
+static int decode(state *s, huffman *h)
+{
+ int len; /* current number of bits in code */
+ int code; /* len bits being decoded */
+ int first; /* first code of length len */
+ int count; /* number of codes of length len */
+ int index; /* index of first code of length len in symbol table */
+
+ // TODO: support chained assigns
+ // code = first = index = 0;
+ code = 0;
+ first = 0;
+ index = 0;
+ for (len = 1; len <= MAXBITS; len++) {
+ code |= bits(s, 1); /* get next bit */
+ count = h->count[len];
+ if (code - count < first) /* if length len, return symbol */
+ return h->symbol[index + (code - first)];
+ index += count; /* else update for next length */
+ first += count;
+ first <<= 1;
+ code <<= 1;
+ }
+ return -10; /* ran out of codes */
+}
+
+/*
+ * Given the list of code lengths length[0..n-1] representing a canonical
+ * Huffman code for n symbols, construct the tables required to decode those
+ * codes. Those tables are the number of codes of each length, and the symbols
+ * sorted by length, retaining their original order within each length. The
+ * return value is zero for a complete code set, negative for an over-
+ * subscribed code set, and positive for an incomplete code set. The tables
+ * can be used if the return value is zero or positive, but they cannot be used
+ * if the return value is negative. If the return value is zero, it is not
+ * possible for decode() using that table to return an error--any stream of
+ * enough bits will resolve to a symbol. If the return value is positive, then
+ * it is possible for decode() using that table to return an error for received
+ * codes past the end of the incomplete lengths.
+ *
+ * Not used by decode(), but used for error checking, h->count[0] is the number
+ * of the n symbols not in the code. So n - h->count[0] is the number of
+ * codes. This is useful for checking for incomplete codes that have more than
+ * one symbol, which is an error in a dynamic block.
+ *
+ * Assumption: for all i in 0..n-1, 0 <= length[i] <= MAXBITS
+ * This is assured by the construction of the length arrays in dynamic() and
+ * fixed() and is not verified by construct().
+ *
+ * Format notes:
+ *
+ * - Permitted and expected examples of incomplete codes are one of the fixed
+ * codes and any code with a single symbol which in deflate is coded as one
+ * bit instead of zero bits. See the format notes for fixed() and dynamic().
+ *
+ * - Within a given code length, the symbols are kept in ascending order for
+ * the code bits definition.
+ */
+static int construct(huffman *h, short *length, int n)
+{
+ int symbol; /* current symbol when stepping through length[] */
+ int len; /* current length when stepping through h->count[] */
+ int left; /* number of possible codes left of current length */
+ short offs[MAXBITSPLUSONE]; /* offsets in symbol table for each length */
+
+ /* count number of codes of each length */
+ for (len = 0; len <= MAXBITS; len++)
+ h->count[len] = 0;
+ for (symbol = 0; symbol < n; symbol++)
+ // TODO: I get a tokenization error with:
+ // (h->count[length[symbol]])++;
+ h->count[length[symbol]]++; /* assumes lengths are within bounds */
+ if (h->count[0] == n) /* no codes! */
+ return 0; /* complete, but decode() will fail */
+
+ /* check for an over-subscribed or incomplete set of lengths */
+ left = 1; /* one possible code of zero length */
+ for (len = 1; len <= MAXBITS; len++) {
+ left <<= 1; /* one more bit, double codes left */
+ left -= h->count[len]; /* deduct count from possible codes */
+ if (left < 0)
+ return left; /* over-subscribed--return negative */
+ } /* left > 0 means incomplete */
+
+ /* generate offsets into symbol table for each length for sorting */
+ offs[1] = 0;
+ for (len = 1; len < MAXBITS; len++)
+ offs[len + 1] = offs[len] + h->count[len];
+
+ /*
+ * put symbols in table sorted by length, by symbol order within each
+ * length
+ */
+ for (symbol = 0; symbol < n; symbol++)
+ if (length[symbol] != 0)
+ h->symbol[offs[length[symbol]]++] = symbol;
+
+ /* return zero for complete set, positive for incomplete set */
+ return left;
+}
+
+/*
+ * Decode literal/length and distance codes until an end-of-block code.
+ *
+ * Format notes:
+ *
+ * - Compressed data that is after the block type if fixed or after the code
+ * description if dynamic is a combination of literals and length/distance
+ * pairs terminated by and end-of-block code. Literals are simply Huffman
+ * coded bytes. A length/distance pair is a coded length followed by a
+ * coded distance to represent a string that occurs earlier in the
+ * uncompressed data that occurs again at the current location.
+ *
+ * - Literals, lengths, and the end-of-block code are combined into a single
+ * code of up to 286 symbols. They are 256 literals (0..255), 29 length
+ * symbols (257..285), and the end-of-block symbol (256).
+ *
+ * - There are 256 possible lengths (3..258), and so 29 symbols are not enough
+ * to represent all of those. Lengths 3..10 and 258 are in fact represented
+ * by just a length symbol. Lengths 11..257 are represented as a symbol and
+ * some number of extra bits that are added as an integer to the base length
+ * of the length symbol. The number of extra bits is determined by the base
+ * length symbol. These are in the static arrays below, lens[] for the base
+ * lengths and lext[] for the corresponding number of extra bits.
+ *
+ * - The reason that 258 gets its own symbol is that the longest length is used
+ * often in highly redundant files. Note that 258 can also be coded as the
+ * base value 227 plus the maximum extra value of 31. While a good deflate
+ * should never do this, it is not an error, and should be decoded properly.
+ *
+ * - If a length is decoded, including its extra bits if any, then it is
+ * followed a distance code. There are up to 30 distance symbols. Again
+ * there are many more possible distances (1..32768), so extra bits are added
+ * to a base value represented by the symbol. The distances 1..4 get their
+ * own symbol, but the rest require extra bits. The base distances and
+ * corresponding number of extra bits are below in the static arrays dist[]
+ * and dext[].
+ *
+ * - Literal bytes are simply written to the output. A length/distance pair is
+ * an instruction to copy previously uncompressed bytes to the output. The
+ * copy is from distance bytes back in the output stream, copying for length
+ * bytes.
+ *
+ * - Distances pointing before the beginning of the output data are not
+ * permitted.
+ *
+ * - Overlapped copies, where the length is greater than the distance, are
+ * allowed and common. For example, a distance of one and a length of 258
+ * simply copies the last byte 258 times. A distance of four and a length of
+ * twelve copies the last four bytes three times. A simple forward copy
+ * ignoring whether the length is greater than the distance or not implements
+ * this correctly. You should not use memcpy() since its behavior is not
+ * defined for overlapped arrays. You should not use memmove() or bcopy()
+ * since though their behavior -is- defined for overlapping arrays, it is
+ * defined to do the wrong thing in this case.
+ */
+static short lens[29] = { /* Size base for length 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};
+static short lext[29] = { /* Extra bits for length 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};
+static short dists[30] = { /* Offset base 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 short dext[30] = { /* Extra bits for distance codes 0..29 */
+ 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};
+static int codes(state *s, huffman *lencode, huffman *distcode)
+{
+ int symbol; /* decoded symbol */
+ int len; /* length for copy */
+ unsigned int dist; /* distance for copy */
+
+ /* decode literals and length/distance pairs */
+ do {
+ symbol = decode(s, lencode);
+ if (symbol < 0)
+ return symbol; /* invalid symbol */
+ if (symbol < 256) { /* literal: symbol is the byte */
+ /* write out the literal */
+ if (s->out != NULL) {
+ if (s->outcnt == s->outlen)
+ return 1;
+ s->out[s->outcnt] = symbol;
+ }
+ s->outcnt++;
+ }
+ else if (symbol > 256) { /* length */
+ /* get and compute length */
+ symbol -= 257;
+ if (symbol >= 29)
+ return -10; /* invalid fixed code */
+ len = lens[symbol] + bits(s, lext[symbol]);
+
+ /* get and check distance */
+ symbol = decode(s, distcode);
+ if (symbol < 0)
+ return symbol; /* invalid symbol */
+ dist = dists[symbol] + bits(s, dext[symbol]);
+ if (dist > s->outcnt)
+ return -11; /* distance too far back */
+
+ /* copy length bytes from distance bytes back */
+ if (s->out != NULL) {
+ if (s->outcnt + len > s->outlen)
+ return 1;
+ while (len--) {
+ // TODO: add "cond ? x : y" form
+ if (dist > s->outcnt)
+ s->out[s->outcnt] = 0;
+ else
+ s->out[s->outcnt] = s->out[s->outcnt - dist];
+ s->outcnt++;
+ }
+ }
+ else
+ s->outcnt += len;
+ }
+ } while (symbol != 256); /* end of block symbol */
+
+ /* done with a valid fixed or dynamic block */
+ return 0;
+}
+
+/*
+ * Process a fixed codes block.
+ *
+ * Format notes:
+ *
+ * - This block type can be useful for compressing small amounts of data for
+ * which the size of the code descriptions in a dynamic block exceeds the
+ * benefit of custom codes for that block. For fixed codes, no bits are
+ * spent on code descriptions. Instead the code lengths for literal/length
+ * codes and distance codes are fixed. The specific lengths for each symbol
+ * can be seen in the "for" loops below.
+ *
+ * - The literal/length code is complete, but has two symbols that are invalid
+ * and should result in an error if received. This cannot be implemented
+ * simply as an incomplete code since those two symbols are in the "middle"
+ * of the code. They are eight bits long and the longest literal/length\
+ * code is nine bits. Therefore the code must be constructed with those
+ * symbols, and the invalid symbols must be detected after decoding.
+ *
+ * - The fixed distance codes also have two invalid symbols that should result
+ * in an error if received. Since all of the distance codes are the same
+ * length, this can be implemented as an incomplete code. Then the invalid
+ * codes are detected while decoding.
+ */
+
+static int virgin = 1;
+static short lencnt[MAXBITSPLUSONE], lensym[FIXLCODES];
+static short distcnt[MAXBITSPLUSONE], distsym[MAXDCODES];
+static huffman lencode, distcode;
+
+static int fixed(state *s)
+{
+ int symbol;
+ short lengths[FIXLCODES];
+
+ /* build fixed huffman tables if first call (may not be thread safe) */
+ if (virgin) {
+ /* construct lencode and distcode */
+ lencode.count = lencnt;
+ lencode.symbol = lensym;
+ distcode.count = distcnt;
+ distcode.symbol = distsym;
+
+ /* literal/length table */
+ for (symbol = 0; symbol < 144; symbol++)
+ lengths[symbol] = 8;
+ // TODO: fix error when for()'s initialization is empty
+ // meanwhile: dummy "symbol=symbol"
+ for (symbol=symbol; symbol < 256; symbol++)
+ lengths[symbol] = 9;
+ for (symbol=symbol; symbol < 280; symbol++)
+ lengths[symbol] = 7;
+ for (symbol=symbol; symbol < FIXLCODES; symbol++)
+ lengths[symbol] = 8;
+ construct(&lencode, lengths, FIXLCODES);
+
+ /* distance table */
+ for (symbol = 0; symbol < MAXDCODES; symbol++)
+ lengths[symbol] = 5;
+ construct(&distcode, lengths, MAXDCODES);
+
+ /* do this just once */
+ virgin = 0;
+ }
+
+ /* decode data until end-of-block code */
+ return codes(s, &lencode, &distcode);
+}
+
+/*
+ * Process a dynamic codes block.
+ *
+ * Format notes:
+ *
+ * - A dynamic block starts with a description of the literal/length and
+ * distance codes for that block. New dynamic blocks allow the compressor to
+ * rapidly adapt to changing data with new codes optimized for that data.
+ *
+ * - The codes used by the deflate format are "canonical", which means that
+ * the actual bits of the codes are generated in an unambiguous way simply
+ * from the number of bits in each code. Therefore the code descriptions
+ * are simply a list of code lengths for each symbol.
+ *
+ * - The code lengths are stored in order for the symbols, so lengths are
+ * provided for each of the literal/length symbols, and for each of the
+ * distance symbols.
+ *
+ * - If a symbol is not used in the block, this is represented by a zero as
+ * as the code length. This does not mean a zero-length code, but rather
+ * that no code should be created for this symbol. There is no way in the
+ * deflate format to represent a zero-length code.
+ *
+ * - The maximum number of bits in a code is 15, so the possible lengths for
+ * any code are 1..15.
+ *
+ * - The fact that a length of zero is not permitted for a code has an
+ * interesting consequence. Normally if only one symbol is used for a given
+ * code, then in fact that code could be represented with zero bits. However
+ * in deflate, that code has to be at least one bit. So for example, if
+ * only a single distance base symbol appears in a block, then it will be
+ * represented by a single code of length one, in particular one 0 bit. This
+ * is an incomplete code, since if a 1 bit is received, it has no meaning,
+ * and should result in an error. So incomplete distance codes of one symbol
+ * should be permitted, and the receipt of invalid codes should be handled.
+ *
+ * - It is also possible to have a single literal/length code, but that code
+ * must be the end-of-block code, since every dynamic block has one. This
+ * is not the most efficient way to create an empty block (an empty fixed
+ * block is fewer bits), but it is allowed by the format. So incomplete
+ * literal/length codes of one symbol should also be permitted.
+ *
+ * - If there are only literal codes and no lengths, then there are no distance
+ * codes. This is represented by one distance code with zero bits.
+ *
+ * - The list of up to 286 length/literal lengths and up to 30 distance lengths
+ * are themselves compressed using Huffman codes and run-length encoding. In
+ * the list of code lengths, a 0 symbol means no code, a 1..15 symbol means
+ * that length, and the symbols 16, 17, and 18 are run-length instructions.
+ * Each of 16, 17, and 18 are followed by extra bits to define the length of
+ * the run. 16 copies the last length 3 to 6 times. 17 represents 3 to 10
+ * zero lengths, and 18 represents 11 to 138 zero lengths. Unused symbols
+ * are common, hence the special coding for zero lengths.
+ *
+ * - The symbols for 0..18 are Huffman coded, and so that code must be
+ * described first. This is simply a sequence of up to 19 three-bit values
+ * representing no code (0) or the code length for that symbol (1..7).
+ *
+ * - A dynamic block starts with three fixed-size counts from which is computed
+ * the number of literal/length code lengths, the number of distance code
+ * lengths, and the number of code length code lengths (ok, you come up with
+ * a better name!) in the code descriptions. For the literal/length and
+ * distance codes, lengths after those provided are considered zero, i.e. no
+ * code. The code length code lengths are received in a permuted order (see
+ * the order[] array below) to make a short code length code length list more
+ * likely. As it turns out, very short and very long codes are less likely
+ * to be seen in a dynamic code description, hence what may appear initially
+ * to be a peculiar ordering.
+ *
+ * - Given the number of literal/length code lengths (nlen) and distance code
+ * lengths (ndist), then they are treated as one long list of nlen + ndist
+ * code lengths. Therefore run-length coding can and often does cross the
+ * boundary between the two sets of lengths.
+ *
+ * - So to summarize, the code description at the start of a dynamic block is
+ * three counts for the number of code lengths for the literal/length codes,
+ * the distance codes, and the code length codes. This is followed by the
+ * code length code lengths, three bits each. This is used to construct the
+ * code length code which is used to read the remainder of the lengths. Then
+ * the literal/length code lengths and distance lengths are read as a single
+ * set of lengths using the code length codes. Codes are constructed from
+ * the resulting two sets of lengths, and then finally you can start
+ * decoding actual compressed data in the block.
+ *
+ * - For reference, a "typical" size for the code description in a dynamic
+ * block is around 80 bytes.
+ */
+static short order[19] = /* permutation of code length codes */
+ {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+static int dynamic(state *s)
+{
+ int nlen, ndist, ncode; /* number of lengths in descriptor */
+ int index; /* index of lengths[] */
+ int err; /* construct() return value */
+ short lengths[MAXCODES]; /* descriptor code lengths */
+ short lencnt[MAXBITSPLUSONE], lensym[MAXLCODES]; /* lencode memory */
+ short distcnt[MAXBITSPLUSONE], distsym[MAXDCODES]; /* distcode memory */
+ huffman lencode, distcode; /* length and distance codes */
+ int symbol; /* decoded value */
+ int len; /* last length to repeat */
+
+ /* construct lencode and distcode */
+ lencode.count = lencnt;
+ lencode.symbol = lensym;
+ distcode.count = distcnt;
+ distcode.symbol = distsym;
+
+ /* get number of lengths in each table, check lengths */
+ nlen = bits(s, 5) + 257;
+ ndist = bits(s, 5) + 1;
+ ncode = bits(s, 4) + 4;
+ if (nlen > MAXLCODES || ndist > MAXDCODES)
+ return -3; /* bad counts */
+
+ /* read code length code lengths (really), missing lengths are zero */
+ for (index = 0; index < ncode; index++)
+ lengths[order[index]] = bits(s, 3);
+ // TODO: empty for init. dummy "index=index"
+ for (index = index; index < 19; index++)
+ lengths[order[index]] = 0;
+
+ /* build huffman table for code lengths codes (use lencode temporarily) */
+ err = construct(&lencode, lengths, 19);
+ if (err != 0) /* require complete code set here */
+ return -4;
+
+ /* read length/literal and distance code length tables */
+ index = 0;
+ while (index < nlen + ndist) {
+ symbol = decode(s, &lencode);
+ if (symbol < 0)
+ return symbol; /* invalid symbol */
+ if (symbol < 16) /* length in 0..15 */
+ lengths[index++] = symbol;
+ else { /* repeat instruction */
+ len = 0; /* assume repeating zeros */
+ if (symbol == 16) { /* repeat last length 3..6 times */
+ if (index == 0)
+ return -5; /* no last length! */
+ len = lengths[index - 1]; /* last length */
+ symbol = 3 + bits(s, 2);
+ }
+ else if (symbol == 17) /* repeat zero 3..10 times */
+ symbol = 3 + bits(s, 3);
+ else /* == 18, repeat zero 11..138 times */
+ symbol = 11 + bits(s, 7);
+ if (index + symbol > nlen + ndist)
+ return -6; /* too many lengths! */
+ while (symbol--) /* repeat last or zero symbol times */
+ lengths[index++] = len;
+ }
+ }
+
+ /* check for end-of-block code -- there better be one! */
+ if (lengths[256] == 0)
+ return -9;
+
+ /* build huffman table for literal/length codes */
+ err = construct(&lencode, lengths, nlen);
+ if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1]))
+ return -7; /* incomplete code ok only for single length 1 code */
+
+ /* build huffman table for distance codes */
+ err = construct(&distcode, lengths + nlen, ndist);
+ if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1]))
+ return -8; /* incomplete code ok only for single length 1 code */
+
+ /* decode data until end-of-block code */
+ return codes(s, &lencode, &distcode);
+}
+
+/*
+ * Inflate source to dest. On return, destlen and sourcelen are updated to the
+ * size of the uncompressed data and the size of the deflate data respectively.
+ * On success, the return value of puff() is zero. If there is an error in the
+ * source data, i.e. it is not in the deflate format, then a negative value is
+ * returned. If there is not enough input available or there is not enough
+ * output space, then a positive error is returned. In that case, destlen and
+ * sourcelen are not updated to facilitate retrying from the beginning with the
+ * provision of more input data or more output space. In the case of invalid
+ * inflate data (a negative error), the dest and source pointers are updated to
+ * facilitate the debugging of deflators.
+ *
+ * puff() also has a mode to determine the size of the uncompressed output with
+ * no output written. For this dest must be (unsigned char *)0. In this case,
+ * the input value of *destlen is ignored, and on return *destlen is set to the
+ * size of the uncompressed output.
+ *
+ * The return codes are:
+ *
+ * 2: available inflate data did not terminate
+ * 1: output space exhausted before completing inflate
+ * 0: successful inflate
+ * -1: invalid block type (type == 3)
+ * -2: stored block length did not match one's complement
+ * -3: dynamic block code description: too many length or distance codes
+ * -4: dynamic block code description: code lengths codes incomplete
+ * -5: dynamic block code description: repeat lengths with no first length
+ * -6: dynamic block code description: repeat more than specified lengths
+ * -7: dynamic block code description: invalid literal/length code lengths
+ * -8: dynamic block code description: invalid distance code lengths
+ * -9: dynamic block code description: missing end-of-block code
+ * -10: invalid literal/length or distance code in fixed or dynamic block
+ * -11: distance is too far back in fixed or dynamic block
+ *
+ * Format notes:
+ *
+ * - Three bits are read for each block to determine the kind of block and
+ * whether or not it is the last block. Then the block is decoded and the
+ * process repeated if it was not the last block.
+ *
+ * - The leftover bits in the last byte of the deflate data after the last
+ * block (if it was a fixed or dynamic block) are undefined and have no
+ * expected values to check.
+ */
+int puff(unsigned char *dest, /* pointer to destination pointer */
+ unsigned int *destlen, /* amount of output space */
+ unsigned char *source, /* pointer to source data pointer */
+ unsigned int *sourcelen) /* amount of input available */
+{
+ state s; /* input/output state */
+ int last, type; /* block information */
+ int err; /* return value */
+
+ /* initialize output state */
+ s.out = dest;
+ s.outlen = *destlen; /* ignored if dest is NULL */
+ s.outcnt = 0;
+
+ /* initialize input state */
+ s.in = source;
+ s.inlen = *sourcelen;
+ s.incnt = 0;
+ s.bitbuf = 0;
+ s.bitcnt = 0;
+
+ /* process blocks until last block or error */
+ do {
+ last = bits(&s, 1); /* one if last block */
+ type = bits(&s, 2); /* block type 0..3 */
+ if (type == 0) err = stored(&s);
+ else if (type == 1) err = fixed(&s);
+ else if (type == 2) err = dynamic(&s);
+ else err = -1;
+ if (err != 0)
+ break; /* return with error */
+ } while (!last);
+
+ /* update the lengths and return */
+ if (err <= 0) {
+ *destlen = s.outcnt;
+ *sourcelen = s.incnt;
+ }
+ return err;
+}
diff --git a/fs/ar/puff.fs b/fs/ar/puff.fs
@@ -0,0 +1,2 @@
+?f<< /comp/c/lib.fs
+cc<< /ar/puff.c
diff --git a/fs/ar/ungz.c b/fs/ar/ungz.c
@@ -1,933 +0,0 @@
-/* Source: https://github.com/oriansj/mescc-tools-extra
- * License: /license/oriansj-ungz.txt
- */
-
-typedef unsigned int size_t;
-typedef int long;
-
-/*
- * Maximums for allocations and loops. It is not useful to change these --
- * they are fixed by the deflate format.
- */
-/* maximum bits in a code */
-#define MAXBITS 15
-/* TODO: allow constant expressions array typedefs, for example MAXBITS+1 */
-#define MAXBITSPLUSONE 16
-/* maximum number of literal/length codes */
-#define MAXLCODES 286
-/* maximum number of distance codes */
-#define MAXDCODES 30
-/* maximum codes lengths to read (MAXLCODES+MAXDCODES) */
-#define MAXCODES 316
-/* number of fixed literal/length codes */
-#define FIXLCODES 288
-
-/* input and output state */
-struct state {
- /* output state */
- char *out; /* output buffer */
- size_t outlen; /* available space at out */
- size_t outcnt; /* bytes written to out so far */
-
- /* input state */
- char *in; /* input buffer */
- size_t inlen; /* available input at in */
- size_t incnt; /* bytes read so far */
- int bitbuf; /* bit buffer */
- int bitcnt; /* number of bits in bit buffer */
-};
-
-/*
- * Return need bits from the input stream. This always leaves less than
- * eight bits in the buffer. bits() works properly for need == 0.
- *
- * Format notes:
- *
- * - Bits are stored in bytes from the least significant bit to the most
- * significant bit. Therefore bits are dropped from the bottom of the bit
- * buffer, using shift right, and new bytes are appended to the top of the
- * bit buffer, using shift left.
- */
-static int bits(state *s, int need)
-{
- long val; /* bit accumulator (can use up to 20 bits) */
- long hold;
-
- /* load at least need bits into val */
- val = s->bitbuf;
- while (s->bitcnt < need)
- {
- if (s->incnt == s->inlen)
- {
- fputs("out of input\n", ConsoleOut());
- abort();
- }
- hold = (s->in[s->incnt] & $FF);
- s->incnt = s->incnt + 1;
- val = val | (hold << s->bitcnt); /* load eight bits */
- s->bitcnt = s->bitcnt + 8;
- }
-
- /* drop need bits and update buffer, always zero to seven bits left */
- s->bitbuf = (val >> need);
- s->bitcnt = s->bitcnt - need;
-
- /* return need bits, zeroing the bits above that */
- val = (val & ((1 << need) - 1));
- return val;
-}
-
-/*
- * Process a stored block.
- *
- * Format notes:
- *
- * - After the two-bit stored block type (00), the stored block length and
- * stored bytes are byte-aligned for fast copying. Therefore any leftover
- * bits in the byte that has the last bit of the type, as many as seven, are
- * discarded. The value of the discarded bits are not defined and should not
- * be checked against any expectation.
- *
- * - The second inverted copy of the stored block length does not have to be
- * checked, but it's probably a good idea to do so anyway.
- *
- * - A stored block can have zero length. This is sometimes used to byte-align
- * subsets of the compressed data for random access or partial recovery.
- */
-static int stored(state *s)
-{
- unsigned int len; /* length of stored block */
-
- /* discard leftover bits from current byte (assumes s->bitcnt < 8) */
- s->bitbuf = 0;
- s->bitcnt = 0;
-
- /* get length and check against its one's complement */
- if ((s->incnt + 4) > s->inlen) return 2; /* not enough input */
- len = s->in[s->incnt];
- s->incnt = s->incnt + 1;
- len = len | (s->in[s->incnt] << 8);
- s->incnt = s->incnt + 1;
- if(s->in[s->incnt] != (~len & $ff)) return -2; /* didn't match complement! */
- s->incnt = s->incnt + 1;
- if(s->in[s->incnt] != ((~len >> 8) & $ff)) return -2; /* didn't match complement! */
- s->incnt = s->incnt + 1;
-
- /* copy len bytes from in to out */
- if ((s->incnt + len) > s->inlen) return 2; /* not enough input */
- if (s->out != 0)
- {
- if ((s->outcnt + len) > s->outlen) return 1; /* not enough output space */
- while (0 != len)
- {
- len = len - 1;
- s->out[s->outcnt] = s->in[s->incnt];
- s->outcnt = s->outcnt + 1;
- s->incnt = s->incnt + 1;
- }
- }
- else
- { /* just scanning */
- s->outcnt = s->outcnt + len;
- s->incnt = s->incnt + len;
- }
-
- /* done with a valid stored block */
- return 0;
-}
-
-/*
- * Huffman code decoding tables. count[1..MAXBITS] is the number of symbols of
- * each length, which for a canonical code are stepped through in order.
- * symbol[] are the symbol values in canonical order, where the number of
- * entries is the sum of the counts in count[]. The decoding process can be
- * seen in the function decode() below.
- */
-struct huffman
-{
- int count[MAXBITSPLUSONE]; /* number of symbols of each length */
- int symbol[FIXLCODES]; /* canonically ordered symbols */
-};
-
-/*
- * Decode a code from the stream s using huffman table h. Return the symbol or
- * a negative value if there is an error. If all of the lengths are zero, i.e.
- * an empty code, or if the code is incomplete and an invalid code is received,
- * then -10 is returned after reading MAXBITS bits.
- *
- * Format notes:
- *
- * - The codes as stored in the compressed data are bit-reversed relative to
- * a simple integer ordering of codes of the same lengths. Hence below the
- * bits are pulled from the compressed data one at a time and used to
- * build the code value reversed from what is in the stream in order to
- * permit simple integer comparisons for decoding. A table-based decoding
- * scheme (as used in zlib) does not need to do this reversal.
- *
- * - The first code for the shortest length is all zeros. Subsequent codes of
- * the same length are simply integer increments of the previous code. When
- * moving up a length, a zero bit is appended to the code. For a complete
- * code, the last code of the longest length will be all ones.
- *
- * - Incomplete codes are handled by this decoder, since they are permitted
- * in the deflate format. See the format notes for fixed() and dynamic().
- */
-int decode(state *s, huffman *h)
-{
- int len; /* current number of bits in code */
- int code = 0; /* len bits being decoded */
- int first = 0; /* first code of length len */
- int count; /* number of codes of length len */
- int index = 0; /* index of first code of length len in symbol table */
- long hold;
-
- for (len = 1; len <= MAXBITS; len = len + 1)
- {
- hold = bits(s, 1); /* get next bit */
- code = code | hold;
- count = h->count[len];
- if ((code - count) < first)
- {
- hold = index + (code - first);
- return h->symbol[hold]; /* if length len, return symbol */
- }
- index = index + count; /* else update for next length */
- first = first + count;
- first = first << 1;
- code = code << 1;
- }
- return -10; /* ran out of codes */
-}
-
-/*
- * Given the list of code lengths length[0..n-1] representing a canonical
- * Huffman code for n symbols, construct the tables required to decode those
- * codes. Those tables are the number of codes of each length, and the symbols
- * sorted by length, retaining their original order within each length. The
- * return value is zero for a complete code set, negative for an over-
- * subscribed code set, and positive for an incomplete code set. The tables
- * can be used if the return value is zero or positive, but they cannot be used
- * if the return value is negative. If the return value is zero, it is not
- * possible for decode() using that table to return an error--any stream of
- * enough bits will resolve to a symbol. If the return value is positive, then
- * it is possible for decode() using that table to return an error for received
- * codes past the end of the incomplete lengths.
- *
- * Not used by decode(), but used for error checking, h->count[0] is the number
- * of the n symbols not in the code. So n - h->count[0] is the number of
- * codes. This is useful for checking for incomplete codes that have more than
- * one symbol, which is an error in a dynamic block.
- *
- * Assumption: for all i in 0..n-1, 0 <= length[i] <= MAXBITS
- * This is assured by the construction of the length arrays in dynamic() and
- * fixed() and is not verified by construct().
- *
- * Format notes:
- *
- * - Permitted and expected examples of incomplete codes are one of the fixed
- * codes and any code with a single symbol which in deflate is coded as one
- * bit instead of zero bits. See the format notes for fixed() and dynamic().
- *
- * - Within a given code length, the symbols are kept in ascending order for
- * the code bits definition.
- */
-int construct(huffman *h, int *length, int n)
-{
- int symbol; /* current symbol when stepping through length[] */
- int len; /* current length when stepping through h->count[] */
- int left; /* number of possible codes left of current length */
- int offs[MAXBITSPLUSONE]; /* offsets in symbol table for each length */
- long hold;
-
- /* count number of codes of each length */
- for (len = 0; len <= MAXBITS; len = len + 1)
- {
- h->count[len] = 0;
- }
-
- for (symbol = 0; symbol < n; symbol = symbol + 1)
- {
- hold = length[symbol];
- h->count[hold] = h->count[hold] + 1; /* assumes lengths are within bounds */
- }
-
- if (h->count[0] == n) return 0; /* no codes! complete, but decode() will fail */
-
- /* check for an over-subscribed or incomplete set of lengths */
- left = 1; /* one possible code of zero length */
- for (len = 1; len <= MAXBITS; len = len + 1)
- {
- left = left << 1; /* one more bit, double codes left */
- left = left - h->count[len]; /* deduct count from possible codes */
- if (left < 0) return left; /* over-subscribed--return negative */
- } /* left > 0 means incomplete */
-
- /* generate offsets into symbol table for each length for sorting */
- offs[1] = 0;
- for (len = 1; len < MAXBITS; len = len + 1)
- {
- offs[len + 1] = offs[len] + h->count[len];
- }
-
- /*
- * put symbols in table sorted by length, by symbol order within each
- * length
- */
- for (symbol = 0; symbol < n; symbol = symbol + 1)
- {
- if (length[symbol] != 0)
- {
- hold = length[symbol];
- hold = offs[hold];
- h->symbol[hold] = symbol;
- hold = length[symbol];
- offs[hold] = offs[hold] + 1;
- }
- }
-
- /* return zero for complete set, positive for incomplete set */
- return left;
-}
-
-static int codes_lens[30] = {
- 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};
-
-static int codes_lext[30] = {
- 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, 0};
-
-static int codes_dists[31] = {
- 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, 0};
-
-static int codes_dext[31] = {
- 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, 0};
-
-int codes(state *s, huffman *lencode, huffman *distcode)
-{
- int symbol; /* decoded symbol */
- int len; /* length for copy */
- unsigned int dist; /* distance for copy */
-
- /* decode literals and length/distance pairs */
- do
- {
- symbol = decode(s, lencode);
- if (symbol < 0) return symbol; /* invalid symbol */
- if (symbol < 256) /* literal: symbol is the byte */
- {
- /* write out the literal */
- if (s->out != 0)
- {
- if (s->outcnt == s->outlen) return 1;
- s->out[s->outcnt] = symbol;
- }
- s->outcnt = s->outcnt + 1;
- }
- else if (symbol > 256) /* length */
- {
- /* get and compute length */
- symbol = symbol - 257;
- if (symbol >= 29) return -10; /* invalid fixed code */
- len = codes_lens[symbol] + bits(s, codes_lext[symbol]);
-
- /* get and check distance */
- symbol = decode(s, distcode);
- if (symbol < 0) return symbol; /* invalid symbol */
- dist = codes_dists[symbol] + bits(s, codes_dext[symbol]);
- if (dist > s->outcnt) return -11; /* distance too far back */
-
- /* copy length bytes from distance bytes back */
- if (s->out != 0)
- {
- if (s->outcnt + len > s->outlen) return 1;
- while (0 != len)
- {
- len = len - 1;
- if(dist > s->outcnt) s->out[s->outcnt] = 0;
- else s->out[s->outcnt] = s->out[s->outcnt - dist];
- s->outcnt = s->outcnt + 1;
- }
- }
- else s->outcnt = s->outcnt + len;
- }
- } while (symbol != 256); /* end of block symbol */
-
- /* done with a valid fixed or dynamic block */
- return 0;
-}
-
-/*
- * Process a fixed codes block.
- *
- * Format notes:
- *
- * - This block type can be useful for compressing small amounts of data for
- * which the size of the code descriptions in a dynamic block exceeds the
- * benefit of custom codes for that block. For fixed codes, no bits are
- * spent on code descriptions. Instead the code lengths for literal/length
- * codes and distance codes are fixed. The specific lengths for each symbol
- * can be seen in the "for" loops below.
- *
- * - The literal/length code is complete, but has two symbols that are invalid
- * and should result in an error if received. This cannot be implemented
- * simply as an incomplete code since those two symbols are in the "middle"
- * of the code. They are eight bits long and the longest literal/length\
- * code is nine bits. Therefore the code must be constructed with those
- * symbols, and the invalid symbols must be detected after decoding.
- *
- * - The fixed distance codes also have two invalid symbols that should result
- * in an error if received. Since all of the distance codes are the same
- * length, this can be implemented as an incomplete code. Then the invalid
- * codes are detected while decoding.
- */
-int fixed(state *s)
-{
- huffman lencode;
- huffman distcode;
- int hold;
-
- /* build fixed huffman tables if first call (may not be thread safe) */
- int symbol;
- int lengths[FIXLCODES];
-
- /* literal/length table */
- for (symbol = 0; symbol < 144; symbol = symbol + 1)
- {
- lengths[symbol] = 8;
- }
-
- while(symbol < 256)
- {
- lengths[symbol] = 9;
- symbol = symbol + 1;
- }
-
- while(symbol < 280)
- {
- lengths[symbol] = 7;
- symbol = symbol + 1;
- }
-
- while(symbol < FIXLCODES)
- {
- lengths[symbol] = 8;
- symbol = symbol + 1;
- }
-
- construct(&lencode, lengths, FIXLCODES);
-
- /* distance table */
- for (symbol = 0; symbol < MAXDCODES; symbol = symbol + 1)
- {
- lengths[symbol] = 5;
- }
-
- construct(&distcode, lengths, MAXDCODES);
-
- /* decode data until end-of-block code */
- hold = codes(s, &lencode, &distcode);
- return hold;
-}
-
-/*
- * Process a dynamic codes block.
- *
- * Format notes:
- *
- * - A dynamic block starts with a description of the literal/length and
- * distance codes for that block. New dynamic blocks allow the compressor to
- * rapidly adapt to changing data with new codes optimized for that data.
- *
- * - The codes used by the deflate format are "canonical", which means that
- * the actual bits of the codes are generated in an unambiguous way simply
- * from the number of bits in each code. Therefore the code descriptions
- * are simply a list of code lengths for each symbol.
- *
- * - The code lengths are stored in order for the symbols, so lengths are
- * provided for each of the literal/length symbols, and for each of the
- * distance symbols.
- *
- * - If a symbol is not used in the block, this is represented by a zero as
- * as the code length. This does not mean a zero-length code, but rather
- * that no code should be created for this symbol. There is no way in the
- * deflate format to represent a zero-length code.
- *
- * - The maximum number of bits in a code is 15, so the possible lengths for
- * any code are 1..15.
- *
- * - The fact that a length of zero is not permitted for a code has an
- * interesting consequence. Normally if only one symbol is used for a given
- * code, then in fact that code could be represented with zero bits. However
- * in deflate, that code has to be at least one bit. So for example, if
- * only a single distance base symbol appears in a block, then it will be
- * represented by a single code of length one, in particular one 0 bit. This
- * is an incomplete code, since if a 1 bit is received, it has no meaning,
- * and should result in an error. So incomplete distance codes of one symbol
- * should be permitted, and the receipt of invalid codes should be handled.
- *
- * - It is also possible to have a single literal/length code, but that code
- * must be the end-of-block code, since every dynamic block has one. This
- * is not the most efficient way to create an empty block (an empty fixed
- * block is fewer bits), but it is allowed by the format. So incomplete
- * literal/length codes of one symbol should also be permitted.
- *
- * - If there are only literal codes and no lengths, then there are no distance
- * codes. This is represented by one distance code with zero bits.
- *
- * - The list of up to 286 length/literal lengths and up to 30 distance lengths
- * are themselves compressed using Huffman codes and run-length encoding. In
- * the list of code lengths, a 0 symbol means no code, a 1..15 symbol means
- * that length, and the symbols 16, 17, and 18 are run-length instructions.
- * Each of 16, 17, and 18 are follwed by extra bits to define the length of
- * the run. 16 copies the last length 3 to 6 times. 17 represents 3 to 10
- * zero lengths, and 18 represents 11 to 138 zero lengths. Unused symbols
- * are common, hence the special coding for zero lengths.
- *
- * - The symbols for 0..18 are Huffman coded, and so that code must be
- * described first. This is simply a sequence of up to 19 three-bit values
- * representing no code (0) or the code length for that symbol (1..7).
- *
- * - A dynamic block starts with three fixed-size counts from which is computed
- * the number of literal/length code lengths, the number of distance code
- * lengths, and the number of code length code lengths (ok, you come up with
- * a better name!) in the code descriptions. For the literal/length and
- * distance codes, lengths after those provided are considered zero, i.e. no
- * code. The code length code lengths are received in a permuted order (see
- * the order[] array below) to make a short code length code length list more
- * likely. As it turns out, very short and very long codes are less likely
- * to be seen in a dynamic code description, hence what may appear initially
- * to be a peculiar ordering.
- *
- * - Given the number of literal/length code lengths (nlen) and distance code
- * lengths (ndist), then they are treated as one long list of nlen + ndist
- * code lengths. Therefore run-length coding can and often does cross the
- * boundary between the two sets of lengths.
- *
- * - So to summarize, the code description at the start of a dynamic block is
- * three counts for the number of code lengths for the literal/length codes,
- * the distance codes, and the code length codes. This is followed by the
- * code length code lengths, three bits each. This is used to construct the
- * code length code which is used to read the remainder of the lengths. Then
- * the literal/length code lengths and distance lengths are read as a single
- * set of lengths using the code length codes. Codes are constructed from
- * the resulting two sets of lengths, and then finally you can start
- * decoding actual compressed data in the block.
- *
- * - For reference, a "typical" size for the code description in a dynamic
- * block is around 80 bytes.
- */
-
-static int dynamic_order[20] = {
- 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15, 0};
-
-static int dynamic(state *s)
-{
- int nlen;
- int ndist;
- int ncode; /* number of lengths in descriptor */
- int index; /* index of lengths[] */
- int err; /* construct() return value */
- int lengths[MAXCODES];
- huffman lencode;
- huffman distcode;
- long hold;
- int* set;
- int symbol; /* decoded value */
- int len; /* last length to repeat */
-
- /* get number of lengths in each table, check lengths */
- nlen = bits(s, 5) + 257;
- ndist = bits(s, 5) + 1;
- ncode = bits(s, 4) + 4;
- if (nlen > MAXLCODES) return -3; /* bad counts */
- if(ndist > MAXDCODES) return -3; /* bad counts */
-
- /* read code length code lengths (really), missing lengths are zero */
- for (index = 0; index < ncode; index = index + 1)
- {
- hold = dynamic_order[index];
- lengths[hold] = bits(s, 3);
- }
-
- while(index < 19)
- {
- hold = dynamic_order[index];
- lengths[hold] = 0;
- index = index + 1;
- }
-
- /* build huffman table for code lengths codes (use lencode temporarily) */
- err = construct(&lencode, lengths, 19);
- if (err != 0) return -4; /* require complete code set here */
-
- /* read length/literal and distance code length tables */
- index = 0;
- while (index < (nlen + ndist))
- {
- symbol = decode(s, &lencode);
- if (symbol < 0) return symbol; /* invalid symbol */
-
- if (symbol < 16) /* length in 0..15 */
- {
- lengths[index] = symbol;
- index = index + 1;
- }
- else /* repeat instruction */
- {
- len = 0; /* assume repeating zeros */
- if (symbol == 16) /* repeat last length 3..6 times */
- {
- if (index == 0) return -5; /* no last length! */
- len = lengths[index - 1]; /* last length */
- symbol = 3 + bits(s, 2);
- }
- else if (symbol == 17) symbol = 3 + bits(s, 3); /* repeat zero 3..10 times */
- else symbol = 11 + bits(s, 7); /* == 18, repeat zero 11..138 times */
-
- if ((index + symbol) > (nlen + ndist)) return -6; /* too many lengths! */
-
- while(0 != symbol) /* repeat last or zero symbol times */
- {
- lengths[index] = len;
- index = index + 1;
- symbol = symbol - 1;
- }
- }
- }
-
- /* check for end-of-block code -- there better be one! */
- if (lengths[256] == 0) return -9;
-
- /* build huffman table for literal/length codes */
- err = construct(&lencode, lengths, nlen);
-
- /* incomplete code ok only for single length 1 code */
- if (err < 0) return -7;
- if((0 != err) && (nlen != (lencode.count[0] + lencode.count[1]))) return -7;
-
- /* build huffman table for distance codes */
- set = lengths + nlen;
- err = construct(&distcode, set, ndist);
-
- /* incomplete code ok only for single length 1 code */
- if (err < 0) return -8;
- if((0 != err) && (ndist != (distcode.count[0] + distcode.count[1]))) return -8;
-
- /* decode data until end-of-block code */
- hold = codes(s, &lencode, &distcode);
- return hold;
-}
-
-/*
- * Inflate source to dest. On return, destlen and sourcelen are updated to the
- * size of the uncompressed data and the size of the deflate data respectively.
- * On success, the return value of puff() is zero. If there is an error in the
- * source data, i.e. it is not in the deflate format, then a negative value is
- * returned. If there is not enough input available or there is not enough
- * output space, then a positive error is returned. In that case, destlen and
- * sourcelen are not updated to facilitate retrying from the beginning with the
- * provision of more input data or more output space. In the case of invalid
- * inflate data (a negative error), the dest and source pointers are updated to
- * facilitate the debugging of deflators.
- *
- * puff() also has a mode to determine the size of the uncompressed output with
- * no output written. For this dest must be (unsigned char *)0. In this case,
- * the input value of *destlen is ignored, and on return *destlen is set to the
- * size of the uncompressed output.
- *
- * The return codes are:
- *
- * 2: available inflate data did not terminate
- * 1: output space exhausted before completing inflate
- * 0: successful inflate
- * -1: invalid block type (type == 3)
- * -2: stored block length did not match one's complement
- * -3: dynamic block code description: too many length or distance codes
- * -4: dynamic block code description: code lengths codes incomplete
- * -5: dynamic block code description: repeat lengths with no first length
- * -6: dynamic block code description: repeat more than specified lengths
- * -7: dynamic block code description: invalid literal/length code lengths
- * -8: dynamic block code description: invalid distance code lengths
- * -9: dynamic block code description: missing end-of-block code
- * -10: invalid literal/length or distance code in fixed or dynamic block
- * -11: distance is too far back in fixed or dynamic block
- *
- * Format notes:
- *
- * - Three bits are read for each block to determine the kind of block and
- * whether or not it is the last block. Then the block is decoded and the
- * process repeated if it was not the last block.
- *
- * - The leftover bits in the last byte of the deflate data after the last
- * block (if it was a fixed or dynamic block) are undefined and have no
- * expected values to check.
- */
-
-struct puffer
-{
- int error;
- size_t destlen;
- size_t sourcelen;
-};
-
-static puffer _puffer;
-
-puffer* puff(char* dest, size_t destlen, char* source, size_t sourcelen)
-{
- state s; /* input/output state */
- int last;
- int type; /* block information */
- int err; /* return value */
-
- /* initialize output state */
- s.out = dest;
- s.outlen = destlen; /* ignored if dest is NIL */
- s.outcnt = 0;
-
- /* initialize input state */
- s.in = source;
- s.inlen = sourcelen;
- s.incnt = 0;
- s.bitbuf = 0;
- s.bitcnt = 0;
-
- /* process blocks until last block or error */
- do
- {
- last = bits(&s, 1); /* one if last block */
- type = bits(&s, 2); /* block type 0..3 */
-
- if(0 == type)
- {
- err = stored(&s);
- }
- else if(1 == type)
- {
- err = fixed(&s);
- }
- else if(2 == type)
- {
- err = dynamic(&s);
- }
- else err = -1;
-
- if (err != 0) break; /* return with error */
- } while (!last);
-
- /* update the lengths and return */
- _puffer.error = err;
- _puffer.destlen = s.outcnt;
- _puffer.sourcelen = s.incnt;
- return &_puffer;
-}
-
-void write_blob(char* s, int start, int len, File *f)
-{
- char* table = "0123456789ABCDEF";
- int i = s[start] & $FF;
-
- if(start > len) return;
-
- fputc(table[(i >> 4)], f);
- fputc(table[(i & $F)], f);
- fputc(' ', f);
-
- if(start == len) fputc($0a, f);
- else fputc(' ', f);
- write_blob(s, start + 1, len, f);
-}
-
-#define FTEXT $01
-#define FHCRC $02
-#define FEXTRA $04
-#define FNAME $08
-#define FCOMMENT $10
-#define MAXGZSZ $10000
-#define FNAMEMAXSZ $100
-#define FCOMMENTMAXSZ $100
-// TODO: can't #define right after a // comment
-
-static char _block_buf[MAXGZSZ];
-static char _extra_buf[MAXGZSZ];
-static char _fname_buf[FNAMEMAXSZ];
-static char _fcomment_buf[FCOMMENTMAXSZ];
-
-struct gz
-{
- char* HEADER;
- int ID;
- int CM;
- int FLG;
- int MTIME;
- int XFL;
- int OS;
- int XLEN;
- char* FLG_FEXTRA;
- char* FLG_FNAME;
- char* FLG_FCOMMENT;
- int CRC16;
- char* FLG_FHCRC;
- char* block;
- int CRC32;
- size_t ISIZE;
- size_t file_size;
-};
-
-static gz _gz;
-
-/* Read the input file *name, or stdin if name is NULL, into allocated memory.
- Reallocate to larger buffers until the entire file is read in. Return a
- pointer to the allocated data, or NULL if there was a memory allocation
- failure. *len is the number of bytes of data read from the input file (even
- if load() returns NULL). If the input file was empty or could not be opened
- or read, *len is zero. */
-gz* loadgz(char* name)
-{
- gz *r = &_gz;
- char scratch[5];
- File *f = fopen(name);
- int count;
- int ID1;
- int ID2;
- int count1;
- int count2;
- int count3;
- int count4;
- int c;
- int i;
- char s[11];
-
- r->file_size = f->size;
- fread(s, 10, f);
-
- /* Verify header */
- r->HEADER = s;
- ID1 = (s[0] & $FF);
- ID2 = (s[1] & $FF);
- r->ID = ((ID1 << 8) | ID2);
- if($1f8b != r->ID)
- {
- fputs("bad header\n", ConsoleOut());
- return NULL;
- }
-
- /* Verify Compression */
- r->CM = (r->HEADER[2] & $FF);
- if(8 != r->CM)
- {
- fputs("NOT DEFLATE COMPRESSION\n", ConsoleOut());
- return NULL;
- }
-
- /* Get specials specified in flag bits */
- r->FLG = (r->HEADER[3] & $FF);
-
- if(0 != (FEXTRA & r->FLG))
- {
- fread(scratch, 4, f);
- count1 = (scratch[0] & $FF);
- count2 = (scratch[1] & $FF);
- count3 = (scratch[2] & $FF);
- count4 = (scratch[3] & $FF);
- count = (count1 << 24) | (count2 << 16) | (count3 << 8) | count4;
- if (0 > count) {
- fputs("FEXTRA field needs to be a positive number of bytes in size\n", ConsoleOut());
- return NULL;
- }
- if (MAXGZSZ < count) {
- fputs("we don't support FEXTRA fields greater than 1MB in size\n", ConsoleOut());
- return NULL;
- }
- r->FLG_FEXTRA = _extra_buf;
- fread(_extra_buf, count, f);
- }
-
- if(0 != (FNAME & r->FLG))
- {
- r->FLG_FNAME = _fname_buf;
- i = 0;
- do
- {
- if (i == FNAMEMAXSZ) {
- fputs("FNAME field size exceeds buffer size\n", ConsoleOut());
- return NULL;
- }
- c = fgetc(f);
- if (c < 0) {
- fputs("received a non-null terminated filename in the file\n", ConsoleOut());
- return NULL;
- }
- _fname_buf[i] = c;
- i = i + 1;
- } while(0 != c);
- }
-
- if(0 != (FCOMMENT & r->FLG))
- {
- r->FLG_FCOMMENT = _fcomment_buf;
- i = 0;
- do
- {
- if (i == FCOMMENTMAXSZ) {
- fputs("FCOMMENTMAXSZ field size exceeds buffer size\n", ConsoleOut());
- return NULL;
- }
- c = fgetc(f);
- if (c < 0) {
- fputs("received a non-null terminated comment in the file\n", ConsoleOut());
- return NULL;
- }
- r->FLG_FCOMMENT[i] = c;
- i = i + 1;
- } while(0 != c);
- }
-
- if(0 != (FHCRC & r->FLG))
- {
- /* Not implemented */
- fputs("FHCRC is not implemented at this time\n", ConsoleOut());
- return NULL;
- }
-
- if(NULL == r->FLG_FNAME)
- {
- count = strlen(name) - 3;
- r->FLG_FNAME = _fname_buf;
- i = 0;
- while(i < count)
- {
- r->FLG_FNAME[i] = name[i];
- i = i + 1;
- }
- }
-
- r->block = _block_buf;
- printf(r->file_size, f->pos, "hello %d %d\n");
- fread(r->block, r->file_size-f->pos, f);
- r->ISIZE = count;
- fclose(f);
- return r;
-}
-
-int ungz(char *fname)
-{
- puffer* ret;
- char* name;
- char* buffer;
- gz* in;
- File *out;
-
- in = loadgz(name);
-
- if (in == NULL)
- {
- fputs("memory allocation failure\nDidn't read file\n", ConsoleOut());
- abort();
- }
-
- ret = puff(0, 0, in->block, in->ISIZE);
- return 0;
-}
diff --git a/fs/ar/ungz.fs b/fs/ar/ungz.fs
@@ -1,4 +0,0 @@
-?f<< /comp/c/lib.fs
-cc<< /ar/ungz.c
-
-S" gz" findTypedef CType :export
diff --git a/fs/tests/ar/all.fs b/fs/tests/ar/all.fs
@@ -1 +1 @@
-f<< /tests/ar/ungz.fs
+f<< /tests/ar/puff.fs
diff --git a/fs/tests/ar/puff.fs b/fs/tests/ar/puff.fs
@@ -0,0 +1,5 @@
+?f<< /tests/harness.fs
+?f<< /ar/puff.fs
+testbegin
+\ Testing ar/puff
+testend
diff --git a/fs/tests/ar/ungz.fs b/fs/tests/ar/ungz.fs
@@ -1,10 +0,0 @@
-?f<< /tests/harness.fs
-?f<< /ar/ungz.fs
-testbegin
-\ Testing ar/ungz
-\ a file with a GZ header returns nonzero
-S" /tests/ar/hello.gz" loadgz dup #
-gz FLG_FNAME dump
-\ a file without one returns 0
-S" /tests/ar/all.fs" loadgz not #
-testend
diff --git a/license/madler-puff.txt b/license/madler-puff.txt
@@ -0,0 +1,20 @@
+Copyright (C) 2002-2013 Mark Adler, all rights reserved
+version 2.3, 21 Jan 2013
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the author be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+
+Mark Adler madler@alumni.caltech.edu
diff --git a/license/oriansj-ungz.txt b/license/oriansj-ungz.txt
@@ -1,37 +0,0 @@
-/* Copyright (C) 2002-2013 Mark Adler, all rights reserved
- * Copyright (C) 2021 Jeremiah Orians
- * This file is part of mescc-tools-extra
- *
- * mescc-tools-extra 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 3 of the License, or
- * (at your option) any later version.
- *
- * mescc-tools-extra is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with mescc-tools-extra. If not, see <http://www.gnu.org/licenses/>.
- */
-
-/* puff.c
- * Copyright (C) 2002-2013 Mark Adler, all rights reserved
- * version 2.3, 21 Jan 2013
- * This software is provided 'as-is', without any express or implied
- * warranty. In no event will the author be held liable for any damages
- * arising from the use of this software.
- * Permission is granted to anyone to use this software for any purpose,
- * including commercial applications, and to alter it and redistribute it
- * freely, subject to the following restrictions:
- * 1. The origin of this software must not be misrepresented; you must not
- * claim that you wrote the original software. If you use this software
- * in a product, an acknowledgment in the product documentation would be
- * appreciated but is not required.
- * 2. Altered source versions must be plainly marked as such, and must not be
- * misrepresented as being the original software.
- * 3. This notice may not be removed or altered from any source distribution.
- * Mark Adler madler@alumni.caltech.edu
- */
-
